U.S. patent application number 15/841505 was filed with the patent office on 2018-04-19 for high value organic containing fertilizers and methods of manufacture.
This patent application is currently assigned to Anuvia Plant Nutrients Corporation. The applicant listed for this patent is Anuvia Plant Nutrients Corporation. Invention is credited to Jeffrey C. Burnham, Gary L. Dahms, Barry R. Jarrett, Larry S. Murphy.
Application Number | 20180105474 15/841505 |
Document ID | / |
Family ID | 57442164 |
Filed Date | 2018-04-19 |
United States Patent
Application |
20180105474 |
Kind Code |
A1 |
Burnham; Jeffrey C. ; et
al. |
April 19, 2018 |
High Value Organic Containing Fertilizers and Methods of
Manufacture
Abstract
The invention is directed to manufacturing fertilizers having
commercial levels of nitrogen reacted with organic substances. The
process comprises treatment of organics with acid that acidifies
and heats a mix causing the hydrolysis of polymers. The acidified
organic mix is injected sequentially with a nitrogen base under
conditions that result in a partially neutralized melt. The
sterilized and liquefied organic matter is disbursed over recycled
material for production of granules in a granulator before final
drying. The process is green scalable, and safe for the location of
community organics processing facilities in locations without
generating a nuisance to local communities. Fertilizers also
provide a green, dual nitrogen-release profile when applied to
crops releasing a bolus of nitrogen over one to two weeks following
application followed by a continued slow or enhanced efficiency
release of nitrogen over a growing season.
Inventors: |
Burnham; Jeffrey C.; (Marco
Island, FL) ; Dahms; Gary L.; (Mesquite, NV) ;
Jarrett; Barry R.; (Olive Branch, MS) ; Murphy; Larry
S.; (Manhattan, KS) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Anuvia Plant Nutrients Corporation |
Zellwood |
FL |
US |
|
|
Assignee: |
Anuvia Plant Nutrients
Corporation
Zellwood
FL
|
Family ID: |
57442164 |
Appl. No.: |
15/841505 |
Filed: |
December 14, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15174491 |
Jun 6, 2016 |
9856178 |
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15841505 |
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15174491 |
Jun 6, 2016 |
9856178 |
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15174491 |
|
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62171541 |
Jun 5, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C05C 3/005 20130101;
C05G 3/00 20130101; Y02P 20/145 20151101; Y02A 40/205 20180101;
C05F 11/00 20130101; C05D 1/005 20130101; C05D 9/00 20130101; Y02A
40/20 20180101; C05D 9/02 20130101; C05G 3/60 20200201; C05G 1/00
20130101; C05C 9/02 20130101; C05F 3/00 20130101 |
International
Class: |
C05C 3/00 20060101
C05C003/00; C05D 9/02 20060101 C05D009/02; C05C 9/02 20060101
C05C009/02; C05D 1/00 20060101 C05D001/00; C05G 3/02 20060101
C05G003/02; C05G 3/00 20060101 C05G003/00; C05D 9/00 20060101
C05D009/00; C05F 3/00 20060101 C05F003/00; C05F 11/00 20060101
C05F011/00; C05G 1/00 20060101 C05G001/00 |
Claims
1. A fertilizer manufactured with a slow release nutrient profile
comprising: conditioning an amount of an organic material to a
predetermined degree of wetness forming a mixture, wherein the type
and/or amount of organic material establishes the slow release
nutrient profile of the fertilizer; transferring the mixture to a
first vessel to which is added a concentrated acid creating an
exothermic reaction, wherein the amount of acid added creates a
predetermined temperature forming a liquid mixture; agitating the
liquid mixture for a first period of time; transferring the liquid
mixture under pressure to a second vessel to which is added an
amount of anhydrous ammonium sufficient to further increase the
temperature and pressure of the liquid mixture such that the liquid
mixture contains a predetermined amount of nitrogen; agitating the
liquid mixture in the second vessel for a second period of time;
and discharging the liquid mixture from the second vessel to form
the fertilizer with the slow release nutrient profile.
2. The fertilizer of claim 1, wherein the organic material
comprises one or more of municipal biosolids, heat-dried biosolids,
pharmaceutical fermentation wastes, microbial digests of organic
products, agricultural waste products, food stuffs and digested
food stuffs, food byproducts, animal manures, digested animal
manures, organic biosolids, biosolids containing microorganisms,
wastewater plant biosolids, extracted liquid organic fractions from
municipal solid waste, animal residuals and digested animal
residuals, algae harvested from eutrophic surface water sources,
iron humates containing fulvic and/or humic acids, and combinations
thereof.
3. The fertilizer of claim 1, wherein an odor control agent is
added to the organic material.
4. The fertilizer of claim 3, wherein the odor control agent
comprises one or more of calcium ferrate, sodium ferrate, potassium
ferrate, ferrous sulfate heptahydrate, rozenite, melanterite,
ferric chloride, ferrous sulfate, ferrous sulfate monohydrate,
hydrogen peroxide, ozone and salts, derivatives and combinations
thereof.
5. The fertilizer of claim 1, wherein the slow release nutrient
profile comprises the rate, amount and/or differential of release
of one or more nutrients of the fertilizer.
6. The fertilizer of claim 5, wherein the one or more nutrients
comprise one or more of nitrogen, phosphorus, potassium, sulfur,
iron, manganese, magnesium, copper, calcium, selenium, boron, zinc
and combinations thereof.
7. The fertilizer of claim 5, wherein the one or more nutrients
comprises nitrogen, sulfur and/or phosphorous.
8. The fertilizer of claim 5, wherein the one or more nutrients are
chelated or electrostatically bound to the organic matter of the
fertilizer.
9. The fertilizer of claim 1, which, when applied to a crops,
releases nitrogen to soil at a rate slower than nitrogen release by
fertilizer containing urea as the nitrogen source.
10. The fertilizer of claim 1, which, when applied to a crops,
releases nutrients to soil at a rate slower than nitrogen release
by non-organic fertilizer.
11. The fertilizer of claim 1, in which is homogenous,
non-hydroscopic and black in color.
12. The fertilizer of claim 1, which improves soil tilth, stress
resistance of crops to heat and drought, and the micro-ecology of
soil as compared to non-organic fertilizer.
13. The fertilizer of claim 1, which has a hardness of between 4
and 9 pounds or between 6 and 8 pounds and/or a bulk density of
between 52 and 56 pounds/cubic foot.
14. The fertilizer of claim 1, which has a content of from 8-17%
nitrogen, from 0-10% phosphorus, from 0-10% potassium, from 5-20%
sulfur 5 to 20%, from 0-5% iron and from 5-20% organics.
15. The fertilizer of claim 1, which, once applied to a crop,
provides one or more nutrients to the crop sufficient for all or a
portion of a single growing season.
Description
REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 15/174,491 filed Jun. 6, 2016, which issued as U.S. Pat. No.
9,856,178 Jan. 2, 2018, which claims priority to U.S. Provisional
Application No. 62/171,541 entitled "High Value Fertilizers and
Methods of Manufacture" filed Jun. 5, 2015, the entirety of each of
which is hereby incorporated by reference.
BACKGROUND
[0002] 1. Field of the Invention
[0003] This invention is directed to methods, systems, and
processes for the manufacturing of fertilizer and the fertilizer
product manufactured by these methods. In particular, the invention
is also directed to the manufacture of fertilizers with
predetermined concentrations or absences of nitrogen, phosphate
and/or potassium.
[0004] 2. Description of the Background
[0005] The disposition of municipal organics is a huge problem in
society today. Wastewater sludge, for example, is estimated to be
produced at a rate of over 7.5 million dry metric tons annually or
roughly about 64 dry pounds of biosolids for every individual in
the United States. The term sludge has been replaced with the term
biosolid which can include all forms of municipal organic wastes
such as, for example, domestic septage, farm and factory organic
wastes that are collected or otherwise find their way to
waste-water treatment, sewer run offs, pharmaceutical wastes
including fermentation and processing wastes, microbial digests,
food wastes and food byproducts, animal manures, digested animal
manures, organic sludge, organisms and microorganisms and all
combinations thereof. Most all industrial organic wastes find their
way into municipal sludge or are otherwise disposed of in landfills
or as may be common in the particular industry. As can be
envisioned, all forms of discarded organic-containing material can
and typically do wind up in municipal sludge including
biologically-active molecules such as pharmaceuticals as well as
their metabolized products, paper, plastics, metals and most all
forms of garbage.
[0006] Wastewater biosolids are collected typically by
municipalities through existing infrastructures such as sewers and
other types of residential and industrial plumbing systems.
Collected material is sent to one or more central facilities
referred to as waste-water treatment plants. At these plants water
is separated from the solids and sent through purification
procedures for reclamation. The solids are either burned or
transported by truck for burial or used in a land application
program as a weak fertilizer. Burning or incineration and
landfilling has become more common in part because of the awareness
the dangers of unprocessed biosolids. In all biosolids are assumed
to be not only harmful chemicals but also bioactive compounds, and
pathogens. Federal, state and local regulations exist that strictly
control the handling of biosolids for the safety of both workers
and the public. But whether burned or buried, such procedures are
highly inefficient and extremely costly.
[0007] Burning destroys most of the harmful materials present in
the biosolids, but the cost in damage to the environment is always
tremendous. Incinerators have been built specifically to deal with
municipal waste. These incinerators create huge amounts of
contaminated smoke spoiling the air within hundreds of square miles
around the facility. The smoke that's emitted contains whatever
contaminants as were present in the biosolids such as metals and
other non-combustible components. Those contaminants settle onto
fields and bodies of water creating ecological nightmares around
the plants and sometimes for great distances down-wind of the
plants. Although burning can produce energy, energy production is
highly inefficient requiring huge amounts of biosolids to become
cost effective. The amount of energy produced is always small in
comparison to the amount of material incinerated. Even after
burning, large amounts of ash remain that must be removed and
disposed. As compared to the original biosolid, the ash is devoid
of any positive impact to the environment whatsoever and is simply
and unceremoniously buried. Overall burning negatively increases
the impact of biosolid disposal to the environment and for many
years into the future.
[0008] Biosolids that have been treated to some degree of
processing are classified according to federal standards
established by the United States Environmental Protection Agency as
Class A or Class B with regard to microbial safety. "Class A"
biosolids are considered free of detectable pathogens and
sufficiently safe as a fertilizer for animal or human crop usage.
Pathogens such as, for example, Salmonella sp. bacteria, fecal
coliform indicator bacteria, enteric viruses, and viable helminth
ova must be below published levels. When pathogen indicator
organisms, such as fecal coliform, can be detected in the biosolids
at levels greater than one million per gram of dried product, the
USEPA has classed such treated biosolids as "Class B" implying that
they are of a lower standard than the "Class A" treated biosolids
which must contain less than 1000 indicator organisms per gram of
dried product. Because Class B biosolids contain pathogen
indicators--and therefore potential pathogens, they are restricted
in the manner by which they can be applied to crops intended for
animal and human consumption.
[0009] The Part 503 rule (Title 40 of the Code of Federal
Regulations, Part 503, incorporated herein by reference) lists six
alternatives for treating biosolids so they can be classified in
Class A with respect to pathogens. Alternative 1 requires biosolids
to be subjected to one of four time-temperature regimes.
Alternative 2 requires that biosolids processing meets pH,
temperature and air-drying requirements. Alternative 3 requires
that when biosolids are treated in other processes, it must be
demonstrated that the process can reduce enteric viruses and viable
helminthes ova, and operating conditions used in the demonstration
after pathogen reduction demonstration is completed must be
maintained. Alternative 4 requires that when treated in unknown
processes, biosolids be tested for pathogens at the time the
biosolids are used or disposed or, in certain situations, prepared
for use or disposal. Alternative 5 requires that biosolids be
treated in one of the Processes to Further Reduce Pathogens.
Alternative 6 requires that biosolids be treated in a process
equivalent to one of the Processes to Further Reduce Pathogens, as
determined by the permitting authority.
[0010] Class A pathogen biosolids must also possess a density of
fecal coliform of less than 1,000 most probable numbers (MPN) per
gram total solids (dry-weight basis) or a density of Salmonella sp.
bacteria of less than 3 MPN per 4 grams of total solids (dry-weight
basis). Either of these two requirements must be met at one of the
following times: when the biosolids are used or disposed; when the
biosolids are prepared for sale or give-away in a bag or other
container for land application; or when the biosolids or derived
materials are prepared to meet the requirements for Exceptional
Quality biosolids.
[0011] All biosolids applied to the land must meet the ceiling
concentration for pollutants, comprising nine heavy metal
pollutants: arsenic, cadmium, chromium, copper, lead, mercury,
nickel, selenium, and zinc. If a limit for any one of these is
exceeded, the biosolids cannot be applied to the land without the
incorporation of significant restrictions. Exceptional Quality (EQ)
is a term used by the USEPA Guide Part 503 Rule 7 to characterize
biosolids that meet low-pollutant and Class A pathogen reduction
(virtual absence of pathogens) limits and that have a reduced level
of degradable compounds that attract vectors. Achievement of the EQ
standards is an important goal for high quality products that
contain an biosolids organic material. Biosolids that are merely
dried have several disadvantages for agricultural use.
[0012] Biosolids have a low fertilization value, typically having
nitrogen content of only about two to six percent. Volume is large
and costs per unit of nitrogen are high. The heat-dried biosolids
often have a disagreeable odor, particularly when moist. Also,
dried pellets have low density and hardness and when blended with
other commercial fertilizer materials, the pellets may segregate,
and disintegrate and may not spread on the field uniformly with
other more dense ingredients. The disagreeable odor associated with
the use of biosolids, unless adequately treated, will continue to
be present during further processing of a nitrogen rich fertilizer
product, and can continue to be present in the final product. This
complicates the placement of suitable fertilizer processing plants
to locations that are not in close proximity to residential
communities. Additionally, the longer distance that biosolids must
be transported adds to the cost and logistics of disposing of this
waste product. Another disadvantage to current biosolids-enhanced
fertilizers is that bacterial action may continue when the material
becomes moist, and under storage conditions, the material's
temperature may rise to the point of auto-ignition via oxidation of
contained organic materials. Hence, except for special markets that
value its organic content for soil amendment or filler in blended
fertilizer, there is relatively poor demand for the heat-dried
biosolids product. In many cases municipalities must pay freight
charges, or may offer other incentives for commercial growers to
use the material. However, this is frequently still more economical
than alternative disposal schemes.
[0013] The market value for agricultural fertilizers is principally
based on their nitrogen and sulfur content. A need exists for a
practical, safe and economic method for increasing the nitrogen and
sulfur content of biosolids to a level approaching that of
commercial mineral fertilizers, e.g., eight to twenty percent for
nitrogen. If such a municipal organics containing fertilizer could
be manufactured, then the overall value of the product and demand
for the product would likely increase. Moreover, a properly
manufactured organic-containing fertilizer will have an advantage
in that much of its nitrogen will be of the slow-release type. A
slow-release or controlled release fertilizer or Enhanced
Efficiency Fertilizer ("EEF") is one in which the nutrient, e.g.,
nitrogen as in ammonium ions, phosphorus as phosphate and/or sulfur
as sulfate, becomes available in the soil column at rates slower
than fast-available nutrients as from traditional fertilizers such
as urea, ammonium sulfate and diammonium phosphate. This slower
action and/or prolonged availability of the nutrient in the soil
column is very desirable and provides nutrients to the plant
throughout the plant growing cycle with the implication that less
nitrogen needs to be applied to the soil or crop thereby reducing
the potential of environmental contamination and reducing the cost
of fertilizer usage. Further, slow-release fertilizers are much
greener than traditional inorganic fertilizers. For example,
slow-release fertilizers not only provide nutrients to plants over
much of their productive crop cycle they also retain more of the
contained nutrients in the soil column thereby avoiding loss of the
nutrients via leaching into the ground water. The more advantageous
slow-release fertilizers further, do not volatize their contained
nutrients, especially nitrogen, into the environment upon
application to the soil environment. Traditional inorganic
manufactured slow release nitrogen fertilizers have a price many
times that of ordinary mineral nitrogen fertilizers. Under the
scenario of high nitrogen biosolids-containing fertilizer
production from their biosolids, municipalities would enjoy public
and regulatory support for their biosolids disposition program.
Such a program would ensure the regular removal of their dewatered
or dried biosolids, for example, by recycling biosolids into a high
nitrogen fertilizer which then can be sold directly into the mature
national fertilizer distribution industry, thereby eliminating one
of the major problems traditionally associated with biosolids
treatment programs.
[0014] Prior attempts have been made to reach some of these
objectives. U.S. Pat. Nos. 3,942,970, 3,655,395, 3,939,280,
4,304,588, and 4,519,831 describe processes for converting sewage
biosolids to fertilizer. In each of these processes a
urea/formaldehyde condensation product is formed in situ with the
biosolids. Thus, the processes require the handling of
formaldehyde, a highly toxic lachrymator and suspected
cancer-causing agent.
[0015] Other processes require costly process equipment and/or
special conditions not readily incorporated in existing sewage
treatment facilities (see, Japanese Patent No. 58032638; French
Patent No. 2,757,504).
[0016] A simple method for increasing the nitrogen in biosolids
would be to blend commercial nitrogen fertilizer materials to the
wet biosolids prior to drying and pelletizing. There are
significant disadvantages to such a strategy. There are only a few
high-nitrogen fertilizer materials that are economical for use in
agriculture. Examples include: ammonia (82 wt. percent N), urea (46
wt. percent N--{nitrogen}), and ammonium nitrate (33.54 wt. percent
N). Ammonia has high volatility and is subject to strict regulation
of discharges to the atmosphere. Urea is a solid that adsorbs
moisture quite readily and makes the mixed organic more difficult
to dry. Urea is also highly susceptible to breakdown to ammonia by
the microbes and enzymes in biosolids and the soil if they are not
properly prepared, resulting in nitrogen loss and an odor problem.
Ammonium nitrate is a strong oxidizer and can result in a potential
explosion problem which has all but eliminated this fertilizer from
the commercial market after 2001. All of these fertilizers have
high nitrogen content, but are less than ideal for combining with
municipal organics such as biosolids or food waste absent special
processing.
[0017] Other references, such as European Patent No. 0143392,
Japanese Patent No. 9110570 A2, and "Granulation of Compost from
Sewage Sludge. V. Reduction of Ammonia Emission from Drying
Process", Hokkaidoritsu Kogyo Shikenjo Hokoku, 287, 85-89 (1988)
fail to disclose the use of acids with ammonium sulfate additions
and do not discuss the issue of corrosion of steel process
equipment under acid conditions.
[0018] Over the past thirty years, alkaline stabilization of
biosolids has been a standard and successful method of making
biosolids into beneficially useful materials that can be used
principally as soil-conditioning materials. Because these alkaline
stabilized biosolids products have high calcium carbonate
equivalencies, they have been produced and marketed as Agricultural
liming or Ag-lime materials, usually as a replacement for calcium
carbonate in farm soil management strategies. Because of this
usage, the value of these materials has been restricted to only a
few dollars per ton of product. However, transportation costs are
high in large part due to the significant water content of the
finished material. Amounts of water up to fifty or sixty percent
render transportation economically and geographically restricted to
areas close to the source of their treatment.
[0019] Thus, there is a long standing need for practical means of
increasing the economic value of municipal organic materials
through increasing its nitrogen content, and increasing the ability
to be spread as well as a need to treat these materials such that
they are converted into commodity and specialty fertilizers with
physical and chemical and nutrient properties such that they can
command significant value in the national and international
commodity fertilizer marketplace. A series of U.S. patents, U.S.
Pat. Nos. 5,984,992; 6,159,263; 6,758,879 and 7,128,880 describe
methods of production of high nitrogen organically-enhanced
ammonium sulfate fertilizers made with biosolids utilizing a
pipe-cross reactor as originated by the Tennessee Valley Authority
(TVA). The pipe, tee and pipe-cross reactor are defined by the
International Fertilizer Development Center (IFDC) in the IFDC
Fertilizer Manual (1998), p 440 as: "the pipe reactor consists
basically of a length of corrosion-resistant pipe (about 5-15 m
long) to which phosphoric acid, ammonia and often water are
simultaneously added to one end through a piping configuration
resembling a tee, thus the name `tee reactor.`" The tee reactor was
modified by TVA to also accept an additional flow of sulfuric acid
through another pipe inlet located opposite the phosphoric acid
inlet, giving the unit a "cross" configuration and thus the name
"pipe-cross reactor".
[0020] Both the IFDC Fertilizer Manual (1998) and the Fertilizer
Technical Data Book (2000) refer to the pipe-cross reactors.
Pipe-cross reactors deliver a concentrated mix to the granulator
shaping device and more efficiently evaporate undesired water from
the fertilizer mix than other devices, but these references
demonstrate a long-felt need for improvement, indicating that one
of the shortcomings of the pipe-cross reactor is scale formation
inside the pipe which can result in clogging.
[0021] The methodologies taught by this group of patents (U.S. Pat.
Nos. 5,984,992; 6,159,263; 6,758,879 and 7,128,880) are plagued by
problems related to the pluggage of these narrow (relative to their
length) "pipe-cross" reactor configurations, the very short
duration of reaction time in such "pipe-cross" reactors and the
difficulty of control of the reaction temperature and pressure and
retention time of the mix within such pipe-cross reactors. These
pipe-cross reactors are narrow in contrast to their length, e.g.,
up to six to eight inches in diameter and often fifteen feet in
length or longer. The plant practicing the manufacture of
organically-enhanced ammonium sulfate fertilizers often had to shut
down and disassemble the pipe-cross reactor either due to blockage
from biosolids buildup or from destructive over heating in such
reactors such that the commonly used Teflon.RTM. coating on the
interior-reaction side of the reactor was melted and ruined.
Further, the use of the pipe-cross reactor has the distinct
disadvantage of having very short reactor retention times (usually
less than twenty seconds) which is an advantage in the manufacture
of traditional fertilizers like ammonium sulfate but is a
disadvantage when coupled to the simultaneous processing of
biosolids. Such short processing time increases the probability of
untreated or non-homogenous mixing as the three material inputs
pass through this reactor. Also limiting is the lack of control
over the atmospheric pressure within such pipe-cross reactors since
these reactors have open-ended discharges usually directly into a
granulator. Related to but distinct from the lack of control of
internal pressures, pipe-cross reactors also have little to no
temperature control over the mix passing through the reactor.
[0022] U.S. Pat. No. 4,743,287 to Robinson describes a method to
use two reaction vessels in sequence to incorporate organic
biosolids into nitrogen fertilizers of low or medium nitrogen
concentration (a range of four weight-percent nitrogen to a maximum
of nitrogen concentration of ten weight-percent). Robinson uses his
first reaction vessel to achieve very low pH values of the mixture
(pH 0.2 to 1.5) to achieve hydrolysis of molecules present and to
prepare the mix for reaction in a second reaction vessel. Robinson
does indicate that a single reactor can be used, but only in a
batch configuration and not in a continuous flow manufacturing
method. Robinson also indicates that the acid and ammonia may not
be injected in any order, but must be injected in sequence. This
patent describes the reaction vessels capable of achieving high
pressures (30 psig) with relatively long retention times as
compared to the pipe-cross reactors. However, Robinson fails to
meet the need for a novel and practical continuous flow method of
manufacturing high nitrogen (greater than 8 wt. percent nitrogen)
and biosolids-containing fertilizer products under the advantages
of defined temperatures, pressures and reaction retention
times.
[0023] Thus, an urgent need exists for an effective, efficient, and
economical process for treating biosolids. In addition, there
exists an urgent need for a variety of fertilizers that can be
specifically tailored for a particular crop such that the nutrients
provided by the fertilizer follow the nutrient needs of the crops
during a particular period or even a growing season.
SUMMARY OF THE INVENTION
[0024] The present invention overcomes the problems and
disadvantages associated with current strategies and designs, and
provides new tools and methods for the manufacture of
fertilizers.
[0025] One embodiment of the invention is directed to methods for
manufacture of a fertilizer with a predetermined nutrient release
profile comprising: conditioning an amount of an organic material
to a predetermined degree of wetness, wherein the type and/or
amount of organic material establishes the slow release nutrient
profile of the fertilizer; adding an odor control agent to the
conditioned organic material to form a mixture; transferring the
mixture to a first vessel to which is added a concentrated acid
creating an exothermic reaction, wherein the amount of acid added
creates a predetermined temperature forming a liquid mixture;
agitating the acidified mixture for a first period of time;
transferring the liquid mixture under pressure to a second vessel
to which is added an amount of anhydrous ammonium sufficient to
further increase the temperature and pressure of the liquid mixture
such that the liquid mixture contains a predetermined amount of
nitrogen; agitating the liquid mixture in the second vessel for a
second period of time; and discharging the liquid mixture from the
second vessel to form the fertilizer with a predetermined slow
release profile of nitrogen, sulfur and/or phosphorous. Preferably
the nutrient release profile is a profile of the release of one or
more of nitrogen, phosphorous, potassium, sulfur, iron, organics
and combinations thereof, and can generally matche the growth needs
of a particular crop for the one or more of nitrogen, phosphorous,
potassium, sulfur, iron, organics and combinations thereof.
Preferably the nutrient release profile comprises the rate, amount
and/or differential of release of one or more nutrients of the
fertilizer. Preferably organic material comprises one or more of
municipal biosolids, heat-dried biosolids, pharmaceutical
fermentation wastes, microbial digests of organic products,
agricultural waste products, food stuffs and digested food stuffs,
food byproducts, animal manures, digested animal manures, organic
biosolids, biosolids containing microorganisms, wastewater plant
biosolids, extracted liquid organic fractions from municipal solid
waste, animal residuals and digested animal residuals, algae
harvested from eutrophic surface water sources, iron humates
containing fulvic and/or humic acids, and combinations thereof, and
also that plastic and hair that may be present do not require
removal before processing because they are liquified. Preferably
additional ingredients are adding such as, for example, zinc
sulfate and/or soluble forms of boron, nutrients, peptides,
vitamins, polypeptides, amino acids, saccharides, polysaccharides,
herbicides and/or pesticides to the organic material, the mixture
and/or the liquid mixture. In addition, one or more agents that
create and/or reduce that electrostatic state of the organic
material can be added to the organic material, the mixture and/or
the liquid mixture. Such agents include, but are not limited to one
or more of anionic and cationic chemicals, chelating agents, ionic
sequestering agents, metal ions, citric acid, amino acids, glutamic
acid, histidine, lysine, glycine, peptides, proteins, sugars,
saccharides and polysaccharides, iron, sulfur, phosphorous and
nitrogen-binding compounds and combinations thereof. Preferably the
predetermined degree of wetness comprises a percent solids of from
15-30%, and also preferably the aqueous liquid removed from the
organic material is recycled. Preferably the odor control agent
comprises one or more of calcium ferrate, sodium ferrate, potassium
ferrate, ferrous sulfate heptahydrate, rozenite, melanterite,
ferric chloride, ferrous sulfate, ferrous sulfate monohydrate,
hydrogen peroxide, ozone and salts, derivatives and combinations
thereof. Preferably the concentrated acid comprises sulfuric acid
or phosphoric acid concentrated at 90% or greater, the amount of
acid creates a temperature of 100.degree. C. or greater, the first
period of time is from 2-20 minutes, the second vessel has a
pressure of 2 atmospheres or greater and a temperature of
120.degree. C. or greater, the second period of time is 5 minutes
or greater, and discharging comprises coating the liquid fertilizer
onto recycled fertilizer granules (an alternative embodiment can be
wherein the first and second vessels may be at or near ambient
pressures). Preferably the liquid mixture has a viscosity of 2,000
cP or less that increases after addition of anhydrous ammonium.
Also preferably the coated recycled fertilizer granules are dried
to a solids content of 98% or greater. Preferably a hardening agent
is added to the fertilizer such as, for example, ligno-sulfonate,
molasses, alum or a combination thereof or no hardening agent is
utilized.
[0026] Preferably the fertilizer is formed into granules and
granules are selecting granules by size. Preferably granules
between 0.5 and 4 mm and selected, and granules that are of greater
than 4 mm are crushed and combined with granules that are of less
than 0.5 mm and comprise recycled fertilizer granules. Preferably
the predetermined amount of ammonium is that amount which creates
5% or greater of nitrogen in the fertilizer.
[0027] Another embodiment of the invention is directed to
fertilizer made by the methods of the invention. Preferably
fertilizers, when applied to a crops, release nitrogen and other
nutrients to soil at a rate slower than nitrogen release by
inorganic fertilizers containing the same nutrients such as urea as
a nitrogen source. Preferably the nutrients comprise one or more of
nitrogen, phosphorus, potassium, sulfur, iron, manganese,
magnesium, copper, calcium, selenium, boron, zinc and combinations
thereof, and also preferably are chelated or electrostatically
bound to the organic matter of the fertilizer. Preferably the
fertilizers are homogenous in composition, non-hydroscopic and
black or otherwise very dark in color. Preferably the fertilizers
improve soil tilth, stress resistance of crops to heat and drought,
and the micro-ecology of soil as compared to non-organic
fertilizers. Also preferably, fertilizers of the invention have a
hardness of between 4 and 9 pounds, more desirably between 6 and 8
pounds and/or a bulk density of between 52 and 56 pounds/cubic
foot, and from 8-17% nitrogen, from 0-10% phosphorus, from 0-10%
potassium, from 5-20% sulfur 5 to 20%, from 0-5% iron and from
5-20% organics. Also preferably, fertilizers, once applied to a
crop, provide one or more nutrients to the crop sufficient for all
or a portion of a single growing season.
[0028] Another embodiment of the invention is directed to methods
for manufacture of a fertilizer comprising: providing an organic
material that preferably contains municipal organics wherein the
organic material has a solids content of at least eight percent;
optionally adding an odor control agent to the organic material to
create a mixture; adding an acid to the mixture under a first
pressure and elevated temperature for a first period of time
forming a liquefied mixture; adding ammonia to the liquefied
mixture under a second pressure and elevated temperature for a
second period of time; and processing the liquefied mixture to form
the fertilizer. The phrase organic material includes all biosolids,
but is not limited to biosolids such as organic biosolids,
biosolids containing microorganisms, municipal biosolids or
heat-dried biosolids, and also includes pharmaceutical and
laboratory processing and fermentation wastes, farm and
agricultural wastes, decayed and digested organic materials, mined
humates and fulvic and humic acids, harvested plants including
farmed crop materials such as roughage and silage of corn and
soybean plants as well as wheat, rice and barley plants, algae and
cyanobacteria that may be harvested from ponds and other bodies of
water, bacteria, mold and fungi, industrial wastes and their
by-products, microbial, chemical and enzymatic digests of organic
products, plant and animal foods, food stuffs, and byproducts,
recycled fertilizers, and all combinations thereof. An element of
the invention is that the organic material that contains plastic
and hair and similar material does not need to be removed prior to
processing. Preferably, the organic material is dewatered or
hydrated to a solids content of between 14 and 40 percent, more
preferably the organic material has a percent dryness of about 22
percent plus or minus 5 percent. Also, a portion of the organic
material may be dewatered to a dryness greater than 70 or 85
percent, and blended with the remaining portion of the organic
material to achieve a desired percent dryness. Preferably, the
organic material is hydrated with process water recovered from one
or more steps of the method to minimize or prevent any loss of
nutrient-containing water.
[0029] Optionally, odor control agents may be added to the organic
material. Preferred odor control agents include, but are not
limited to one or more of calcium ferrate, sodium ferrate,
potassium ferrate, ferrous sulfate heptahydrate, rozenite,
melanterite, ferric chloride, ferrous sulfate, ferrous sulfate
monohydrate, ferrous sulfate heptahydrate, ferric humate, hydrogen
peroxide, ozone and salts, derivatives and combinations thereof, as
well as various salts thereof. Preferably, the mixture of the
organic material with the odor control agent forms a thixotropic
mixture. The mixture may be optionally heated prior to the addition
of acid, which is useful in climates where the organics are
maintained at about 4.degree. C. (about 40.degree. F.). Also
preferably, process heating is performed in a first pressure vessel
and the first pressure is maintained at between 20 and 60 psig, the
first temperature is between 66.degree. C. (150.degree. F.) and
12720 C. (260.degree. F.), and the first period of time is between
2 minutes and 30 minutes. More preferably, the first temperature
may be between 93.degree. C. (200.degree. F.) and 121.degree. C.
(250.degree. F.) and the first period of time may be between 5
minutes and 10 minutes. Preferably the viscosity of the acidified
and heated mixture is about 1000 cP or less. The acid added to the
mixture is preferably a phosphoric acid, a sulfuric acid, or a
combination thereof. After acidification, the liquefied mixture is
transferred to a second pressure vessel and, preferably, ammonia is
heated under pressure to form a gas prior to being added to the
liquefied mixture. The preferred second temperature in the second
pressure vessel is between 121.degree. C. (250.degree. F.) and
199.degree. C. (390.degree. F.), the preferred second period of
time is between 1 minute and 30 minutes, and the preferred pressure
within the second pressure vessel is maintained at between 30 and
150 psig. The viscosity of the ammoniated mixture is preferably
about 1,200 cP or less. Processing of liquefied mixture comprises
forming the usable fertilizer. Preferably, the processing comprises
drying the combination to a solids content of greater than 92
percent, or more preferably to a solids content is at least 98
percent. One or more hardening agents may be added during
processing such as, for example, ligno-sulfonate, molasses, alum or
a combination thereof. Preferably processing is performed in a
granulator to form granules and the granules are sized and granules
of between 0.5 and 4 mm selected. Preferably, granules of greater
than 4 mm are further crushed, and combined with granules of less
than 0.5 mm and both are added during processing. An element of the
invention is that each step of the method can be performed in a
continuous process without interruption, although batch processing
is also possible. The processes of the invention preferably also
comprise a dust control system that collects and recycles dust
material created from the processing.
[0030] Another embodiment of the invention is directed to
fertilizer manufactured by the methods of the invention.
Fertilizers will typically contain hydrolyzed polymers of one or
more of plastics, pharmaceutical compounds, antibiotics, hormones,
hormone-like molecules, biologically active compounds,
macromolecules, carbohydrates, nucleic acids, fats, lipids,
proteins, and microorganisms that are present in the biosolids.
Preferably the hydrolyzed polymers are various chain length
polypeptides and amino acids, most of which are not destroyed
during the method of processing, that supplement and substantially
increase the value of the fertilizer. Preferably, fertilizer of the
invention has a nitrogen content of between 6 and 20 percent, a
phosphate content of between 0 and 10 percent, a potassium content
of between 0 and 5 percent, a sulfur content of between 9 and 25
percent, an iron content of between 0 and 10 percent, and an
organic content of between 4 and 30 percent. Also preferably, the
fertilizer has no or almost no unpleasant or disagreeable
odors.
[0031] Another embodiment of the invention is directed to processes
for manufacture of a fertilizer with a predetermined content of one
or more of nitrogen, phosphate and potassium comprising: providing
an organic material containing biosolids wherein the organic
material has a solids content of at least eight percent; optionally
adding an odor control agent to the organic material to create a
mixture; adding an amount of a predetermined acid to the mixture,
thereby creating an exothermic heat-of-hydration reaction and
forming a liquefied mixture; adding a predetermined amount of
ammonia to the liquefied mixture under a pressure and heating the
mixture to a second temperature for a second period of time,
wherein the amount of ammonia added is determined from the
composition of the organic material and the amount of acid
contained; and processing the liquefied mixture to form the
fertilizer with a determined pH that is soil and crop compatible
with predetermined content of one or more of nitrogen, phosphate,
potassium and sulfur. The process of the invention may optionally
further comprise adding one or more plant nutrients to during
processing. Such plant nutrients that can be added include, but are
not limited to one or more of urea, ammonium nitrate, ammonium
sulfate, monoammonium phosphate, diammonium phosphate, urea
ammonium nitrate, liquid urea, potash, iron oxide, soluble iron,
chelated iron and combinations thereof. The process preferably
further comprises adding and one or more hardening agents during
processing such as, for example, ferric oxides, alum attapulgite
clay, industrial molasses, lignin, ligno sulfonate, urea
formaldehyde polymerizer and combinations thereof. The process may
also be performed without a hardening agent such as, for example,
when the granules produced are of acceptable hardness for use.
[0032] Another embodiment of the invention is directed to systems
for the manufacture of a fertilizer comprising: a mixer that blends
municipal organics with an odor control agent; a first reaction or
pressure vessel wherein the blended organic materials are mixed
with an acid and heated to a first predetermined temperature and
pressurized to a first predetermined pressure for a period of time
forming a liquid; a second reaction or pressure vessel wherein the
liquid is mixed with ammonia from an ammonia source and heated to a
second predetermined temperature and pressurized to a second
predetermined pressure for a second period of time; and a rotary
granulator wherein the ammoniated liquid is mixed with preformed
granules to form dried granules of the fertilizer. Preferably the
ammonia source is liquefied or gaseous ammonia under pressure and
the first and second reaction or pressure vessels each contain an
agitator. The systems may also include a screening process to
select product sized fertilizer granules, and one or more of a
cooling and coating apparatus to reduce temperature and control
dust prior to storage. Optionally, the cooler may include an ozone
generator that provides ozone to the cooling fertilizer to
eliminate or at least substantially reduce remaining disagreeable
odors. Preferably, systems also comprise a conveyer for
transporting municipal organics to the mixer and another conveyer
for transporting the blended organics to the first reaction or
pressure vessel; a pressurized piping system that transports
acidified biosolids from the first reaction or pressure vessel to
the second reaction or pressure vessel, ammonia into the second
reaction or pressure vessel; and disperses the ammoniated liquid,
usually as a spray, into the granulator. Preferred systems further
comprise one or more screens for selecting granules of a
predetermined size and a rotary cooler for cooling and polishing
the sized granules, and both a dust control apparatus that collects
and recycles dust from the granulator and a water recovery system
whereby water extracted from biosolids during processing is
recovered and recycled. In certain embodiments, the first and/or
second reaction or pressure vessel may be a pipe-cross reactor, or
both reaction and pressure vessels are pipe-cross reactors. The
process may be performed as a continuous or batch process.
[0033] Another embodiment of the invention is directed to methods
for manufacture of a product comprising: providing an organic
material wherein the organic material has a solids content of at
least eight percent; adding an acid to the organic material under
an elevated temperature for a first period of time forming a
liquefied mixture; adding ammonia to the liquefied mixture under a
pressure and elevated temperature for a second period of time; and
processing the liquefied mixture to form the fertilizer. Preferably
the organic material is plant or bacterial material and or food or
digested food material, also preferably, the plant or bacterial
material is algae, bacteria, fungi or a combination thereof.
Preferably there are toxic materials present in the organic
materials that are hydrolyzed or otherwise rendered nontoxic or
inactivated by the process of the invention. Preferably there may
be only ambient pressure in the first vessel when the elevated
temperature is between 66.degree. C. (150.degree. F.) and
127.degree. C. (260.degree. F.) and the first period of time is
between 2 minutes and 30 minutes. Also preferably, the second
pressure and elevated temperature for a second period of time are,
respectively, between 30 and 150 psig and between 121.degree. C.
(250.degree. F.) and 204.degree. C. (400.degree. F.), between 1
minute and 30 minutes. Preferably the product is a fertilizer.
[0034] Another embodiment of the invention is directed to
fertilizer manufactured by the methods of the invention.
Preferably, fertilizers of the invention have both fast and slow
nitrogen release profiles so that a percentage of available
nitrogen is released to the soil within 0 to 14 days upon
application of the fertilizer, preferably from 10 percent to 70
percent, and a second, slower release representing about 30 percent
to 90 percent of the available nitrogen content of the fertilizer
releases into the soil over a period of 2 weeks to 4 months
following application. Preferably, nitrogen release is timed to
match the needs of the growing crops or plants.
[0035] Other embodiments and advantages of the invention are set
forth in part in the description, which follows, and in part, may
be obvious from this description, or may be learned from the
practice of the invention.
DESCRIPTION OF THE FIGURES
[0036] FIGS. 1A-C. Fertilizer Plant Flow Chart of one embodiment of
the Invention illustrated from: unloading of municipal organics
(FIG. 1A); to the reactor (FIG. 1B); and to drying (FIG. 1C).
[0037] FIGS. 2A-C. Fertilizer Plant Flow Chart of another
embodiment of the Invention illustrated from: unloading of
municipal organics (FIG. 2A); to the reactor (FIG. 2B); and to
drying (FIG. 2C).
[0038] FIG. 3. Schematic of a modified Ammonium Sulfate Process of
one embodiment of the invention.
[0039] FIG. 4. Physical and chemical characteristics of organically
modified ammonium sulfate fertilizer of one embodiment of the
invention.
[0040] FIG. 5. The organic matrix provided by the invention showing
a variation of binding abilities.
[0041] FIG. 6. Nitrogen release curve showing percent nitrogen
released into soil over number of days for ammonium sulfate (AS),
organically-modified ammonium sulfate of the invention (Anuvia),
and conventional biomass (MILORGANITE).
[0042] FIG. 7. Academic nitrogen release curve of plants fertilized
with ammonium sulfate, organically-modified ammonium sulfate of the
invention, and biosolids showing percent nitrogen released into
soil over number of weeks.
[0043] FIG. 8. Soil nitrogen leaching in tomato culture as
influenced by nitrogen source.
[0044] FIGS. 9 (A-C). Controlled condition nitrification study
results using Anuvia product (FIG. 9A), using urea (FIG. 9B), and
using urea plus agrotain (FIG. 9C).
[0045] FIG. 10. Effects of treatment of endocrine disrupting
chemicals (EDC) seeded into biosolids.
[0046] FIG. 11. Graph showing percent nitrogen releases over time
for selected materials.
DESCRIPTION OF THE INVENTION
[0047] All countries and population regions around the world create
waste in the form of organic materials. The phrase organic material
includes, but is not limited to biosolids such as organic
biosolids, biosolids containing microorganisms, municipal biosolids
and heat-dried biosolids, and also includes pharmaceutical and
laboratory processing and fermentation wastes, farm and
agricultural wastes, decayed and digested organic materials,
harvested plant and plant-like materials such as algae including
blue/green algae, bacteria including blue/green bacteria,
cyanobacteria (e.g., blue/green, rust, black), mold and fungi,
humates, humic acids and fulvic acids, industrial wastes and their
by-products, microbial, chemical and enzymatic digests of organic
products, plant and animal foods, food stuffs, and byproducts,
animal manures, digested and processed animal manures, recycled
fertilizers, and all combinations thereof. Disposal of organic
waste materials pose a major problem as well as expense to all
communities. Traditional disposal methods involve burial, burial at
sea or incineration. Each of these options compounds the problem by
creating untenable amounts of pollution that foul the community as
well as the planet. New techniques have been developed that involve
heat treatment to inactivate microorganisms and other potentially
contaminants that can result in a product that can be as a low
value fertilizer. Although these techniques are ecologically sound,
they have not caught on because, in large part, the product is of
such low value that there is little to no commercial incentive for
communities to switch from the traditional bury and burn
philosophy, and no funds that allow for the creation of safe
processing facilities.
[0048] It has been surprisingly discovered that high-value
fertilizers with specific and predetermined release profiles of one
or more nutrients can be efficiently manufactured from organic
materials, including but not limited to raw and semi-processed
organic materials such as biosolids, agricultural materials and
industrial wastes. Such fertilizers can be specifically tailored to
crops so that the release profile of the fertilizer matches the
needs that arise during the growth and development of the
particular crop. In addition, the process of the invention destroys
not only all potentially harmful microorganisms, but hydrolyzes
many polymers including forms of biopolymers (e.g., DNA, proteins,
carbohydrates, toxins, antibiotics, hormones, etc.), forms of
composite materials, and even forms of plastics. The resulting
fertilizer product is of high value and also contains the
hydrolyzed monomers (e.g. amino acids, sugars, etc.) that are
beneficial and desirable for a fertilizer.
[0049] The process of the invention allows for the production of
fertilizers with pre-selected release profiles that can be tailored
for specific crops. It was unexpectedly discovered that the
nutrient content of the organic material selected is not
determinative of the release profile. In other words, a fertilizer
that consists mostly of algae as the organic matter, which is
relatively high in nitrogen, will not have nitrogen release profile
that's significantly different from a fertilizer made from organic
material with a low nitrogen content. What was discovered in that
the release profile is determined by the electrostatic state or
condition of the organic material (see FIG. 5). Organic material
that has a greater ability to bind and hold, for example ferrous
iron, when processed according to the invention will have a
specific release profile for ferrous iron. Similarly, organic
material that has a greater ability to bind and hold, for example
nitrogen, when processed according to the invention will have a
specific release profile for nitrogen. In other words, the amount
and type of organic materials can be manipulated in processing
according to the invention to pre-determine the release profile of
the fertilizer. Thus, fertilizers can be created with nutrient
release profiles that closely or exactly match the nutrient needs
of the particular plant or crop. The availability of specific
nutrients can determine one or more growth characteristics of a
plant. For example, making a certain nutrient or combination of
nutrients more or less available to a plant during various aspects
of a growth cycle can shift growth to more or less seeds, to more
or less flowers, to larger or smaller leaves, fruits or overall
biomass, or various combinations thereof. The growth
characteristics of various plants are well known to those of
ordinary skill in the art, and the fertilizer can be matched to the
particular grown characteristics desired.
[0050] In addition, it also was surprisingly discovered that the
release profile of the organic material can be altered by the
combination of different organic materials and/or the addition of
one or more agents that create and/or reduce that electrostatic
state of the organic material. Various such agents include, for
example, anionic and cationic chemicals, chelating agents (e.g.,
EDTA, EGTA), ionic sequestering agents, metal ions, citric acid,
amino acids (e.g., glutamic acid, histidine, lysine, glycine),
peptides, proteins, sugars, saccharides and polysaccharides, iron,
sulfur, phosphorous and nitrogen-binding compounds, and other
chemical and chemical compounds well known to those of ordinary
skill in the art. The rate, amount and/or type of fertilizer
component released includes, but is not limited to the components
of nitrogen, phosphorous, potassium, sulfur, iron, organics and
combinations thereof. The electrostatic state of large collections
of different organic matter was surprisingly consistent, although
difference may exist between types. The electrostatic state of
organic materials is known or easily determined by those of
ordinary skill. Nevertheless, procedures for determining the
electrostatic state of a particular organic material or collection
can be determined using commercially available equipment by those
of ordinary skill in the art. As discussed herein, those difference
can be utilized by the methods of the invention.
[0051] Thus, fertilizers can be manufactured for all or parts of a
growing season for any particular crop. With a nutrient release
profile that matches the entire growing season of a specific crop,
fertilizer of the invention only needs to be applied once. If
nutrient requirements change over one growing season, two or more
fertilizers of the invention can be applied at the appropriate
times during growth and development of the crop. As the nutrient
requirements of agricultural crops are very well known, one of
ordinary skill in the art need only preselect, according to the
invention, desired nutrient release profiles into the
fertilizer.
[0052] The present invention allows for the generation of an
ecologically and financially circular economy. This occurs
ecologically when organics in the terms of food from the farm are
consumed by society, organic wastes are created and successfully
incorporated into a high nutrient fertilizer and returned to the
farm to benefit soil health. This is accomplished financially when
manufacture the fertilizer causes funds to be paid to the community
businesses for the chemical inputs to create the said fertilizer.
Once the fertilizer is manufactured it is sold back to community
farms to create the soil nutrient environment necessary for optimum
crop production.
[0053] One embodiment of the invention is directed to methods for
the manufacture of a fertilizer with a predetermined release
profile of one or more nutrients. The release profile may comprise
the amount, rate and/or differential level of release of one or
more of the nutrients of the fertilizer. A schematic of the general
process of the invention is depicted by FIG. 3. The method
comprises providing an organic material which may contain biosolids
or another organic material to which, optionally, is added an odor
control agent, that itself can be utilized as an important plant
nutrient in the final fertilizer product, to reduce or eliminate
odors that may be present from the organic material or other
components of the starting materials. The organic material and/or
mixture optionally may be heated. Heating is often needed in
environments where the climate temperature is below 10.degree. C.
such as below 4.degree. C. The resulting mixture, which may contain
added water recycled from other steps of the method, is preferably
thoroughly mixed. To this mixed material is added an acid that
reacts exothermically with the organic material and the water that
it is suspended in resulting in increases in both temperature and
pressure (when mixture is contained in a pressure tight reaction
vessel). The temperature increase desired may be determined by the
amount and concentration of the particular acid selected and/or
period of incubation. During this time, preferably two to ten
minutes, the components are mostly or entirely liquefied. One of
ordinary skill in the art can determine the time necessary for
mixing and the mixing intensity with more vigorous mixing for a
short time, or less vigorous for longer times. To the heated
liquefied material, which is transferred, preferably under
pressure, to a second pressure vessel, is added ammonia, which is
preferably also liquefied or vaporized and also under pressure, and
the subsequent reaction with the acid component of the mixture
serves to further increase temperature and pressure. The ammoniated
and liquefied biosolids are maintained for a short period of time
under these conditions, preferably two to ten minutes, and then
processed, preferably into granules of fertilizer. This embodiment
may also be accomplished, less efficiently, but sufficient to form
a fertilizer melt, if the acidified mix is transferred to a second
vessel which is maintained at ambient pressure conditions during
addition of the ammonia.
[0054] The ammoniation reaction may be carried out to completion
whereby all or nearly all of the acid is reacted such that the
result is a fluid with a viscosity of less than 1200 cP in the form
of a fertilizer melt. The combination of acid and ammonia creates a
salt melt (a partially ammoniated mix) (e.g. with sulfuric acid the
salt produced is ammonium sulfate) which retains fluidity to permit
dispersing, such as for example spraying, into a granulator that
may contain recycled fertilizer material. Preferably, upon
ammoniation salt to melt ratios are about 20/80, about 25/75, about
30/70, about 35/65, about 40/60, about 45/55, about 50/50, about
55/45, about 60/40, about 65/35, about 70/30, about 75/25, and
about 80/20. The purpose of these ratios is to maintain melt
fluidity. If the neutralization by the ammonia is carried to
completion a complete salt is formed and fluidity may be
insufficient to transfer the mixture to a granulator for shaping
and forming granules. Salt formation may be determined and in real
time by the measurement of the pH of the mixture. Preferred pH
values of the melt are between 2.0 and 4.0. It is preferable to
partially ammoniate the acid mixture in the reactor (thereby
forming a melt) and complete the ammoniation in a second vessel
(e.g., pugmill) or in the granulation process as in a
granulator.
[0055] An advantage of this invention is that, because the organic
materials are liquefied, the liquid can be more easily transported
as needed through pipes preferably using pressure differentials as
compared with any solid, semisolid or thixotropic material. The
liquefied organic materials can also be more evenly applied to
acceptor material in the granulator thereby permitting the
formation of a more evenly formed spherically-shaped granule.
Although spherical shapes are preferred commercially, any shape of
granule can be created by one of ordinary skill in the art using
commercially available equipment. Organic materials are preferably
entirely liquefied, although mostly liquefied is typically
sufficient. Preferably the liquid exhibits a characteristic
readiness to flow, little or no tendency to disperse, and
relatively high incompressibility.
[0056] Viscosity of the starting organic material is typically in
excess of 100,000 cP and typically 150,000 cP at ambient
temperature and does not change significantly even at elevated
temperatures typical in a processing facility. For comparative
purposes, at about room temperatures, molasses has a viscosity of
about 5,000 to 10,000 cP, honey has a viscosity of about 2,000 to
10,000 cP, chocolate syrup has a viscosity of about 900 to 1,150
cP, and olive oil has a viscosity of about 81 cP. With the addition
of acid and heat according to invention, viscosity of the organic
material decreases to a range of from about 500 to 5,000 cP, and
preferably to less than 4,000 cP, more preferably to less than
3,000 cP, more preferably to less than 2,000 cP, and more
preferably to less than 1,000 cP. With the addition of ammonia and
the added temperature increase from the resulting exothermic
reaction, viscosity increases to a range of 500 to 4,000 cP, and
preferably to 2,000 cP or less, more preferably to 1,500 cP or
less. Also, problems typically associate with solid debris that is
normally present in organic material such as wastewater biosolids,
with debris such as plastic and hair, are eliminated as all such
material is hydrolyzed resulting in a decreased viscosity as
well.
[0057] The low viscosity material of the invention facilitates
fertilizer manufacturing by permitting the establishment of control
related to temperature, pressure and time of reaction. The fluidity
is advantageous so problems and inefficiencies commonly associated
with solid debris clogging or otherwise blocking transport from one
vessel to another and thereby requiring shutting down the system
for maintenance are eliminated. No solids or semi-solids are
present that would otherwise increase wear and tear on equipment
and thus, shorten equipment life. Further, organic solid materials
including, for example, plastic and hair, well known to cause
blockages in conventional processing, are completely broken down
and hydrolyzed to their monomer components. The acid reaction
hydrolyzes many polymers that may be present such as proteins and
other materials including plastics, hair, and biologically active
compounds (whether naturally present or artificially created), and
breaks down and destroys many and nearly all and preferably all
macromolecules and microorganisms that may be present. The acid and
subsequent ammonia environment creates a sterile fluid melt. This
increases the safety to process workers and further simplifies and
increases the efficiency of any cleaning or maintenance of the
system that may be required periodically. This hydrolysis further
increases the safety in the use of the resultant fertilizer product
in comparison to other traditional organics-containing fertilizer
products such as those made in biosolids alkaline-stabilization or
composting or traditional Class B land application processes. The
fertilizer produced is sterile thereby meeting the most stringent
of the USEPA Class and EQ microbial standards.
[0058] Another advantage of the invention is that, because the
process can be easily contained, the need for dust and odor control
apparatus within the manufacturing plant is minimized. The
processing steps are closed and under negative pressure and no
steps are performed in open or areas exposed to the environment or
the environment of the facility. Odor control agents are preferably
added initially, but could optionally as easily be added at any
step in the process. The key to this invention is that the physical
chemical conditions created in the described embodiments eliminate
noxious odors from the resultant fertilizer. Alternatively, or in
addition to other odor control processing, the granules may be
exposed to ozone during formation and/or cooling. Ozone will
substantially reduce or eliminate disagreeable odors of the
fertilizer. The manufacturing plant has a robust process odor
control treatment such that no noxious odors from reduced sulfur
compounds, amines, or other organics-related odorants are present
at the manufacturing fence line. Thus the invention is a major
improvement as compared to conventional fertilizer manufacturing
practices in which a large manufacturing facility is located as far
away from communities as possible thereby requiring that input
materials be shipped over long distances to operate the plant. A
good example of this odor problem was the biosolids
conversion-to-fertilizer plant located in Helena, Ark. which
practiced the manufacturing processes taught in U.S. Pat. Nos.
5,984,992; 6,159,263; 6,758,879; and 7,128,880, and utilized
biosolids that were transported all the way from New York City.
This AR plant did not have the odor control system necessary to
eliminate noxious odors from being released to the environment.
[0059] Another advantage of the invention is that, because acid and
ammonia are added in a controlled manner, the final components of
the fertilizer can be predetermined. The exact amount of nitrogen
in the final product can be regulated based on the amount of the
starting materials including the biosolids, acid, base, water, and
any other components. Similarly, the exact amount of sulfur, iron,
phosphate, potassium and even organic matter can also be regulated
or, if desired, eliminated from the final product producing a
custom-made fertilizer product. Many crops that require
fertilization are grown in areas known to be high in phosphate,
sulfur, potassium or other elements. Fertilizing with conventional
fertilizers, although needed, typically exacerbates the
contamination. Fertilizers produced by the methods of the present
invention would not only overcome such problems, but could be
tailored for use in conjunction with a specific type of soil or
specific need of a select type of crop. In addition, the process of
the invention allows for supplementation of the fertilizer during
processing with additional ingredients.
[0060] Another advantage of the invention is that it is easily
performed in large scale, with continuous processing and under
automation. No significant retention times are required, thus no
delays, so that processing continues from start to finish without
interruption as can be required when material is required to
incubate for days as is common for some types of conventional
biosolids processing as in composting or alkaline stabilization
processes. The process of the invention is scalable to any amount
of organic material. This is highly preferred at least because most
municipal regions vary in size and thus, the amounts of organics
such as biosolids produced per day vary widely. Also, amounts are
expected to also vary over time. Further, each step of the process
can be performed under complete automation including accounting for
necessary variation per day and over time.
[0061] Another advantage of the invention is that it allows for
co-location of the facilities for processing organic materials such
as biosolids with the municipal wastewater treatment plants.
Biosolids can be then taken directly from wastewater treatment
plants to processing thereby minimizing transport and potential
spillage of potentially harmful compounds. Another preferred
embodiment is to locate close enough to the wastewater treatment
plant to be connected by a screw or belt conveyor or a biosolids
pumping system. Alternatively, another preferred embodiment is to
locate adjacent to the wastewater plant. The goal of the present
invention is to place the processing plant as close to the
wastewater plant as possible. Thus the present invention eliminates
most of the cost of transportation by locating the physical
equipment necessary to perform the manufacturing process adjacent
or close to the source of the biosolids such as municipal
wastewater treatment plants. Manufacturing plants of the invention
preferably allow for adjacent storage facilities. Again, by being
adjacent, transportation logistics are simplified or eliminated
thereby reducing transportation costs of the product as well as the
transportation costs of input organics such as biosolids. Also, the
processes of the invention have the advantage that they may be
interfaced with other production facilities. Those facilities may
be associated with an unrelated commercial enterprise. Further and
more commonly, co-locating near a commercial enterprise that
creates excess heat, as in a furnace, or kiln, would advantageously
permit the use of this excess heat by the present invention as in
the replacement of the need for fossil fuels such as natural gas or
by the co-generation of electricity by utilization of said excess
heat.
[0062] Another advantage of the invention is that because the
process minimizes the amount of water and power (e.g. electrical)
needed, and amount of waste byproducts formed, as compared to
conventional processing, manufacturing can be sized to service the
needs of the size of the particular community in which the plant is
located. This tailoring design allows for a biosolids
processing/fertilizer manufacturing plant that can process smaller
amounts of biosolids (e.g., less than 3 tons per hour of dewatered
biosolids) or scaled up for larger plants (e.g., up to 20 tons per
hour or more). In a preferred embodiment the optimal size is
between 10 and 12 tons per hour, which allows for local operations
and does not require long distance transportation of raw
materials.
[0063] Types of community organics that may be utilized in this
invention include municipal biosolids, domestic septage, farm and
agricultural wastes, animal manures, digested and processed animal
manures, recycled biosolid fertilizers, organic biosolids,
biosolids containing microorganisms, and heat-dried biosolids.
Other organic materials that can be processed according to the
method of the invention include, but are not limited to
pharmaceutical and laboratory processing and fermentation wastes,
organic industrial wastes, microbial materials, decayed and
digested organic materials, humate and humic acids and fulvic
acids, farm and agricultural wastes, harvested plant materials such
as algae including blue/green algae, seaweed and other aquatic
plants and water-borne organic detritus, bacteria including
blue/green bacteria and cyanobacteria (e.g., blue/green, rust,
black), slime, insects and insect biomass (e.g., body parts,
manure), mold and fungi, industrial wastes and their by-products,
microbial, chemical and enzymatic digests of organic products,
foods, food stuffs and food byproducts, and combinations thereof.
In addition to conventional biosolids, most all organic materials
can be processed by the methods of the invention including spoiled
or otherwise rotted food stuffs such as, but not limited to
vegetables, meats, fish, and agricultural products as well as
plastics, and carbon-containing household trash and
recyclables.
[0064] Another advantage of the invention is that organic
materials, and even in combination with certain non-organic
materials, that are otherwise difficult to dispose can be processed
according to the invention as a method of turning into a useful
product what would otherwise be waste material occupying space in a
landfill or the ocean. By way of non-limiting example, algae is
skimmed from the surface or otherwise collected from eutrophic
bodies of water for aesthetic purposes as well as for the general
health of the plants and animals that habitat the environment.
Often algae may be contaminated with natural toxins or toxic
compounds absorbed or metabolized and concentrated within the algae
from the environment. By processing the algae according to the
methods of the invention, the algae can be converted to fertilizer
and, importantly, the toxins destroyed or otherwise inactivated. In
addition, algae or other plants or bacteria may be intentionally
grown and harvested to be processed according to the invention.
[0065] The organic material is preferably dewatered or hydrated to
a solids content of between 10 and 40 percent, more preferably
between 15 and 30 percent, and more preferably between 20 and 25
percent. The optimal solids content of a particular organic
material can also be empirically or experimentally determined.
Organic material received for processing according to the invention
will typically have lower solids content than the optimal level.
Preferably, the organic material of insufficient solids content can
be adjusted to the desired concentration through blending/mixing
with `dry` organic materials with a solids concentration of 70 to
95 percent and preferably 85 to 92 percent. The `dry` organic
materials may be available through third party sources or may be
produced with the available organic material through heat drying.
Heat drying processes include heated screw conveyors, disc dryers,
rotary dryers, paddle mixer/dryers, fluid bed dryers and other
commercially available processes/equipment. The dried organic
materials and the organic material of insufficient solids
concentration will be mixed in a mixing vessel to reach the ideal
solids content as determined empirically or experimentally. The
mixing vessel may be a pugmill, a mixing screw conveyor, a
multi-shaft mixer, a ribbon paddle blender, a high shear mixer, a
static mixer or other commercial high viscosity slurry mixer. Less
preferably, the organic material of insufficient solids content can
be adjusted to the desired concentration by heating the material to
remove water as necessary to attain the desired concentration. This
can also be done in the same heat drying equipment listed above.
Organic materials received for processing may need hydration and,
when necessary, additional water is preferably added from water
collected during other steps of processing. This use of recycled
water further adds to both the efficiency and beneficial economics
of the invention.
[0066] If necessary during the intake processing, the organic
material can be conditioned by injection of steam, water, and/or
heat (e.g. made thixotropic) and/or subjected to violent agitation
and physical disruption to enable or enhance flow or movement. In
these initial steps, the organic material can be blended with
chemical additives such as oxidizing agents or iron containing
compounds, for the initial odor control and to prepare the
biosolids for reaction in the pressure vessel. For example,
biosolids may be infused with black or agricultural grad phosphoric
acid to minimize odors. In this example, the phosphoric acid added
here will alter the final concentration of phosphate in the
fertilizer product. The amount of phosphate added to the product in
this step can be as little as 0.5 percent and as much as 16
percent. In addition to odor minimization, the phosphoric acid adds
a valuable nutrient component to the product fertilizer.
[0067] Preferably the odor control agent is added to the initial
organic material to be processed, although one or more odor control
agents can be added at any time during processing including during
granule formation and cooling. Preferred odor control agents
include, but are not limited to calcium ferrate, sodium ferrate,
potassium ferrate, ferrous sulfate heptahydrate, rozenite,
melanterite, ferric chloride, ferrous sulfate, ferrous sulfate
monohydrate, hydrogen peroxide, and/or ozone as well as various
other salts, derivatives and combinations thereof. The amount and
type of odor control agent can be determined empirically by one of
ordinary skill in the art, but typical amounts range from 0.01
percent by weight of the mix or of the granules, to up to 6 percent
of the mix or granules, and is preferably about 0.05%, 0.1%, 0.25%,
0.5%, 0.75%, 1.0%, 1.5%, or 2.0%.
[0068] The organic material, odor control agent and possibly
recycle water are delivered to a mixing vessel where they are
thoroughly mixed and may form a thixotropic paste that is pumped or
easily transported. The mixing vessel may be a pug mill, a mixing
screw conveyor, a multi-shaft mixer, a ribbon paddle blender, a
static mixer, a high shear mixer or other commercial high viscosity
slurry mixer. Pug-mills, blenders and mixers are mixing chambers
having blade-shaped blending elements mounted on a powerfully
driven shaft or shafts that rotate at a variable but controlled
speed which divide, mix, back-mix and re-divide the materials to be
blended multiple times a second to yield a thorough, uniform blend
with reliable consistency.
[0069] Alternatively, the mixing vessel to reach solids
concentration and the mixing vessel for the conditioning with
recycle water, phosphoric acid, odor control agents or other
additives may be combined in a single mixer of adequate size to
give desired mixing energy and time.
[0070] To the mixture is added acid, in the preferred embodiment at
the inlet of the first pressure vessel, creating an exothermic
reaction, which thereby causes additional heating.
[0071] As pressure is optional, the term pressure vessel does not
imply that increased (or decreased) pressure is required, only that
a suitable vessel is to be utilized. The acid is added to the
mixture by direct injection into a pressure vessel or injection at
the vessel inlet. In the pressure vessel the mixture is agitated or
otherwise continuously mixed. The acid is at a very low pH and
preferably in the range of pH negative 4.0 to pH positive 1.0. As
is known to those skilled in the art, with very strong aqueous
acids there are too few water molecules to disassociate the acid
completely. As a consequence, the true pH is much lower than an
actual measurement. A negative pH indicates that the pH calculation
would be a negative log of the molarity where the molarity of
hydrogen ions is greater than 1. Preferred pH values for acids
utilized are, for example, pH of 2.0 or less, pH of 1.0 or less, pH
of 0.8 or less, pH of negative 1.0 or less, pH of negative 2.0 or
less. Preferred acids include, but are not limited to hydrochloric
acid, boric acid, hypochlorous acid, perchloric acid, carbonic
acid, phosphoric acid, sulfuric acid, nitric acid, hydrofluoric
acid, carboxylic acid, and derivatives, mixtures, and combinations
thereof. The amount and type of acid added is determined by one of
ordinary skill in the art from the amount of organic materials
being treated and/or the desired result, which includes but is not
limited to one or more of, achieving a predetermined temperature or
pressure or liquefying the mixture. In part because the organic
materials are liquefied, there is little to no build up of calcium
silicate, insoluble phosphate compounds or other insoluble
compounds in pipes, a typical problem with conventional biosolids
processing facilities. Addition of the acid causes an exothermic
reaction that heats and increases the pressure of the container
(when in a pressure tight reaction vessel). This pressure which
upon commencement of the reaction is at ambient may in fact be
maintained at ambient or a desired pressure throughout the
acidification process by monitored or controlled venting.
Alternatively, the pressure may be allowed to increase with
increasing temperature due to the exothermic heat of hydration
reaction. Such pressures may reach an upper range of 40 psig by
controlling venting or in the absence of venting. In addition,
acidification can be performed under negative pressure. Preferred
negative pressure ranges are from one atmosphere (atm) (14.7 psi)
to 0.9 atm, to 0.8 atm, to 0.7 atm, to 0.5 atm, to 0.4 atm, to 0.3
atm to 0.2 atm, and to 0.1 atm or less.
[0072] Temperature of the mixture increases, preferably to or above
38.degree. C. (100.degree. F.), to or above 43.degree. C.
(110.degree. F.), to or above 49.degree. C. (120.degree. F.), to or
above 54.degree. C. (130.degree. F.), to or above 60.degree. C.
(140.degree. F.), or to or above 66.degree. C. (150.degree. F.),
such as for example to or above 82.degree. C. (180.degree. F.) or
93.degree. C. (200.degree. F.), and more preferably to or above
104.degree. C. (220.degree. F.), 110.degree. C. (230.degree. F.),
116.degree. C. (240.degree. F.), 121.degree. C. (250.degree. F.).
This acidification may be carried out without pressure in the
reactor by permitting release of vessel air during acidification,
however in the preferred embodiment to facilitate the transfer of
the acidified mix into the second vessel the pressure in the first
or acidification vessel will be maintained above the pressure
achieved the second vessel. The acidification process is carried
out for a retention time of between 2 minutes and 30 minutes with a
preferred time of between 4 minutes and 8 minutes. In an
alternative embodiment, all pre-acidification ingredients including
the organic material, odor control agent, phosphoric acid and
possible recycled water, may be mixed in the acid reaction vessel
either before or simultaneously with the acidification.
[0073] After reaction of the acid at the desired time, temperature
and pressure, the acidified mixture is discharged from the acid
pressure vessel and transferred to a second pressure vessel. At the
second pressure vessel, ammonia is injected to the mixture either
at the second pressure vessel inlet or directly into the second
pressure vessel. The amount and form of ammonia added is determined
by one of ordinary skill in the art from the amount of acidified
mixture or organic materials being treated and the desired result,
which includes but is not limited to one or more of, achieving a
predetermined temperature or pressure or liquefying the mixture.
The addition of ammonia increases the temperature of the mixture
liberating steam which increases the headspace pressure within the
second pressure vessel. Pressures can again be regulated with
pressure relief valves or by controlling the discharge of melt from
the ammoniation vessel. Subsequent addition of the ammonia base,
preferably in a second pressure vessel, further affects the
temperature of the mix, preferably raising the temperature to at or
above 121.degree. C. (250.degree. F.) such as 138.degree. C.
(280.degree. F.) or 143.degree. C. (290.degree. F.), more
preferably to at or above 149.degree. C. (300.degree. F.), more
preferably to at or above 154.degree. C. (310.degree. F.),
160.degree. C. (320.degree. F.), 166.degree. C. (330.degree. F.) or
171.degree. C. (340.degree. F.), and more preferably to at or above
177.degree. C. (350.degree. F.) such as for example to at or above
182.degree. C. (360.degree. F.), 188.degree. C. (370.degree. F.),
191.degree. C. (375.degree. F.), 193.degree. C. (380.degree. F.),
199.degree. C. (390.degree. F.), 204.degree. C. (400.degree. F.)
210.degree. C. (410.degree. F.), 216.degree. C. (420.degree. F.),
221.degree. C. (430.degree. F.), 227.degree. C. (440.degree. F.) or
232.degree. C. (450.degree. F.). Preferably heating is performed
for a retention period of time that is equivalent to the time
required to achieve the desired temperature and allow completion of
reactions. Preferred periods of reaction time, which may include
exothermic heating time, are between 1 and 30 minutes, more
preferably between 3 and 15 minutes, more preferably between 5 and
10 minutes, or any combinations of these ranges. Also, reacting
times may also be dependent on the constituents and/or makeup of
mixture being reacted and/or the amount and/or type of acid added.
Reactions take place in closed container vessels, and pressure in
the headspace of the container vessel increases as well. Pressures
can again be regulated with pressure relief valves and are
preferably maintained between 5 psig and 150 psig, more preferably
between 30 psig and 100 psig, and more preferably between 40 and 80
psig. Preferred pressures include, but are not limited to 5, 10,
20, 30, 40, 50, 60, 70, 75, 80, 90, 100, 110, 120, 125, 130, 140,
150 psig.
[0074] The processes of the present invention with biosolids and
others forms of organic materials produce a fertilizer that is
preferably safe to handle and work with and preferably meets and/or
exceeds the minimum requirements of a USEPA Class A and EQ
biosolids. Fertilizer product is preferably sterilized and
biological and chemical contaminants are at least partially and
preferably completely hydrolyzed and biological agents are
denatured to the point of inactivation and/or destruction. Typical
biological or chemical contaminants include, but are not limited to
one or more of pharmaceutical compounds, antibiotics, hormones,
hormone-like molecules, biologically active compounds,
macromolecules, carbohydrates, lipids, proteins, nucleic acids, and
combinations thereof.
[0075] The present invention preferably includes a stress
conditioning over a predetermined retention period that creates
stress conditions that meet or exceed those associated with
traditional autoclaving of materials. This autoclave effect
destroys and/or inactivates or simply sterilizes the organic
material. Microorganisms in the organic material, including for
example, bacteria, viruses, fungi, parasites, parasite eggs,
bacterial and fungal spores and combinations thereof, are destroyed
and/or inactivated. In addition, the processes of the invention are
preferably designed to hydrolyze macromolecules such as proteins,
nucleic acids, lipids, fats, carbohydrates and combinations
thereof, and/or other biologically-active substances that may be
present. The majority of microbial cells are physically broken down
during this processing with the resultant organic compounds
contributing to the organic material or matrix of the
fertilizer.
[0076] At any time during the steps of the method, one or more
hardening agents can be added to the mixture. Preferred hardening
agents include, but are not limited to ferric oxides, alum
attapulgite clay, industrial molasses, lignin, ligno sulfonate,
urea formaldehyde polymerizer and combinations thereof.
[0077] At the desired time, which may be determined empirically or
experimentally, the liquid is processed into fertilizer. Preferably
processing involves transfer to a granulator for removal of water
and formation of dried fertilizer granules. Preferred is processing
in a granulator which contains 60-88 percent by weight old
granules, and drying the granules preferably with heat to greater
than 90 percent solids, and preferably 98 or 99 percent solids or
greater. Preferably, water extracted from the granules is collected
with a portion recycled in the steps of the process and the
remainder treated for discharge. Granules are typically quite hot
during the drying process and, optionally, may be allowed to cool
by transfer to a cooling room or cooling apparatus. During cooling,
ozone may be injected into the cooler as an odor control measure.
Preferred amounts of ozone to be injected are from 0.01% to 5% of
the weight of the cooling granules, more preferably from 0.1% to 2%
and more preferably from about 0.5% to 1%. Preferably, ozone is
introduced to the cooling apparatus by sparging.
[0078] Once dried and formed and optionally after cooling, the
granules are sized and preferred are granule size of 0.5 mm to 4
mm. More preferred are standard fertilizer granules of about 2.8 mm
and specialty "mini" granules of about 1 mm.
[0079] One or more commercially available hardening agents can be
added to the granulator. Preferred hardening agents include, but
are not limited to ligno-sulfonate, lignin, molasses, or a
combination thereof. Granules of greater than 4 mm and less than
0.5 mm are recycled in the granulator. Granules of the desired size
are further processed by coating with one or more commercially
available dust control agents. Preferably, granules greater than 4
mm are crushed and mixed with the granules of less than 0.5 mm, and
all is recycled in the granulator.
[0080] The invention preferably provides for both dust and odor
control systems to ensure community acceptance of the manufacturing
plant as well as making the process more efficient through the
capture and incorporation of valuable nitrogen or other potential
and/or fugitive plant nutrients from the processed air of the
plant.
[0081] Another embodiment of the invention is the fertilizer
manufactured by the methods of the invention. The physical and
chemical characteristics of organically modified ammonium sulfate
fertilizer of one preferred embodiment of the invention are listed
in FIG. 4. Fertilizer from organic materials such as biosolids may
be powdered or in pellets, or is preferably in the form of granules
that are of a predetermined size and are resistant to crushing.
Further, preferred granules are generally spherical having a smooth
exterior with few pits or crevices and circular or oval in shape.
Preferably, the fertilizer contains no or negligible detectable
un-hydrolyzed polymers and preferably the polymers within the
organic mixture have been hydrolyzed including, but not limited to
plastics, pharmaceutical compounds, antibiotics, hormones,
hormone-like molecules, biologically active compounds,
macromolecules, carbohydrates, nucleic acids, fats, lipids,
proteins, and microorganisms. Hydrolyzed polymers form monomers of
the polymer that accumulate in the product and are preferably
multiple chain length polypeptides and amino acids.
[0082] The process of the invention preferably results in the
production of granules or pellets of USEPA Class A and or EQ
fertilizer product of suitable dryness, hardness, and chemical
quality to produce a valuable, high-nitrogen, slow-release (e.g.
enhanced efficiency, controlled release, dual release,
predetermined release) commercial fertilizer product that is
capable of competing in the national and international marketplace
against traditional inorganic fertilizers. Preferably, the
fertilizer product has a controlled and preferably slow-release of
nutrients to the soil, wherein control can be exercised by adding
different types and amounts of organic material during manufacture.
For example, a product in which the different nutrients are
converted to a slow-release form due to sequestration of the ions
by the organic matter in the fertilizer, including nitrogen,
phosphorus, potassium, sulfur and various micronutrients selected
from the group comprised of iron, manganese, magnesium, copper,
calcium, selenium, boron and zinc (see FIG. 5).
[0083] Significantly this invention instructs that the degree of
slow-release nutrients contained in the fertilizer may be adjusted
on demand as in a "dial-up" or controlled ability for degree of
slow-release or enhanced efficiency. In the preferred embodiment
the slow-release nutrient, such as nitrogen, may constitute 10% to
80% of the nutrient concentration by dry weight contained in said
fertilizer. More preferably the slow-release nutrient component is
30% to 70% of the said fertilizer. The degree of slow-release of
the product can be adjusted by changing the amount of added organic
materials such as wastewater plant biosolids, digested food stuffs,
other microbially digested materials such as pharmaceutical
fermentation waste, digested food waste; extracted liquid organic
fraction from municipal solid waste; animal residuals; digested
animal residuals and algae harvested from eutrophic surface water
sources, and or humates, humic acids, fulvic acids or, iron humates
containing fulvic and humic acids. Additionally, the amount of
slow-release nutrient can by directly changed by adding specific
stabilizing chemicals such as Nutrisphere-N (commercially available
from Verdesian Life Sciences), a proprietary nitrogen binding agent
used in agriculture to reduce volatilization and leaching and or
other inorganic compounds that react with ammonia to create slowly
soluble forms that are then slow-release nutrient compounds in the
fertilizer. Additional nutrient-binding agents, such as nitrogen
(ammonium ion) binding can be added to the process, preferably at
the second mixer or granulator and include, for example, amino
acids such as lysine, polypeptides containing nutrient-binding
amino acids, and magnesium ammonium phosphate. The addition of such
agents directly changes the percentage of nutrient ions that are
slow-release. This ability to change the percent of nutrients that
are slow release also directly increases the commercial value of
said fertilizer as the conversion of nutrients to a slow-release
form provides better crop production due to these nutrients being
available over more of the growth cycle.
[0084] FIG. 5 illustrates the electrostatic binding of the
inorganic nutrients such as the positively charged ammonium ion,
the negatively charged sulfate ion and the positively charged
ferrous ion to the corresponding opposite charges located on the
organic molecules such as variably length polypeptides and
monomeric amino acids thereby creating the organic matrix entity.
This organic matrix serves as a mechanism of delivering a
slow-release or enhanced efficiency release of the nutrients into
the soil column over the growth period for the target crops. This
slow-release of nutrients is facilitated by the action of soil
microbes.
[0085] Slow-release or dual release fertilizers of the invention
allow for a single application of fertilizer that provides a rapid
first release (e.g. bolus) of nitrogen to growing or emerging
plants such as commercial crops (e.g., fruits, vegetables, grains,
grasses, trees), then a continued amount preferably over an entire
or part of a growing season (e.g., see FIG. 7). This minimizes the
number of fertilizer applications needed per crop which provides
substantially savings in application expenses.
[0086] Stress resistant ammonia binders such as municipal organics
can be added in the mixer prior to the first hydrolysis and/or
acidification vessel. Compounds that are more heat or pressure
sensitive can be added directly to the granulator such as is shown
in FIGS. 1A, 1B and 1C. Nutrients are sequestered or chelated by
organic molecules of the product in which said inorganic nutrients
are released to the soil environment by microorganism metabolism
over time after fertilizer application. Organics are comprised of
macromolecules obtained from microorganisms broken down during
product processing including: denatured proteins; peptides and
amino acids; nucleic acids, cytokinin-like compounds, lipids and
carbohydrates as well as hydrolyzed and denatured organics from the
community organics defined in this invention. The organics form a
matrix within the fertilizer which is comprised of a complex of
variable chain length amphoterically charged organic molecules
which attract and electrostatically bind both positive and
negatively charged inorganic nutrient molecules such as ammonium
ion and sulfate ions. The product provides ammonium-N which can be
utilized by plants before they develop a nitrate-N reduction system
and is as a result very energy efficient. Ammonium-N
(NH.sub.4.sup.+) in fertilizer of the invention requires less of
the plants' stored metabolic energy for incorporation into plant
components. In this invention it has been demonstrated that the
conversion from the ammonium ion to the nitrate ion is retarded
thereby beneficiating the target plants. Plants can use both
ammonium and nitrate N, but ammonium-N is a more energy efficient
form of N for plants and is less leachable. That means that more
sugars formed by photosynthesis can be stored in grain or fruit as
starch resulting in increased yield. It has been estimated that
utilizing ammonium nitrogen can save 10-17% of photosynthetic
energy which plants have stored.
[0087] Preferred fertilizer products are ones from which nitrogen
uptake as the ammonium ion reduces the possibility of nitrogen
losses by leaching and denitrification by soil bacteria. Such
losses can be sizeable from nitrogen fertilizers that do not
contain ammonium or are rapidly converted to nitrate-N.
Multi-nutrient fertilizers are preferably homogeneous and contain
several essential nutrients. FIG. 8 illustrates soil nitrogen
leaching in tomato cultures as influenced by nitrogen source.
[0088] A useful range of nutrient concentrations for plant
development includes, for example, nitrogen 8 to 18%; phosphorus 0
to 10%; potassium 0 to 10%; sulfur 5 to 20%; iron 0 to 5% and
organics 4% to 18%. Preferably, the product of the invention does
not lose an amount of its contained nitrogen (N) greater than 3% as
ammonia to the atmospheric environment upon surface application to
a dry soil and not more than 30% as ammonia from a flooded soil.
Preferably, product manufactured according to the invention has an
amount of zinc sulfate or soluble forms of boron added as plant
nutrients. Sequestration improves plant iron use efficiency by
retaining the added iron primarily in the plant-available ferrous
ion form. Preferably the product delivers sulfur in the
plant-available form as the sulfate ion. The organic content
contributes to the soil carbon pool which improves soil
quality.
[0089] Product of the invention has an organic nutrient complex
that facilitates ion exchange uptake by the root hairs of the
target crop, improves the micro-ecology in the root zone and soil
tilth, and increases target plant stress resistance to heat and
drought. Preferred product is non-hydroscopic with a granule
hardness of between 4 and 9 pounds, more desirably between 6 and 8
pounds, with a bulk density of between 52 and 56 pounds/cubic foot
optimizing its blendability with other agricultural fertilizers.
Preferably, selected herbicides and pesticides may be introduced to
the granule surface area or mixed within granules of the product.
The fertilizer is preferably uniformly black in color. However,
fertilizer of the invention can be manufactured in any color which
can be useful to assess distribution patterns and marketing
advantages.
[0090] A commercial, high-nitrogen fertilizer preferably has
greater than 8 percent nitrogen by dry weight of the finished
fertilizer and more preferably at least 15 percent nitrogen by dry
weight of the finished fertilizer. The Class A characteristic
refers to the microbiological quality of the finished fertilizer
product, which meets the United States Environmental Protection
Agency Class A microbiological standards for a product containing
municipal biosolids as defined in 40 C.F.R. .sctn. 503. Also,
fertilizer of the present invention meets or exceeds this standard
on the basis of the stress conditions, the retention time, and
processing conditions utilized thus ensuring that the three
conditions associated with USEPA Exceptional Quality (EQ) standards
are met. These include the Class A standard as above, the metals
concentration level in the product as defined in CFR 503 and the
Vector Attraction Standards are met (90 percent solids or greater
in the finished product), that the finished fertilizer granule is
optimized for minimal water content increasing the hardness
characteristic and eliminating water with respect to product
optimization of the finished fertilizer. The percent solids of the
finished product are preferably greater than 92 percent solids,
more preferably greater than 97 percent solids, and more preferably
greater than 98 percent solids.
[0091] Biosolids treated according to the processes of the
invention typically contain low levels of metals such as arsenic,
cadmium, copper, lead, mercury, molybdenum, nickel, selenium and/or
zinc. Low levels are levels below what are considered harmful and
less than the Exceptional Quality ("EQ") standard for metals as
published by the USEPA for products containing municipal biosolids.
Thus, by exceeding the USEPA regulation and the conditions of the
hydrolyzer or pressure vessel for macromolecules (e.g., personal
pharmaceutical products such as antibiotics or hormones or
hormone-like substances), the resulting fertilizer is safe for use
in agriculture and horticulture (plants and animals) and is
exceptionally safe for handling by workers during processing,
handling, distribution, sales and agricultural application.
[0092] As the fertilizer product produced contains both biosolids
and a high-content of desirable nitrogen, a preferred embodiment
results in a variety of specific nutrient analysis fertilizers of
which the following are typical: 16-1-0-18-3-15 or 16-1-2-17-3-14
(Nitrogen -Phosphorus-Potassium-Sulfur-Iron-Organics). The slow or
controlled enhanced efficiency release granular fertilizer is at
least 98 percent dry and exceeds the United States Environmental
Protection Agency (USEPA) Class A requirements and Exceptional
Quality (EQ) Standards. Thirty percent of the total product N is
slow release organic nitrogen (16% N.times.30%=4.8% slow release N)
which is bound to components of the biosolids. Slow release
ammonium N is slowly converted to leachable nitrate by soil
bacteria land does not volatilize to the atmosphere as ammonia. The
result is higher nitrogen use efficiency by plants and less
environmental impact of the product nitrogen.
[0093] The fertilizer product may be tailored to a desirable
content of elemental components. Preferably the fertilizer has a
nitrogen content of between 6 and 20 percent, more preferably from
8 to 18 percent, a phosphate content of between 0 and 10 percent,
more preferably from none to 5 percent, a potassium content of
between 0 and 5 percent, more preferably from one to four percent,
a sulfur content of between 10 and 30 percent, more preferably from
15 to 20 percent, an iron content of between 0 and 8 percent, more
preferably from one to four percent, and an organic content of
between 5 and 30 percent, more preferably from 10 to 20 percent (or
any combinations of these ranges).
[0094] The fertilizer product contains nitrogen in the form of
ammonium ions non-covalently bound to organic and other chemical
compounds of the fertilizer. Unlike ammonium sulfate fertilizer,
the bound ammonium ions are not all immediately released into the
soil upon application. Instead, there is a first release over a
period of two weeks after application of an amount of nitrogen to
the soil that represents from about 30-65% of the available
nitrogen of the fertilizer. This fast release typically ranges over
a period of one to three weeks, slower than a conventional ammonium
sulfate fertilizer that typically releases 90% or more of its
available nitrogen to the soil in about 5 to 10 days, but faster
than the nitrogen release of the 2% to 6% nitrogen in conventional
biosolids fertilizers. Over the subsequent days and weeks, the bulk
of the remaining nitrogen (for example, 35%,) of the fertilizers of
the invention gradually releases into the soil. Sun, heat, water
and/or microbes in the soil act on the fertilizer and slowly break
down the ionic bonds releasing available nitrogen to the roots of
the plant. Preferably, the nitrogen release is from about 1% to 5%
per week, and more preferably from about 2% to 4% per week. A small
amount of nitrogen may be covalently bound to compounds of the
fertilizer, and thereby is further dependent upon microbial
catalysis of the organic molecule for release to the soil and
plants. Preferably this amount of unavailable nitrogen is 5% or
less, more preferably 2% or less, and more preferably 1% or less of
all nitrogen of the fertilizer product. This dual nitrogen-release
profile is advantageous to turf and agricultural use and not
characteristic of conventional commercial fertilizers.
[0095] Another embodiment of the invention is directed to a process
for manufacture of a fertilizer with a predetermined content of one
or more of nitrogen, phosphate and/or potassium. Processing of
organic materials proceeds as described herein wherein the acid
selected is of the type and amount desired in the final fertilizer
product. For example, using a set amount of phosphoric acid will
result in a set amount of phosphate in the final fertilizer
product. By using a particular amount of sulfuric acid, a
particular amount of sulfur will be retained in the fertilizer. By
selecting the type and amount of acid, one can pre-select the
content of the fertilizer product produced. Preferably, the
fertilizer is supplemented with one or more plant nutrients added
during one or more steps of the processing. The one or more plant
nutrients include, but are not limited to urea, ammonium nitrate,
ammonium sulfate, monoammonium phosphate, diammonium phosphate,
urea ammonium nitrate, liquid urea, potash, iron oxide, soluble
iron, chelated iron, micronutrients like magnesium, manganese,
copper, zinc, molybdenum or boron, and combinations thereof.
[0096] Another embodiment of the invention is directed to a system
for the manufacture of a fertilizer. The invention comprises a
mixer that blends the organic component containing biosolids,
optionally with an odor control agent. The mixture is then
transferred to a first pressure vessel. The pressure vessel is
preferably of a construction that allows for a vigorous mixing with
continuous exothermic reaction with the aqueous phase of the
conditioned organics paste and a direct hydrolysis of the organic
compounds in the material. An agitator/mixer is incorporated into
the first pressure vessel. Optional heating elements that may be
external to or internal within the vessel may also be incorporated
into the pressure vessel. Acid may be blended directly with the
organics in the first pressure vessel or, preferably, the acid and
heated biosolids are combined in a mixing tee and together added to
the pressure vessel. Within the pressure vessel heat and pressure
buildup is continued for a period of time to form a liquid from the
paste-like organics mix. The liquid mix may be further treated in
the same pressure vessel, or preferably transferred to a second
pressure vessel through a pipe or conduit. The mix is preferably
transferred in a turbulent flow so as to prevent or minimize the
possibility of organic material remaining in the conduit. Also
preferably, the acidified liquid mix is combined in a mixing tee
with the ammonia from an ammonia source, preferably vaporized
ammonia, and together forcibly injected to the second pressure
vessel. Preferably the liquid mix is forced through the conduit by
the pressure built up by the heating reaction in the first vessel
or by a pressure that is added to the system behind the liquid
mixture to ensure that all of the liquid mix has been transferred
to the second vessel. Preferably the gas, which may be air or
another gaseous compound or mixture, is purged, if necessary, by
way of a relief valve in the second vessel. Within the second
pressure vessel, the acidified and nitrogen-fortified liquid mix
exothermically heats due to the acid/base reactions and/or is
heated to a second predetermined temperature and pressurized to a
second predetermined pressure for a second period of time.
Preferably the ammonia source is liquefied and/or vaporized ammonia
under pressure. Also preferred, is a system whereby the first and
second pressure vessels each contain an agitator or other mechanism
that continually mixes the mixture. Alternatively, the first and
second pressure vessels may be the same with the acid and the
ammonia added sequentially. Following ammoniation, the mixture is
transferred to a pugmill or granulator wherein the steam and water
vapor is released and the ammoniated liquid is mixed with preformed
granules (commonly referred to as "recycle" to form or shape the
new fertilizer granules. These granules are then heated in a rotary
dryer or fluidized bed dryer to form dried granules of the
fertilizer. In a preferred embodiment, the entire reaction process
is controlled by a closed loop computer control that continuously
monitors and adjusts the exothermic reaction through addition of
sulfuric acid, ammonia, plant nutrients, pH adjusters and pressure
control. The preferred control mechanism is through adjustment of
the head space pressure above the biosolids in this pressure vessel
and by valve control of the exit volume. The system also preferably
contains a conveyer (e.g. pump or screw conveyer, conveyer belt)
for transporting organic materials to the mixer and another pump
for transporting the blended organics to the first pressure vessel;
a pressurized piping system that transports acidified organics from
the first pressure vessel to the second pressure vessel, ammonia
into the second pressure vessel; and disperses the ammoniated
liquid melt to the granulator. Thus, the entire process is carried
out without the need for stopping the continuous flow of biosolids
into and out of the pressure vessels.
[0097] From the granulator, or incorporated with it, is preferably
a rotary dryer or alternatively a fluidized bed dryer that further
dries the biosolids fertilizer to less than 2 percent water
content. Upon exiting the dryer the biosolids fertilizer is further
screened for size and separated into product, undersize and
oversize granule groups. The undersized particles are recycled back
into the entrance of the granulator. The oversized particles are
sent to a hammer mill where they are crushed and then recycled to
the granulator. After leaving the screening process the biosolids
fertilizer granules are processed through the rotary cooler where
the organic-containing fertilizer is cooled. Optionally, the cooler
may include an ozone generator that provides ozone to the cooling
fertilizer. In the presence of ozone, odor-causing material
complexes with oxygen and possible other molecules present in the
biosolids and substantially reduces or eliminates disagreeable
odors. The fertilizer granules empty into the final polishing
screens to remove undersize granules or dust created in the cooling
process. After processing through the polishing screens, the
product passes through a coating drum where a coating agent that
inhibits dusting is added. The biosolids fertilizer is then
warehoused ready for bulk shipping or subsequent packaging.
Alternatively, granules may be subject to an air polishing system
that continuously recycles the hot air generated in the cooling
process to the drying stage resulting in a reduction in fuel usage
and waste air for processing. The air drawn from the screens and
equipment is cleaned in a dust collector, cooled through a heat
exchanger and reused as inlet air to the cooler. The heated air
discharging from the cooler is again cleaned in a dust collector.
The cleaned, heated air is used as inlet air for the rotary dryer.
The system also preferably contains one or more screens for
selecting granules of a predetermined size and a rotary cooler for
cooling and polishing the sized granules. The system of the
invention preferably comprising a dust control apparatus such as,
for example, vacuums and baghouses that collect dust from the
granulator and also a water recovery system whereby water extracted
from biosolids during processing is recovered and recycled
rendering the system very efficient.
[0098] In a preferred embodiment, process air is acid scrubbed to
remove any fugitive odorants and especially vaporized or gaseous
ammonia. The captured ammonia, as an ammonium salt, is mixed back
into the biosolids mix prior to its entering the reaction vessel or
mixer thereby increasing the efficiency of the entire system and
maximizing the final nitrogen concentration in the finished
fertilizer. Miscellaneous residuals including dust,
non-specification or reclaimed product and dried fertilizer that is
too small or undersized or oversize material that is crushed in a
crushing or mill apparatus or may include other additives, e.g.,
iron that a customer would prefer can be added to the composition
of the finished fertilizer are added to an optional pug-mill or
mixer positioned downstream from the pressure vessel or directly
into the granulator. During the granulation process, a hardener or
hardeners which help to agglomerate the mix and contribute to the
hardness of the dried pellet or granule are added at the second
pug-mill or granulator. The hardener or hardeners are selected from
the group comprised of attapulgite clay, lignin, industrial
molasses, lignosulfonate, and alum among others or mixtures of
these hardeners as known by one skilled in the art.
[0099] Optionally, dependent upon the requirements of the customer,
additional plant nutrients, for example, potash or other forms of
potassium, e.g., potassium hydroxide or potassium sulfate, are
preferably added at the pug mill or granulator to directly affect
the nutrient formulation of the fertilizer. Additional solid
nutrients that may be added also comprise urea, thiosulfate,
ammonium nitrate, urea ammonium nitrate (UAN), 10-34-0 liquid
fertilizer, mono-ammonium phosphate, diammonium phosphate, zinc
chloride, liquid ammonia, and/or potash. Also added in this second
pug-mill or granulator is any additional iron required. The iron
contributes an important and valuable plant nutrient to the
fertilizer mix, serves as a granulation aid and as described in the
invention earlier serves to reduce noxious odors associated with
the use of the community organic materials.
[0100] Also, additional ammonia may be sparged into the pug-mill
and into the granulator directly to complete the formation of the
ammonium salt and to control the pH of the mix and to facilitate
the formation of the finished granule. The solids used to adjust
the pH may also be principally alkaline agents selected from the
group comprised of calcium carbonate, sodium hydroxide, potassium
hydroxide, calcium oxide, cement kiln dust, lime kiln dust, Class C
fly ash, Class F fly ash, multistage burner ash, alum, alum
biosolids from water treatment and wood ash. These are added via
screw conveyors at specific rates for each compound. The liquid
additions also include pH adjustment materials such as acids, e.g.,
phosphoric acid or sulfuric acid, or caustic solutions, e.g.,
ammonium hydroxide, sodium hydroxide or potassium hydroxide. These
are pumped at respective rates to the injection ring to enter the
pug-mill.
[0101] The fertilizer product of the present invention preferably
has a pH of between 4.5 and 7.5, more preferably between pH 5.0 and
pH 7.0, and more preferably between pH 5.5 and pH 6.9. The
remainder of the processing for shaping as in pellet or granule
production includes standard fertilizer granulation technology
especially for high volume throughput plants. The pellet or granule
product, especially in smaller throughput plants considered to be
those of less than 25 tons product production per day, may involve
more innovative technologies such as injection or extrusion
followed by milling or spherulizing the pellet or granule or
involves simple discharge from a granulator or granulating
pug-mill. When a granulator or granulating pug-mill is used, it is
preferable to feed some recycle, as in dry seed material, i.e., dry
fines and fines produced by the crusher or mill or
sub-specification or reclaim material of the fertilizer product,
into the pug-mill and the granulator to adjust the percent moisture
present in the mix so that agglomeration or nucleation can occur
resulting in granule formation.
[0102] Other preferred embodiments comprise adjustments to the
processes disclosed herein. Embodiments incorporate a pelletizer in
place of the granulator in the process train. The pelletizer may
include the drying step to the preferred dryness or the formed
pellets may then be transferred to a dryer, preferably a fluidized
bed dryer to reach the preferred dryness. These other embodiments
may also incorporate adjustments to control pH, dryness, nutrients
in the product, shape, concentrations etc. to produce a plethora of
fertilizers specific for different plants such as roses,
rhododendrons, and any other flowers, vegetables, herbs, as well as
specialty crops such as fruits and vegetables and unrelated
products such as cat litters. Adjustments can also be made
according to the geographic area in which the product is to be
applied, to vary, for example, nutrients that may be inherently or
otherwise missing in the location. Examples of such variations
include the addition of calcium, potassium, phosphorus and metals
such as magnesium, manganese, boron and zinc in different
amounts.
[0103] Normal drying for final drying is conducted using a
horizontal fluidized bed dryer, or a rotary drum dryer. The dried
pellets or granules which are greater than 92 percent solids and
preferably are greater than 95 percent solids and more preferably
are greater than 98 percent and even more preferably are greater
than 99 percent solids are then sized through one or more screens.
The specification size may be varied dependent upon customer
requirements, however, the range of suitable product for sale is
between 0.5 mm and 4 mm with the commercial range for normal sized
fertilizer is between 2 mm and 3 mm. The present invention also can
manufacture a minimal sized product suitable for use in golf course
applications which ranges from 0.5 mm to 1.3 mm. The proper sized
material is separated and then cooled and then coated and then
cooled in an apparatus, preferably a rotary drum, to less than
60.degree. C. (140.degree. F.), preferably to less than 49.degree.
C. (120.degree. F.) and more preferably to less than 43.degree. C.
(110.degree. F.). Cooling the granule or pellet optimally occurs in
a rotary drum apparatus using ambient air or cooled air as from an
ammonia evaporation cooler. Coating may occur in a coating vessel
specifically for that purpose typically a rotary drum or a mixer.
Alternatively, cooling and coating may be accomplished in a single
vessel which cools the material and mixes the coating agent with
the granules. Coating is with a de-duster or glazing material which
minimizes dust generation during transport, storage and
application. The finished coated granule or pellet is then conveyed
to storage as finished high nitrogen containing bioorganic-enhanced
inorganic ammonium fertilizer until shipment from the manufacturing
site. Properly coated and dried pellets or granules have a hardness
of greater than 5 pounds crush resistance in order to resist
dusting and handing during transport, shipment and application. The
de-duster coating or glazing material often requires a higher
temperature, often 71.degree. C.-105.degree. C. (160.degree. F. to
220.degree. F.), to maintain a molten condition for application in
the coating apparatus.
[0104] The granule storage facility or warehouse, usually
incorporating bins or silos to contain the granules, must be dry to
prevent agglomeration of the granules leading to degradation and
destruction. The finished product is upon manufacture a sterile
fertilizer having substantially no detectable amount of viable
microorganisms, such as E. coli or streptococci, or viruses harmful
to animals or humans. Even upon storage the product has
substantially no viable microorganisms which means that the
fertilizer is microbially-safe and has no detectable amount or a
detectable amount well below a threshold for safe handling and use
of microorganisms originating from the organic materials. Although
the fertilizer is rendered sterile during manufacturing,
contamination can be expected from external air-borne
microorganisms or by microorganisms deposited by animal or other
contamination during storage or use. In any case, because the
fertilizer product is dry and predominantly inorganic ammonium
salts will not support microorganism multiplication at a rate which
would lead to an animal or public health problem.
[0105] The fertilizer of the present invention is preferably
chemically adjusted to fit the needs of nitrogen fertilizer
requirements containing significant amounts of phosphate, sulfur
and iron to enhance the targeted nitrogen (N) content of between 8
and 18 percent by weight, and preferably 16 weight-percent
permitting significant commercial valuation.
[0106] FIGS. 1A-C and 2A-C provide schematic diagrams of
embodiments of the present invention, wherein the process of these
embodiments utilizes dewatered municipal biosolids combined with
additional plant nutrients, ammonium salt fertilizers, and binding
agents. In this example, the organics to be treated is a dewatered
municipal biosolids, often referred to as a "biosolids cake." This
biosolids are delivered to the manufacturing facility where they
are stored in a storage bin or silo until the biosolids are ready
to be conditioned. The conditioning initially takes place in a
first pugmill by a vigorous mixing or blending with iron or other
agent for odor control, which converts the thixotropic biosolids
into a pumpable mix, paste, or paste-like mix. The iron reacts with
reduced sulfur compounds and other odorants present in the
biosolids. If phosphoric acid is added to this first pugmill it
assists in modifying odorants present in the biosolids and
contributes the majority of the phosphorus nutrient found in the
final product. As the biosolids proceed through the equipment train
additional plant nutrients can be infused into the mix. In this
embodiment biosolids are optionally heated during their passage
through the pugmill prior to being pumped to the first reaction
vessel. In the preferred embodiment shown here one or two sulfuric
acid streams (in a concentration range of 68 percent up to 105
percent sulfuric) are injected into the vessel where in the mix is
acidified and liquefaction commences. Once the mix exits the first
pressure vessel it is transferred under pressure into a second
pressure vessel where the primary nitrogen infusion reaction
occurs. In these figures, a sparger injects ammonia (or other
nitrogen source) as a gas or liquid. This reaction in both vessels
is carefully controlled to optimize temperature, pressure,
retention time, and pH, all of which can be empirically determined
based on the input organic materials and the desired output content
of organics. The pressure vessels include a plurality of valves and
controls that serve to automate the system. Additives can be used
to control the temperature, pressure, and pH and nutrient levels.
The nitrogen source that is pumped into the pressure vessel
comprises a base, such as anhydrous (either liquid or vaporized) or
aqueous ammonia. A mix of organics and ammonium sulfate and
ammonium phosphate (if phosphoric acid is used) is formed that
becomes molecularly integrated in that the ammonium ions become
electrically bound to the amphoteric organic molecules from the
biosolids thereby creating a slow release or enhanced efficiency of
nitrogen in the final fertilizer granule. Similarly, this electric
bonding can occur between the sulfate and phosphate and iron (or
other plant useful metals such as magnesium, calcium, copper,
manganese, boron or zinc) molecules present in the mix thereby
rendering these nutrient molecules similarly to a slow-release or
enhanced efficiency release state. This mix is maintained in a
stress condition for a retention period as determined by its
retention time (which in turn is based on the head pressure and
release volume as described herein) as the mix moves through the
pressure vessel. The stress condition preferably includes elevated
temperature, and/or elevated pressure. The elevated temperature is
produced partly or entirely by the exothermic reaction of the
components, which can increase the temperature of the mix. In the
preferred embodiment 100% of the elevated temperature is provided
by the exothermic reaction. At these temperatures steam is
generated from the mix. This steam is allowed to exit the pressure
vessel under valve-controlled release, accomplishing a partial
drying of the mix. The release of moisture from the exothermic heat
allows the use of less fossil fuels such as natural gas to dry the
fertilizer granules. This reduces the formation of carbon dioxide
or greenhouse gas by approximately 40% compared to the production
of heat dried biosolids or the production of standard commercial
fertilizers such as urea. This generation of chemical heat makes
the fertilizer of this invention very green and environmentally
friendly. The stress condition the biosolids undergo in the
pressure vessel and the retention period are controlled so as to
result in the production of a mix that is sterile and that contains
hydrolyzed macromolecules from the organics. Control of the stress
condition and the retention period also results in the fusion of
the ammonium ions formed with the organic molecules present
creating an organic matrix which is a natural slow-release property
for the nitrogen and other nutrients present, and the
denaturization and or hydrolysis of many macromolecules present in
the organics, such as proteins, plastics and other polymers. When
such molecules are biologically active, this denaturization and/or
hydrolysis renders them less active or inactive thereby creating a
safer product for public usage or exposure. The retention time to
induce the necessary fertilizer properties and biological
inactivation are controlled by the continuous pumping and flow of
the organics into the pressure vessel. This continuous flow
processing of the invention versus the traditional batch processing
of older plants aids the high throughput of this invention. The
continuous flow also minimizes the problems associated with
clogging of the process necessitating down time to clear the
clog.
[0107] The liquid organics melt mixture flows from the pressure
vessel and, optionally, is mixed with a hardening agent or agents
and possibly additional nutrients to fine tune the fertilizer as
desired. That mix is further treated by granulation or extrusion
into granules such as pellets or other, smaller structures. The
granules are dried in rotary dryer and passed through one or more
screens to separate oversized materials and undersized materials
from proper-sized materials. The oversized materials can be crushed
in a crusher or mill. Subsequently, the undersized materials and
the crushed oversized materials can be recycled to facilitate the
granulation of the fertilizer mix. The resulting proper-sized
granules are then dried in rotary cooler, sized, coated, cooled and
stored. When a traditional granulator is used in the shaping
process, ammoniation by vaporized ammonia and recycle addition may
occur. Water removed from the mix as steam from the pressure vessel
and from subsequent vessels as steam and/or water vapor may be
condensed and preferably returned to the wastewater treatment plant
(WWTP), or may be treated and discharged into adjacent water
resources, or into the atmosphere. Water that is retained from the
capture of ammonia in the process emission air is returned to a
process water containment vessel or alternatively may be contained
in a separate tank for conversion to a saleable liquid
nitrogen-containing fertilizer. This liquid fertilizer may have its
nutrient formulation directly changed by the addition of other
nutrient compounds selected from the group: potash or other forms
of potassium, e.g., potassium hydroxide or potassium sulfate, urea,
thiosulfate, ammonium nitrate, urea ammonium nitrate (UAN), 10-34-0
liquid fertilizer, mono-ammonium phosphate, diammonium phosphate,
zinc chloride, liquid ammonia, potash, iron containing compounds
and or other traditional inorganic fertilizers.
[0108] For optimal odor control of the process and optimization of
the odor of the resultant fertilizer from the present invention
this process water may be treated with 25 percent to 50 percent
liquid hydrogen peroxide to eliminate most of the chemical odorants
associated with this process water before it is subsequently added
to the biosolids mix immediately prior or in the first pugmill.
Alternatively, the odorous process water can be treated with
gaseous ozone which is bubbled by diffuser through the process
water thereby also eliminating the majority of odorant associated
with this water.
[0109] In another embodiment a series of reaction vessels may be
used to accomplish the acid/base reactions described herein. In a
preferred embodiment of the present invention the sequence of two
reactor vessels can be utilized. In one optional embodiment a
combination of one reactor vessel for acid reaction can be followed
by an ammoniation conducted in a pipe-cross reactor. In another
embodiment the reactions could be carried out in the sequence of a
first pipe-cross reactor for acidification of the biosolids mix
followed by the ammoniation conducted in a pressure vessel. Also
described is an embodiment whereby the acidification reaction is
conducted in a first pipe-cross reactor followed by the ammoniation
reaction in a second pipe-cross reactor.
[0110] Another embodiment of the present invention can have the
acidification of the biosolids mix to partly or fully occur in the
first pugmill. The partly or fully acidified biosolids mix could
then be treated by ammoniation in a first reaction vessel thereby
eliminating the need for a second reaction vessel. If the mix were
partially acidified the acid/base reaction could then be completed
in this first vessel or the incomplete mix transferred to a second
reactor vessel (or pipe-cross reactor) for completion.
[0111] Another embodiment of the invention is directed to a system
for the manufacture of a product from organic materials treated in
accordance with the method of the invention as described herein.
The combination of pressure, heat and ammonia treatment destroys or
otherwise inactivates toxins and other hazardous compounds that are
present in an otherwise contaminated organic material. The
resulting product may be used as a fertilizer or other nutrient or
support for plants and/or animals. The fertilizer product of this
invention is of homogeneous construction containing multiple
nutrients.
[0112] Fertilizers made by the methods of the invention may
optionally include one or more of anionic and cationic chemicals,
chelating agents, ionic sequestering agents, metal ions, citric
acid, amino acids, glutamic acid, histidine, lysine, glycine,
peptides, proteins, sugars, saccharides and polysaccharides, iron,
sulfur, phosphorous and nitrogen-binding compounds and combinations
thereof. Nitrogen-binding agents include, for example, amino acids,
lysine, peptides, polypeptides, ammonium-N. These agents can be
utilized by plants even before they develop a nitrate-N reduction
system and is as a result very energy efficient. Ammonium-N
(NH.sub.4.sup.+) in fertilizer of the invention requires less of
the plants' stored metabolic energy for incorporation into plant
components. Plants can use both ammonium and nitrate N but
ammonium-N is a more energy efficient form of nitrogen for plants
and is less leachable. That means that more sugars formed by
photosynthesis can be stored in grain or fruit as starch resulting
in increased yield. Utilizing ammonium nitrogen can save 10%-17% of
photosynthetic energy which plants have stored.
[0113] Preferably, fertilizers of the invention, when applied to a
crops, releases nutrients such as nitrogen to soil at a rate slower
than such components are releases by fertilizer containing
non-organic fertilizers such as fertilizers that use urea as the
nitrogen source. Fertilizers of the invention are preferably
supplemented with nutrients comprise one or more of nitrogen,
phosphorus, potassium, sulfur, iron, manganese, magnesium, copper,
calcium, selenium, boron, zinc and combinations thereof, and those
nutrients are chelated or electrostatically bound to the organic
matter of the fertilizer. Fertilizers of the invention are
preferably homogenous in composition, non-hydroscopic and black or
very dark in color.
[0114] Crops to which the fertilizer of the invention are applied
show improved soil tilth, stress resistance to heat and drought,
and improved soil micro-ecology as compared to non-organic
fertilizer. Preferably fertilizers have a hardness of between 4 and
9 pounds, more desirably between 6 and 8 pounds and/or a bulk
density of between 52 and 56 pounds/cubic foot. Also preferably,
fertilizers have a content of from 8-17% nitrogen, from 0-10%
phosphorus, from 0-10% potassium, from 5-20% sulfur 5 to 20%, from
0-5% iron and from 5-20% organics. Preferably fertilizers of the
invention, when applied to a crop, provides one or more nutrients
to the crop sufficient for all or a portion (e.g., half, quarter)
of a single growing season.
[0115] Fertilizer of the invention provides for an increased
nutrient uptake by crops such as nitrogen. Crops show increased
root growth and density, increased bulk and biomass and, preferably
increased number and/or size of seed, fruits and/or flower. The
ammonium ion negates the possibility of nitrogen losses by leaching
and denitrification by soil bacteria which can be sizeable in
nitrogen fertilizer that do not contain ammonium as compared to
inorganic fertilizers. Preferably upon application to crops, the
fertilizer does not lose greater than 5% of its contained nitrogen
(N) to the atmospheric environment upon surface application to a
dry soil and not more than 35% from a flooded soil. Preferably
fertilizer delivers nutrients such as, for example, iron, nitrogen,
phosphorous, in a plant-available form as compared to non-organic
fertilizer.
[0116] Preferably crops to which have applied fertilizer of the
invention show improved nutrient use and efficiency, such as iron,
by retaining the iron primarily in the plant-available ferrous ion
form, and contributes to the carbon nutrient pool available for
crop production in the soil column.
[0117] The following examples illustrate embodiments of the
invention, but should not be viewed as limiting the scope of the
invention.
EXAMPLES
Example 1
[0118] Wet community organics comprised of biosolids from a
municipal waste water plant are received at the fertilizer
manufacturing plant of this invention with a percent solids of 16.0
percent. The plant is set up to operate at a wet biosolids
processing rate of 220 wet tons per day. A portion of this 16%
solids material was dried in a pre-dryer to 85% dry solids at a
rate to yield sufficient 85% dry material to mix with the 16%
material to yield a preferred percent solids of 20% to 26% but more
preferably 22% to 24% solids. Additionally, a dry solids material
of iron sulfate was mixed in the same mixer sufficient to yield a
concentration of 3% iron in the finished fertilizer. This
conditioned organics mix is then pumped into the first hydrolysis
vessel wherein at the orifice of the pressure vessel it is mixed
with 93% sulfuric acid in an amount pre-calculated to yield a
degree of heat of hydration of 110.degree. C. (230.degree. F.) and
a total of 17% sulfur in the finished fertilizer. The contents of
the first pressure vessel are mixed vigorously at a rate of 360 RPM
for six minutes within the vessel as the acidified mix gradually is
forced to the upper quarter of the vessel where in it is discharged
after six minutes of reaction in the first vessel. In this first
vessel the contained proteins from the community organics are
hydrolyzed to various length polypeptides and monomeric amino
acids. Other macro-organic compounds are also hydrolyzed to smaller
molecular forms thereby increasing the fluidity of the contents of
the vessel to preferably less than 1000 cP. This fluidized
acidified mix is then transferred under pressure to the bottom
orifice of the second pressure vessel or the ammoniation vessel
wherein it is mixed with vaporized anhydrous ammonia sufficient to
raise the temperature of the mix to over 150.degree. C.
(300.degree. F.) and the internal pressure of the second vessel of
over 35 psi and sufficient to cause the concentration of nitrogen
(N) in the final formulation of the resultant fertilizer to between
16% and 17% nitrogen by dry weight of the finished product. The
ammoniated mix is maintained in the second pressure vessel for six
minutes of reaction time before it is discharged through an orifice
that can be valve controlled to the granulator. The discharged mix
or melt is slightly increased in viscosity compared to the
discharge of the first pressure vessel but preferably less than
1200 cP. This discharged melt is under pressure and therefore when
it enters the granulator is sprayed onto a receiving bed of crushed
fertilizer material or undersized fertilizer material or fertilizer
dust material collected from the various dust collectors contained
in the process air treatment system. The spray coats the receiving
fertilizer material and gradually builds up a series of coatings or
agglomerated material such that the granular fertilizer is produced
in which the majority of the material is of the proper product size
such as the 1.7 mm to 3.0 mm (170 sgn to 300 sgn; "size guide
number") diameter granules that are suitable for use in commercial
agriculture. The granulator in this example also received an amount
of potash sufficient to cause the final concentration of potassium
to be 2% by dry weight of the finished product. The granulator also
received an amount of molasses sufficient to cause the hardness of
the finished granules to reach a range of 5 lbs. to 8 lbs. crush
strength (e.g., from 0-2% by weight, preferably less than 1%). This
material is then dried to over 98% solids in a rotary drum dryer
and then screened to one of three commercial sizes of 1.7 mm to 1.9
mm, 1.2 mm to 1.4 mm, and to 2.6 mm to 3.0 mm. All smaller material
is returned to the granulator as part of the recycle bed. All
larger material is crushed in a chain mill and then returned to the
granulator as part of the recycle. A portion of the proper sized
product, preferably 2.6 mm to 3.0 mm for commercial product size,
may also be returned to the recycle bed to maintain the mass
balance of the production process. All of the steps of this process
were maintained in this example under negative pressure so that no
process dust or odors are released into the manufacturing
environment. All process air was treated through a robust odor
control system such that no noxious odors were perceived at the
fence line of the manufacturing property. Scrubbed nutrients such
as ammonium, now ammonium sulfate, were returned to a process water
tank wherein it was added to the first mixer to help control the
solids and fluidity of the conditioned mix entering the first
pressure vessel. In this way the efficiency of the manufacturing
process can be optimized so that the only discharges from the
fertilizer manufacturing process are treated condensed water (from
the municipal organic material and any cooling water that may need
to be discharged from the cooling system) along with the treated
process air. In the fertilizer manufactured by this process
described the slow release percentage of nitrogen was 30% of the
total nitrogen in the product. This slow release nitrogen is in the
form of an organic matrix in which the positive charged ammonium
ion is electrostatically bound to a negative charge on the organic
compounds such as polypeptides and amino acids that comprise the
core of the matrix. The product of this example of the invention
contained a 99% dry granular fertilizer with a nutrient formulation
of 16-1-2-17-3-16 (N--P--K--S--Fe-Organic) by dry weight of the
finished granular in which 33% of the nitrogen is in a slow-release
form.
Example 2
Ammonia Absorption
[0119] In this example the fertilizer was manufactured by a similar
process with the difference that an amount of ammonia absorbing
compound, such as Nutrisphere-N (commercially available from
Verdesian Life Sciences), a proprietary nitrogen binding agent, was
added into the granulator such that the slow-release component of
the N is increased to 45% N from the standard 30% of total N. This
increases the commercial value of the fertilizer and rendered 15%
more of the contained nitrogen available in the stages of crop
growth later than 2 weeks following the original field application
of the fertilizer product.
Example 3
Nitrogen Release Profiles
[0120] Nitrogen release profiles of the organically modified
ammonium sulfate of the invention are determined in comparison to
traditional, pure ammonium sulfate fertilizer and pure biosolids as
controls. First, ammonium sulfate is applied over sterilized sand
in a laboratory environment (ambient temperatures with no sun,
water or soil organisms) and allowed to permeate the sand over a
period of time. As can be seen in FIG. 6, about 90% of the nitrogen
of AS is released through the sand within about one week of
application. In comparison, about 35% of the nitrogen of
traditional biosolids is released which increased to about 70% over
two weeks where it remained. Organically augmented ammonium sulfate
of the invention released about 60% of its nitrogen within the
first week which increased to about 70% over two weeks.
[0121] Also, a theoretical nitrogen release profile is determined
for these same three fertilizer materials in normal soil. Soil is
presumed to contain microorganisms that break down
nitrogen-containing molecules thereby releasing additional nitrogen
into the soil. As can be seen in FIG. 7, ammonium sulfate again
releases its nitrogen content within the first week. Pure biosolids
release only about 30% of its nitrogen in the first two weeks,
which gradually increases to about 90% over a period of 26 weeks.
However, organically modified ammonium sulfate prepared according
to the processes of the invention releases just under 60% of its
nitrogen over two weeks which gradually increased to about 90% over
the next 26 weeks. Thus, organically modified ammonium sulfate
fertilizer prepared according to the processes of the invention
initially releases just over half of its nitrogen and slowly
releases the remaining half over a period of weeks to months. This
two-stage nitrogen release profile (e.g., dual-release, two-step
release, combined fast/slow release) is characteristic of the
fertilizers of the invention.
Example 4
Ammonium Nitrogen
[0122] One product of the invention contains 16% nitrogen primarily
in the ammonium form. Depending on the situation where the product
nutrient is applied, this amount will provide sufficient nitrogen
or the product can be supplemented by blending with additional
nitrogen sources. Normally when plants are fertilized, they have a
high demand for nitrogen to drive the rapid growth and development.
The product releases approximately 60% of its nitrogen immediately
in the form of NH.sub.4.sup.+-N , which is readily available and
usable by plants (see FIG. 11). Ammonium-N can be utilized by
plants even before they develop a nitrate-N reduction system which
is energy efficient as well. The efficient utilization of nitrogen
early in growth produces studier plants that have increased disease
resistance and greater growth potential in all respects including
root density, leaf number and broadness, and flower and seed
production. Nitrogen uptake as ammonium negates the possibility of
nitrogen losses by leaching and denitrification by soil bacteria
which can be sizeable. The balance of the product nitrogen becomes
available via the natural slow release mechanism of bacterial
action which can break the bonds between the OM and the nitrogen as
shown in FIG. 11. This system can be altered by variations of soil
type, temperature, and other parameters.
[0123] A controlled nitrification study was performed with product
of the invention (Anuvia), urea and urea plus agrotain. Results are
shown in FIG. 9 which demonstrates that the fertilizer product of
the invention (FIG. 9A) converts nitrogen more slowly that
commercial urea (FIG. 9B) or urea plus agrotain (urease inhibitor)
(FIG. 9C).
Example 5
[0124] Four female hormones and a common herbicide were
quantitatively mixed with a wet municipal biosolids cake prior to
the biosolids being processed by an embodiment of the invention.
The combination of process stresses, such as extremely low pH of
less than 0.1 pH in temperature environment greater than
110.degree. C. (230.degree. F.) for six minutes followed by
exposure to vaporized anhydrous ammonia under a pressure of 40 psi
and a temperature of 200.degree. C. (390.degree. F.) for six
additional minutes, caused a loss of over 96% of the detectability
of these endocrine disruptor compounds (see FIG. 10). Such a
molecular destruction by the process of the present invention of
bioactive compounds that can be found in municipal organic
materials renders the resultant fertilizer product inherently
safer.
Example 6
Potassium
[0125] Plants require potassium (K) is amounts second only to
nitrogen. Potassium in fertilizers is often referred to as potash
and listed in fertilizer analyses as K.sub.2O. However, plants take
up and utilize only the potassium ion. Potassium impacts crop
quality and is particularly important in carbohydrate and starch
synthesis, making adequate potassium critical for high-carbohydrate
crops like potatoes, sugar cane, sugar beets, citrus and
grapes.
[0126] It is an enzyme activator that helps plants withstand
moisture stress and helps perennial crops like alfalfa avoid winter
kill by ensuring the plants have enough stored starch in their
roots to get through the winter. Potassium, like nitrogen, also
helps plants produce protein as they grow. Potassium effects on
crops include: increased weight per kernel and more kernels per ear
in corn; increased oil content in soybeans; improved milling and
baking quality in wheat. Potassium can be plentiful in some soils,
but as with nitrogen (N) and phosphorus (P), the problem is
availability. Up to 98 percent of potassium in the soil is
unavailable to plants in its existing form. The fertilizer product
described herein contains a modest amount of this essential element
in the potassium cation form (K.sup.+) but can be supplemented in
the formulation or in the crop fertilization program by blending
with other blended fertilizers.
Example 7
Sulfur
[0127] Sulfur is an essential nutrient in crop production and has
been classified as a secondary element, along with Mg and Ca, but
now is more commonly considered "the 4th major nutrient". Some
crops can take up as much sulfur S as phosphorus. Sulfur has become
more important as a limiting nutrient in crop production in recent
years for several reasons. These include higher crop yields that
require more sulfur, less sulfur impurities in modern fertilizers,
less use of sulfur-containing pesticides, reduced industrial sulfur
emissions to the atmosphere, and a greater awareness of sulfur
needs. Plants can only use sulfate-S, which is susceptible to
leaching like nitrate.
[0128] Sulfur serves many functions in plants. It is essential in
the formation of amino acids, proteins, and oils. It is necessary
for chlorophyll formation, promotes nodulation in legumes and is
essential for atmospheric nitrogen (N.sub.2) fixation, helps
develop and activate certain enzymes (nitrate reductase), and is a
structural component of two of the 21 amino acids that form
protein. Sulfur also provides plant health benefits in crop
production. The form in which the product delivers sulfur
(SO.sub.4.sup.= Sulfate ion) is the only form that the plant can
utilize.
[0129] The plant essential sulfate sulfur in the product of the
invention is both immediately and slowly available to plants and in
a usable form. This is in contrast to other sulfur containing
products which contain elemental sulfur which must be oxidized by
soil bacteria to the sulfate form in order for it to be utilized by
plants. That process is affected by a number of factors including
size of the elemental sulfur particles, soil temperature, soil pH,
soil moisture and the activity of sulfur-oxidizing organisms in the
soil. Sulfur binding to the organic matrix in the product is less
leachable under excessive rainfall conditions than sulfur from
ammonium sulfate.
Example 8
Iron
[0130] Iron (Fe) is one of the essential micronutrients which
include zinc (Zn), manganese (Mn), copper (Cu), molybdenum (Mo) and
boron (B). Iron is involved in many biochemical processes in plants
including photosynthesis, respiration (utilization of stored
sugars), oxidation-reduction reactions, symbiotic nitrogen fixation
by legumes (Rhizobia bacteria) and the formation of chlorophyll.
Iron deficient plants are notoriously chlorotic and severity of the
chlorosis varies with the genetics of the particular plant species.
The problem develops as soon as the plants germinate and grows
worse as time goes by. Plants can only use ferrous iron
(Fe.sup.+2). Most of the iron in the soil is in the unavailable
ferric (Fe.sup.+3) form. When iron is added to the soil in an
inorganic form such as ferrous sulfate (FeSO.sub.4), normal soil
reactions quickly convert (oxidize) it to the ineffective ferric
form. High soil pH and low organic matter content contribute to
iron availability and uptake problems. Conditions in the
rhizosphere (region around plant roots) have tremendous effects on
Fe availability and uptake and vary widely with varietal
differences in the same species.
[0131] Over the years, many types of iron-containing fertilizers
have been developed but few have been both effective and economic.
Soil applications have been particularly ineffective. High cost
chelated forms of iron have been the most effective but economics
have been a limiting factor. Foliar sprays or frequent applications
of very acidic iron fertilizers have diminished the chlorosis but
must be repeated several times during the growing season. Yet, the
conditions remain and the problems recur.
[0132] The sequestered ferrous iron in product of the invention is
less subject to the undesirable soil oxidation reactions which
convert to the unavailable ferric iron form. The products' organic
matrix provides an excellent vehicle to effectively deliver iron in
the ferrous form which is usable by plants. Having iron available
in a usable ferrous form contributes to the carbon nutrient pool,
improving ion exchange, improving the micro-ecology in the root
zone, improving soil tilth, and increasing plant stress resistance
to heat and drought.
Example 9
Lower Ammonia Volatilization and Higher Crop Yields
[0133] An ammonia volatilization study conducted by IFDC on two
soils under upland and flooded conditions, demonstrated that the
invention's fertilizer product had significantly lower NH.sub.3-N
volatilization loss than urea. In general, the fertilizer of the
invention had similar NH.sub.3-N volatilization losses as ammonium
sulfate on both the soils and under both flooded and upland
conditions. However, on the upland soil, the Invention's fertilizer
had significantly lower losses at 2.5% of applied N fertilizer,
compared with ammonium sulfate at 3.2%. Compared to urea where the
percentage of applied nitrogen loss due to NH.sub.3-N
volatilization under upland conditions was 27-33%, the NH.sub.3-N
volatilization loss by the invention's fertilizer was only 2.5-3%
of applied nitrogen fertilizer. Under flooded conditions percentage
of applied nitrogen loss from urea due to NH.sub.3-N volatilization
loss was 59% and 61% for the two soils, while invention product
losses were 26 percent and 32 percent. Field studies of rice
fertilization in Arkansas showed a 20 bushel per acre average yield
advantage for a hybrid rice with the invention's fertilizer
compared to urea when applied to the soil surface 1-10 days prior
to flood.
Example 10
[0134] In this example, a higher percentage slow-release nitrogen
is created. In Example 1 above the product of the invention
contained 325 pounds of organic material per 1 ton of product. This
one ton of product contains 16% nitrogen or 320 pounds of nitrogen
per ton of product. Of this 320 pounds of nitrogen, 33% is
slow-release (105.6 pounds) as a result of the formation of the
organic matrix complexes whereby the positive charged ammonium ions
and the negative charged sulfate ions are electrostatically bound
to the opposite charges contained in the amphoteric organic
molecules contributed by the community organic materials. In other
words, the efficiency of slow-release nitrogen is 105.6 pounds of
slow-release nitrogen per every 325 pounds of municipal organics
contained in the final product mass or 105.6/325 equals 32.5
percent. By increasing the total organic mass of the final
fertilizer product with additional community organics such as
biosolids, as in replacing other heavier components of the
fertilizer, the two percent potassium mass in the product in the
Example 1, the amount of organic in the final product is increased
to 433 pounds, that is a final product nutrient composition of
16-1-0-17-21. At an average efficiency of 32.5% which yields a new
amount of slow- release nitrogen of 140.7 pounds or an increase of
44.7 pounds of slow-release nitrogen per ton of the product of this
invention. The percent slow-release nitrogen in this example is
increased from 33% to 140.7/322.5 (2.5 pounds of N are contributed
by the additional 40 pounds of organics=43.6 percent. Substitutions
are made for different amounts of the potassium or the iron
component in the fertilizer composition to produce the desired or
specific amount of slow-release nitrogen without changing the
amount of added total nitrogen in the final product of the
invention.
[0135] Other embodiments and uses of the invention will be apparent
to those skilled in the art from consideration of the specification
and practice of the invention disclosed herein. All references
cited herein, including all publications, U.S. and foreign patents
and patent applications such as U.S. Pat. No. 8,105,413; U.S. Pat.
No. 7,662,205, U.S. Pat. No. 7,513,927, U.S. Pat. No. 7,662,206,
U.S. Pat. No. 7,947,104, and U.S. Pat. No. 8,992,654, are
specifically and entirely incorporated by reference. The term
comprising, where ever used, is intended to include the terms
consisting and consisting essentially of. It is intended that the
specification and examples be considered exemplary only with the
true scope and spirit of the invention indicated by the following
claims.
* * * * *