U.S. patent application number 12/062499 was filed with the patent office on 2008-10-09 for biodiesel compositions.
Invention is credited to Kenneth Hazen Tarbet Kenneth.
Application Number | 20080244965 12/062499 |
Document ID | / |
Family ID | 39825708 |
Filed Date | 2008-10-09 |
United States Patent
Application |
20080244965 |
Kind Code |
A1 |
Tarbet Kenneth; Kenneth
Hazen |
October 9, 2008 |
Biodiesel compositions
Abstract
In a first aspect, systems and methods for producing biodiesel
fuel include a modular production unit incorporated onto a single
platform or into a housing for ease of relocatability. The modular
production unit preferably includes a mixing unit, a reaction
chamber, a separation unit, a filtering unit, all incorporated onto
or into a self-contained platform or housing that is able to be
easily relocated. In a second aspect, the modular production unit
is combined with additional fixed and/or relocatable components to
provide a biodiesel processing plant.
Inventors: |
Tarbet Kenneth; Kenneth Hazen;
(Snowflake, AZ) |
Correspondence
Address: |
KENNETH H. TARBET
P.O. Box 2823
Snowflake
AZ
85937
US
|
Family ID: |
39825708 |
Appl. No.: |
12/062499 |
Filed: |
April 3, 2008 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
60909908 |
Apr 3, 2007 |
|
|
|
Current U.S.
Class: |
44/385 |
Current CPC
Class: |
Y02E 50/13 20130101;
C10L 1/026 20130101; Y02E 50/10 20130101 |
Class at
Publication: |
44/385 |
International
Class: |
C10L 1/18 20060101
C10L001/18 |
Claims
1. A biodiesel composition having a cloud point below 32.degree. F.
comprising: a cloud-point reducing quantity of higher alkyl esters
of triglyceride oils.
2. The biodiesel composition, according to claim 1 having a cloud
point below 32.degree. F. wherein the higher alkyl esters of
triglyceride oils is a glycol esters of a triglyceride.
3. A biodiesel comprising: at least one molecule according to
structure I where R1, R2, R3 and R4 are independently alkyl, aryl
amino, hetero, heteroalkyl, heteroaryl, saturated, unsaturated,
branched, a glycol-ether, a polyheteroalkane and combinations
thereof, and R.sub.5 is a heteroatom ##STR00001##
4. A system for a continuous transesterification of a triglyceride
feed stock at below 80.degree. F. comprising: combining a
triglyceride and an activated nucleophile in a reaction chamber;
causing the activated nucleophile to replace a hydroxylated moiety
on the triglyceride; causing sound energy to pass through the
reaction chamber; extracting a post reaction mixture; causing
enhanced gravitational forces to act on the post reaction mixture;
obtaining a transesterified product.
5. (canceled)
6. (canceled)
Description
[0001] This application claims priority filing date of U.S.
provisional application Ser. No. 60,909,908 filed Apr. 3, 2007, the
contents of which are incorporated by reference in their
entirety.
FIELD OF THE INVENTION
[0002] The invention primarily relates to systems and methods for
manufacturing and processing fuels and, more particularly, relates
to systems and methods for manufacturing and processing biodiesel
fuels without the use of a water-washing step. The present system,
methods and composition relate to the conversion of the produced
glycerin to tri-ethers, useful as additives and biodiesel
modifiers. The present composition relates to the generation of
unique molecular configurations providing a winterized biodiesel
and a biofuel of improved properties.
BACKGROUND OF THE INVENTION
[0003] Biodiesel is the name for a variety of ester-based
oxygenated fuels made from vegetable oils, fats, greases, or other
sources of triglycerides. It is a nontoxic and biodegradable
substitute and supplement for petroleum diesel. Even in blends as
low as 20% biodiesel to 80% petroleum diesel (B20), biodiesel can
substantially reduce the emission levels and toxicity of diesel
exhaust. Biodiesel has been designated as an alternative fuel by
the United States Department of Energy and the United States
Department of Transportation, and is registered with the United
States Environmental Protection Agency as a fuel and fuel additive.
It can be used in any diesel engine, without the need for
mechanical alterations, and is compatible with existing petroleum
distribution infrastructure.
[0004] As reported in "Biodiesel: On the Road to Fueling the
Future," (National Biodiesel Board 2001), the disclosure and
subject matter of which is hereby incorporated by reference in its
entirety, most biodiesel is produced by the process of acid or base
catalyzed transesterification. The transesterification process is a
low temperature (150.degree. F.), low pressure (20 psi) reaction
having a high conversion factor (e.g. 98%) with minimal side
reactions and reaction time.
[0005] A fat or oil is reacted with an alcohol (such as methanol or
ethanol) in the presence of a catalyst to produce glycerin and
alkyl esters, the latter of which comprises biodiesel.
Traditionally, the alcohol is charged in an excess stoichiometric
amount to drive the reaction and is recovered for reuse. The
catalyst is typically sodium or potassium hydroxide which is mixed
with the alcohol prior to the transesterification reaction. The
biodiesel is separated from the glycerin. Variations, improvements,
and modifications of this general process are described in several
patents, including U.S. Pat. No. 5,424,467 entitled "Method for
Purifying Alcohol Esters," issued to Bam et al. on Jun. 13,
1995.
[0006] Conventional biodiesel production systems are based upon
large, fixed base plants which require expensive capitalization and
on site construction. For example, in order to generate an
economically viable amount of biodiesel product, a conventional
biodiesel plant contains large, batch-type reactors, large
separation units (e.g., decanters, centrifuges, clarifiers), and
distillation columns as tall as 50 to 200 feet or more. As a
result, current biodiesel production is limited to discrete
locations where fixed plants may be constructed. This results in
inefficiencies that may otherwise be obtained by locating a plant
near a source of raw materials, or near an end user of the
biodiesel product. Further, the conventional process relies upon
batch processing, in which the transesterification reaction
proceeds in at least two multi-hour stages and in which the
separation processes cannot be performed continuously. Moreover,
the conventional process relies on at least one washing of the
crude biodiesel product with water.
SUMMARY OF THE INVENTION
[0007] The present invention was created in order to solve the
above problems associated with large, fixed base plants that are
conventionally used to produce biodiesel, other fuels, and other
products. An object of the present invention is to provide a
modular production system capable of producing small to large
quantities of biodiesel. In another embodiment of the present
invention is to provide molecular blends of biodiesel that have a
cloud point below 32.degree. F. In yet another embodiment of the
present invention is provided the separate transformation of the
waste glycerin into a fuel additive. In a still further embodiment
of the present invention is directed to selectively combining
feedstock oils providing a blend of triglycerides of varied carbon
chain lengths and double bonds, which result in a biodiesel having
a gel point below 32.degree. F. In another aspect of the invention
is provided a system for producing biodiesel without a step wherein
the biodiesel is washed with water.
[0008] In the preferred embodiments, the described production
systems are capable of producing biodiesel at a rate of about 1
million to about 25 million gallons per month. While the systems
and methods are described herein in specific relation to the
production of biodiesel, those of ordinary skill in the art will
recognize that the advantages obtained by these systems and methods
may be applied to the production of other fuels and other products
as well.
[0009] In a first aspect, a preferred biodiesel manufacturing and
processing system and method includes a preassembled, modular
production unit that, in a preferred form, includes the following
system components: a. a mixing unit; b. a reaction chamber; c. a
separator unit; d. a filtering unit.
[0010] The above components of the modular production unit are
preferably incorporated onto a single platform, such as a skid
mount, or into a housing, such as a standard ISO Intermodal
Shipping Container, such that the system is easily shipped or
transferred to a remote site by either truck, rail, ship, or other
means of transportation. Thus, each component and the overall
system are designed to address the constraints of limited space
availability, while at the same time providing for maximum
throughput and processing of the widest variety of feedstocks into
fuel products.
[0011] The basic biodiesel reaction of converting organic oils into
alkyl esters (biodiesel) and glycerin involves the reaction of a
raw oil with an alcohol (typically methanol or ethanol, although
most alcohols can be made to work) and a catalyst (typically sodium
hydroxide or potassium hydroxide). The equipment used for this
process generally consists of large reactor tanks with paddle type
mixers in steam jacketed tanks. The alcohol and the catalyst are
mixed first, then the alcohol/catalyst mixture is mixed with the
raw oil heated to about 140.degree.-160.degree. F. and allowed to
react over a 4 to 8 hour time.
[0012] One challenge for the modular production unit of the present
invention was to create an alcohol/catalyst mixer and a separation
reactor that could both react and separate waste within the space
constraints of the modular unit. This is accomplished according to
a preferred embodiment of the present invention by replacing the
conventional heated tank with a mixing tank connected to a smaller
reaction chamber that is exposed to an ultrasonication reaction
device. A traditional pump facilitates circulation of reactants and
their passage through the reaction chamber, yet an elevated mixing
tank could rely on gravity and function according to the present
disclosure. A tank for each reactant may be employed, where the
proper amount of each reactant is metered into the reaction
chamber. Where space requirements or desire demand the use of one
tank, the reactants are combined therein and are drawn from a
cone-shaped bottom portion of the tank. This creates a central
vortex within the reaction tank that allows rapid and complete
mixing of the reactants prior to entering the reaction chamber.
Similar, yet standard pumps are also used for filling and emptying
the alcohol/catalyst mixer and the separation reactor. A venturi
valve or similar device as is known in the art, couples the
alcohol/catalyst mixer with the separation reactor to allow the
constant introduction of the correct proportion of alcohol/catalyst
to raw oil.
[0013] Once the reactants pass through the reaction chamber the
crude product begins to separate into biodiesel and glycerin.
[0014] According to convention and practice known in the art, as
the glycerin is formed the reaction approaches equilibrium and
begins to slow, and eventually stops, even before all of the raw
oil has been reacted. Moreover, the conventional practice is to
allow the product to reach saturation, draw off the glycerin (along
with any excess alcohol), and then re-commence the
transesterification reaction using the remaining mixture of raw
oil, alcohol and biodiesel. This process generally takes four to
six hours and significant excess alcohol. By using the
alcohol/catalyst mixer the reaction chamber and the separation
reactors in the manner provided by the present invention, the
process is sped up to occur within minutes.
[0015] As glycerin is formed it naturally drops to the cone-shaped
bottom of the separation reactor. As part of the recirculation of
the reactants, the reactants are run through an array, preferably
three, of serial centrifuges to separate the glycerin from the
reactants and biodiesel. The present system may be performed in a
continuous mode or in a continuous batch mode as will be further
provided in the examples. Yet in brief, under continuous mode,
reactants are pulled together at a metered amount and into a common
tube which feeds into the reaction chamber wherein the reactants
are exposed to the ultrisonification energy whereby
transesterification is caused. The crude mixture then passes
through a centrifuge where the biodiesel and glycerin are
separated. Under a continuous batch mode system, the reactants are
combined in a single reaction vessel and pumped through a static
mixer, as known in the art, and into the reaction chamber. The
reactants are exposed to the ultrasonication energy whereby
transesterification occurs. The reaction mixture is recycled
through the storage tank, in a circulation fashion which includes
the reaction chamber. Although there are reasons for adopting
either system and reaction paradigm, they are both encompassed by
the present invention and claims.
[0016] In the preferred embodiment, the alcohol/catalyst mixer and
separation reactor comprise tanks made of epoxy coated steel, or
entirely in stainless, or some combination of the two. The number
and size of pumps and static mixers can be varied to optimize the
creation of a mixing vortex, and the direction angle can be varied
in the same manner, and/or optimized for Coriolis efficiency
(counter clockwise in the Northern Hemisphere, and clockwise in the
Southern Hemisphere). Further embodiments include embedded
instrumentation for monitoring temperature, PH, flow rates and
volumes, and fill levels.
[0017] Although several advantages are obtained by providing the
systems and methods described herein in a self-contained, modular
production unit, those skilled in the art will recognize that one
or more of the described system components may be provided in a
scaled up form for use in a fixed base, nonmodular configuration to
obtain the other advantages provided by those components.
[0018] In a second aspect, the modular production unit described
above is combined with additional fixed and/or relocatable system
components in a biodiesel processing plant. In a preferred form,
the plant is provided with components and functionality to provide
raw materials processing and finished biodiesel product processing.
In particular, the raw materials processing includes filtering and
separation functionality to remove waste and particulate matter
from recycled triglycerides starting materials. Further, the
finished biodiesel product processing includes filtering and
separation functionality to reprocess the glycerin into alkyl,
heteroalkyl, aryl or similar triethers. Modified glycerin in this
manner functions as a gel-point depressant and a CETANE
enhancer.
[0019] In a particularly preferred form, the raw materials
processing and finished biodiesel product processing systems are
co-located on a single or double transportable platform, such as a
skid mount, or in a transportable housing, such as a standard
shipping container. In this manner, similar to the modular
production unit described herein, the raw materials and finished
product processing systems may be relocated to a desired site.
[0020] The biodiesel processing plant is preferably provided with
additional optional components, including storage tanks, spill
areas, and/or other components that may provide auxiliary
functionality to the plant.
[0021] The systems, methods, and apparatus of the present invention
will be better understood by reference to the Detailed Description
in connection with the Drawings.
[0022] The above components are preferably incorporated onto a
single or double platform, such as a skid mount, or into a housing,
such as a standard ISO Intermodal Shipping Container, such that the
system is easily shipped or transferred to a remote site by either
truck, rail, ship, or other means of transportation, or operated in
place while situated on a truck trailer, rail car, or ship. Thus,
each component and the overall system are designed to address the
constraints of limited space availability, while at the same time
providing for maximum throughput and processing of the widest
variety of feedstocks into fuel products.
[0023] The preferred mixing unit is an alcohol/catalyst mixer that
receives the alcohol and catalyst as feeds and mixes the two prior
to supplying the mixture to the reaction chamber. In the preferred
embodiment, the alcohol is methanol, and the catalyst is sodium
hydroxide, although those of skill in the art will recognize that
other alcohols and catalysts are suitable for producing biodiesel
fuel. Indeed, in other preferred embodiments a mixture of alcohols
is used to provide a biodiesel blend having a cloud point below
32.degree. F. In the preferred embodiment, the alcohol/catalyst
mixer comprises a 300 gallon mixing tank having a cone shaped
bottom section. The tank may includes a cone-shaped bottom portion
and a drain located at the bottom. When used as a mixing tank the
tank advantageously includes mixing looper jets that function in a
manner described below. One advantage of the cone-shaped bottom is
that it allows the catalyst, which is typically in solid granular
or flake form, to fall to the bottom and then be continuously
recirculated and mixed until it goes into solution with the
alcohol. The size of the alcohol/catalyst mixer is sufficient to
produce the volume of mixed alcohol and catalyst.
[0024] The reaction chamber receives the alcohol/catalyst mixture
from the mixing unit as a second feed, and the triglyceride source
as a first feed, and the ultrisonification device causes the
transesterification reaction to occur. After sufficient completion
of the transesterification reaction, the reactor unit outputs one
or more streams comprising the reaction products of the
transesterification reaction, namely, biodiesel fuel (alkyl esters)
and glycerin.
[0025] The separation tanks of the preferred embodiment are
constructed and operate in a manner different from the batch
processing reactor tanks used in conventional biodiesel
manufacturing processes. The conventional batch reactors are
uniform cylinders that use paddle mixers or other similar mixing.
The separation tanks employed in the preferred embodiment, on the
other hand, are constructed having a cone-shaped bottom equipped
with a drain to facilitate removal of the glycerin phase during the
transesterification process in order to provide a continuous
process, unlike the prior art. The cone-shaped bottom portion and
drain provided on the preferred reaction chamber facilitate this
process.
[0026] The reaction chamber is further operatively connected to one
or more pumps (e.g., centrifugal or gear driven) that recirculate
the reaction materials through the jets to provide mixing. The jets
are oriented such that, in combination with the drain at the
cone-shaped bottom of the tank, a vortex is created within the
reaction chamber to facilitate mixing of the materials to help
drive the transesterification reaction, thereby eliminating the
need for mixing paddles.
[0027] In the preferred method of operation, the separation reactor
tanks are operated in a continuous mode, rather than a batch mode
that is used in conventional biodiesel manufacturing processes.
[0028] For example, the conventional biodiesel manufacturing
process employs a first stage reaction of approximately four hours
at 140.degree. to 160.degree. F., after which the glycerin reaction
product is drawn off, additional alcohol and catalyst are added,
and a second stage reaction is conducted for approximately two
additional hours, also at 140.degree. to 160.degree. F.
[0029] In the preferred mode of operation of the present invention,
the transesterification reaction is driven to completion in a
single stage within the reaction chamber, during which the reaction
product streams are continuously drawn off for the separation
processes described below. A complete conversion of triglyceride to
biodiesel is accomplished at the rate of 2 liters per minuet.
[0030] The conventional biodiesel manufacturing process relies upon
two or more distinct batch operations, whereas the system and
method of the present invention advantageously provides for
continuous removal of the glycerin as it is formed and for
reintroduction of the alcohol/catalyst mixture, where needed.
[0031] The separation component comprises one or more components
that are capable of separating the reaction products of the
transesterification reaction. In the preferred embodiment, these
separation components comprise an array of centrifuge units,
preferably three in number, connected in series. The first
centrifuge unit receives the output stream from the reactor unit,
comprising the glycerin and alkyl esters along with unreacted
alcohol. The first centrifuge unit separates the glycerin
by-product and unreacted alcohol from the alkyl esters (biodiesel).
The glycerin and alcohol are initially stored in a first holding
tank, and ultimately fed to the glycerin processing reactors to
produce the triethers of the present invention. The alkyl esters
cut from the first centrifuge unit are then fed as an input to the
second centrifuge unit, and perhaps the third as purity
demands.
[0032] The modular production unit may be made entirely energy
self-sufficient by operating a proper generator with biodiesel
produced by the modular production unit, thus allowing the modular
production unit to operate in remote locations or areas where power
service is expensive and/or unreliable.
[0033] The modular production unit is preferably incorporated onto
a single or double platform, such as a skid mount, or into a
housing, such as a shipping container, such that the system is
easily shipped or transferred to a remote site by either truck,
rail, ship, or other means of transportation, or operated in place
on a truck trailer, rail car, or ship.
[0034] In a particularly preferred form, the modular production
unit is housed in a standard ISO Intermodal Shipping Container
having dimensions of 8'.times.8'.times.40'. Thus, the components
associated with this preferred form of the modular production unit
are of a size and shape that may be accommodated within the space
limitations of the platform or housing.
[0035] Although several advantages are obtained by providing the
systems and methods described herein in a self-contained, modular
production unit, those skilled in the art will recognize that one
or more of the described system components may be provided in a
scaled up form for use in a fixed base, nonmodular configuration to
obtain the other advantages provided by those components.
[0036] In the preferred embodiment, the raw materials processing is
performed by a pair of settling tanks and a coalescing basket
filter. The preferred raw materials processing also, optionally,
includes a hot box member described in more detail below. The
preferred triglycerides feedstock is any organic fat or oil,
including virgin vegetable oils such as soy, canola or cottonseed,
as well as recycled oils, such as used fryer oil and grease trap
materials, or animal fats, such as lard or beef tallow. Many of
these materials, particularly the recycled oils, will have
impurities, including coarse particulates and water. The water
impurities may be in the form of bulk water, entrained water, or
microemulsions. The triglycerides feedstock is fed as an input to
the coalescing basket filter, where the feedstock is filtered to
remove particulates and/or water. The filtered feedstock is routed
to one of the settling tanks, where it is stored until needed as
feed to the reactor units of the modular production unit. The
settling tanks are preferably heated (e.g., to at least 120.degree.
F.) and are provided with cone-shaped bottom portions and drains to
promote settling and facilitate removal of waste and particulates.
Such waste and particulates are advantageously removed by directing
the output flow from the bottom drain through an additional
coalescing basket filter of finer mesh prior to being transferred
to the separation reactor tanks.
[0037] Additionally, the settling tanks may be optionally fitted
with one or more metering pumps for delivering acid (such as
phosphoric acid or sulfuric acid) which, in combination with heat,
assists in breaking up emulsions (particularly in grease trap
material) and facilitates the phase separation of the water and
fats/oils/greases. Once the water is drained off, additional acid
may be added to convert free fatty acids to fatty acids that can be
more easily converted into alkyl esters. The acidified
fats/oils/greases can then be reacted with alcohol as a first step
in the separation reactors (i.e. acid catalysis) followed by a
reaction with the alcohol/catalyst mixture (i.e. base catalysis) to
more efficiently produce alkyl esters from high free fatty acid
feedstocks such as grease trap materials.
[0038] The automated filter system serves as a fail-safe to prevent
flow of biodiesel product that contains greater than the maximum
amount of water desired, and preferably comprises a combination of
a salt filter, a coalescing filter, a clarification filter, and a
gel filter. In a preferred embodiment, the filtering system is
automated to sense water build up in the first stage salt dryer and
the second stage coalescing basket filter, and to sense back
pressure caused by the build up of impurities in the entire system.
In a further preferred embodiment, the third stage filters are 10
to 30 micron glass filters, and the fourth stage filters are a 10
to 2 micron gel filter composed of corn starch polymer embedded
paper elements. In a still further preferred embodiment, the entire
filtering system is designed to recirculate the biodiesel in the
settling tanks, and incorporates sight glasses and sampling valves
for obtaining biodiesel samples for testing prior to the biodiesel
being transferred to the final distribution tank. In yet another
embodiment, the filtering system is fitted with a metering system,
which allows for the introduction of additives to the biodiesel in
the necessary ratios.
[0039] This system allows for the custom blending of biodiesel with
additives to meet the specification of a variety of end users under
different climatic and operating conditions.
[0040] The interrelationship of the above components that comprise
the biodiesel processing plant are illustrated in the Figures. The
alcohol storage unit is connected by a suitable flow path to the
mixing unit contained in the modular production unit. The
triglycerides storage unit is connected by a suitable flow path to
each of the feedstock settling tanks contained in the processing
unit. The feedstock settling tanks, in turn, are connected by a
suitable flow path to the reaction chamber.
[0041] While various preferred embodiments of the invention have
been shown for purposes of illustration, it will be understood that
those skilled in the art may make modifications thereof without
departing from the true scope of the invention as set forth in the
appended claims including equivalents thereof.
* * * * *