EP0536149A1 - Method of manufacturing sterilized organic fertilizer and apparatus therefor - Google Patents

Abstract

Method and device for sterilizing organic fertilizer, said method comprises the step of formulating, in the mixing sections (1 and 2) of wet and dry ingredients, constituents of the composite fertilizer, after which said constituents are treated with an acid to form an acidic mixture (i.e. with a pH below 5) in the sterilization reactor (33). The bacteria in the mixture quickly adapt to the acid environment and proliferate there. The constituents are then treated with a basic material, such as anhydrous ammonia, NH3 from a tank (38). The transition from a strongly acidic to moderately acidic or basic pH is of such an abrupt nature that bacteria cannot adapt to the changed pH as well as to changes in heat which leads to their death in the space of a few seconds. The finished fertilizer product (51) is therefore made sterile from the point of view of bacteria, otherwise the bacteria would proliferate and consume the nitrogen contained in the fertilizer. The nitrogen in the fertilizer is then safely contained in the organic fertilizer. Nitrogen is then released when applied to the soil when bacteria at ground level feed on the fertilizer. The bacteria consume nitrogen and they modify the constituents transforming the elements into nutritive substances allowing the growth of plants.

Description

METHOD OF MANUFACTURING STERILIZED ORGANIC FERTILIZER AND APPARATUS THEREFOR

BACKGROUND OF THE INVENTION

Field; The invention is directed to organic fertilizers together with methods and apparatus for their manufacture including sterilization and enriching. Statement of the Art: Over the years chemically treated soils have been found to undergo a decrease in fertility and a reduction in the quality of plants produced. The microbiological community has been found to have been altered. The soil has becoming nearly sterile of living organisms. The soil became hard, less capable of taking in water. Humus, the primary nutrient conveyor from soil to plant, is decreased and soil tilth is greatly reduced. In healthy soils metabolites that can be directly assimilated by the plants are acted upon by the soil microbes to generate vitamins, auxins, gebberellins, antibodies, enzymes, and hormones.

Agronomists worldwide are now recognizing that the exclusive use of chemical fertilizer is harmful to the soil's natural ability to microbiologically replenish plant nutrients. In the United States, top soil is considered one of the nation's greatest natural resources. However, since the advent of chemical fertilizers in 1940 and the subsequent changes in farm practices, the natural microbiology humus content of U.S. top soil has depleted from 4%-6% of the topsoil to today's humus content of only about 1.5% of the topsoil's content. At a 2.5% organic matter level, leaching cannot be controlled. Below a 2% level, there exist insufficient metallic trace elements to form good enzyme systems in plants. A recent approach to fertilizer use has been expressed by the maxim "feed the soil's bacteria, and the soil's bacteria will feed the plants." Bacteria alter fertilizer constituents making them assumable as nutrients for the growth of the plants. Before they are suitable for plant use, microbes activity typically causes alterations changing compounds to the "ate or ide" form such as nitrate, phosphate, sulphate, chloride, borate, and molbedate. The necessity that fertilizer be water soluble is a misnomer. Producing organic fertilizer by composting leads to as much as 60-80% losses in loss of nutrients. Appreciable quantities of nitrogen in the form of NH₄ are lost during the composting process due to the breakdown of proteinacεous compounds found in the original organic materials. Further, nutrient loss results from the bacterial oxidation of the original organic material. This oxidation is represented by the following expression: + 60₂ → 6C0₂t + 6H₂0t + energy As indicated by the expression, oxidation results in the loss of carbon to the environment in the form of carbon dioxide. Further, energy is also lost to the environment. Composting is a destructive process, which results in the reduction of high energy molecules to a final low energy form. Also, the subsequent spreading of composted material onto farm land effectively plants weed seeds in the farm land. Thus, composting is not generally viewed with favor as an efficient means of producing a viable organic fertilizer. There continues to be a need for means of producing organic fertilizers having high nutrient contents while avoiding the many drawbacks associated with the composting method of producing such fertilizers.

SUMMARY OF THE INVENTION

The present invention provides an apparatus and method for promoting nitrogen, mineral, and nutrient retention in an organic fertilizer product so that the retained nutrients can later be assimilated by bacteria residing in the soil being fertilized. The bacteria in turn utilize the fertilizer to produce substances which may be taken and used by plants for their enhanced growth. It has been discovered that plants are fed from matter acted upon by soil bacteria. The bacteria, in turn, are fed by the nutrient components of an organic fertilizer. This plant growth cycle is in opposition to the old adage that "fertilizer feeds the soil and the soil feeds the plants." Thus, fertilizer is a food for soil- borne bacteria. In the instant invention, the manufactured fertilizer is produced sterile of bacteria so that it remains intact, inert and unaltered until its application on the soil.

The total nutrient content of the organic material is largely locked into the material at the time of processing. The processing makes the energy of complex molecules contained within the fertilizer available to soil microbes upon the subsequent application of the processed fertilizer to the soil.

The instant process provides a fertilizer which is well adapted for working in harmony with the natural processes occurring in the soil. An example of this is the conversion of the a ino acids NH₂ NH₃ by common heterotrophic bacteria. NH₃ is rapidly converted into NH₄ in the soil. By nitrification, NH is converted to the more stable NO₃ as shown by the following expression:

2NH⁺ + 0₂ + nitrosome bacteria → 2N0₂ + 4H⁺ + energy N0₂ is then converted as follows:

2N0₂ ^" + 0₂ + nitrobacteria → 2N0₃ + energy

It follows that the instant process produces nitrogen compounds of two forms specifically adapted for use by plants, namely NH4⁺ and N03^" in the slow release organic complex. The more stable compound, namely N03^" is specifically adapted for use by plants.

Observably, the instant fertilizer includes a formulation which provides a means of time-releasing nitrogen for the use of plants. As the above-identified reaction occurs, the nitrogen is made available to the plants. In the instant method, organic fertilizer produced from organic matter such as manure, fish, and crop waste, is sterilized. Sterilization destroys the bacteria population within the organic fertilizer, thereby curtailing, if not eliminating, any bacteria-promoted oxidation of the constituent elements and compounds found in the organic fertilizer. Furthermore, the sterilization effectively kills any weed seeds found in the organic matter. Due to the effects of sterilization, the resulting fertilizer can be stored for extended periods of time without any significant degradation in the nutrient content of the fertilizer. The resultant fertilizer may be applied without further treatment of the soil. The native bacteria populations in the soil readily assume the fertilizer, and process it for assimilation by the plants growing in the soil.

The instant invention discloses a method wherein the acid is added, a desired acidic state is achieved, and thereafter a anhydrous ammonium gas is injected as a base to sharply alter the pH, temperature, enrich the mixture and simultaneously dry the biomass. The method of this invention has produced organic fertilizers with nitrogen and other constituent fractions comparable to chemical fertilizers, thereby eliminating the nutrient losses previously experienced in conventional organic fertilizer- producing methods. The invention produced fertilizers which have been substantially tested and have been found to have retained their nitrogen levels after years of storage. When the fertilizer of the invention is used on soils with leached characteristics, favorable results are realized because the fertilizer not only supplies nutrients to the soil but furthermore, the fertilizer provides organic material to feed the micro organisms in the soil, thereby facilitating the processing of plant nutrients into a usable form. Fundamental to the instant invention is the concept that a beneficial fertilizer is not necessarily water soluble; instead the fertilizer must be assumable by the bacteria which consume the fertilizer. In so doing the bacteria alters the components of the fertilizer to render them assumable by the plants. It is further believed that the bacteria may in some instances feed on the components of the fertilizer and subsequently produce excretes which are assumable by the plant, where the fertilizer was not previously assumable directly. The new organic fertilizer is thus bacteria assumable, and not necessarily water soluble.

In addition to disclosing a method of microbiological sterilization, the instant invention provides an apparatus adapted for formulating organic fertilizer. The apparatus is a total system to formulate organic fertilizer, which is hereafter described.

The apparatus of the invention includes a container means adapted for receiving and containing a quantity of organic fertilizer. A mixer means is mounted within the container means. The mixing means is adapted to mix the quantity of organic fertilizer. The mixer means may include a structure adapted for adding and blending, preferably to a homogeneous content, an acidic material and water into the quantity of organic matter sufficiently to render the pH of the resulting mixture acidic, and preferably strongly acidic.

The container means may also be fitted with a plurality of primary reservoirs. Each of the primary reservoirs is adapted to contain a supply of a chemical composition selected from the following: phosphate, ammonium sulfate, potash, and humic acid. Each primary reservoir is further adapted to supply a selected quantity of its respective chemical composition to the container means. The container means may also be fitted with a plurality of secondary reservoirs. Each of the secondary reservoirs is adapted to contain a chemical element selected from the following: copper, iron, magnesium, manganese and zinc. Each of these secondary reservoirs is adapted to supply a selected quantity of the respective chemical element in the container means.

A grinding means may be associated with the container means for receiving organic matter, and processing that material to break up the mass of material into selected small masses.

A sterilizer means is associated with the container means. The sterilizer means is adapted for introducing a quantity of a material having a base pH into the quantity of matter contained in the container means. The sterilizer means is adapted to introduce this base material, e.g., anhydrous ammonium into the container means in sufficient quantities and with sufficient rapidity to quickly alter the pH of the resulting mixture from strongly acidic to slightly acidic or basic, i.e., a pH of 4.5 to 6.5. The sterilizer means may include means of blending the contents of the container means so as to achieve a homogeneous mixture.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows a process diagram representation of the assimilation of materials in formatting the organic fertilizer wherein the sterilization of bacteria occurs in the reactor where anhydrous ammonia makes the mix nearly neutral or just slightly acidic after it's highly acidic treatment of sulfuric acid in the mixer.

DETAILED DESCRIPTION OF THE DRAWINGS

The method and apparatus for sterilization of organic fertilizer includes the initial step of formulating components of the composite fertilizer including agglomeration. The instant process may utilize various organic matters as the original organic material to form the principal constituent of the fertilizer. For example, steer manure, fish, refuse from garbage recycling centers, feed lot refuse, crops, waste from grapes, mint, apples, onions, sludge and solid waste from sewer treatment plants may all be utilized as the original organic matter. At this stage various chemical compounds may be added to the organic matter in order to supplement its nutrient content. It should be understood that the instant method can be adapted to produce fertilizers of various nutrient contents. Previous analysis of the soil to be treated provides the user with the means of determining the desired nutrient content of the fertilizer to be produced. It is anticipated that phosphate, ammonium sulfate, potash and humic acid may be added to the organic matter in order to yield a fertilizer having the proper nutrients to redress any inadequacies in the soil being treated. The instant method also provides for the addition of various elements to the organic matter. In typical practice, copper, iron, magnesium, manganese, and zinc may be added to the organic matter to rectify any deficiencies of these elements in the soil being treated. In the instant method, the organic matter is thoroughly mixed with the desired chemical compounds and elements. The mixture at this point is largely dry in nature. The mixture is then treated with an acid, e.g., sulfuric acid. As the acid is added to the mixture, water is also added. This results in a liquid, slurry-like wet mixture. A sufficient quantity of acid is added to the mixture to yield a wet mixture having a pH which is acidic. The wet mixture thus has a pH which is less than 5. Preferably, the mixture will have a pH of between about 4 and 5 on the standard pH scale. In preferred processes the pH of the wet, slurry-like mixture is adapted by the addition of the sulphuric acid to be 4-5 on the pH scale. It should be recognized that the pH can be lowered below the preferred range. The acid is thoroughly mixed with the dry mixture and water such that resulting wet mixture is uniformly acidic throughout. The bacteria adapt to the acidic fertilizer environment within a short time after the addition of the acid, and thereafter thrive in the acidic environment.

The wet mixture is then further treated with a basic material, such as anhydrous ammonia NH3 in sufficient quantities to result in a sudden transition of the fertilizer pH from being strongly acidic to a mildly acidic or basic pH. In one method, anhydrous ammonia is injected into the wet mixture by means of nozzles positioned within the bottom of the reactor vessel which contains the wet mixture. The anhydrous ammonia, in a liquid and gaseous form, is quickly introduced into and mixed within the wet mixture, preferably over approximately a one-minute interval. The quantity of anhydrous ammonia which is introduced into the wet mixture is that quantity which is required to raise the pH of the wet mixture to approximately 6.5 or higher on the Ph scale. The transition is of a sufficiently severe nature that the microbes, parasites, weed seeds and other life forms cannot survive the radical pH change. As a result, the bacteria, weed seeds, and other life forms die in seconds. The finished organic fertilizer product is thus rendered sterile of bacteria which would otherwise thrive and consume the nitrogen. Since the bacteria have been eliminated, the fertilizer-held nitrogen and other ingredients are safely locked into the organic fertilizer, there being no viable life form remaining in the fertilizer which could oxidize the constituents of the fertilizer. Later, after the organic fertilizer is applied to the soil, the fertilizer is assumed by soil-borne bacteria. The bacteria assimilate the nitrogen, and alter it together with the other constituents of the fertilizer to make the constituents of the fertilizer assumable as nutrients by plants. This invention produces organic fertilizer by a process wherein elimination of the bacteria in the fertilizer is accomplished during the production of the fertilizer itself by the use of chemicals which themselves are basic components of the fertilizer. Thus, not only are the sulfuric acid and anhydrous ammonia utilized to sterilize the fertilizer, these chemicals actually form part of the nutrient components of the fertilizer. Sterilization of the organic fertilizer product mix is done to kill bacteria in the product to prevent ingestion of the fertilizer's components by bacteria prior to the application of the fertilizer to the soil. The elimination of the bacteria in the fertilizer precludes the consumption of the available nitrogen in the fertilizer prior to the fertilizer's application to the soil.

Example

A fertilizer mixture having an 8-8-8 nitrogen- phosphorus-potassium percent composition was prepared by the following procedure: A dry organic mixture having the following composition was prepared by mixing the various constituents together.

Rock phosphorus 693 lbs.

Steer manure 785 lbs. Potash (KCL) 346.5 lbs.

Trace minerals 23 lbs

Ammonium sulfate 462 lbs.

Total weight 2,309.5 lbs.

The dry organic mixture was thoroughly mixed in a.reactor vessel. 240 pounds of water and 300 pounds of 92% sulphuric acid were subsequently added to the dry organic mixture to form a wet slurry-like mixture which was then mixed thoroughly for approximately four minutes. The temperature of the wet mixture began to rise, eventually reaching a temperature of between 200 and 230 degrees Fahrenheit. The pH of the wet mixture was taken and found to be approximately 4-5 on the standard pH scale.

150 pounds of anhydrous ammonia was then injected into the wet mixture by means of injection nozzles positioned within the bottom of the reactor vessel. The anhydrous ammonia was thoroughly mixed with the wet mixture. The anhydrous ammonia was completely injected to the wet mixture within sixty seconds. The resulting reaction of the anhydrous ammonia with the wet mixture produced a sticky, paste-like mixture having a pH of 6.5 to 7. The temperature of the resulting mixture was approximately 160°F. The paste-like mixture was then naturally dried to form a dry mixture which was subsequently packaged for storage. The instant process and equipment permits the processing of the original organic material in a manner which minimizes the possibility of either air or groundwater pollution. The instant process is effected in a reactor vessel which is adapted to be sealed whereby effluents may be controlled and directed to environmental treatment equipment. Odors may also be controlled, thereby rendering the process amenable for practice in populated areas. The equipment limits the spatial requirements needed to effect the process. Whereas prior composting methods require large areas for their operation, the instant method utilizes a reactor vessel of relatively confined spatial dimensions. As shown in FIG. 1, the equipment includes a dry ingredients mixer section 1 and a wet ingredients mixer section 2. As a first step, organic matter 3, e.g. manure, is broken up to a relatively fine consistency by a rotary clump buster 5. The rotary clump buster 5 includes a power rotated scraper blade 7 rotating over a breaker grill 8. The broken-up organic matter 3, being screened by grill 8, falls under the force of gravity to a surge hopper 9. A rotated screw feeder 12 receives the organic matter 3 and transports it along the length of the screw. Trace elements 4 and dry ingredients 1 are added to the organic matter as it proceeds along the length of the screw feeder.

Ideally, a soil analysis will dictate the proper amount of trace elements 4 and other dry ingredients 1 required. Otherwise, standard mixes may be made. Typically added trace elements are copper 13, iron 14, magnesium 15, manganese 16, and zinc 17. Each of the named trace elements are retained in a respective reservoir or hopper 22 which is fitted with a respective mix feeder 18. Each mix feeder 18 has a small rotary screw 19, which is motor driven for feeding from a hopper 22 at a controlled rate. The dry mix ingredients 1 namely potash 23, ammonium sulphate 24, rock phosphate 25 and humic acid 26 are added to the organic matter 3 contained in screw feeder 12. As shown in FIG. 1, each of the dry mix ingredients is retained in a respective hopper 21 which is fitted with its own respective screw feeder. The speed of each screw feeder is selectively controlled to add a determined quantity of a given dry ingredient to the organic matter 3. The composite dry mix formed by the organic matter 3, trace elements 4 and dry ingredients 1 is fed by the screw blade 27 to a pug mixer 28 where paddle mixer blades 29 blend the dry batch to a selected consistency. A secondary screw feeder 31 delivers the dry mix through a one way feed valve 32 to a reactor 33. The one way feed valve 32 precludes the wet ingredients 2 from entering into the screw feeder 31. Water 36 and sulfuric acid 37 are added to the composite dry mix as it enters the sterilizing reactor 33 to form a pH acidic mixture. A reactor 33 pug mixer 39 mixes and blends the composite dry mix with the water 36 and sulfuric acid 37. In a short time, the bacteria within the dry mix adapt to the acidic environment of the water/sulfuric acid/composite dry mixture. After sufficient mixing and adaption time, anhydrous ammonia (NH3) from reservoir 38 is pumped into reactor vessel 33 in a sufficient quantity to rapidly modify the pH of the mixture. The anhydrous ammonia is added to the wet slurry-like mixture by means of injection ports or nozzles mounted within the bottom of the reactor vessel. Note here that the chemical anhydrous ammonia has a strong affinity for water. It is a drying agent and can be very harmful to the human skin, even causing blindness if it should contact an eye. The anhydrous ammonia is mixed thoroughly with the wet mixture while it is being introduced into the wet mixture. In a preferred method, the ammonia is introduced into the wet mixture and mixed therethrough over a period of approximately one minute, i.e. sixty seconds. The quantity of anhydrous ammonia being added to the wet mixture is determined to be that quantity required to raise the pH of the wet mixture to between 6 and 7.5 on the pH scale and preferably 6.5. Preferably, the anhydrous ammonia is introduced into the container means by utilizing injection nozzles mounted within the bottom of the container means. The ammonia is added to the mixture in a liquid form. The anhydrous ammonia reverses the mixture from being highly acidic to being basic or only mildly acidic. This rapid reversal in pH from strong acidic to basic kills the bacteria and sterilizes the mixture. The anhydrous ammonia 38 treatment gives off considerable fumes 41 which are directed through a gas scrubber 42. The chemistry of the mixture is thus stabilized and will remain unchanged without further bacterial action.

The wet blended and reacted mixture, which will now be termed an enriched "organic fertilizer," exits the reactor 33 via a one way valve 46 to a disk priller 47. Prilled fertilizer is carried on a belt conveyor 48 where the mixture is finally dried. The finished fertilizer is then bagged for distribution.

Since the finished bagged fertilizer 51 is sterile, it can be stored for considerable time without deterioration or loss of its nitrogen content. The finished organic fertilizer is eventually applied to a soil where bacteria feed upon the fertilizer and create conditions where nutrients are drawn up by the plants producing exceptional plants and foods.

It is to be understood that the embodiments of the invention herein described are merely illustrative of the application of the principles of the invention. Reference herein to details of the illustrated embodiment is not intended to limit the scope of the claims which themselves recite those features regarded as essential to the invention.

Claims

CLAIMSWhat is claimed:

1. A method for retaining nitrogen in an organic fertilizer, said method comprising: first treating an organic fertilizer with an acid to render the pH of said organic fertilizer strongly acidic; subsequently treating said organic fertilizer with a base in a sufficient quantity to raise the pH of said organic fertilizer to mildly acidic; wherein a rise in the pH of said organic fertilizer is of sufficient rapidity and severity that bacteria within said organic fertilizer are killed by said raising of pH.

2. The method of Claim 1 wherein said acid is sulfuric acid.

3. The method of Claim 1 wherein said base material is anhydrous ammonia.

4. The method of Claim 1 wherein said acid is thoroughly mixed with said organic fertilizer to render said organic fertilizer homogeneously acidic at between 4 and 5 on the pH scale.

5. The method of Claim 1 wherein said pH is raised sufficiently to render said organic fertilizer approximately 6.5 on the pH scale.

6. A method of Claim 1 wherein said pH is raised sufficiently to cause said organic fertilizer to be in the range of 6.0 to 7.5 on the pH scale.

7. A reactor for sterilizing an organic fertilizer, comprising: container means for containing a quantity of organic fertilizer; a mixer means mounted in said container means for adding and blending an acidic material into a quantity of dry mix fertilizer components to produce a mixture having a strongly acidic pH; and sterilizing means for adding and blending a basic material into said dry mixture at a sufficient rate and quantity to produce a transition of a pH of said mixture from strongly acidic pH to mildly acidic pH, said transition being sufficiently severe to sterilize said dry mix fertilizer by killing bacteria within said dry mix fertilizer because of their inability to adapt to said transition.

8. The reactor of Claim 7 further including a primary supply means adapted for storing and introducing potash, ammonium sulfate, phosphate, and humic acid into said container means.

9. The reactor of Claim 7 further including a secondary supply means adapted for storing and introducing copper, iron, manganese, magnesium and zinc into said container means.

10. A reactor for sterilizing an organic fertilizer, said reactor comprising: container means for containing a quantity of organic fertilizer; mixing means mounted in said container means for mixing a quantity of organic fertilizer; a screw feeder associated with said container means; a pug mixer mounted within said screw feeder; a plurality of primary reservoirs, each primary reservoir being adapted to contain a chemical composition selected from the following: phosphate. ammonium sulphate, potash and humic acid; said primary reservoirs each being connected to said screw feeder; a plurality of secondary reservoirs, each secondary reservoir being adapted to contain a chemical element selected from the following: iron, magnesium, manganese, zinc and copper, said secondary reservoirs being connected to said screw feeder; a guiding means associated with said container means, said guiding means being adapted to break up organic material and subsequently direct said organic material to said container means; a sulfuric acid reservoir interconnected with said container means; an anhydrous ammonia reservoir interconnected to said container means; and a disk priller associated with said container means adapted for receiving said quantity of organic fertilizer from said container means and conveying said quantity of organic fertilizer to a conveyor belt for drying.