U.S. patent application number 15/173448 was filed with the patent office on 2016-12-08 for methods and systems for recovering protein powder and natural omega-3 oil from animal tissue.
The applicant listed for this patent is ADVANCE INTERNATIONAL INC.. Invention is credited to Kerry COLTUN, Shahmard Maziar GHORBANI.
Application Number | 20160355546 15/173448 |
Document ID | / |
Family ID | 57442096 |
Filed Date | 2016-12-08 |
United States Patent
Application |
20160355546 |
Kind Code |
A1 |
GHORBANI; Shahmard Maziar ;
et al. |
December 8, 2016 |
METHODS AND SYSTEMS FOR RECOVERING PROTEIN POWDER AND NATURAL
OMEGA-3 OIL FROM ANIMAL TISSUE
Abstract
Provided are methods and systems for recovering protein product
powder, purified water and omega-3 oil from an animal tissue. The
methods and systems use high throughput extraction filtration
separation systems. Animal tissue, for example fish, and organic
solvent are directly or indirectly transferred into one of the
optional extraction or filtration systems. The
extraction-filtration systems provide a high degree of filtration
performance and product washing efficiency. Each system ultimately
yields a product wet cake that includes the protein product. The
protein product wet cake is then further dried in a drying unit to
yield the final protein powder product. In each system, the process
filtrates undergo further processing by filtration and distillation
to recover the organic solvent and separate out the omega-3 fish
oil. The recovered organic solvent can be recycled back into the
process. Solid protein product powder is thus recovered, along with
omega-3 oil, purified water and recovered solvent.
Inventors: |
GHORBANI; Shahmard Maziar;
(Alamo, CA) ; COLTUN; Kerry; (Alamo, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ADVANCE INTERNATIONAL INC. |
Livermore |
CA |
US |
|
|
Family ID: |
57442096 |
Appl. No.: |
15/173448 |
Filed: |
June 3, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62171173 |
Jun 4, 2015 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C11B 3/001 20130101;
C11B 13/00 20130101; Y02W 30/74 20150501; C11B 3/16 20130101; C11B
1/10 20130101; C11B 1/108 20130101; A23J 1/04 20130101; C11B 1/12
20130101; C07K 1/36 20130101 |
International
Class: |
C07K 1/36 20060101
C07K001/36; A23D 9/02 20060101 A23D009/02; A23J 1/04 20060101
A23J001/04; C07K 14/46 20060101 C07K014/46; C11B 1/10 20060101
C11B001/10 |
Claims
1. A system for recovering a protein product powder, an omega-3 oil
and water from an animal tissue, comprising: a) a grinding unit; b)
a slurry preparation unit; c) a dewatering device; d) a closed
system product separation system for separating the slurry into a
liquid phase and a solid phase, the filtration system including a
continuous conveyance filtration system selected from among a belt
filtration system, a rotary drum filter, an immersion extractor, a
percolator extractor, a decanter/centrifuge and a screw press and a
combination thereof; and e) a solvent/liquid recovery (SLR) system
comprising: a liquid phase processing unit; a separation unit that
separates the liquid phase into recovered organic solvent, water
and an omega-3 oil; and a recovered organic solvent storage
tank.
2. The system of claim 1, further comprising a drying unit.
3. The system of claim 1, further comprising a milling unit.
4. The system of claim 1, wherein the system is automated.
5. The system of claim 4, wherein the system is automated by using
a programmable logic controller (PLC) and a customizable
recipe-driven software architecture, wherein the PLC is the
automated programmable device for controlling the process
automatically without the need for manual intervention.
6. The system of claim 1, wherein the separation unit includes a
distillation unit or a centrifugation unit or a combination
thereof.
7. The system of claim 6, wherein the distillation unit comprises a
distillation column, a thin film evaporator or a wiped film
evaporator or any combination thereof.
8. The system of claim 6, further comprising a process control
system that analyzes the overhead vapor pressure and the
temperature of the distillation unit.
9. The system of claim 1, wherein the liquid phase processing unit
comprises an adsorber system or an activated carbon filtration
system or both.
10. The system of claim 9, further comprising an analyzer
system.
11. The system of claim 10, wherein the analyzer system analyzes
the adsorber effluent stream for detection free amines or small
chain hydrocarbon materials.
12. The system of claim 1, wherein the slurry preparation unit
comprises a preparation tank for receiving and mixing ground animal
tissue from the grinding unit with a solvent to form a slurry.
13. The system of claim 1, further comprising a closed system
recycling solvent loop that transports recovered organic solvent
from the recovered organic solvent storage tank to slurry
preparation unit.
14. The system of claim 1, further comprising a volatile organic
carbon recycling system that: captures process emissions of the
organic solvent to form a condensed liquid solvent from the
filtration process via condensation; and transports the condensed
liquid solvent to the closed loop recycler.
15. The system of claim 1, wherein speed of the conveyance
filtration system is controlled using a variable frequency drive
(VFD).
16. A method for recovering protein product powder and omega-3 oil
from an animal tissue, comprising: mixing the animal tissue with an
organic solvent in a preparation tank; comminuting the animal
tissue with the organic solvent to produce a slurry; separating the
slurry into a liquid phase and a solid phase using a filtration
system selected from among a belt filtration system, a rotary drum
filtration system, an immersion extraction system, a percolation
extraction system and a screw press filtration system and any
combination thereof; recovering the liquid phase and separating it
into a recovered organic solvent portion and an omega-3 oil
portion; recovering the solid phase and drying it to yield a
protein wetcake; and milling the protein wetcake to yield protein
product powder.
17. The method of claim 16, wherein the animal tissue includes raw
fish that is processed through a dewatering device to remove excess
water prior to mixing with the organic solvent.
18. The method of claim 16, wherein the organic solvent mixed with
the animal tissue includes an alcohol, an aliphatic hydrocarbon, an
ester, water or any combination thereof.
19. The method of claim 16, further comprising: capturing the vapor
produced during drying the solid phase; condensing the vapor into a
liquid; and separating the organic solvent from the liquid.
20. The method of claim 19, wherein the wherein the organic solvent
mixed with the animal tissue includes at least a portion of the
recovered organic solvent derived from the condensed vapor derived
from the drying step of an earlier processed slurry.
21. The method of claim 16, wherein the milling is via a jet
mill.
22. The method of claim 16, wherein: the yield of protein is about
18 wt % or greater based on the total weight of the starting animal
tissue; or the yield of protein is from about 10 wt % to about 20
wt % based on the total weight of the starting animal tissue.
23. The method of claim 16, wherein the protein product powder has
a moisture content of less than about 10 wt %.
24. The method of claim 16, wherein the protein product powder has
an amount of residual organic solvent of less than about 0.5 wt
%.
25. The method of claim 16, wherein the amount of protein in the
protein product powder is in the range of from about 45 wt % to
about 96 wt %.
26. The method of claim 25, wherein the protein product powder has
a protein content from about 90 wt % to about 96 wt %.
27. The method of claim 16, wherein the protein product powder has
a crude fat content of less than about 1.5 wt %.
28. The method of claim 16, wherein the protein product powder has
a cholesterol content of less than about 0.1 wt %.
29. The method of claim 16, further comprising separating water
from the liquid phase.
30. A protein product produced by the method of claim 16.
31. The system of claim 1 configured for installation on a marine
vessel.
Description
RELATED APPLICATIONS
[0001] Benefit of priority is claimed to U.S. Provisional
Application No. 62/171,173 to SHAHMARD MAZIAR GHORBANI and KERRY
COLTUN, titled "IMPROVED METHODS AND SYSTEMS FOR RECOVERING PROTEIN
POWDER AND NATURAL OMEGA-3 OIL FROM ANIMAL TISSUE," filed Jun. 4,
2015, the subject matter of which is incorporated by reference
herein in its entirety.
[0002] This application is related to International PCT Application
No. (Attorney Docket No. 36115.00010.WO00, filed the same day
herewith, entitled "IMPROVED METHODS AND SYSTEMS FOR RECOVERING
PROTEIN POWDER AND NATURAL OMEGA-3 OIL FROM ANIMAL TISSUE," which
also claims priority to U.S. Provisional Application Ser. No.
62/171,173. The subject matter of the above-noted International
application is incorporated by reference in its entirety.
FIELD
[0003] The present invention relates generally to methods and
systems for producing a concentrated low-moisture piscine or marine
animal protein powder concentrate and natural omega-3 oil for human
consumption. The methods and systems provide for recovering protein
product powder, natural omega-3 oil and water from any type of
fresh or frozen piscine or marine animal or eggs or parts thereof,
or from dehydrated fishmeal and/or commodity dried fish, as
starting raw materials. The general methodology involves the use of
an extraction solvent in conjunction with several equipment system
options that can be used independently or in various combinations.
The methods and systems provide a recovery mechanism that allows
reuse of the extraction solvent efficiently and cost effectively.
The recovered protein powder, omega-3 oil and water can be used in
many applications, for example, as main ingredients in food
manufacturing, nutritional supplement products, hunger relief
packages, cosmetics, and high quality pet foods. The recovered
water also can be used as a beverage, for use in brewing and for
industrial applications. The process also can yield an all-natural
liquid fertilizer. The recovered water, which can be recovered via
distillation or membrane filtration or combinations thereof,
typically contains little or no ions. The recovered water can be
similar to desalinized water. It should be noted that the methods
and systems of the present invention can be used with any animal
tissue, although preferably, the methods and systems are used in
conjunction with almost any fish and fish bi-catch and recyclable
fresh fish parts, as this source of raw material is a plentiful and
sustainable resource. The protein powder, omega-3 oil and purified
water are fit for human consumption.
[0004] The systems and methods can be land-based or used on marine
vessels. In some applications, the systems are configured for
installation and use on a marine vessel. For example, the system
can be configured to fit within the confines of a portion of a
lower deck of the vessel. Modules of the system can be configured
to be removably fixed to a wall or deck of the vessel. A lateral
dampening attachment can be used between modules or between a
module and a fixed surface, such as the deck or a wall, to minimize
lateral movement which could be caused by movement of the vessel,
e.g., due to ocean waves.
[0005] More specifically, given the mounting world food shortage
problems in many areas of the globe, the present invention provides
a methodology for producing a high quality protein supplement,
which can provide a means to combat the ever growing malnutrition
crisis. The protein supplement can be derived from a wide variety
of optional 100% natural resources, such as small, short lived,
fresh and plentiful ocean fish. These resources are considered
green and sustainable and are an excellent renewable natural
resource. Their use will combat overfishing of certain species, and
help balance the oceanic ecosystem by reducing the environmental
impact due to discarded fresh fish parts and carcasses generated by
the fish processing industries. Environmental benefits are realized
by recycling these otherwise discarded fresh fish materials using
the methods and systems provided herein. In an age where there is a
growing requirement for green and environmentally conscientious
processing, the ability to reuse and recycle fresh and
nutritionally valuable waste materials generated by the general
fishery industry affords a certain unique benefit to the current
invention.
RELATED ART
[0006] A number of processes are available for recovering protein
from fish or marine animal tissue (e.g., see U.S. Pat. Nos.
4,405,649; 4,976,973; and 5,972,403). In these wet processes, fish
are treated with acids, proteases or high temperatures or
combinations thereof before or after grinding the fish in blenders.
In a different process (e.g., see U.S. Pat. No. 8,663,725), the
fish tissue is processed using an organic solvent to produce a
slurry. The resulting slurry contains recoverable solid particles
of tissue that contain protein and crude omega-3 oil.
[0007] While animal tissue purification systems and techniques
already exist in the marketplace, one major setback is the
efficiency in recovering products. Inefficiencies generally are
attributed to downtime caused by equipment maintenance and
replacement. For example, equipment inlets and outlets, as well as
conduits for transferring product, may become clogged and create
obstructions to material flow. Also, employing many pieces of
equipment in the purification system requires additional labor
hours to individually inspect each piece of equipment prior to
verifying the system is appropriate for further processing. What is
desired in the art is a more efficient system and process for
purifying animal tissue to meet present consumer demands. Also
desired is a system and process for improving yield of recovered
products from animal tissue. Further desired is a system and
process for recovering products with long shelf-lives. What is
further desired is a solvent recycling system that recycles the
organic solvent, and thus reduces the usage of the organic solvent
and the volatile organic compound (VOC) emissions of organic
solvent into the atmosphere.
[0008] Various techniques have been used for isolating solid
product materials from a slurry. Examples of such techniques
include separation by gravity by maintaining the slurry in a
holding tank for extended periods of time, filtration, and
centrifugation systems. Filtration systems typically employ a
filter media through which the liquid phase of the slurry is drawn,
using only gravity or a combination of vacuum to draw the liquid
through the filter in conjunction with gas pressure to force the
liquid phase through the solid cake and filter media. The result is
a protein powder filter cake on the filter media which is further
dried. Batch filtration and centrifugation systems have a high
capital cost and a limited product throughput that can prove
challenging for meeting market demands in a cost effective manner.
Additional costs and possible loss of product during material
transfer to a suitable drying unit also can occur with use of
typical centrifugation or batch filtration systems.
[0009] Accordingly, a need exists for methods and systems that more
efficiently produce protein powder for piscine and marine
animals.
SUMMARY OF THE INVENTION
[0010] Accordingly, the present invention is directed to improved
methods and systems for producing protein powder concentrate,
natural omega-3 oils and purified water that substantially obviate
one or more of the problems due to limitations and disadvantages of
the related art.
[0011] The objectives of the systems and methods provided herein
include providing more efficient systems and methods for recovering
nutritionally superior products from animal tissue with a
substantially increased production rate in an environmentally
friendly and socially responsible manner. The animal tissue can be
raw fish. The raw fish can be any kind of fish and any part of the
fish, including sustainable abundant species of fish and fish parts
that are ordinarily considered waste by the fish processing
industries.
[0012] Malnutrition is an issue in developing countries having
inadequate techniques and resources for storing perishable foods.
Namely, modern technological advances, such as refrigeration
systems, come at a price few can afford in remote, impoverished
areas. While water may be one of earth's most abundant resources,
obtaining purified drinking water still poses a challenge for
millions of people living in developing countries. One reason may
be attributed to the proximity to available water sources, e.g.,
landlocked countries and countries in proximity to bodies of salt
water, but not fresh water. Even if proximity is of no concern,
financial constraints in developing countries may result in the
lack of readily available, efficient water purification systems.
The present invention allows for the recovery of water from the
process, where the recovered water is purified for drinking and
human consumption.
[0013] One solution is to extract vital resources from animal
tissue. Whether landlocked or next to the sea, many developing
countries have access to an abundant supply of land or marine
animals. Marine animals, more specifically fish, are made up of
resources including protein, fish oils including omega-3, and water
derived from the fish itself. In view of the techniques employed by
the present invention to recover these products, the shelf-life can
be extended. By so doing, the necessity to preserve perishable
goods via refrigeration is reduced and/or eliminated.
[0014] The present invention proposes several unique and first of a
kind technologies to produce a highly pure and stable protein
product powder that contains levels of desirable minerals such as
calcium, potassium, zinc and other required inorganic materials.
These constituents are naturally derived from bones and flesh that
are associated with, for example, raw fish ingredients. The
resultant protein product powder is a complete protein source
comprising all of the essential amino acids, whose composition is
further complemented by naturally occurring inorganic mineral
substances. The nature of the technology utilizes pharmaceutical
grade processing systems and unit operations to ensure final
protein product purity and compliance with the manufacturing
requirements that are imposed in a regulated industry.
[0015] An advantage of the present invention is to provide green,
sustainable processes, methods and systems for recovery of protein
and omega-3 oils from piscine and marine animal tissue. The
recovered protein is non-hygroscopic, having been tested to exhibit
a shelf-stable for at least 5 years. In the methods and systems
provided herein, the piscine or marine animal flesh is not
subjected to thermal excesses or treated with acids or enzymes as
pre-digestion measures prior to separating the omega-3 oils from
the protein-containing particles. Another advantage of the present
invention is the recovered protein product is rapidly digestible
and has a superior amino acid content and profile compared to other
available bulk manufactured protein sources. For example, Table 1
shows a comparison of the powdered protein product produced using
the systems and methods provided herein compared to other plant
based and alternate bulk proteins.
[0016] The recovered protein associated with this invention has a
98% digestibility, contains natural minerals, and is lower in fat
and cholesterol than other animal proteins, such as whey, beef, and
chicken. In some embodiments, the powdered protein product can
contain less than about 0.1 wt % or less than 0.05 wt % trans fatty
acid isomers per 100 gram serving. In some embodiments, the
powdered protein product can contain less than about 0.1 wt %, or
less than about 0.05 wt %, or less than about 0.02 wt % cholesterol
per 100 gram serving.
[0017] The recovered protein can be non-GMO (Genetically Modified
Organism), gluten free, odorless and tasteless, and contains no
measurable heavy metals. The recovered protein exhibits a very long
shelf life of 5 years, and is very stable for storage and
manufacturing equipment friendly due to its non-hygroscopic
nature.
[0018] Another advantage of the present invention is the level of
zero grain requirements, thus eliminating the need for sacrificing
land that is otherwise required for the production of important
agricultural based food sources. The fish sources make use of
sustainable small fish, thus giving rise to a superior nutritional
profile. In comparison with land based derived products, the
protein recovered in accordance with this invention can have a much
lower carbon footprint and requires no raw materials (e.g., grains
and water) for feeding the fish sources (see Table 2).
TABLE-US-00001 TABLE 1 Comparison of Recovered Protein with
Alternate Recovered Proteins Standardized to 25 grams of protein
per serving Powdered Source Bulk Food NutriBio NutraBio BulkFood
Protein Blue Organic American Whey Whey Soy Protein Soy Protein
Product Wave Whey Whey Isolate Isolate Isolate Isolate Serving Size
29.2 29.8 28.5 27.5 28.3 28.7 27.5 Calories 100.0 135.0 119.0 104.0
128.8 107.0 110.0 128.8 Protein 25.0 25.0 25.0 25.0 25.0 25.0 25.0
25.0 Carbohydrates 0.3 3.0 2.4 1.4 1.3 1.0 0.0 0.0 Fat in gm 0.0
2.1 1.8 0.0 0.6 1.0 1.0 1.3 Saturated Fats 0.0 2.1 0.6 0.0 NA 1.0
NA NA Cholesterol 0.0 31.3 47.6 4.5 NA 2.0 NA NA Shelf Life 5 years
2 years 2 years 2 years 2 years 2 years 2 years 2 years Taste NONE
strong mild mild milk mild mild milk mild soy mild soy fish milk
Odor NONE strong mild mild milk mild mild milk mild mild fish milk
GMO NO no no yes yes yes yes yes (feed) (feed) (feed) (seed)
(seed)
TABLE-US-00002 TABLE 2 Requirements & Carbon Footprint of
Alternate Protein Sources Requirement Grain Water Carbon Foot Print
of 1 Pound of: (Lbs) (Gallons) (Kg CO.sub.2/Kg edible product) Pork
6 3,500 3-6 Chicken 2.3 2,000 1.5-7 Beef (whey) 13 2,500 16-40
[0019] Another advantage of the present invention is the product's
general positive effect on human health compared to alternate plant
based protein sources. For example, 93% of US grown soy can be
genetically modified which some people believe may be related to
serious health risks, such as toxicity, allergenicity, antibiotic
resistance, immune-suppression, cancer risks, and possible
goitrogenic [thyroid] and carcinogenic effects. A contributor to
these deleterious effects is believed to be farming methods using
GMO technologies that can promote treatments with herbicides and
pesticides. Similarly, protein sources derived from animal based
processes (e.g., beef) can be subjected to hormone and animal
antibiotic treatments.
[0020] Another advantage of the present invention is that the
systems provided herein require a small footprint for manufacturing
the recovered protein, where the required equipment can be
contained on compact automated manufacturing modules. These modules
typically can have a smaller footprint than comparable food
manufacturing factories. These manufacturing modules can be easily
transported to multiple locations and deployable around the globe,
within close proximity to the source of raw materials, including
marine vessels, fish processing vessels and mother ship vessels (a
ship providing facilities and supplies for a number of smaller
vessels).
[0021] The systems can configured for installation and use on a
marine vessel. For example, the system can be configured to fit
within the confines of a portion of a lower deck of the vessel.
Modules of the system can be configured to be removably fixed to a
wall or deck of the vessel, and appropriately sized for ease of
placement within the vessel. The connections between modules or
between a module and a fixed surface, such as a wall of deck floor,
or both, can be selected to minimize displacement of the modules of
the system due to the motion of the vessel through the water. For
example, a lateral dampening attachment can be used between modules
or between a module and a fixed surface, such as the deck or a
wall, or both, in order to minimize lateral movement which could be
caused by movement of the vessel or due to ocean waves or a
combination thereof. A further dampening member can be used to damp
vertical or heave forces to limit the maximum vertical displacement
of the modules. The dampening members independently can be
controlled in order to independently address the separate forces
acting on the module(s). The separate control can allow for the
overall response of the dampening members(s) to be more accurately
tailored to address the conditions in the vessel. Any arrangement
for permitting limited movement, such as springs, hydraulic
cylinders, electronic suspension systems, adaptive suspension
systems, rubber bumpers or connectors, or inter-coupling devices
that permit satisfactory coupling of the modules to each other or
to a fixed surface while allowing sufficient freedom of movement
can be used, alone or in combination.
[0022] Provided herein are methods and apparatus for producing a
low-moisture protein (less than 5 wt % moisture, e.g., less than 1
wt % moisture, or less than 0.5 wt % moisture) product concentrate
and purified low heat (temperature range 45.degree. C.-72.degree.
C.) processed, omega-3 oils for human consumption from piscine or
marine animals or eggs or parts thereof, or from dehydrated
fishmeal or commodity dried fish, or combinations thereof, as
starting raw materials.
[0023] Another embodiment of the present invention concerns a
method for producing a protein product in the form of a low
moisture wet cake containing solid particles of protein. The method
comprises: (a) introducing a slurry containing a solid phase that
includes solid particles containing protein and a liquid phase
containing an organic solvent and omega-3 oil into a product
recovery system; (b) separating the slurry into a liquid phase and
an isolated solid phase, where the solid phase is in the form of an
initial wetcake; (c) washing the initial wetcake with a product
wash stream having a temperature within the range of 25.degree. C.
to 72.degree. C. to produce a washed wetcake and a wash filtrate;
and (d) drying the washed wetcake to produce the final protein
product.
[0024] In the methods and processes provided herein, the solvent
can be reclaimed from the wash filtrate and the slurry extraction
filtrate, where both filtrates are collected and recycled for
subsequent reuse in the process.
[0025] Also provided are methods for isolating solid protein
product and omega-3 oil from a slurry mixture containing a solvent
and ground piscine or marine animal tissue. The methods include
treating a slurry that includes solid particles of ground tissue
and a liquid phase that includes a solvent and an oil fraction.
This mixture is processed within a product recovery system to
separate the slurry, thus producing an isolated liquid phase and a
low-moisture wet cake substantially containing protein. In the
methods provided herein, treatment of the slurry can include
depositing the slurry on a surface of a filter, wherein the solid
particles are retained on the surface of the filter, and washing at
least a portion of the solid particles with a wash stream having a
temperature within the range of 25 to 72.degree. C., thus forming a
wet cake containing the solid particles which are of substantially
recovered protein. The filter can be part of one of several types
of separation systems, e.g., a vacuum belt filtration system, or an
immersion extractor, or a percolation extractor, or a rotary drum
filter, a screw press, a decanter centrifuge, or a combination
thereof. The wetcake can be processed to further remove liquid
through the use of a drying system.
[0026] In the methods provided herein, omega-3 oil can be recovered
from the ground piscine or marine animal tissue or eggs. The
omega-3 oil can be recovered from the liquid phase of the slurry
once the liquid phase is separated from the solid particles of
protein product. Omega-3 oils also can be recovered from the wash
liquids or process filtrates. The solvents used during the process
can be recovered from the process filtrates for subsequent reuse in
the process. The amount of omega-3 oil in the slurry depends on the
particular species of starting piscine or marine animal tissue. In
some embodiments, the slurry can contain 25 wt % or less omega-3
oil.
[0027] Another advantage of the present invention can be to provide
a system and method that improves the yield of recovered
products.
[0028] Yet another advantage of the present invention can be to
provide a system and method that improves shelf-life of the
recovered products.
[0029] A further advantage of the present invention can be to
provide a system and method that recycles the organic solvent and
reduces VOC emissions into the atmosphere.
[0030] The present invention options can be considered a general
recycling process for fish carcasses and related materials fit for
human consumption that are otherwise discarded daily by facilities
in the fish processing industry. The resultant recycling of the
otherwise discarded materials to produce a high quality protein
product affords a green and sustainable process that reduces the
burden on the environment.
[0031] In one aspect of the present invention, an improved system
and method for recovering products from animal tissue is described.
Specifically, the technique involves combining animal tissue and
organic solvent within a slurry tank in sufficient proportions to
produce a mixture thereof. The mixture is agitated, heated
(generally to a temperature no greater than 72.degree. C., e.g.,
within the range of 25.degree. C. to 72.degree. C.) and separated
using various separation options and then dried and milled to
produce protein product powder. Preferably, the slurry tank is a
single unitary structure outfitted with a mixing blade or agitator.
The separation options can include continuous contacting belt or
conveyor type filtration systems or centrifugation systems, such as
vacuum belt filtration system, or an immersion extractor, or a
percolation extractor, or a rotary drum filter, or a screw press,
or a decanter/centrifuge, or combinations thereof. Also recovered
is animal oil and water derived from the animal. In a preferred
embodiment, the animal tissue is fish, and the recovered products
include fish protein, fish oils and water derived from the fish. In
an exemplary embodiment, the solid protein product is transferred
to a grinding mill for further processing into a finely divided
powder. In a yet another exemplary embodiment, a filtered, liquid
portion of the mixture is filtered to separate fish oil from water.
In a further embodiment, the portion of the mixture retained in the
single unitary structure after filtration is combined with recycled
organic solvent. The recycled organic solvent is recovered from the
liquid portion of the mixture.
[0032] In another aspect of the present invention, an improved
method for recovering products from animal tissue is provided.
Specifically, the technique involves the use of a screw press
system which has the effect of separating the water and omega-3
based oils from the fish tissue. The method involves dispensing raw
fish and an organic solvent, such as isopropyl alcohol (IPA) or
ethyl alcohol, in a ratio of at least 1 part volume of organic
solvent to 1 part weight raw fish to a processing vessel, such as
the aforementioned slurry tank, that is outfitted with a mixer or
agitation system. The mixture is then stirred to yield a
homogeneous slurry between a temperature of 25.degree. C. to
72.degree. C. The combined mixture of the organic solvent and raw
fish are then transferred to the screw press where the liquid is
separated from the raw fish. The resultant liquid filtrate derived
from the screw press operation can be stored and subsequently
processed for recovering the organic solvent. The pressed raw fish
is returned to the slurry vessel and a second slurry cycle is
performed. The screw press operation is optionally performed for at
least two to three successive cycles.
[0033] In the methods and systems provided herein, various optional
systems for recovering products from animal tissue can be used.
Preferably, the animal tissue is fish. The systems include a screw
press in combination with either a continuous belt filtration,
immersion extraction system, percolating extraction system, or
rotary drum filter, whereby an intermediate product wet-cake is
discharged into a drying unit. Animal tissue feedstock and organic
solvent are independently, or collectively, transferred onto either
of these optional processing devices. These filtration units allow
the raw material feedstock to be washed with solvent to yield a
purified intermediate product wet-cake. The filtration system
options include subsystems for recycling and removing filtrate, as
well as an output for removing solid product.
[0034] Provided herein are systems for recovering a protein product
powder and purified omega-3 oils from an animal tissue. The systems
include a grinding unit, a slurry preparation unit, a dewatering
device, a closed system product separation system for separating
the slurry into a liquid phase and a solid phase, the separation
system including a continuous conveyance filtration system selected
from among a belt filtration system, a rotary drum filter, an
immersion extractor, a percolator extractor, and a screw press, or
a centrifugation system, such as a decanter centrifuge, or any
combination thereof, and a solvent/liquid recovery (SLR) system
that includes a liquid phase processing unit, a separation unit
that separates the liquid phase into recovered organic solvent,
water and an omega-3 oil, and a recovered organic solvent storage
tank. The system can include a drying unit. The system can include
a milling unit.
[0035] In some embodiments, the system is manual. In some
embodiments, the system is automated. The system can be automated
by using a programmable logic controller (PLC) and a customizable
recipe-driven software architecture (e.g., depending on the fish
species or final desired product characteristics, where the PLC is
the automated programmable device for controlling the process
automatically without the need for manual intervention.
[0036] The separation unit of the system can include a distillation
unit or a centrifugation unit or a combination thereof. The
distillation unit can include single column or a plurality of
distillation columns. The distillation unit can include a thin film
evaporator or a wiped film evaporator. The system can include a
process control system that analyzes the overhead vapor pressure
and the temperature of the distillation unit. The system can
include a liquid phase processing unit that contains an adsorber
system or an activated carbon filtration system or both. The system
can include an analyzer system. The analyzer system can analyze the
adsorber effluent stream for detection free amines or small chain
hydrocarbon materials. If these materials are detected, the
analyzer system can make adjustments in order to minimize or
eliminate free amines or small chain hydrocarbon materials from the
protein product.
[0037] The slurry preparation unit of the system can include a
preparation tank for receiving and mixing ground animal tissue from
a grinding unit with a solvent to form a slurry. The system can
include a closed system recycling solvent loop that transports
recovered organic solvent from the recovered organic solvent
storage tank to slurry preparation unit. The system can include a
volatile organic carbon recycling system that captures process
emissions of the organic solvent to form a condensed liquid solvent
from the filtration process via condensation and transports the
condensed liquid solvent to the closed loop recycler. The system
also can include a variable frequency drive (VFD) to modulate the
speed of the conveyance filtration system or the centrifugation
system.
[0038] Also provided are methods for recovering protein product
powder and omega-3 oil from an animal tissue. The methods include
mixing the animal tissue with an organic solvent in a preparation
tank; comminuting the animal tissue with the organic solvent to
produce a slurry; separating the slurry into a liquid phase and a
solid phase using a separation system selected from among a belt
filtration system, a rotary drum filtration system, an immersion
extraction system, a percolation extraction system, a screw press
filtration system, a centrifugation system, such as a decanter
centrifuge, and any combination thereof; recovering the liquid
phase and separating it into a recovered organic solvent portion
and an omega-3 oil portion; recovering the solid phase and drying
it to yield a protein wetcake; and milling the protein wetcake to
yield protein product powder. In the methods, the animal tissue can
include raw fish that is processed through a dewatering device to
remove excess water. The dewatering device also can be configured
to mix dewatered slurry with the organic solvent to form a
processed slurry. In the methods, the organic solvent mixed with
the animal tissue or with the dewatered slurry can include an
alcohol, an aliphatic hydrocarbon, an ester, water or any
combination thereof.
[0039] In the methods provided, the vapor produced during drying
the solid phase can be captured and condensed into a liquid and
organic solvent can be separated from the liquid and recovered,
e.g., for reuse in the system. The organic solvent mixed with the
animal tissue or with the dewatered slurry can include at least a
portion of the recovered organic solvent derived from the condensed
vapor derived from the drying step of an earlier processed slurry.
In some embodiments, dried protein product is milled into a powder.
In some embodiments, a jet mill reduces the particles size of the
dry protein product into a powder.
[0040] In the methods provided herein, the yield of protein can be
in the range of from about 10% to 20%, based on the total weight of
the starting animal tissue. In some applications, the yield of
protein can be about 18 wt % or greater based on the total weight
of the starting animal tissue. The amount of protein recovered can
depend on the starting material, e.g., the type of species or blend
of species used, and the composition of the starting material,
e.g., the total water/oil/protein content of the starting material.
The systems and methods provided herein can be used to produce a
protein product powder. The protein product powder can have a
moisture content of less than about 10 wt %. In some applications,
the protein product powder can have a moisture content of less than
about 1 wt %, or less than about 0.5%. In some applications, the
protein product powder can have a moisture content in the range
from about 0.15% to about 1%. The protein product powder can have
an amount of residual organic solvent of less than about 0.5 wt %,
or about 250 ppm or less. The amount of protein in the protein
product powder can be at least about 50 wt % protein, or can be
greater than about 80 wt %, or greater than about 90 wt %, or
greater than 95 wt %. In some applications, the amount of protein
in the protein product powder can be between about 90 wt % and 98
wt %, or from about 90 wt % to about 96 wt %. In some applications,
the amount of protein in the protein product powder is in the range
of from about 45 wt % to about 96 wt %. The protein product powder
has a crude fat content of less than about 1.5 wt % and a
cholesterol content of less than about 0.1 wt %. In some
applications, protein product powder can have a crude fat content
of less than about 1 wt %, or less than about 0.5 wt %. In some
applications, protein product powder can have a crude fat content
from about 0.15 wt % to about 0.5 wt %.
[0041] Additional features and advantages of the invention will be
set forth in the description which follows, and in part will be
apparent from the description, or may be learned by practice of the
invention. The objectives and other advantages of the invention
will be realized and attained by the structure particularly pointed
out in the written description and claims hereof as well as the
appended drawings.
[0042] It is to be understood that both the foregoing general
description and the following detailed description are exemplary
and explanatory and are intended to provide further explanation of
the invention as claimed. Reference will now be made in detail to
embodiments of the present invention, examples of which are
illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] The accompanying drawings, which are included to provide a
further understanding of the invention and are incorporated in and
constitute a part of this specification, illustrate embodiments of
the invention and together with the description serve to explain
the principles of the invention.
[0044] In the drawings:
[0045] FIG. 1 is an illustration of the product recovery system
provided herein showing the various protein isolation options in
accordance with exemplary embodiments of the present invention. As
shown, the product recovery system 1000 includes a grinding unit
100, a slurry preparation tank 150, a dewatering device 170, a
product separation system 10 that can include one or more of a belt
filtration system, a rotary drum filter, an immersion extractor, a
percolation extractor, a screw press, a decanter centrifuge. or any
combination thereof. The product recovery system 1000 also includes
a solvent/liquid recovery (SLR) system 700 for recovering the
solvent for reuse and for processing the recovered omega-3 oil. The
SLR system 700 includes a liquid phase processing unit 705 and a
separation unit 715 and optionally a recovered solvent tank 740.
The product recovery system 1000 also includes a solvent supply
tank 180, discharge stage 30, a dryer unit 800, a vapor condenser
805 and a milling unit 815.
[0046] FIG. 2 is a detailed view of a belt filtration system option
that can be used as a protein recovery system in accordance with
exemplary embodiments of the product recovery system provided
herein.
[0047] FIG. 3 a detailed view of a rotary drum filtration system
option that can be used in accordance with exemplary embodiments of
the product recovery system provided herein.
[0048] FIG. 4 is a detailed view of an immersion extraction system
option that can be used in accordance with exemplary embodiments of
the product recovery system provided herein.
[0049] FIG. 5 a detailed view of a percolation extraction system
option that can be used in accordance with exemplary embodiments of
the product recovery system provided herein.
[0050] FIG. 6A is a schematic top view and FIG. 6B is a schematic
side view of a screw press system option that can be used in
accordance with exemplary embodiments of the product recovery
system provided herein.
DETAILED DESCRIPTION
Definitions
[0051] Unless defined otherwise, all technical and scientific terms
used herein have the same meaning as is commonly understood by one
of skill in the art to which the inventions belong.
[0052] All patents, patent applications, published applications and
publications, websites and other published materials referred to
throughout the entire disclosure herein, unless noted otherwise,
are incorporated by reference in their entirety. In the event that
there are a plurality of definitions for terms herein, those in
this section prevail. Where reference is made to a URL or other
such identifier or address, it is understood that such identifiers
can change and particular information on the internet can come and
go, but equivalent information can be found by searching the
internet. Reference thereto evidences the availability and public
dissemination of such information.
[0053] As used herein, "impurities" refers to any substance other
than animal tissue, protein, oils, solvent, and water. Such
impurities can include, e.g., oxidation byproducts, free amines,
such as dimethyl, trimethyl, and homologues of similarly aminated
species, cholesterol, and volatile odoriferous compounds.
[0054] As used herein, "low-moisture wetcake" refers to a wetcake
containing a liquid in an amount in excess of 2 weight percent.
[0055] As used herein, "vacuum belt filter" refers to a device that
uses a pressure differential created by a vacuum source cross a
conveyor belt filter to facilitate solid/liquid separation.
[0056] As used herein, "rotary pressure/vacuum drum filter" refers
to a device that uses a pressure or vacuum differential across a
rotating drum filter to facilitate solid/liquid separation.
[0057] As used herein, a "continuous feed immersion type solvent
extractor" refers to a device that includes serially connected
cascading pools for separating a liquid and a solid where the
solids being processed are soaked in the solvent as the material is
conveyed through the device.
[0058] As used herein, a "continuous feed percolation type solvent
extractor" refers to a device for separating a liquid and a solid
that includes a mechanical conveyance system and a solvent
application system where the solvent is washed through the solids
being processed. The solvent can be applied from the bottom or from
the top of the solids.
[0059] As used herein, a "decanter centrifuge" refers to
centrifugation separation device that separates solids from liquids
using centrifugal forces. Generally, when the mix of solids and
liquids is subject to centrifugal forces in the device, the denser
solids are pressed outward, generally against a rotating bowl wall,
with the lighter liquid layer in a concentric inner layer, and dam
plates can be used to direct the flow of the fluid, resulting in
the separation of the solids from the liquid in a single continuous
process.
[0060] As used here, the singular forms "a," "an" and "the" include
plural referents unless the context clearly dictates otherwise.
[0061] As used herein, ranges and amounts can be expressed as
"about" a particular value or range. "About" also includes the
exact amount. Hence "about 5 percent" means "about 5 percent" and
also "5 percent." "About" means within typical experimental error
for the application or purpose intended.
[0062] As used herein, "optional" or "optionally" means that the
subsequently described element, event or circumstance does or does
not occur, and that the description includes instances where the
element, event or circumstance occurs and instances where it does
not. For example, an optional component in a system means that the
component may be present or may not be present in the system.
[0063] As used herein, "animal tissue" is material that can contain
the complete animal components inclusive of tissue, bones, and
scales.
[0064] In the examples, and throughout this disclosure, all parts
and percentages are by weight (wt %) and all temperatures are in
.degree. C., unless otherwise indicated.
[0065] As used herein, the phrase "based on the weight of the
composition" with reference to % refers to wt % (mass % or (wt/wt)
%).
[0066] As used herein, "natural omega-3 oil" refers to omega-3 oil
that is not chemically modified and that is suitable for human
consumption.
[0067] As used herein, "modular" means that the components of the
system are designed with standardized dimensions or
inter-connections, to allow for easy assembly an disassembly and
flexible arrangement and use.
Product Recovery Systems and Methods
[0068] The present invention describes several systems and
processes for improving the efficiency of recovering products from
animal tissue. Also described are systems and processes for
improving throughput, especially yield of solid protein, based upon
the initial feed of animal tissue. Also provided are systems and
processes for reducing the emission of volatile organic compound
(VOC) gases into the atmosphere during the processing of animal
tissue.
[0069] Generally, condensing plural pieces of third-party
manufacturing equipment modified to fit and accommodate the methods
described herein to output materials fit for human consumption, and
configured into a single modular unitary structure has been shown
by the inventors to reduce downtime caused by material flow
obstructions occurring at multiple locations in the system. Namely,
material flow obstructions occur most frequently at inputs and
outputs of manufacturing equipment. Material flow obstructions also
occur within conduits connecting different pieces of manufacturing
equipment. According to the inventors, processing animal tissue
feedstock using a continuous belt filter or similar mentioned
solvent extraction systems to recover a wet cake including solid
protein significantly improves (i.e. reduces) downtime attributed
to maintenance and repair. In addition, the current systems and
methods can be operated manually or can be automated processes. The
systems and methods are more energy efficient and require less
manpower than a system that includes multiple unit operations.
Another advantage directly attributed to employing the
above-mentioned system is the ability for increased product
throughput in addition to a reduction in capital and operational
costs associated with procuring and maintaining multiple pieces of
equipment required to produce the same quantities of final product.
Yet another advantage realized by the inventors is an improvement
in yield of solid protein and shelf-life, derived from the wet cake
by employing the system and method described herein.
[0070] The systems and processes provided herein will be discussed
in greater detail below in view of the exemplary, non-limiting
embodiments of the present invention. Each of the embodiments
discussed hereinafter, unless expressly noted otherwise, are
combinable and envisaged within the scope of the present invention.
It is also understood that the embodiments, while preferred, are
exemplary, and those of ordinary skilled in the art will understand
certain modifications to the embodiments are possible without
departing from the spirit of the invention.
[0071] Systems
[0072] FIG. 1 is a process overview illustrating an exemplary
embodiment of a protein recovery system provided herein. As shown
in FIG. 1, the recovery system 1000 includes a grinding unit 100
that can receive an animal tissue feedstock, such as raw fish, for
introducing animal tissue. The animal tissue feedstock can be
contained within a storage tank before it is transferred to
grinding unit 100. The storage tank can be temperature controlled.
Alternatively, the animal tissue can be housed in a cold room and
conveyed downstream for processing either manually by technicians,
or by any combination of automatic machinery including but not
limited to screw conveyers, conduits/tubes, pumps, blowers, etc. In
an exemplary embodiment, stainless steel piping can be employed
throughout the system. In another exemplary embodiment, a pump
constructed of stainless steel can be used to assist with
transferring animal tissue to the grinding unit 100.
[0073] The recovery system 1000 also includes a slurry preparation
tank 150 into which the ground animal tissue is discharged via line
105. The ground animal tissue is mixed with a solvent in the slurry
preparation tank to form a crude slurry. The recovery system 1000
includes a solvent storage tank 180 for providing an organic
solvent feed to slurry preparation tank 150 as well as a recycled
solvent feed line 745 that can be used to direct recovered solvent
into slurry preparation tank 150. Any organic solvent, such as
ethanol or isopropyl alcohol (IPA) or ethyl alcohol or combinations
thereof, can be used as a permissible organic solvent. The storage
tank 180 can have a flat bottom or a curved bottom and generally is
closed to the environment (e.g., includes a closed or closable
top). The storage tank 180 can also include a level transmitter for
monitoring solvent inventory. The storage tank 180 can include
nozzles that directly or indirectly communicate with an inlet of
nitrogen or similarly inert gas for introducing an inert gas into
the storage tank 180. The storage tank 180 also can include a
conservation valve, butterfly valve, and/or diaphragm valve. The
organic solvent can be delivered downstream by any combination of
equipment including but not limited to piping, hoses, pumps,
blowers, valves or the like. In some embodiments, a pump is present
to deliver the solvent to other components of recovery system 1000.
When present, the pump can be stainless steel and centrifugal.
Piping and/or tubing can be employed as necessary for
interconnecting the different components of recovery system
1000.
[0074] The present invention involves a highly scalable process and
is capable of yielding protein powder and omega-3 oils ranging from
lower to higher quantities. The process is highly modular and
therefore also reconfigurable in that parallel trains of similar or
combinations of the optional systems can be implemented for
concurrent production requirements. The system can be operated
manually or can be automated. In some embodiments, at least one
process of the system is automated.
[0075] The process can be configured to be highly modular, where
the system includes a plurality of modules, each module comprising
a piece of equipment. The modules can be designed to be movable,
and the modules can be designed to allow connection to other
modules. The connection can be direct, or a connecting unit can
connect different modules together. The modules can be adaptable
for a plurality of manufacturing steps or processes. Very little
time is required to reconfigure the system, such as changing one
module to perform a different step or process, and/or including a
plurality of the same modules, e.g., to extend a process line, or
extend a treatment step. Because of the modular nature of the
system, it is relatively inexpensive to expand the system, or to
acquire additional modules. It also is easy to incorporate new or
additional modules into the system.
[0076] In some applications, all components can be contained in one
module. In some applications, individual components of the system
can be contained in separate modules. For example, individual
modules can include a grinding module, or a slurry preparation
module, or a dewatering module, or a concentrator module (e.g.,
containing a belt filtration system, or rotary drum filter, or
immersion extractor, or percolation extractor, or screw press, or
decanter centrifuge), or a drying module, or a milling module, or a
packaging module, or a solvent/liquid recovery module. Some systems
can contain two or more components in a single module. Some systems
can include multiples of individual modules. For example, several
drying modules can be configured in series in order to extend the
path the product takes through drying equipment contained in the
drying modules. As another example, a concentration module
containing a screw press can be attached to a concentration module
containing a belt filtration system.
[0077] Each module can be separately movable from another module.
modules can take on a plurality of forms, sizes, shapes, and/or
configurations. Any suitable number of modules can be provided in a
particular modular manufacturing system depending on a particular
manufacturing need and/or manufacturing facility space limitation
or requirement. The modules can form a system that is used in a
marine environment. In such configurations, the modules can include
fasteners that can be attached to a frame connected to the deck or
a wall of the ship, or each module can separately be connected to a
deck or wall of a ship. The modules can form a system that is
land-based. In such configurations, the modules can be attached to
a frame affixed to the ground, or each module separately can be
attached to a floor or wall. The equipment within each module is
easily separated from the equipment contained in another module.
The modules allow for easy change-over, such as by modifying,
moving, adding to, and/or reconfiguring equipment mounted to
portion of the modules and/or by simply replacing a module, or
replacing the equipment within a module. For example, a piece of
equipment in a module can be disconnected from a piece of equipment
in another module and the module can be replaced with another
module. In some configurations, the module can be configured to
separately accommodate two or more pieces of equipment, and the
system can be modified by unattaching a piece of equipment in the
module, removing the piece of equipment from the module, and
placing a different piece of equipment in the module.
[0078] The equipment can be held to the portions of the modules
using bolts, pins, rods, quick-connect mechanisms, and/or other
attachment devices. Each module can include one or more mounting
and alignment portions for connecting to, operably engaging with,
and/or aligning with neighboring modules, standard forklift pickup
channels, chains, and/or hooks, and/or built in and/or attachable
conveyors. Each module can include integrated power and
communication systems that can interact with other modules. Each
module can include conduits for wires or cables, and can include
conduits for utilities such as water, compressed air, heating,
cooling, and vacuum systems. Each module can enclosure doors,
shields, or guards or combinations thereof to at least inhibit dust
or dirt infiltration and to reduce the noise produced by the
module.
[0079] Of particular importance, the recovery system can include
one or a combination of six different separation system options,
namely a belt filtration system, a rotary drum filter, an immersion
extraction system, a percolation extraction system, a screw press
system, and a decanter centrifuge system. Any one or combination of
these systems can be included in the product separation system 10
in FIG. 1 and used to separate the protein product from the omega-3
oil. Some of these units can include a filter for separating solids
from heavy liquids. Some of these systems also can include one or
more filtrate pump devices that can recycle the process filtrate
back into the process to allow more efficient washing of the
protein product wet cake. Preferably, these systems can be
constructed of stainless steel or solvent resistant polymeric
material, such as polypropylene, and are of a sanitary design.
[0080] The overall protein recovery system 1000 illustrated in FIG.
1 also includes a product drying system 805 that can be further
followed by a milling unit 815 such as micronizer or milling
device. A solvent/liquid recycle (SLR) system 700 is also present,
as illustrated in FIG. 1. The SLR system 700 includes a processing
unit 705 and separation unit 715, which can include adsorber and
distillation units. The SLR system 700 can include one or more
filtrate recovery tanks (not shown in FIG. 1) for storage or
containing hold up volumes. Preferably, the filtrate recovery tanks
are made of stainless steel. The filtrate tanks can include one or
more inlet nozzles that directly or indirectly communicate with an
inlet for feeding nitrogen or other inert gas into the recovery
tank. The nitrogen or inert gas forms an inert gas blanket that
maintains a reduced level of oxygen in the organic vapor space to
eliminate the potential for explosion or oxidation of products. The
SLR system 700 is used to process the spent filtrates by recovery
of the organic solvent using an adsorber bed contained within
processing unit 705, followed by a distillation system, which is a
part of separation unit 715.
[0081] The distillation system that is a part of separation unit
715 can be a simple batch type still equipped with an overhead
condenser and distillate receiver. The distillation unit also can
be a wiped or thin film evaporator unit. A thin film or wiped film
evaporator (WFE) can be used for concentrating, separating,
refining, decolorizing and deodorizing liquid streams containing
solvents. The liquid streams are separated into distillate and
residue components. In a WFE system, the process filtrate enters
through the inlet of the WFE and is dispersed across a distributor
plate into an internal heating wall. Rotating wipers within the
body of the WFE spread the liquid to a uniform thin film. Vaporized
liquid condenses as distillate. The residue component is collected
in a separate vessel. The resultant distillate includes the
recovered solvent for recycling back into the process, such as via
line 745 or line 750 or both. The distillation residue will contain
a high concentration of omega-3 oil that can exit separation unit
715 via line 725, and can be optionally processed further using
molecular distillation technologies or their equivalent. The
distillation residue can be optionally processed using chemical
reaction processing, such as transesterification.
[0082] In some embodiments, the SLR system 700 can include a
recovered solvent tank 740. Recovered solvent from separation unit
715 can be transferred to recovered solvent tank 740 via line 720.
The recovered solvent tank 740 can have a flat bottom or a curved
bottom and generally is closed to the environment (e.g., includes a
closed or closable top). The recovered solvent tank 740 can also
include a level transmitter for monitoring solvent inventory. The
recovered solvent tank 740 can include nozzles that directly or
indirectly communicate with an inlet of nitrogen or similarly inert
gas for introducing an inert gas into the recovered solvent tank
740. The recovered solvent tank 740 also can include a conservation
valve, butterfly valve, and/or diaphragm valve. The organic solvent
can be delivered downstream by any combination of equipment
including but not limited to piping, hoses, pumps, blowers, valves
or the like. In some embodiments, a pump is present to deliver the
solvent to other components of recovery system 1000. When present,
the pump can be stainless steel and centrifugal. Piping and/or
tubing can be employed as necessary for interconnecting the
different components of recovery system 1000.
[0083] Slurry Preparation
[0084] Still referencing FIG. 1, generation of a crude slurry is
accomplished by first producing a finely ground animal tissue from
the starting material. In some embodiments, the finely ground
animal tissue is prepared using an extraction system that includes
the grinding unit 100 that comminutes the starting material into
small pieces in the presence of an extraction solvent to produce
the crude slurry. The starting material can contain animal tissue
containing a bulk protein mass containing polypeptides and a
mixture of oils, such omega-3 type oils. Suitable examples of the
starting material include, but are not limited to, animal tissue
material derived from flesh or eggs from anchovies, arctic char,
mackerel, sablefish, herrings, sardines, salmon, hake (cod family),
halibut, carp, trout, oysters, hill, squid, shrimp and cuttlefish,
and as an optional starting raw material, dried fishmeal or dried
fish, or any combinations thereof. In some embodiments, the
starting material comprises piscine eggs or tissue or parts thereof
that contain about 65 wt % to about 75 wt % water, about 15 wt % to
about 25 wt % protein, about 4 wt % to about 8 wt % oil, and about
1 wt % to about 5 wt % other material, such as carbohydrates or
ash-producing material, e.g., bones.
[0085] The ground animal tissue can be prepared by dispensing whole
raw fish and/or raw fish parts into the grinding unit 100. The
resultant ground material can contain the complete animal
components inclusive of tissue, bones, and scales. In some
embodiments of the methods and systems provided herein, the ground
material can include water from the starting material, and amounts
of omega-3 oil from the ground starting material, and optionally
can include extraction solvent, which can include water, which can
be added to the starting material during the grinding process. The
ground material contains a solid phase and a liquid phase and can
contain impurities.
[0086] The starting material is subjected to a grinding operation
in grinding unit 100. Grinding unit 100 can include any type of
equipment that can reduce the particle size of the starting
material, such as a pulverizer, homogenizer, high speed blender,
rotor-stator mixer or any combination thereof. The grinding unit
100 includes a vessel equipped with an overhead mixer or agitator
assembly that is used to stir the mixture within the vessel. The
vessel has an inlet feed nozzle for dispensing solvent and a
charging port for dispensing the raw animal tissue. The vessel can
contain a valve, such as a bottom valve, for discharging the ground
material slurry. The grinding of the starting material reduces the
particle size of the raw fish to about 6300 .mu.m (0.25 inches) or
less. In some embodiments, the grinding process is continued until
the average particle size of the ground animal tissue, e.g., ground
raw fish, is about 5000 .mu.m or less, or about 4000 .mu.m or less.
No heat is applied to the starting material in the grinding tank
other than any frictional heating that could occur due to the
grinding and/or mixing process. The grinding process is exclusively
mechanical, and the starting material is not treated with an acid
or a protease prior to grinding. A solvent can be added to the
animal tissue before or during the grinding process. In some
embodiments, the temperature of the ground material is 25.degree.
C. or less after its production. The resulting ground material is
used to make a crude slurry.
[0087] A crude slurry is prepared in slurry preparation tank 150
and can contain a liquid phase in an amount in the range of from
about 40 wt % to 99 wt % based on the weight of the slurry. The
liquid phase of the slurry can include water or an organic solvent
or combinations thereof. The crude slurry also can contain
particles of piscine tissue or marine animal tissue or fish meal or
dried fish or combinations thereof. The particles of piscine tissue
or marine animal tissue or fish meal or dried fish in the slurry
can be present in an amount in the range of from about 1 wt % to
about 99 wt %, or from about 40 wt % to about 99 wt % based on the
weight of the slurry. Depending on the starting material, the
slurry also can include particles of bone or
carbohydrate-containing particles or combinations thereof.
[0088] The crude slurry can be prepared by mixing the ground
starting material, such as ground piscine tissue or parts thereof,
or marine animal tissue or parts thereof, or dehydrated fishmeal,
or commodity dried fish, or combinations thereof, with an
extraction solvent in slurry preparation tank 150 to form a
mixture. The extraction solvent can include water or an organic
solvent or combinations thereof. In some embodiments, the
extraction solvent includes an alcohol, an aliphatic hydrocarbon,
an ester, water or any combination thereof. The ground material can
be introduced into the slurry preparation tank 150 via line 105. An
organic solvent can be introduced into slurry preparation tank 150.
The organic solvent can be fresh virgin solvent from storage tank
180, which can be fed into slurry preparation tank 150 via solvent
line 185. The organic solvent also can be solvent recovered from
the process using the SLR system 700, which includes liquid phase
processing unit 705 and separation unit 715. The separation unit
715 can separate the liquid into water and organic solvent and
omega-3 oils. The recovered solvent from the SLR system 700 can be
fed into slurry preparation tank 150 via feed line 745. The SLR
system 700 can include a closed system recycling solvent loop that
transports recovered organic solvent from the recovered organic
solvent storage tank 740 to the slurry preparation tank 150 or to
the product wash inlet 15 or both. The systems provided herein also
can include a volatile organic carbon recycling system that
captures process emissions of organic solvent and condenses them
into liquid form and transports the condensed liquid solvent to the
closed system recycling solvent loop.
[0089] A combination of fresh virgin solvent and recovered solvent
can be used in the slurry preparation tank 150. In some
embodiments, separation unit 715 includes a distillation system.
The separation unit 715 can separate the $ In the slurry
preparation tank 150, the ground material is mixed with an organic
solvent, and the material is agitated to achieve a homogeneous
mixture and thereby produce the crude slurry. In some embodiments,
the crude slurry preferably comprises a 1:1 ratio (volume of
organic solvent to weight of animal tissue) mixture of ground raw
animal tissue and organic solvent.
[0090] The slurry preparation tank 150 can include a primary
agitator assembly and a temperature control system for modulating
the temperature of the slurry during preparation. The temperature
control system can include a heating source for providing thermal
energy to the slurry preparation tank 150 in order to adjust the
temperature of the slurry mixture in the slurry tank. The primary
agitator assembly can include a rotating mixing shaft with blades,
where the mixing blades can be rotated by an overhead motor to
achieve uniform mixing in the tank. This can ensure uniform mixing
and heating, thus eliminating localized thermally heated zones in
the tank that are in contact with the animal tissue and organic
solvent mixture, particularly that portion of the mixture in
proximity of the heated walls or bottom of the slurry preparation
vessel. Such localized contact with thermally hot zones can induce
decomposition and/or denaturing of the protein. In ensuring a
thermally stable and adequately mixed environment in the slurry
tank, protein conforming to the product specification will be
recovered, specifically with 85% or higher protein content, as
characterized by the resultant amino acid profile conducted through
final product analysis.
[0091] The heating source can include a jacket encompassing at
least a portion of the slurry preparation tank 150 through which a
thermal heating fluid, such as steam or heated oil, can be
circulated or pumped; or an immersion heater that can be inserted
directly into the slurry; or electrical heating elements that are
in thermal communication with at least a portion of the tank; or
any combination thereof. The slurry tank also can include a
jacketing and insulation system to permit cooling of the tank. In
some embodiment, the slurry tank includes a jacketing and
insulation system that can heat and cool the tank. The slurry tank
also can include a variable control system that includes a
temperature sensor that is immersed into the contents of the tank
and that measures the actual temperature of the mixture. The slurry
tank also can include a temperature feedback controller to regulate
the amount of thermal energy provided to the tank to adjust the
temperature of the slurry. In some embodiments, the temperature
feedback controller regulates the amount of steam, thermal heating
fluid, or electrical wattage that is provided to the heating source
used to heat the contents of the tank. For example, the temperature
controller can modulate a control valve, or wattage regulator, or a
combination thereof, to control the steam, thermal heating fluid,
or amperes available to the heating source. Processing in the
slurry preparation tank, and in particular, the heating process,
can be done at a controlled temperature using a variable control
system that includes a temperature sensor that is immersed into the
contents of the tank and that measures the actual temperature of
the mixture. A corresponding temperature feedback controller
measures the process temperature and regulates the amount of steam,
thermal heating fluid, or electrical wattage that is used to heat
the contents of the tank. The temperature controller can modulate a
control valve, or wattage regulator, to control the steam, thermal
heating fluid, or amperes to achieve a specified temperature
setpoint, such as 70.degree. C. to prevent the decomposition and/or
denaturation of the protein material associated with the raw fish
or fishmeal. By preventing decomposition and/or denaturation of the
protein material, the amount of protein recovered generally can be
from about 40 wt % to about 99 wt %, or between 50 wt % and 92 wt
%.+-.8 wt %, or can be greater than 60 wt %, 70 wt %, 80 wt % or 90
wt %, depending on the species, mix of species or the composition
of the original raw starting material.
[0092] Water Reduction
[0093] The initial animal tissue may contain a water content as
high as 75-80%, which can interfere with the efficient processing
of the material. The crude slurry prepared in slurry preparation
tank 150 thus can contain amounts of water that can interfere with
the efficient processing. Therefore, in some embodiments, the crude
slurry can be transferred to a dewatering device 170 where the
crude slurry is processed to separate liquid from the ground solid
animal tissue. Any device or system for removing at least a portion
of the liquid from the crude slurry can be used. For example, the
dewatering device 170 can include a screw press, or a plate press,
or a centrifuge, or a combination thereof for mechanically removing
at least a portion of the liquid from the crude slurry prior to
further processing. Dewatering devices are known in the art (e.g.,
see U.S. Pat. Nos. 4,266,473; 4,441,797; 4,685,899; 5,958,233;
6,634,508; and International Patent Application Publication WO
1997/040941).
[0094] In some embodiments, the dewatering device 170 includes a
screw press. The compression action of the screw press on the crude
slurry can displace some of the liquid from the slurry, including
water that was initially contained in the raw starting material.
The press liquid from the dewatering device 170 can exit the
dewatering device 170 via line 177 and be routed to liquid phase
processing unit 705. The recovered dewatered material can be routed
to inlet I of product separation system 10 via line 175 for further
processing, or can be routed back to dewatering device 170 via line
173 for repeated dewatering. The dewatering operation in dewatering
device 170 can be repeated as necessary to achieve the removal of
the desired amount of liquid. In some embodiments, the dewatering
operation of dewatering device 170 results in the removal of at
least 50%, or at least 75%, or at least 80% of the water that was
initially contained with the raw animal tissue.
[0095] In some embodiments, when the dewatering device 170 includes
a screw press, the speed of the conveyance of material through the
screw press can be controlled using a variable frequency drive
(VFD) technology coordinated with controlling the screw press. A
VFD is a motor controlling device that can operate the motor at
various speeds. By using a VFD, the amount of material produced by
the screw press can be controlled at various rates.
[0096] In some embodiments, the dewatering device 170 is or can
include a decanter centrifuge. Decanter centrifuges are well known
in the art (e.g., see U.S. Pat. Nos. 4,298,162; 4,566,873;
4,731,182; 4,790,806; 4,825,541; 5,047,004; 5,178,602; 5,257,968;
5,261,869; 5,267,936; 5,342,279; 7,156,801; 8,152,708; 8,968,169;
and 9,028,387; and U.S. Pat. Appl. Pub. Nos. US2011/0160031 and
US2011/0315621. These decanter centrifuges are commercially
available. Exemplary decanter centrifuges suitable for use in the
dewatering device 170 are manufactured by Alfa-Laval Inc.
(Richmond, Va.) and GEA Mechanical Equipment, Inc. (Northvale,
N.J.). The decanter centrifuge generally includes a rotating
cylinder with an internal screw. The cylinder and screw are rotated
at high speeds. The crude slurry to be dewatered is fed into the
centrifuge via a central inlet pipe. Rotational forces act upon the
crude slurry, forcing it towards the periphery of the cylinder.
Particles of the ground raw animal tissue are caused to separate
out against the cylinder into a sediment by the centrifugal forces
established by the centrifuge. The screw of the centrifuge moves
the resultant sediment toward an outlet. In some embodiments, the
dewatering device 170 can be configured so that the slurry passes
through it without a significant change in water or solvent
content. In some embodiments, the slurry from slurry tank 150 does
not need to be dewatered. In such embodiments, the slurry can be
transported via appropriate pipes or tubing (not shown in FIG. 1)
directly to inlet I of the product separation system 10.
[0097] After passing through dewatering device 170, the resulting
processed slurry can exit the dewatering device 170 via outlet 171
and can be transferred to any one of the six aforementioned
separation systems of product separation system 10 via slurry
outlet 175 and inlet I of product separation system 10 for further
processing. The processed slurry can be a homogeneous mixture of
animal tissue and organic solvent, and can contain residual water.
The processes slurry also can exit the dewatering device 170 via
outlet 171 and be diverted back to the slurry preparation tank 150
via line 173 for further processing, e.g., to add solvent from
lines 185 or 745 or both to modulate the viscosity or fluidity of
the solvent, or for additional dewatering.
[0098] In some embodiments, the processed slurry can have a
temperature of at least about 25.degree. C. immediately upon being
introduced into the product separation system 10 section of product
recovery system 1000. In some embodiments, the processed slurry can
have a temperature of from about 25.degree. C. to about 72.degree.
C. immediately upon being introduced into product processing system
10.
[0099] At least one section of the product separation system 10 of
the product recovery system 1000 provided herein can separate the
processed slurry into a liquid phase and a solid phase. The liquid
phase can include extraction solvent, residual water that was
contained within the starting material, oxidation byproducts, and
omega-3 oil or any combination thereof. In some embodiments, the
extraction solvent can include water, an aliphatic hydrocarbon,
such as hexane, an alcohol, or an ester or any combination thereof.
The liquid phase can contain an extraction solvent in an amount of
at least about 50 wt %. In some embodiments, the liquid phase can
include an omega-3 oil. The amount of omega-3 oil present will
depend on the starting animal tissue. In some embodiments, the
omega-3 oil is present in an amount of less than about 20 wt %.
[0100] The product separation system 10 separates the processed
slurry into a filtrate and a solid phase wetcake. The solid phase
wetcake contains the recovered protein product. The solid phase
wetcake containing the recovered protein product exits product
separation system 10 through outlet O. In some embodiments, the
solid phase wetcake containing the recovered protein product can be
collected on a discharge stage 30 prior to moving to further
processing stations, such as dryer unit 800 via line 35.
[0101] The solid phase wetcake containing the recovered protein
product can be transported to dryer unit 800 via line 35 for
additional drying. The type and configuration of the dryer unit 800
can be selected to optimize the amount of moisture removed from the
wetcake without negatively impact protein product quality. For
example, forced air, direct infrared (IR), indirect IR or
convection ovens can be used to directly or indirectly dry the
wetcake. Additional drying units can include a tray drying system,
rotary cone vacuum dryer, fluid bed dryer or spray drying unit. In
some embodiments, dryer unit 800 can include a vacuum system. In
some embodiments, the wetcake is dried to a moisture content of 10
wt % or less, or 5 wt % or less, or 1 wt % or less, and a residual
organic solvent content of about 1 wt % or less, or less than 0.5
wt %, or less than about 500 ppm, under full vacuum at a
temperature of 100.degree. C. or less, such as 80.degree. C. or
less, resulting in a dried product
[0102] The dried product is removed from the dryer unit 800 at 810
and subjected to a particle size reduction operation using a
milling unit 815. Milling unit 815 can include any particle size
reducing device suitable for production of particles of a target
particle size. Exemplary particle size reducing devices include
primary impact crushers, secondary crushers, cage mills, ball
mills, hammer mills, jet mills, micronizing devices, pulverizers
and grinders, including ultrafine grinders. In some embodiments,
the milling unit 815 includes a micronizing device or jet mill
device. The milled product 825 is a powdered protein product, which
exits milling unit 815 via outlet 820 and collected into a
packaging device 830. Exemplary packaging devices include a
sealable container, a case, a box, an intermediate bulk container
or tote, a drum, a bag, a barrel, a bag-in-bag container, and a
bag-in-box container.
[0103] The vapor produced in dryer unit 800 can be removed via a
vacuum line. A vapor condenser 840 is attached to the vacuum line
and operates to condense the vapor produced by the dryer unit 800
into a liquid for recycling. The condensed liquid produced in vapor
condenser 840 can be routed to processing unit 705 via line 845 for
further processing and recycling.
[0104] The filtrate that exits the product separation system 10 can
be directed to processing unit 705 via line 25 for further
processing to yield a purified filtrate, which can be directed to
separation unit 715 via line 710 to separate the purified filtrate
into an oil fraction and a solvent fraction. Processing unit 705
can include, e.g., adsorber and carbon filtration units. The
adsorber can be a fixed, packed bed column comprising resin
particles or beads. The particular resin beads selected will have
an affinity for free amines and miscellaneous undesired
hydrocarbons present in the filtrate. The filtrate is transferred
through the adsorber bed, and the resultant stream which exits the
adsorber will be a purified filtrate. Filtered waste material can
exit processing unit 705 at waste exit 760 and removed via line
765. The adsorption process occurs at ambient conditions. The
carbon filtration unit is also a fixed bed operation and is used as
polishing step following the adsorption process. Purified filtrate
then is directed to separation unit 715 via line 710 for separating
the oil fraction from the solvent fraction.
[0105] In some embodiments, separation is accomplished using
centrifugation. In some embodiments, separation is accomplished
using distillation. In some embodiments, separation is accomplished
using a combination of centrifugation and distillation. In some
embodiments, the separation unit 715 can include a distillation
system. The distillation system can be a simple batch type still
equipped with an overhead condenser and distillate receiver. The
distillation system can also be or include a wiped or thin film
evaporator unit. The separation unit 715 can separate the purified
filtrate into recovered solvent, purified water 775, and omega-3
oils 730. Referring to FIG. 1, the omega-3 oil 730 can exit
separation unit 715 via recovered oil transfer line 725. The
purified water 775 can exit separation unit 715 via purified water
outlet 770. The recovered solvent can be directed to recovered
solvent tank 740 via recovered solvent transfer line 720 or
directed to the slurry preparation tank 150 via recovered solvent
line 745. The distillation residue can contain a high concentration
of omega-3 oil that can be optionally processed further using
molecular distillation technologies or chemical processing via
transesterification. The recovered solvent can be reused in the
system, such as by directing the recovered solvent to the slurry
preparation tank 150 via slurry tank feed line 745. The recovered
solvent also can be directed via line 720 to recovered solvent tank
740 where it can be stored for reuse in the system 1000.
[0106] In some embodiments of the methods and systems provided
herein, the product separation system 10 can separate the solid
phase and the liquid phase of the processed slurry by depositing
the processed slurry on a surface of a filter, where the solid
particles are retained on the surface of the filter forming a
wetcake, and at least a portion of the liquid phase of the
processed slurry passes through the filter. In some embodiments,
the product separation system 10 can include, e.g., a vacuum belt
filter, an immersion extractor, a percolation extractor, a rotary
pressure drum filter, a screw press, a decanter centrifuge, or a
combination of any two or more of these. In some embodiments, the
product separation system 10 is a closed system, preventing release
of solvent into the environment and allowing recovery of the
solvent.
[0107] Belt Filtration
[0108] In some embodiments, the product recovery system 1000
includes a product separation system 10 containing a belt
filtration system 200. FIG. 2 is a detailed view of an indexing
belt filter filtration option that can be included in the product
recovery system provided herein. The indexing belt filter 220
receives the processed slurry from the upstream dewatering device
170 via line 175. The processed slurry is discharged onto the
indexing belt filter at 251 (stage 1) and creates a thin film of
wetcake that advances along the length of the conveyor belt. As the
conveyor belt advances, the solid protein wet-cake material is
washed at 252, 253 and 254 (stages 2A, 2B and 2C, respectively)
using a counter-current scheme of recycled filtrate washes. As the
conveyor advances, the washes are increasingly more pure until the
last stage 254 (stage 2C), where the wetcake is washed with fresh
organic solvent producing a washed wetcake. The indexing belt
filtration system was determined to be highly efficient at removing
the oils from the solids. After three equivalent steps, the oil
content realized from the washed cake was 6 times greater than that
of the reslurried cake from an equivalent batch process.
[0109] At least a portion of the washed wetcake can be introduced
into the optional product recycle cell 255 (stage 3). The optional
product recycle cell 255 of stage 3 can operate to receive a
recycle feed stream, thereby enriching the washed wetcake. In some
embodiments, the washed wetcake can have an average residence time
on the order of at least 2-10 minutes in the product recycle cell
of stage 3. The residence time of the washed wetcake in the product
recycle cell 255 of stage 3 may vary depending on the equipment
used in product separation system 10 of the product recovery system
1000 provided herein. After the time in the product recycle cell
255 is complete, a washed and enriched wetcake can be discharged
from the product recycle cell 255 of stage 3. In some embodiments,
the washed wetcake bypasses the product recycle cell 255 of stage
3, resulting in a washed (but not enriched) wetcake.
[0110] The washed wetcake, or washed and enriched wetcake, then
advances to an intermediate drying stage 256 on the belt where a
drying gas is applied to the washed wetcake or washed and enriched
wetcake in addition to vacuum from beneath the belt filter 220 via
common vacuum source 40 to yield a low-moisture product wetcake.
The drying gas can be introduced into the product drying cell 256
of stage 4 through inlet 27 and can have an initial temperature
(measured at the point of entry as the drying is being introduced
into the product drying cell) of at least about 20.degree. C., or a
temperature in the range of from about 20.degree. C. to about
80.degree. C.
[0111] The drying gas introduced into the product drying cell 256
of stage 4 can be any gas capable of removing at least a portion of
the liquid from the washed wetcake or washed and enriched wetcake.
The gas can be an inert gas. In some embodiments, the drying gas
introduced into the product drying cell 256 of stage 4 can include,
for example, argon, nitrogen, carbon dioxide, compressed air or any
combination thereof. Drying gas and vapors and condensable liquids
removed from the washed wetcake or washed and enriched wetcake can
exit the product drying cell 256 of stage 4 via outlet 236, and can
exit in a liquid phase, a vapor phase, or a combination of liquid
and vapor phases. Outlet 236 is connected to vapor condenser 45.
Condensed liquids can be returned to product recycle receiver 225
via line 47 or can be removed from the filtration system via outlet
280.
[0112] After sufficient drying (where the percentage of residual
solvent in the product cake can be approximately equal to or less
than 40%, or less than 30%, or less than 20%), the recovered
protein product, a low-moisture wetcake, can exit the product
drying cell 256 of stage 4 via outlet O of product separation
system 10. In some embodiments, the residence time of the wetcake
in the product drying cell 256 is on the order of at least 2-30
minutes. In some embodiments, the wetcake is retained within the
product drying cell of stage 4 until the liquid content of the
wetcake is less than 30 wt %, or less than 25 wt %, or 20 wt % or
less. In some embodiments, the recovered protein product can
continue to lose moisture as it travels the length of the conveyor
belt filter 220 from the end of vacuum box 256 until it exits the
product drying cell via outlet O. The recovered protein product
from outlet O can be recovered on discharge stage 30.
[0113] The protein product wetcake can be transported from
discharge stage 30 transport line 35 to dryer unit 800. The protein
product wetcake is dried in dryer unit 800 to a target solvent
concentration. In some embodiments, the protein product wetcake it
dried to a moisture content of about 10 wt % or less, or about 5 wt
% or less, or about 1 wt % or less, less than about 0.5 wt %. In
some embodiments, the wetcake is dried until the amount of residual
organic solvent is reduced to about 1 wt % or less, or less than
0.5 wt %. The dried protein product is removed from the dryer unit
800 and then subjected to a particle reduction operation using a
milling unit 815. In some embodiments, the milling unit 815
includes a micronizing device or jet mill device.
[0114] Spent filtrates from the indexing belt filter operation of
200 are continuously transferred to can be recovered by liquid
phase processing unit 705, which can include an absorber, followed
by treatment in the separation unit 715, which can include a
centrifuge and/or distillation unit. In some embodiments,
separation unit 715 includes a distillation unit.
[0115] In some embodiments, the wetcake within the product
separation system 10 is washed with a product wash stream at vacuum
box 254 via product wash inlet 15. The product wash stream can be
supplied to the product separation system 10 via supply line 189
from virgin solvent tank 180 or via line 750 from recovered solvent
tank 740. An in-line mixer can blend the wash streams from lines
189 and 750 prior to entering product wash inlet 15. The product
wash stream introduced into product separation system 10 can wash
at least a portion of the wetcake. In some embodiments, the product
wash stream can have an initial temperature upon being introduced
into product separation system 10 of at least about 25.degree. C.,
or a temperature in the range of from about 25.degree. C. to about
75.degree. C. or a temperature of 72.degree. C. or less. In some
embodiments, the washing steps are performed using a washing liquid
that can be in the temperature range from about 40.degree. C. to
about 80.degree. C., or from about 50.degree. C. to about
72.degree. C., or from about 65.degree. C. to about 72.degree. C.,
or at a temperature of about 72.degree. C., 71.degree. C.,
70.degree. C., 69.degree. C., 68.degree. C., 67.degree. C., or
65.degree. C.
[0116] The residence time of the wetcake in the product wash cell
254 of stage 2 may vary depending on the equipment used in product
separation system 10. In some embodiments of the methods and
systems provided herein, the initial wetcake can have an average
residence time between 2-5 minutes in wash stage 2, or can have a
shorter residence time, such as an average residence time in the
range of about 5 seconds to about 2 minutes in wash stage 2.
[0117] In some embodiments, the product wash stream can include a
solvent, such as an aliphatic hydrocarbon, e.g., hexane, an
alcohol, an ester, water or any combination thereof. In some
embodiments, the solvent includes a combination of water with an
organic solvent, such as an aliphatic hydrocarbon, an alcohol, an
ester, or a combination thereof. Any ratio of water to organic
solvent can be used in the product wash stream, e.g., from 99:1
water:organic solvent to 1:99 water:organic solvent, including up
to 100 percent solvent or 100 percent water.
[0118] Any amount of product wash stream can be used to wash the
retained wetcake resulting from processed slurry. In some
embodiments, the weight ratio of the product wash stream introduced
into product separation system 10 to the solids from the solid
phase separated from the processed slurry can be at least about
0.2:1, or in the range of from about 0.2:1 to about 5:1, where
these ratios are expressed in unit volume of solvent to weight of
solid starting material.
[0119] In some embodiments of the present invention, the product
separation system 10 of the product recovery system 1000 can
include an optional product recycle section to enrich the retained
wetcake from the solid phase separated from the processed slurry.
In the recycle section, wash filtrates can be recycled back into
the product separation system 10 in order to capture any protein
particles that may have passed through into the filtrate. For
example, during initial formation of the wetcake within the product
separation system 10 containing a filter on the surface of which
the wetcake is building, some protein particles may have passed
through or by-passed the filter. By recycling the filtrates in this
manner, any initially lost protein particles can be recaptured,
thereby enriching the wetcake with additional protein particles.
After enriching at least a portion of the wetcake of solid
particles, an optional depleted recycle liquid can be withdrawn
from product separation system 10. The recycle feed stream can have
an initial temperature in the range of from about 20.degree. C. to
about 80.degree. C.
[0120] The vacuum belt filter system 200 depicted in FIG. 2
includes a conveyor belt filter 220, a common vacuum source 40
connected to a plurality of vacuum boxes. The number and size of
the vacuum boxes (stations) can be modulated and customized to suit
the different types of raw material that can be used. In the
embodiment depicted, the conveyor belt filter 220 includes six
vacuum boxes: a separation cell stage 1 vacuum box 251, product
wash cell stage 2A vacuum box 252, a product wash cell stage 2B
vacuum box 253, a product wash cell stage 2C vacuum box 254, an
optional product recycle cell stage 3 vacuum box 255, and a product
drying cell stage 4 vacuum box 256. As illustrated in FIG. 2, the
separation cell of stage 1 can be defined by the horizontal length
of the separation cell stage 1 vacuum box 251. The product wash
cell of stage 2 can be defined by the combined horizontal lengths
of vacuum boxes 252, 253 and 254 of product wash cell stages 2A,
2B, and 2C. The optional product recycle cell of stage 3 can be
defined by the horizontal length of the product recycle cell stage
3 vacuum box 255. The product drying cell of stage 4 can be defined
as the horizontal length beginning at the start of the product
drying cell stage 4 recycle vacuum box 256 and ending at the end of
conveyor belt roller 202. A discharge stage 30 can be provided
following the product drying cell of stage 4.
[0121] Referring still to FIG. 2, conveyor belt filter 220 can
include a filter media such as, for example, a filter cloth. The
filter cloth can be made from any compatible material, such as a
metal mesh screen, nylon, polyester, polysulfone,
polytetrafluoroethylene polypropylene, and polyamide. In some
embodiments, the filter cloth has an internal pore size of 100
.mu.m or less, such as from about 35 .mu.m to about 100 .mu.m, or
from about 10 .mu.m to about 50 .mu.m. On this filter the processed
slurry can be separated by drawing the liquid phase of the slurry
through the filter cloth by means of vacuum, forming a protein
wetcake on the surface of the filter. The protein wetcake is
transported with the moving vacuum belt filter cloth. The speed of
transport can be varied to increase or decrease the amount of time
the protein wetcake reside in each of the product wash cells,
optional product recycle cell, and product drying cell. The protein
wetcake can be washed with product wash stream in the product wash
cells of stage 2, and the wash filtrates are continually drawn
through the filter cloth as a result of the vacuum in the vacuum
boxes.
[0122] Fluid flow through the filter media can be caused by
creating a pressure differential across the filter media. In some
embodiments, the pressure differential across the filter media can
be created at least in part by common vacuum source 40. Fluid flow
through the filter cloth can be discharged into the vacuum boxes of
stages 1-4 (vacuum boxes 251 through 256).
[0123] The vacuum belt filter system 200 depicted in FIG. 2 can
include a processed slurry supply line 290 in fluid communication
with dewatering device 170 via line 175 for depositing processed
slurry onto conveyor belt filter 220 via applicator 275. The
embodiment depicted in FIG. 2 includes a product wash feed line 270
in fluid communication with wash stage 2C of the product wash cell
254 of stage 2, and a drying gas in fluid communication with the
product drying cell 256 of stage 4. As depicted, the product wash
cell of stage 2 is divided into an initial wash stage 2A, an
intermediate wash stage 2B, and a final wash stage 2C. Initial wash
stage 2A can be defined by the horizontal length of the product
wash cell stage 2A vacuum box 252, intermediate wash stage 2B can
be defined by the horizontal length of the product wash cell stage
2B vacuum box 253, and final wash stage 2C can be defined by the
horizontal length of the product wash cell stage 2C vacuum box
254.
[0124] In operation, the processed slurry can enter the separation
cell of stage 1, such as via applicator 275. The processed slurry
introduced into the separation cell of stage 1 can be separated
into a solid phase, which forms an initial wetcake on the filter
media on conveyor belt filter 220, and a liquid phase, which can be
discharged out of the separation cell into stage 1 vacuum box 251.
The liquid phase collected in stage 1 vacuum box 251 can be routed
to receiver 221 via discharge line 231. Receiver 221 is in fluid
communication with common vacuum source 40 via an overhead common
vacuum line 80 to create reduced pressure conditions in receiver
221, which in turn can at least partially create the
above-mentioned pressure differential across conveyor belt filter
220 in vacuum box 251. Receiver 221 can contain therein a vapor
phase and the separated liquid phase from the processed slurry.
[0125] At least a portion of the vapor phase in receiver 221 can be
removed via common vacuum line 80 and can be routed to common
vacuum source 40. In some embodiments, a vapor condenser 45 can be
disposed between common vacuum line 80 and common vacuum source 40.
The vapor condenser 45 can operate to remove any liquid in line so
as to prevent liquid from entering common vacuum source 40. Vacuum
box 256 can be configured so that any liquid collected in vacuum
box 256 of stage 4 can be directed to vapor condenser 45 via outlet
236. The condensed liquid produced in vapor condenser 45 can be
routed to liquid phase processing unit 705. The liquid phase in
receiver 221 can be discharged via line 241 and can be routed to
liquid phase processing unit 705. The liquid phase can be withdrawn
from the liquid phase receiver 221 via pump 211 and can be
discharged via line 241 to liquid phase processing unit 705.
[0126] Still referring to FIG. 2, upon obtaining a desired height
of initial wetcake in the separation cell of stage 1, vacuum box
251 is disengaged and belt rollers 201 and 202 are engaged to
advance conveyor belt filter 220 so that initial wetcake can enter
the product wash cell of stage 2. In the embodiment of FIG. 2,
initial wetcake can have a thickness in the range of from about
0.25 to about 5 inches, or in the range of from about 0.5 to about
4 inches, or in the range of from 1 to 3 inches.
[0127] In the product wash cell of stage 2, initial wetcake can be
washed with a product wash stream. In the embodiment shown in FIG.
2, a counter-current wash is illustrated. Product wash stream
enters final wash stage 2C via product wash feed line 270 and is
applied to the wetcake via applicator 264 to thereby foam a washed
wetcake. The product wash stream entering wash stage 2C can be
fresh solvent, which can be transported from solvent supply tank
180 via supply line 189, or can be recovered solvent delivered by
supply line 750, or a combination thereof. The product wash stream
can include a solvent, such as an aliphatic hydrocarbon, e.g.,
hexane, an alcohol, an ester, water or any combination thereof. In
some embodiments, the solvent includes a combination of water with
an organic solvent, such as an aliphatic hydrocarbon, an alcohol,
an ester, or a combination thereof. Any ratio of water to organic
solvent can be used in the product wash stream, e.g., from 99:1
water:organic solvent to 1:99 water:organic solvent, including up
to 100% solvent or 100% water.
[0128] Application of the product wash stream via applicator 264 to
the wetcake in the product wash cell at stage 2C and downward
through the filter media of conveyor belt filter 220 results in a
first wash liquid, which can be discharged into vacuum box 254 of
stage 2C of the product wash cell. The first wash liquid collected
in vacuum box 254 can be routed to first wash liquid receiver 224
via discharge line 234. First wash liquid receiver 224 can
communicate with common vacuum source 40 to create reduced pressure
conditions in the first wash liquid receiver 224, which in turn can
at least partially create a pressure differential across conveyor
belt filter 220 at vacuum box 224, which is connected to first wash
liquid receiver 224 via discharge line 234. First wash liquid
receiver 224 can contain therein a vapor phase and the first wash
liquid. At least a portion of the vapor phase in the first wash
liquid receiver 224 can be removed via common vacuum source line
80. At least a portion of the first wash liquid can be withdrawn
from first wash liquid receiver tank 224 via vacuum pump 214 and
can be applied to the wetcake in stage 2B via wash line 244 and
applicator 263. The first wash liquid also can be discharged to
liquid phase processing unit 705 via appropriating pipes or tubing
(not shown).
[0129] In some embodiments, at least a portion of the first wash
liquid can be transferred via pump 214 and wash line 244 to
intermediate wash stage 2B to thereby wash at least a portion of
initial wetcake by application to initial wetcake via applicator
263, forming a second wash liquid, which can be discharged downward
through the filter media of conveyor belt filter 220 at stage 2B
into vacuum box 253. The second wash liquid collected in vacuum box
253 can be routed to second wash liquid receiver 223 via discharge
line 233. Second wash liquid receiver 223 can communicate with
common vacuum source 40 to create reduced pressure conditions in
second wash liquid receiver 223, which in turn can at least
partially create a pressure differential across conveyor belt
filter 220 at stage 2B via vacuum box 253. Second wash liquid
receiver 223 can contain therein a vapor phase and the second wash
liquid. At least a portion of the vapor phase in second wash liquid
receiver 223 can be removed via common vacuum line 80 and can be
routed to common vacuum source 40. At least a portion of the second
wash liquid can be withdrawn from the second wash liquid receiver
223 via vacuum pump 213 and can be applied to the wetcake in stage
2A via line 243 and applicator 262. The second wash liquid also can
be discharged to liquid phase processing unit 705 via appropriating
pipes or tubing (not shown).
[0130] In some embodiments, at least a portion of the second wash
liquid can be transferred to initial wash stage 2A to thereby wash
at least a portion of initial wetcake at stage 2A, forming a final
wash liquid, which can be discharged downward through the filter
media of conveyor belt filter 220 into vacuum box 252 of stage 2A.
The final wash liquid collected in vacuum box 252 of stage 2A can
be routed to final wash liquid receiver 222. Final wash liquid
receiver 222 can communicate with common vacuum source 40 to create
reduced pressure conditions in final wash liquid receiver 222,
which in turn can at least partially create a pressure differential
across conveyor belt filter 220 at vacuum box 252. Final wash
liquid receiver 222 can contain therein a vapor phase and the final
wash liquid. At least a portion of the vapor phase in final wash
liquid receiver 222 can be removed by common vacuum source 40 via
common vacuum line 80. The final wash liquid in final wash liquid
receiver 222 can be discharged via pump 212 via lines 242, 280 and
241 to liquid phase processing unit 705.
[0131] In the embodiment illustrated in FIG. 2, the initial wetcake
can have an average residence time of less than about 6 minutes, or
less than about 2 minutes, less than about 1.5 minutes, or less
than 1 minute in the product wash cell of stage 2. In some
embodiments, the initial wetcake is washed in each of stages 2A, 2B
and 2B for about 2 minutes or less for each station. In some
embodiments, the residence time of initial wetcake in stage 2C is
equal to the sum of the residence time of the initial wetcake in
stages 2A and 2B. After suitable washing (e.g., 1-3 displacement
washes), in the product wash cell of stage 2, the conveyor belt
rollers 201 and 202 are engaged to advance conveyor belt filter 220
so that washed wetcake can enter optional recycle stage 3. In some
embodiments, the conveyor belt rollers 201 and 202 are engaged to
advance conveyor belt filter 220 so that washed wetcake enters the
product drying cell of stage 4.
[0132] In embodiments where the conveyor belt filter 220 is
advanced to optional recycle stage 3, washed wetcake can be
enriched by application of a recycle feed from product recycle
receiver 225 via line 245 and applicator 265 by pump 215 to thereby
form a washed and enriched wetcake. The recycle feed can include
the filtrates recovered from the product wash cells of stage 2
and/or the recycle feed stream. After application of the recycle
feed stream to the washed wetcake it discharges downward through
the filter media of conveyor belt filter 220 resulting in a
depleted recycle liquid that is collected into vacuum box 255 of
recycle stage 3. The depleted recycle liquid collected in vacuum
box 255 can be routed back to product recycle receiver via
discharge line 235. Product recycle receiver 225 can communicate
with common vacuum source 40, such as via common vacuum line 80, to
create reduced pressure conditions in product recycle receiver 225,
which in turn can at least partially create a pressure differential
across conveyor belt filter 220 at vacuum box 255. Product recycle
receiver 225 can contain therein a vapor phase and the depleted
recycle liquid. At least a portion of the vapor phase in product
recycle receiver 225 can be removed via common vacuum line 80 and
can be routed to common vacuum source 40.
[0133] In some embodiments, the washed wetcake from the slurry can
have an average residence time in the product recycle cell of stage
3 on the order of 1-5 minutes, where suitable enriching is
performed by recycling solid material that passed through the bed
and into the filtrate receiver. In optional recycle stage 3,
conveyor belt rollers 201 and 202 can be engaged to advance
conveyor belt filter 220 so that washed and enriched wetcake can
enter drying stage 4.
[0134] In drying stage 4, liquid can be removed from washed wetcake
and washed and enriched wetcake by passing a drying gas, from a
drying gas supply via drying gas inlet 27, over, across and/or
through the washed wetcake or washed and enriched wetcake, thereby
producing a final low-moisture protein product wetcake. The drying
gas can include, for example, argon, nitrogen, carbon dioxide,
compressed air or any combination of these gases. Liquid and/or
humid vapor can be removed from stage 4 and from product separation
system 10 in general via, e.g., common vacuum line 80, where a
vapor condenser 45 is disposed between the common vacuum line 80
and common vacuum source 40. The vapor condenser 45 can operate to
remove any liquid in line so as to prevent liquid from entering
common vacuum source 40. Condensed liquids produced by vapor
condenser 45 can be discharged to liquid phase processing unit
705.
[0135] In some embodiments, the average residence time within the
product drying cell of stage 4 for the washed wetcake or the washed
and enriched wetcake can be less than about 5 minutes. After
suitable drying (e.g., when the wetcake has a targeted moisture
content, such as a moisture content of from about 20 wt % to about
40 wt %) in drying stage 4 the conveyor belt rollers 201 and 202
can be engaged to advance conveyor belt filter 220 so that final
wetcake can discharge from stage 4.
[0136] At the end of the product drying cell of stage 4, at least a
portion of final low-moisture wetcake recovered protein product can
be disengaged from conveyor belt filter 220 and can exit product
processing system 10 via outlet O. In some embodiments, a discharge
stage 30 can capture and hold the recovered protein product.
[0137] In some embodiments, a conveyor belt washing step can be
performed after the final low-moisture wetcake recovered protein
product is disengaged from conveyor belt filter 220 to wash out any
wetcake material that may have adhered to the conveyor belt filter
220. Product wash stream or other wash stream containing similar
components, such as, e.g., water, an alcohol, such as ethanol or
isopropyl alcohol, an aliphatic hydrocarbon, an alcohol, or an
ester or any combination thereof, can be applied to the conveyor
belt filter 220 via an applicator to wash the conveyor belt filter
220. In some embodiments, no aliphatic hydrocarbon is used in the
device and/or during the processing. In some embodiments, the
processes and methods provided herein do not include application of
or addition of hexane at any step. Material washed off of conveyor
belt filter 220 and the washing liquid used in washing step can be
directed to product recycle receiver 225.
[0138] Rotary Pressure/Vacuum Drum Filtration
[0139] In some embodiments, the product separation system 10 of the
product recovery system 1000 provided herein can include a rotary
pressure/vacuum drum filtration system 300. Rotary drum filters are
known in the art (e.g., see U.S. Pat. Nos. 5,175,355; 5,643,468;
7,470,370; 7,462,736; 7,888,530; 7,897,810; 8,697,906); and
8,859,825). An exemplary rotary pressure/vacuum drum filter is
illustrated in FIG. 3. The rotary pressure/vacuum drum filter
illustrated in FIG. 3 includes a housing 310 and a rotary drum
filter 312 rotatably disposed within housing 310. An annulus is
defined between the inside of housing 310 and the outside of rotary
drum filter 312. This annulus is divided into various discreet
stages by seals 314a through 314g. The separation stage 360 is
defined in the annulus between seals 314a and 314b. Wash stage 370
is defined in the annulus between seals 314b and 314e. An optional
recycle stage 380 is defined in the annulus between seals 314e and
314f. Drying stage 390 is defined in the annulus between seals 314f
and 314g. Housing 310 can be open between seals 314g and 314a. This
open portion of housing 310 can include a discharge stage 322 and a
filter wash stage 324.
[0140] Referring still to FIG. 3, rotary drum filter 312 can define
a plurality of filter cells 326 located on the periphery of the
drum filter 312. The bottom of each filter cell 326 can be formed
of a filter media (e.g., a synthetic cloth, single-layer metal, or
multi-layer metal). Fluid flow through the filter media can be
caused by creating a pressure differential across the filter media.
Each filter cell 326 has its own outlet for discharging fluids
inwardly towards the axis of rotation of rotary drum filter 312.
The outlets of axially-aligned filter cells 326 can be manifolded.
The manifolds (not shown) can rotate with the rotary drum filter
312 and can communicate with a service/control head (not shown)
which can collect the fluids from the manifolds in a manner that
allows the fluids discharged from stages 360, 370, 380, and 390 to
be kept separate. The discharged fluids also can be combined and
discharged to liquid phase processing unit 705.
[0141] Housing 310 can include a slurry inlet 301 that can be in
fluid communication with separation stage 360, a wash feed inlet
330 that can communicate with wash stage 370, an optional recycle
feed inlet 348 that can be in fluid communication with optional
recycle stage 380, and a drying gas inlet 350 that can be in fluid
communication with drying stage 390. Wash stage 370 can be divided
into an initial wash stage 336, an intermediate wash stage 338, and
a final wash stage 340, where intermediate wash stage 338 is
separated from initial wash stage 336 by seal 314c and final wash
stage 340 is separated from intermediate wash stage 338 by seal
314d. Housing 310 and rotary drum filter 312 can be configured to
permit filtrate discharged from final wash stage 340 to enter
intermediate wash stage 338, and filtrate discharged from
intermediate wash stage 338 to enter initial wash stage 336 to
product a counter-current wash.
[0142] In operation, the processed slurry can enter separation
stage 360 via slurry inlet 301. The processed slurry introduced
into separation stage 360 can form an initial wetcake 342 in filter
cells 326 on the periphery of rotary filter drum 312. In separation
stage 360, the liquid phase separated from the processed slurry can
be discharged radially inward from the bottom of each filter cell
326. The liquid phase collected from separation stage 360 can be
discharged from the apparatus via discharge line 385. Upon
obtaining a desired height of initial wetcake 342 in separation
stage 360, rotary drum filter 312 can rotate so that initial
wetcake 342 enters wash stage 370. In the embodiment illustrated in
FIG. 3, initial wetcake 342 can have a thickness in the range of
from about 0.1 to about 10 inches, or in the range from about 2 to
about 8 inches, or in the range of from about 3 to about 7 inches,
or in the range of from 4 to 6 inches.
[0143] In wash stage 370, initial wetcake 342 can be washed with a
product wash stream 3 entering final wash stage 340 via wash feed
inlet 330 and applied to initial wetcake 342 to thereby form a
washed wetcake 344. The first wash filtrate from final wash stage
340 can then be transferred to intermediate wash stage 338 via
first wash filtrate inlet 332 and applied to the wetcake to form a
second wash liquid, and the second wash liquid from intermediate
wash stage 338 can then be transferred to initial wash stage 336
via second wash filtrate inlet 334 and applied to the wetcake. The
final wash liquid from initial wash stage 336 can then be
discharged from product processing system 10. For example, as shown
in FIG. 3, the final wash liquid can be discharged via discharge
line 341 to liquid phase processing unit 705.
[0144] In the embodiment illustrated in FIG. 3, the wetcake
containing the separated solid phase of the processed slurry
containing protein particles can have an average residence time of
less than about 2 minutes, or less than about 1 minute, or less
than about 40 seconds, or less than 25 seconds in wash stage 370.
After suitable washing (which can be defined by using 1-3
displacement washes) in wash stage 370, rotary drum filter 312 can
rotate so that washed wetcake 344 can enter optional recycle stage
380.
[0145] Still referring to FIG. 3, in optional recycle stage 380,
washed wetcake 344 can be optionally enriched with a recycle feed
stream 5 entering optional recycle stage 380 via recycle feed inlet
348 to thereby form a washed and enriched wetcake 346. After
recycle, depleted recycle liquid can be discharged from product
processing system 10. For example, as illustrated in FIG. 3,
depleted recycle liquid can be discharged via discharge line 387.
In the embodiment illustrated in FIG. 3, the wetcake can have an
average residence time of less than about 2 minutes, or less than
about 1 minute, or less than about 40 seconds, or less than 25
seconds in optional recycle stage 3. After suitable enriching,
where suitable enriching is performed by recycling solid material
that passed through the rotary drum filter into the filtrate
receiver in optional recycle stage 3, rotary drum filter 312 can
rotate so that washed and enriched wetcake 346 can enter drying
stage 390.
[0146] In drying stage 390, liquid can be removed from washed
wetcake 344 or washed and enriched wetcake 346 by passing a drying
gas 7, entering via gas inlet 350, around and/or through washed
wetcake 344 or washed and enriched wetcake 346, thereby producing a
final low-moisture wetcake protein product 355. The drying gas 7
introduced into inlet 350 can include, for example, argon,
nitrogen, carbon dioxide, compressed air or any combination
thereof.
[0147] In the embodiment illustrated in FIG. 3, the washed wetcake
344 or washed and enriched wetcake 346 can have an average
residence time of less than about 2 minutes, or less than about 1
minute, or less than about 45 seconds in drying stage 390. After
suitable drying (e.g., to a targeted moisture content, such as a
wetcake moisture content of approximately 20-40 wt %) in drying
stage 390, rotary drum filter 312 can rotate so that final
low-moisture wetcake protein product 355 can be discharged to
discharge stage 322 via line 390.
[0148] In discharge stage 322, at least a portion of the final
low-moisture wetcake protein product 355 can be disengaged from
rotary drum filter 312 and can exit product separation system 10
via discharge line 395. Rotary drum filter 312 can then rotate into
filter wash stage 324, where any solid particles remaining in
filter cells 326 can be removed. In some embodiments, the material
washed out of filter cells 326 in filter wash stage 324 and the
wash liquid can be added to recycle stream 5.
[0149] Spent filtrates from rotary drum filter extraction unit 300
are continuously removed from the extraction unit 300 to liquid
phase processing unit 705, which can include an absorber, followed
by treatment in the separation unit 715, which can include a
distillation unit.
[0150] It will be understood by one skilled in the art that many
different configurations of rotary pressure drum filters are
possible, any of which can be used in the present invention.
Examples of suitable, commercially available rotary pressure drum
filters that can be used in product separation system 10 include,
but are not limited to, a BHS-FEST Rotary Pressure Filter,
available from BHS-Sonthofen GmbH, D-87527, Sonthofen, Germany; and
Rotapress FRP continuous rotary filters, available from 3V-Tech,
Bergamo, Italy.
[0151] Immersion Extraction Filtration
[0152] In some embodiments, the product separation system 10 of the
product recovery system 1000 can include an immersion extraction
filtration system 400. An exemplary immersion extraction filtration
system is described in U.S. Pat. No. 4,751,060. The extractor
includes a plurality of pools through which a solid to be extracted
is moved in a counter-flow direction, usually by a plurality of
conveyor belts. The belts move the material across the bottom of
the extractor, maintaining the solid material immersed in solvent,
which is flowing in a counter-current direction. Commercial
immersion extraction filtration devices are available, e.g., the
Model IV Extractor from Crown Iron Works (Minneapolis, Minn.).
[0153] FIG. 4 is a detailed view of an exemplary immersion
extraction filtration option that can be included in the product
recovery system provided herein. In the system illustrated, 6
separate conveyor belts 420, 421, 422, 423, 424, and 425 moving in
the same direction (counter-clockwise is illustrated to maintain
the material moving through solvent bath 410 and under the upper
level 415 of the solvent bath 410) pull the deposited material
through the solvent bath 410. Each conveyor belt has a first end
and a second end. Except for the last conveyor belt in the system,
the second end of each conveyor belt extends over at least a
portion of the first end of the next conveyor belt. Each conveyor
belt includes protrusions 430 that extend above the conveyor belt
and are brought into contact with a bottom surface of the
filtration unit as the conveyor belts moves and can push slurry
material through the unit while the material remains submerged and
in intimate contact with the solvent. The immersion extraction unit
400 receives the processed slurry from the upstream dewatering
device 170 via line 175. The processed slurry is discharged to the
immersion extraction unit 400 via entry port 405. The processed
slurry maintains intimate contact with wash solvent while advancing
towards the discharge 450 of the immersion extraction unit due to
the movement of each of the conveyor belts. Filtrate is removed
from the lower compartment of the immersion extraction unit via
filtrate outlet line 495 and is then discharged to the liquid phase
processing unit 705.
[0154] Once deposited on the last conveyor belt, the processed
slurry forms a protein product wetcake as the liquid phase of the
slurry is removed. The protein product wet cake is washed with
product wash stream from product wash inlet 15 and applied to the
protein product wetcake via applicator 440 and the washed protein
product wetcake is then discharged from the immersion extraction
unit via port 450 and transferred to discharge stage 30 via line
490. The protein product wetcake is transferred to dryer unit 800
and dried to a moisture content of about 10 wt % or less, or about
5 wt % or less, or about 1 wt % or less, or less than about 0.5 wt
%. In some embodiments, the wetcake is dried until the amount of
residual organic solvent is reduced to about 1 wt % or less, or
less than 0.5 wt %. The dried protein product is removed from the
dryer unit 800 and then subjected to a particle reduction operation
using mill unit 815, which can include a micronizing device or jet
mill device. Spent filtrates from the immersion extraction unit 400
can be recovered by directing the material to liquid phase
processing unit 705, which can include an absorber, followed by
treatment in the separation unit 715, which can include a
centrifugation unit and/or a distillation unit.
[0155] Percolation Extractor
[0156] In some embodiments, the product separation system 10 of the
product recovery system 1000 can include a percolation extractor
system 500. Percolation extractors are known in the art (e.g., see
U.S. Pat. Nos. 4,144,229; and 4,859,371). Typical percolation
extractors include a conveyor belts that slowly moves a material to
be extracted over a stationary screen. As the conveyor moves, a
washing solvent is applied to the upper surface of the material on
the conveyor, and the washing solvent percolates down through the
material and through the screen. Commercial percolation extractor
devices are available, e.g., the Model III Percolation Extractor
and the Model V Percolation Extractor from Crown Iron Works
(Minneapolis, Minn.).
[0157] FIG. 5 is a detailed view of an exemplary percolation
extraction filtration option that can be included in the product
recovery system provided herein. The percolation extraction unit
500 receives the processed slurry from the upstream dewatering
device 170 via line 175. The processed slurry is discharged to the
percolation extraction unit 500 via entry port 505 where the slurry
is deposited on a stationary screen 545 and advances towards the
discharge of the percolation extraction unit 500 by the belt
protrusions 542 on conveyor belt 540. Pump 510 creates a pressure
differential between the applied processed slurry and the
collection compartment 560 forming a protein product wetcake, the
filtrate being removed into collection compartment 560 and removed
from system 500 via pump 510 and line 595 to liquid phase
processing unit 705. The protein product wetcake advances by
movement of belt 540 across stationary screen 545 and is washed
until it exits percolation extraction unit 500. The conveyor belt
540 is advanced by motor assembly 550.
[0158] Filtrate is drawn out of the protein product wetcake as it
moves across the screen by pumps (e.g., pumps 511, 512 and 513 in
FIG. 5) and collected in filtrate receiving compartments (e.g.,
compartments 561, 562 and 563 in FIG. 5). The collected filtrate is
recycled back into the percolation unit 500 and used to wash the
protein product wetcake (e.g., via applicators 571, 572 and 573 in
FIG. 5). At the last stage prior to exiting system 500, protein
product wetcake is washed with product wash from product wash inlet
15 via applicator 580. Filtrate from this wash is collected into
receiving compartment 564 via the pressure differential created by
pump 514 and the filtrate is removed from filtrate receiving
compartment 564 by pump 514 and discharged to liquid phase
processing unit 705.
[0159] In some embodiments (not shown in FIG. 5), the device can be
configured with appropriate lines or tubing so that the protein
product wetcake be washed in a counter-current method. For example,
referencing the item numbers shown in FIG. 5, in one embodiment,
the filtrate collected in filtrate receiving compartment 563 can be
directed to filtrate receiving compartment 562, which then is
applied to wetcake via applicator 572. The filtrate collected in
filtrate receiving compartment 562 then can be directed to filtrate
receiving compartment 561, which then is applied to wetcake via
applicator 571.
[0160] In another example (not shown in FIG. 5), the device can be
configured with appropriate lines or tubing so that the protein
product wetcake can be washed with a recovered filtrate produced by
the washing of the wetcake with product wash applied using
applicator 580. For example, referencing the item numbers shown in
FIG. 5, recovered filtrate produced by the washing of the wetcake
with product wash applied using applicator 580 can be collected
into filtrate receiving compartment 564 using pump 514. The
filtrate then can be pumped via pump 514 to applicator 573, which
applies the filtrate to the upper surface of the wetcake. Filtrate
produced by the washing of the wetcake with filtrate applied by
applicator 573 can be collected into and removed from filtrate
receiving compartment 563 by pump 513. The filtrate then can be
pumped via line 533 to applicator 572, which applies the filtrate
to the upper surface of the wetcake. Filtrate produced by the
washing of the wetcake with filtrate applied by applicator 572 can
be collected into and removed from filtrate receiving compartment
562 by pump 512. The filtrate then can be pumped via line 532 to
applicator 571, which applies the filtrate to the upper surface of
the wetcake.
[0161] Constant washing of the wetcake allows a high degree of mass
transfer to effect purification of the wetcake as it moves through
the unit. The wetcake advances toward the end of the percolation
extraction unit where it is ultimately given a fresh solvent wash
with product wash via wash applicator 580. Filtrate is collected in
filtrate receiving compartment 564 and protein product wetcake is
then discharged from percolation extraction unit 500 via exit 590
onto discharge stage 30. The protein product wet cake then can be
transferred to a drying unit 800 via transport line 35. The protein
product wetcake is dried to a targeted solvent concentration. In
some embodiments, the protein product wetcake is dried to a
moisture content of about 10 wt % or less, or about 5 wt % or less,
or about 1 wt % or less, or about 0.5 wt % or less. In some
embodiments, the wetcake is dried until the amount of residual
organic solvent is reduced to about 1 wt % or less, or less than
0.5 wt %. The dried protein product wetcake is removed from the
dryer unit 800 and then subjected to a particle reduction operation
using a mill unit 815, which can include micronizing device or jet
mill device. Spent filtrates from percolation extraction unit 500
are continuously removed from the extraction unit 500 by pump 510
via line 595 to liquid phase processing unit 705, which can include
an absorber, followed by treatment in the separation unit 715,
which can include a centrifugation unit and/or a distillation
unit.
[0162] Screw Press System
[0163] In some embodiments, the product separation system 10 of the
product recovery system 100 provided herein can include a screw
press system. An exemplary screw press system 600 is illustrated in
FIGS. 6A and 6B. FIG. 6A shows a schematic top view of a twin screw
press 600. The screw press illustrated in FIG. 6A includes a motor
601 attached to frame 630. The motor 601 connects to a gear
reduction drive 603 (not shown in FIG. 6A) which is connected to a
shaft coupling 605 which is connected to at least one of screw
shaft 650. Gear boxes 645 can connect screw shafts 650 of dual
overlapping screws 635 (a single screw is optional but not shown)
with continuous feeder flighting 640 and drive the screw action,
directing processed slurry into screen chamber 615. Through one or
more shaft couplings 605 the gearboxes drive the screws 635. Any
necessary adjustments of the system can be accomplished by adjuster
660, which can include springs, bladders, counterweights, and
hydraulic cylinders to provide adjustment, e.g., of back pressure,
during press operation. Expelled liquid drains through screen
chamber 615 and can be removed via liquid drain 620. Wetcake
discharges at press cake discharge 625 before restraining cone
655.
[0164] FIG. 6B shows a schematic side view of a twin screw press
600. The screw press 600 illustrated in FIG. 6B includes a motor
601, a gear reduction drive 603, a shaft coupling 605 connecting
dual overlapping screws (however, a single screw is optional), an
inlet port 610 for introducing the processed slurry, a screen
chamber 615, a solids restrainer 618, a liquid drain 620, a press
cake discharge 625, an adjuster 660 and a frame 630. Press liquid
drains from liquid drain 620 while press cake can be collected from
press cake discharge 625. The screw press 600 can further include a
liquid or filtrate discharge line attached to liquid drain 620 to
direct the filtrate to liquid phase processing unit 705, and a
solids discharge line for discharging the pressed wet cake from
press cake discharge 625 to discharge stage 30. The figures show a
screw press in a horizontal configuration. Vertical configurations,
with material flowing either upward or downward, also can be
used.
[0165] The processed slurry containing the raw fish and organic
solvent, are dispensed into the screw press liquid inlet port 610.
The screws 635 rotate in a manner to compress the combined liquid
and solids comprising the slurry. Liquid filtrate is discharged
from screw press 600 via liquid drain 620 and transferred to the
solvent recovery system (SLR) for subsequent recovery of the
organic solvent and omega-3 oil.
[0166] Solid wetcake product is discharged from the screw press 600
via press cake discharge 625 with a moisture content in the range
of 20-40 wt %. In some embodiments, the solid wetcake can be
returned to slurry tank 150 containing fresh or recovered organic
solvent via appropriate lines, tubing or piping (not shown). The
combined mixture can be stirred in slurry tank 150 until a
homogeneous slurry is achieved, and the homogeneous slurry can then
transferred to the dewatering device 170 where separation of the
liquid filtrate and solid wet cake occur. The combination of
preparing the slurry in conjunction with transferring the slurry to
the dewatering device 170 can be optionally performed several times
until the desired level of water removal is achieved. In similar
embodiments, water removal levels of 75% have been achieved. The
final protein product wet cake is then transferred to product
separation system 10 for further processing, and exits product
separation system 10 via outlet O and ultimately is transported to
a drying unit 800 where the solid product is dried to a moisture
content of 10 wt % or less, or 5 wt % or less, of 1 wt % or less,
or less than 0.5 wt %. In some embodiments, the wetcake is dried
until the amount of residual organic solvent is reduced to about 1
wt % or less, or less than 0.5 wt %.
[0167] Decanter Centrifuge System
[0168] In some embodiments, the product separation system 10 of the
product recovery system 100 provided herein can include a decanter
centrifuge system 675. Any of the various configurations of
decanter centrifuges can be included in decanter centrifuge system
675 (see, e.g., U.S. Pat. Nos. 4,298,162; 4,566,873; 4,731,182;
4,790,806; 4,825,541; 5,047,004; 5,178,602; 5,257,968; 5,261,869;
5,267,936; 5,342,279; 7,156,801; 8,152,708; 8,968,169; and
9,028,387; and U.S. Pat. Appl. Pub. Nos. US2011/0160031 and
US2011/0315621). These centrifuges generally share as a centrifuge
bowl that can be cylindrical or frustoconical in shape, or that has
at least one cylindrical section and at least one frustoconical
section, the longitudinal axis of the bowl being generally
horizontal. The bowl generally is rotated by means of an electric
motor about its longitudinal axis at a speed sufficient to generate
a centrifugal acceleration many times that of gravity. A slurry
containing a liquid fraction and a solid fraction can be introduced
into the interior of the rotating bowl and forms a pond of annular
cross section around the peripheral region of the bowl. The heavier
particles of the solid fraction are preferentially flung to the
walls of the bowl. A scroll mechanism, such as a helical screw, can
be mounted inside the bowl and is rotatable about the same
longitudinal axis as the bowl. The scroll mechanism can be driven
by the same electric motor as the bowl, through a gearbox that can
cause the scroll mechanism to rotate at a different speed from that
of the bowl, and in a direction that conveys the heavier particles
deposited on the wall of the bowl towards one end of the bowl where
suitable discharge ports for this fraction are provided.
Alternatively, the scroll mechanism can be driven by its own
independent motor. In the case in which the bowl has a
frustoconical section, the solid fraction is generally discharged
at the end of the bowl that has the smaller diameter as this
arrangement makes it possible for the solid fraction to be drawn up
an inwardly tapering region of the bowl so that some draining of
this fraction can take place, and a relatively dry solid fraction
can be obtained.
[0169] Vacuum System
[0170] Preferably, each of the aforementioned filtration options
includes a vacuum system capable of drawing a vacuum for removal of
solvent. The vacuum system can include a vacuum pump and condenser
to prevent organic solvent vapors from reaching the vacuum pump.
Condensed vapors arising from the vacuum system condenser are
recycled into the solvent recovery system where the organic solvent
can be recovered and reused in the process.
[0171] Automation
[0172] The systems provided herein can be operated either manually
or automatically such as by computer control. In some embodiments,
the systems and methods herein are automated. In some embodiments,
the system includes a computer module for automation of the system.
The computer module can be in communication with and/or in control
one or more components of the device. In some embodiments, the
computer module can be used to modulate the pressure generated by
the common vacuum source. In some embodiments, the computer module
can be used to modulate the flow of solvent to one or more devices.
In some embodiments, the computer module can be used to modulate
the temperature of the slurry preparation tank. In some
embodiments, the computer module can be used to modulate the speed
at which slurry is processed through the product processing system.
In some embodiments, the system can be automated by using a
programmable logic controller (PLC) and a customizable
recipe-driven software architecture. The PLC is the automated
programmable device for controlling the process automatically
without the need for significant manual intervention. Customizable
recipe-driven software allows the process to be tailored to a
specific raw material input type and/or processing scheme involving
the various optional protein recovery systems illustrated in FIGS.
2-6B.
[0173] The PLC can be in direct communication with a control unit,
and can be programmable and reprogrammable through the control
unit. Logic control allows certain specific actions to occur based
upon other actions or conditions. PLCs have the ability to quickly
scan inputs and control outputs based upon the condition of the
inputs. The inputs can be signals from one or a number of separate
meters monitoring the analytical parameters of the system, such as
temperature, speed, amount of solvent dispensed, drying
temperature, heating temperature, etc. These parameters generally
are monitored by separate discrete instruments. These instruments
then send a signal, usually some type of analog signal, to a
standard input module on the PLC. The PLC can be programmed for
each application, such as for different filtration or extraction
devices, and different logic control functions can be programmed
into the PLC.
[0174] Process
[0175] The product recovery systems provided herein can include one
of several of the aforementioned optional processes for recovering
products derived from animal tissue. In the methods and devices
provided herein, the processed slurry can be separated into a
liquid phase and a solid phase using these separation systems.
Exemplary separation systems include vacuum belt filters, indexing
belt filters, rotary drum filters, rotary disc filters, belt press
filters, filter presses, horizontal disc filters, leaf filters,
belt and drum filters, immersion extraction units, percolating
extraction units, screw presses, centrifuge systems or any
combination thereof. In one embodiment, solid protein product is
recovered using an indexing belt filter, such as a unit
manufactured by BHS-Filtration, Charlotte, N.C. Belt filter devices
are well known in the art (e.g., see U.S. Pat. Nos. 3,943,233;
4,595,501; 4,659,469; 4,861,495; 5,200,557; and 8,697,906). In
another embodiment, solid protein product is recovered using an
immersion extraction unit, an example of which is one manufactured
by Crown Ironworks (Roseville, Minn.). In another embodiment, solid
protein product is recovered using a percolating extraction unit,
an example of which is one manufactured by Crown Ironworks
(Roseville, Minn.). In yet another embodiment, solid protein
product is recovered using a rotary drum filtration unit, such as
those units manufactured by BHS-Sonthofen Inc. (Charlotte, N.C.)
and 3VTech (Bergamo, Italy). In another embodiment, solid protein
product is recovered using a decanter centrifuge, such as one
manufactured by Alfa Laval Inc. (Richmond, Va.) or GEA Westfalia
Separator Division of GEA Mechanical Equipment US, Inc. (Northvale,
N.J.).
[0176] The starting material from which protein is to be recovered
includes animal tissue. Animal tissue includes eukaryotic cells of
various shapes and sizes. Animal cells are further characterized as
excluding cell walls which are present in all plant cells. The
animal tissue may include, but is not limited to, land and marine
animals such as insects, fish, poultry and red meat. In an
exemplary embodiment, the starting material includes animal tissue
from a piscine animal or marine animal. Suitable examples of the
starting material include, but are not limited to, tissue material
derived from flesh or eggs from anchovies, arctic char, mackerel,
sablefish, herrings, sardines, salmon, hake (cod family), halibut,
carp, trout, oysters, krill, squid, shrimp and cuttlefish, and as
an optional starting raw material, dried fishmeal or dried fish, or
any combinations thereof. In some embodiments, the starting
material is maintained at temperatures less than 50.degree. F.,
preferably less than 45.degree. F., and more preferably less than
or equal to 40.degree. F., prior to being processed by the product
recovery systems provided herein. The starting material can include
animal tissue from fish, and in particular, raw fish. The raw fish
should be fresh and handled in a sanitary manner. The quality of
the raw material should also be verified. The fish is ground, as
explained above (see e.g., grinding unit 100), into pieces prior to
mixing with organic solvent and further processing. The ground
animal tissue is prepared by dispensing whole raw fish and/or raw
fish parts to a grinding unit. The resultant ground material will
contain the complete animal components inclusive of tissue, bones,
and scales. The ground material is then dispensed into a suitable
vessel containing an organic solvent.
[0177] A finely ground raw fish, such as those materials with a
resultant particle size of less than 5000 .mu.m, demonstrates
improved filtration characteristics over an otherwise coarsely
ground material, such as a material having a particle size greater
than 5000 .mu.m. The improved filtration is evident on the belt
filter system where the filtration time is significantly faster for
finely ground material in comparison to a ground fish material
having a particle size greater than 5000 .mu.m. An organic solvent
is generally used in the process. The solvent may include an
alcohol. In some embodiments, the solvent may include one or more
organic solvents with a VOC ranging between about 200-500 g/L. In
some embodiments, the solvent is selected such that it meets VOC
regulations promulgated by local governing authority. In a
preferred embodiment, the solvent includes or is IPA (isopropyl
alcohol).
[0178] In some embodiments, fishmeal can be used as the starting
material. A mixture of fishmeal and solvent is initially heated;
however, a low heat, at a temperature below 75.degree. C., is
preferably used so there is no risk of decomposition, as determined
by final product analysis measuring the protein content, of the
protein product due to thermal degradation effects. The ratio of
solvent to fishmeal in the mixture should be in the range of from
about 1:1 to about 2:1 so that the fishmeal hydrates into a viscous
liquid during processing in the slurry preparation tank, and in
particular, the heating process, which is done at a controlled
temperature using a variable control system that includes a
temperature sensor that is immersed into the contents of the tank
and that measures the actual temperature of the mixture. A
corresponding temperature feedback controller measures the process
temperature and regulates the amount of steam, thermal heating
fluid, or electrical wattage that is used to heat the contents of
the tank. The temperature controller can modulate a control valve,
or wattage regulator, to control the steam, thermal heating fluid,
or amperes to achieve a specified temperature setpoint, such as
70.degree. C. to prevent the decomposition and/or denaturation of
the protein material associated with the raw fish or fishmeal. By
preventing decomposition and/or denaturation of the protein
material, the amount of protein recovered generally is greater than
85%. The ratio of animal tissue to solvent will depend on various
factors including, but not limited to, the specific animal tissue
and solvent used. Where the starting material is raw fish and IPA
is used as the organic solvent, the ratio of raw fish in kilograms
to IPA in liters ranges from about 1:1 to 1:2.2; or from about 1:1
to 1:2.1; or from about 1:1 to 1:2.0; or from about 1:1 to 1:1.9;
or from about 1:1 to 1:1.8; or from about 1:1 to 1:1.7; or from
about 1:1 to 1:1.6; or from about 1:1 to 1:1.5; or from about 1:1
to 1:1.4; or from about 1:1 to 1:1.3; or from about 1:1 to 1:1.2;
or from about 1:1 to 1:1.1. More preferably the ratio is about 1:2.
In a preferred embodiment of the present invention, upon scale-up,
about 5,000 Kg of raw fish and about 10,000 L of organic solvent
are combined to form the mixture of raw fish and solvent.
[0179] As illustrated in FIG. 1, a slurry mixture of animal tissue
and organic solvent is prepared, where it is heated in the slurry
tank, with agitation at a temperature ranging from about 25.degree.
C. to about 72.degree. C. The slurry tank includes a primary
agitator assembly and a heating source for providing thermal energy
to the tank in order to adjust the temperature of the slurry
mixture in the slurry tank. The primary agitator assembly, which
consists of a rotating mixing shaft with blades, where the mixing
blades are rotated by an overhead motor to achieve uniform mixing
in the tank, ensures uniform mixing and heating, thus eliminating
localized thermally heated zones in the tank that are in contact
with the animal tissue and organic solvent mixture, particularly
that portion of the mixture in proximity of the heated walls or
bottom of the slurry preparation vessel. Such localized contact
with thermally hot zones can induce decomposition and/or denaturing
of the protein. In ensuring a thermally stable and adequately mixed
environment in the slurry tank, protein conforming to the product
specification will be recovered, specifically with 85% or higher
protein content, as characterized by the resultant amino acid
profile conducted through final product analysis.
[0180] The heating source can include a jacket encompassing at
least a portion of the tank through which a thermal heating fluid,
such as steam or heated oil, can be circulated or pumped; or an
immersion heater that can be inserted directly into the slurry; or
electrical heating elements that are in thermal communication with
at least a portion of the tank; or any combination thereof. The
slurry tank also can include a jacketing and insulation system to
permit cooling of the tank. In some embodiment, the slurry tank
includes a jacketing and insulation system that can heat and cool
the tank. The slurry tank also can include a variable control
system that includes a temperature sensor that is immersed into the
contents of the tank and that measures the actual temperature of
the mixture. The slurry tank also can include a temperature
feedback controller to regulate the amount of thermal energy
provided to the tank to adjust the temperature of the slurry. In
some embodiments, the temperature feedback controller regulates the
amount of steam, thermal heating fluid, or electrical wattage that
is provided to the heating source used to heat the contents of the
tank. For example, the temperature controller can modulate a
control valve, or wattage regulator, or a combination thereof, to
control the steam, thermal heating fluid, or amperes available to
the heating source.
[0181] After processing in the slurry tank, the slurry is then
transferred to a dewatering system where it undergoes dewatering to
reduce the amount of water present. The dewatering system then
transfers the processed slurry to the one of the 5 optional
filtration extraction units.
[0182] The animal tissue may be fed by the dewatering system back
into the slurry preparation tank for further processing before
directing the processes slurry to a filtration extraction unit. As
discussed above, the slurry preparation tank can include an
agitator, as well as a jacketing and insulation system to permit
external heating and cooling. Preferably, the mixture is heated to
a temperature not exceeding 75.degree. C., for example, about
25-72.degree. C. The resulting homogeneous slurry mixture is then
transferred to the dewatering system and then to a filtration
extraction unit of the product processing system provided herein.
The product processing system, in some embodiments, includes one of
a belt filtration system (an example of which is shown in FIG. 2),
a rotary drum filter (an example of which is shown in FIG. 3), an
immersion extractor (an example of which is shown in FIG. 4), a
percolation extractor (an example of which is shown in FIG. 5, or a
screw press system (an example of which is shown in FIG. 6), or any
combination thereof.
[0183] In the systems provided herein, the protein material is
filtered and washed. In some embodiments, a counter-current washing
is used. In some embodiments, a counter-current washing system
using captured filtrate is used, followed by a final fresh solvent
wash. The final solvent wash can use fresh, virgin solvent, or can
use solvent recovered from the system, such as by the SLR system,
or a combination of the two. The recovered protein product wetcake
is then dried, preferably using heat and vacuum. The nature of the
continuous conveyor and filtration systems has the result of
substantially increased production throughput. Continuous
filtration options allow the process to be automated and to operate
in closed circuit, e.g., closed system. The system also can be
operated manually. In some embodiments, at least one process of the
system is automated.
[0184] The low-moisture wetcake product recovered from the product
processing system is further dried in a dryer and discharged from
the dryer and into a particle reduction system where a micronized
particle size for the product is established in the range of less
than 75 .mu.m to 250 .mu.m. The resultant powdered protein product
is then transferred to a product receptacle. The powdered protein
product can be analyzed to establish whether the protein product
conforms to target specifications. In an exemplary embodiment, the
yield of solid protein is from about 10 wt % to about 25 wt % based
upon the starting weight of the raw animal tissue starting
material. Preferably, the yield of protein is in the range of from
about 10 wt % to about 18 wt % based upon the starting weight of
the animal tissue entering the grinding unit. In some embodiments,
the yield of protein is greater than about 15 wt % based upon the
starting weight of the animal tissue.
[0185] A laboratory analysis of the powdered protein product from
the product recovery systems provided herein showed that the
recovered powdered protein product has a protein concentration in
the range from about 80 wt % to about 95 wt %, generally from about
85 wt % to about 95 wt %. An amino acid profile identifies the
amino acids present in a product depending on the type of animal
tissue. The recovered powdered protein product can be a complete
protein, non-hygroscopic, and substantially free of fish odor or
smell contributed by amines, particularly volatile amines. The
recovered powdered protein product can also be non-hygroscopic and
sterile, and visually, the protein can exhibit a cream color. The
typical composition profile of the final powdered protein product
shows that the protein includes all of the essential and
non-essential amino acids. The final product has very low fat and
cholesterol levels, negligible heavy metals residue, has over 95%
digestibility, and is non-hygroscopic. Additional constituents
include natural fish essential minerals, such as calcium and
collagen, phosphorous, selenium, sodium, zinc, magnesium, iron, and
copper.
[0186] The final product has an extremely mild flavor and aroma,
and is non-gelling. The product serves as an excellent source of
dietary supplements and protein meal replacement products. In
addition, the final product does not degrade over time, as the
process is low temperature, e.g., not exceeding 80.degree. C., in
order to prevent thermal degradation of the protein. The
organoleptic properties (i.e. smell and taste), amino acid profile,
and concentration of protein of the final product are stable upon
long term storage. The amount of protein in the final product can
vary from about 40 wt % to about 99 wt %, such as at least 50 wt %,
or at least 60 wt %, or at least 70 wt %, or at least 80 wt %, or
at least 90 wt % are stable upon long term storage. The final
product exceeds all FDA requirements for a supplement and is an
excellent product for world food needs.
[0187] In the processes provided herein, the raw starting material
generally is mixed with a food grade solvent, such as ethanol or
IPA, at concentrations that can act as a disinfectant or an
anti-bacterial during many stages of the process. The separated
solid material containing the protein component can be in contact
with at least some amount of the food grade solvent throughout the
process, making material and equipment handling easier and making
maintenance of sanitary conditions throughout the process easier.
This can insure that the finished protein product and omega-3 oil
product obtained using the processes provided herein are sanitary
and safe for human consumption.
[0188] The final product also has a long shelf life of at least 5
years as determined by maintaining a fairly constant analytical
profile from the time of its original manufacturing. In one
embodiment, the recovered solid protein product was tested in a
laboratory simulating environmental conditions over 10 years. The
constant profile may be attributed to the final product's
non-hygroscopic, or substantially non-hygroscopic, nature. That is,
because the final product does not absorb humidity, it maintains a
low water activity that prevents bacteriological growth. Preferably
the moisture content of the final product is less than about 8 wt
%. The recovered protein has amino acid compositions that are
balanced to afford a nutritionally advantageous characteristic.
[0189] In the methods and systems provided herein, the filtrates
that are extracted as a result of the process recovery system,
which can use any filtering system, such as a belt filtration
system, a rotary drum filter, an immersion extractor, a percolation
extractor, or a screw press, or combinations thereof, are
transferred to the solvent liquid recovery system (SLR). The SLR
includes an adsorber system and a carbon filtration system. The
filtrate can include, but is not limited to, oils, fats, solvent
and water. When the animal tissue is fish, the oil can include
omega-3 fatty acids. In the SLR system, the filtrate can first be
transferred to an adsorber system, then to a carbon filtration
system and, optionally, subsequently filtered once again to remove
residual solids. In some embodiments, the adsorber system includes
a fixed, packed bed column containing resin particles or beads. The
particular resin beads will have an affinity for free amines and
miscellaneous undesired hydrocarbons that can be present in the
filtrate. The filtrate is transferred through the adsorber system,
and the resultant stream that exits the adsorber system will be
purified via treatment using the carbon filtration system. The
adsorption process generally is done at ambient temperature. In
some embodiments, a pump can be used to pump the filtrate through
the adsorber system. The stream leaving the adsorber system can be
directed to the carbon filtration system. The carbon filtration is
also a fixed bed operation and is used as polishing step following
the adsorber process. Alternatively, the stream leaving the
adsorber system can be directed directly to a solvent recovery
system, which can include a distillation tower or a centrifuge or
both, in order to separate the organic solvent/water from
oils/fats. The solvent can be separated from water to yield a
recovered organic solvent, which can be transferred to a recovery
tank, and thereafter, used as recycled organic solvent in the
methods and systems provided herein.
[0190] The recovered oils, for example, omega-3 fatty acids, can be
filtered to remove residue and to increase the purity thereof. The
recovered oils also can be treated with activated carbon to remove
the odor by neutralizing any amines present in the oil. The residue
produced can be separated from the oil and transferred to a
discarding tank. The oils, including omega-3 fatty acids, can be
transferred to a first recovery tank. There, the oil can undergo
further purification via molecular distillation and/or
transesterification. The recovered oils including omega-3 fatty
acids are polyunsaturated fatty acids with a double bond on the end
of the carbon chain. They are considered essential fatty acids.
Humans cannot readily make omega-3 fatty acids in their bodies, and
therefore it must be obtained from other sources since omega-3
fatty acids play an important role for normal metabolism.
[0191] In an exemplary embodiment, omega-3 fatty acids are
recovered in amounts greater than or equal to about 5 wt % based on
the weight of the original animal tissue feedstock. Preferably
omega-3 fatty acids are recovered in amounts of greater than or
equal to 6 wt % of the original animal tissue feedstock. More
preferably, omega-3 fatty acids are recovered in amounts greater
than or equal to 7 wt % of original animal tissue feedstock. The
level and composition of fatty acids and omega-3 oils contained in
raw fish are a function of the fish species and their origin of
habitat.
[0192] In yet another embodiment, the organic solvent/water
independently can be recovered using the solvent/liquid recovery
(SLR) system, e.g., by using extractive distillation. Namely, a
third component can be introduced into the process. For example,
when isopropyl alcohol (IPA) is the organic solvent, diisopropyl
ether (IPE) can be used, whereby IPA and IPE combine to completely
separate water from the IPA. The IPA/IPE mixture is then further
distilled in a secondary distillation column to recover IPA. The
IPA then can be transferred to a recovery tank for further
processing as discussed above. The water can be recovered for human
consumption and/or industrial applications. The recovered water
contains few or no ions.
[0193] Recovered Low-Moisture Wetcake
[0194] In some embodiments of the methods and systems provided
herein, the protein product wetcake can be withdrawn from product
separation system 10 via outlet O. The protein product wetcake
discharged via outlet O can contain at least about 50 wt % protein.
In some embodiments, the protein product wetcake can contain
impurities or omega-3 oil. In some embodiments, the protein product
wetcake contains no or less than 0.1% of any one impurity. In some
embodiments, the protein product wetcake contains 0.1% or less, or
0.05% or less fat. In some embodiments, the protein product wetcake
is free of any fish odor. In some embodiments, the protein product
wetcake is odorless. In some embodiments, the protein product
wetcake is free of cholesterol. In some embodiments, the protein
product wetcake is free of sugar. In some embodiments, the protein
product wetcake can be a washed wetcake or an optionally enriched
wetcake or a washed, enriched wetcake.
[0195] The protein product wetcake can be dried in a dryer unit 800
to further reduce the amount of moisture and/or residual organic
solvent present in the washed wetcake or washed and enriched
wetcake. The dried protein product wetcake can be recovered at
outlet 820 into a packaging device 830. The type and configuration
of the dryer unit 800 can be selected to optimize the amount of
moisture and/or organic solvent removed without negatively impact
protein product quality. For example, forced air, direct IR,
indirect IR or convection ovens can be used to directly or
indirectly dry the wetcake. Additional drying units can include a
tray drying system, rotary cone vacuum dryer, fluid bed dryer or
spray drying unit. In some embodiments, the wetcake is dried to a
moisture content of about 10 wt % or less, or about 5 wt % or less,
and a residual organic solvent content of about 1 wt % or less, or
0.5% or less under full vacuum at a temperature of 100.degree. C.
or less, such as 80.degree. C. or less.
[0196] The dried wetcake can be stored as wetcake, or can be milled
into small particle sizes using a milling unit. In some
embodiments, the product recovery system 1000 provided herein can
include a mill unit 815 for milling the dried wetcake. Examples of
mills that can be incorporated into the system include, but are not
limited to, a Micronizer.RTM. jet mill or Powderizer.RTM. mill or
Simpactor.RTM. mill (each of which is available from Sturtevant,
Inc., Hanover, Mass.), a hammer mill, a roll crusher or a rotary
crusher. The dry powdered protein product 825 can be recovered from
mill unit 815 via mill outlet 820 and stored in packaging device
830.
Examples
[0197] The following examples illustrate specific aspects of the
present invention. The examples are not intended to limit the scope
of the present invention.
[0198] Pepsin Analysis
[0199] A powdered protein recovered from fish was prepared using
the system and methods provided herein. A typical analytical
profile for the powdered protein product showed that the yield of
protein from the fish starting material was 85.4%, the moisture
content of the dried powdered protein product was 7.68%, and crude
fat content was 1.42%. The recovered powdered protein product
derived from fish was tested using the well-known pepsin test (0.2%
pepsin, AOAC method 971.09) to assess the quality of the protein.
Pepsin is an enzyme that is used to digest protein structures. The
pepsin test is used to determine how much protein is within a
mixture. The powdered protein product sample was defatted and
digested with a 0.02% solution of pepsin for 16 hours. The
resultant digest was filtered and washed to isolate the
indigestible residue, which is then analyzed for protein. The
"Pepsin Digestible Protein" then can be calculated as a percentage
of the crude protein by the relationship (crude
protein-indigestible protein)/crude protein=Pepsin Digestible
Protein. The recovered powdered protein product derived from fish
had over 98% digestible protein.
[0200] The sample also was tested for trans fatty acid and
cholesterol. The amount of trans fatty acid isomers was less than
0.1 wt. % of a 100 g serving, and the amount of cholesterol was
less than 0.05 wt. % of a 100 g serving.
[0201] Mineral Content Comparison
[0202] The powdered protein product was analyzed for mineral
content. An elemental scan of the product showed that the powdered
protein product is a good source of calcium, iron, magnesium, zinc,
and phosphorus, while having low levels or sodium and potassium.
The results are shown in Table 3. Table 3 shows the amount of the
listed elements in a 25 g sample of one example of the recovered
powdered protein product derived from fish using the process and
methods described herein. The amounts are shown as a percentage of
the recommended daily allowance (RDA) for the mineral. Also shown
are the amounts of the listed elements in a 25 g sample of
commercial protein powders on the market.
[0203] Notably, the calcium, iron and zinc contents of 25 mg APP is
significantly greater than for each of DFH whey, JF whey, GNC whey,
Whey Isolate, Whey concentrate, JF soy and NB soy. The amount of
iron present in APP is significantly greater than in each of DFH
whey, JF whey, GNC whey, Whey Isolate, and Whey concentrate.
TABLE-US-00003 TABLE 5 Comparative mineral content. Comparing
mineral content per 25 grams of protein as a percentage of the RDA
Powdered Protein DFH GNC Whey Whey Product whey JF whey whey
Isolate conc. JF soy NB soy Calcium 55% 12.5 9.0% 8.3% 18.8% 2.9%
5.0% Iron 18.1% 4.2% 1.8% 22.2 22.2% Magnesium 10% 3.5% 2.8% Zinc
9.8% 6.7% Sodium 2.1% 2.0% 1.7% 2.6% 2% 2.3% 0.6% Potassium 4.6%
4.6% 3.7% 5.7% 8.7% 3.7% 10.6 12.9% Phosphorus 18.4% 21.3 8.9%
29.3%
[0204] It will be understood by one skilled in the art that each of
the above-described embodiments, as well as any sub-parts of those
embodiments, can be operated in a continuous or a non-continuous
manner. Non-continuous operations include, but are not limited to,
batch-wise operations, cyclical operations, and/or intermittent
operations. Additionally, it will be understood that two or more of
the above embodiments can be used in combination.
[0205] It will be apparent to those skilled in the art that various
modifications and variation can be made in the present invention
without departing from the spirit or scope of the invention. Thus,
it is intended that the present invention cover the modifications
and variations of this invention provided are within the scope of
the appended claims and their equivalents.
TABLE-US-00004 LIST OF FIGURE ELEMENTS I Inlet to filtration system
10 O Outlet of filtration system 10 3 Product Wash stream 5 Recycle
feed stream 7 Drying gas 10 Product separation system 15 Product
wash inlet 25 Process filtrates outlet line 27 Drying gas inlet 30
Discharge stage 35 Wetcake transport line 40 Common vacuum source
45 Vapor condenser 47 Outlet from vapor condenser 80 Common vacuum
line 100 Grinding unit 105 Discharge line from grinding unit 150
Slurry preparation tank 155 Preparation tank outlet 170 Dewatering
device 171 Dewatering device outlet 173 Return line to feed prep
tank 175 Processed slurry line to filtration system 177 Press
liquid outlet line 180 Solvent Supply tank 185 Virgin solvent line
to prep tank 189 Virgin solvent line to filtration system 200 Belt
filtration system 201 Beginning belt roller 202 Ending belt roller
211 Pump from 221 212 Pump from 222 213 Pump from 223 214 Pump from
224 215 Pump from 225 220 Conveyor belt filter 221 Receiver from
box 251 (stage 1) 222 Receiver from box 252 (stage 2A) 223 Receiver
from box 253 (stage 2B) 224 Receiver from box 254 (stage 2C) 225
Recycle receiver (from box 255, stage 3) 231 discharge line from
box 251 232 discharge line from box 252 233 discharge line from box
253 234 discharge line from box 254 235 discharge line from box 255
236 discharge line from box 256 241 line from pump 211 242 line
from pump 212 243 wash line from pump 213 to 262 244 wash line from
pump 214 to 263 245 wash line from pump 215 to 265 251 vacuum box
of stage 1 252 vacuum box of stage 2A 253 vacuum box of stage 2B
254 vacuum box of stage 2C 255 vacuum box of stage 3 256 vacuum box
of stage 4 262 applicator X (to stage 2A, box 252) 263 applicator Y
(to stage 2B, box 253) 264 applicator Z (to stage 2C, box 254) 265
applicator R (recycle stage 3, box 255) 270 Product wash feed line
275 Stage 1 applicator 280 Outlet 290 Processed slurry supply line
300 Drum filtration system 301 Slurry inlet 310 Housing 312 Rotary
drum filter 314a Seal 314b Seal 314c Seal 314d Seal 314e Seal 314f
Seal 314g Seal 322 Discharge stage 324 Filter wash stage 326 Filter
cells 330 Wash feed inlet 332 first wash filtrate inlet 334 Second
wash filtrate inlet 336 Initial wash stage 338 Intermediate wash
stage 340 Final wash stage 341 Discharge line (e.g., to 705) 342
initial wetcake 344 washed wetcake 346 washed and enriched wetcake
348 recycle feed inlet 350 drying gas inlet 355 recovered product
(low-moisture wetcake) 360 Stage 1 - separation stage 370 Stage 2 -
wash stage 380 Stage 3 - optional recycle stage 385 Discharge line
387 Recycle discharge line 390 Stage 4 - drying stage 395 Discharge
line 400 Immersion extraction unit 405 Entry port 407 Processed
slurry 410 Solvent bath 415 Upper level of solvent bath 410 421
Conveyor belt 422 Conveyor belt 423 Conveyor belt 424 Conveyor belt
425 Conveyor belt 430 Belt protrusions 440 Solvent wash applicator
450 Discharge port 490 Discharge line (e.g., to 30) 495 Filtrate
outlet line (e.g., to 705) 500 Percolation extraction system 505
entry port 510 Pump 511 Pump 512 Pump 513 Pump 514 Pump 520
Filtrate outlet to pump 510 521 Filtrate outlet to pump 511 522
Filtrate outlet to pump 512 523 Filtrate outlet to pump 513 524
Filtrate outlet to pump 514 540 Conveyor belt 542 Belt protrusions
545 Stationary screen 550 Motor assembly 560 Filtrate receiving
compartment 561 Filtrate receiving compartment 562 Filtrate
receiving compartment 563 Filtrate receiving compartment 564
Filtrate receiving compartment 571 Spray applicator 572 Spray
applicator 573 Spray applicator 580 Wash applicator 585 Discharge
line (from pump 514) 590 Exit 595 Discharge line (from pump 510)
600 Screw press system 601 Motor 603 Gear reduction drive 605 Shaft
coupling 610 Inlet port 615 Screen chamber 618 Solids restrainer
620 Liquid drain 625 Press cake discharge 630 Frame 635 Screw 640
Continuous feeder flighting 645 Gear box 650 Screw shaft 655
Restraining cone 660 Adjuster 675 Decanter Centrifuge 700
Solvent/liquid recovery (SLR) system 705 Liquid phase processing
unit 710 Processer outlet line 715 Separation unit 720 Recovered
solvent transfer line 725 Recovered oil transfer line 730 Omega-3
oil 740 Recovered solvent tank 745 Recovered solvent line to slurry
tank 750 Recovered solvent line to wash inlet 760 Waste outlet 765
Waste outlet line 770 Purified water outlet 775 Purified water 800
Dryer unit 810 Dryer unit outlet 815 Milling unit 820 Mill outlet
825 Dry powdered protein product 830 Packaging device 840 Vapor
Condenser 845 Condenser outlet 1000 Product recovery system
* * * * *