EP4615815A1

EP4615815A1 - Process for the production of biofertilizers obtained from organic waste

Info

Publication number: EP4615815A1
Application number: EP23888220.3A
Authority: EP
Inventors: Luis Alejandro LANDÍN GARZA
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-11-10
Filing date: 2023-11-09
Publication date: 2025-09-17
Also published as: MX2022014137A; WO2024100602A1

Abstract

The present invention relates to the production of biofertilizers containing mineral nutrients and active compounds present in organic food waste. The process disclosed herein is intended to transform the mineral nutrients and active compounds present in organic food waste, rendering them suitable for use as soil conditioners or biofertilizers in agricultural crops of importance.

Description

PROCESS FOR THE PRODUCTION OF BIOFERTILIZERS OBTAINED FROM ORGANIC WASTE

Field of Invention

The present invention relates to the field of organic waste processing to produce biomass or biomass-derived materials. Specifically, the process disclosed herein is related to the production of biofertilizers containing mineral nutrients and active compounds found in organic food waste or other sources.

Background of the invention

Various processes are currently available for the generation of biofertilizers from organic waste. Most of these technologies are based on by-products from brewing, vegetable, and agricultural wastes, and even oils.

Most commonly, such processes employ enzymatic degradation steps (hydrolytic enzymes) or fermentations with bacterial strains. In some cases, animal excreta are also used to support the fermentation process.

However, these processes can be very time-consuming given the fermentation time required, the final product does not contain essential nutrients and can be harmful to plants or crops as it may contain complex chemical agents that affect the quality of soil and crops.

Some related processes are known in the prior art. For example, patent MX 354126 discloses methods for processing carbohydrate-containing materials and products made from structurally modified materials. Such methods include a treatment selected from radiation, sonication, pyrolysis, oxidation, steam explosion, and chemical treatment. The feedstock comprises a cellulosic or lignocellulosic material.

Similarly, US patent application 2017226535 discloses methods for pre-treating feedstock for sugar recovery that can be used to produce biofuels and biochemicals. Pretreatment steps such as mechanical, thermal, pressure, chemical, thermochemical, and biochemical treatments can be applied to the feedstock prior to its use in a bioprocess for the production of fuels and chemicals; however, untreated biomass material can also be used in the process. Mechanical processes can reduce the particle size of the biomass material so that it can be handled more conveniently in the bioprocess and can increase the surface area of the feedstock to facilitate contact with chemicals/biochemicals/biocatalysts. Mechanical processes can also be used to isolate one type of biomass material from another. The biomass material can also be exposed to thermal and/or chemical pre-treatments to make plant polymers more accessible. Nevertheless, all the above technologies include additional steps that make the processes much more complex or costly, e.g. irradiation or iterations in order to obtain higher quality products.

Therefore, there is a need for processes that can carry out the degradation of organic matter in less time, and wherein the treatment of such organic matter contributes to the reduction of greenhouse gas emissions (in contrast with the processes disclosed in the prior art, that on the contrary increase the emission of such gases), and which also allow obtaining products with a high amount of macronutrients and bioactive compounds that, together with the addition of recalcitrant carbon, help to capture CO2 from the environment. The addition of recalcitrant carbon to organic matter favors the concentration of nutrients and promotes ion exchange capacity for better nutrient adsorption, gas emission control, and an increase in microbial activity in soils.

Summary of the Invention

It is therefore an objective of the present invention to provide a process for obtaining biofertilizers or other agricultural products. In this sense, the products obtained through the process of the present invention can also be employed as additives in the construction industry, packaging, and industrial molds by making use of the organic fibers obtained. In other words, the process disclosed herein offers an alternative for the final disposal of the organic part of special waste, with a special focus on minimizing its volume. Consequently, the process disclosed herein provides an alternative to be applied in landfills and has also applications in the waste management industry, helping to reduce environmental pollution. The process of the present invention aims to make mineral nutrients and active compounds in organic food waste bioavailable for its use as potential soil enrichment products or biofertilizers that can be applied to crops of agricultural importance.

Likewise, the process disclosed herein is intended to function as a pre-treatment for energy generation and biofuel production. Due to its physicochemical characteristics, the biomass resulting from the thermochemical process can be fed to biodigesters for biogas production and contribute to the balance of CO2 emissions. Even the residual mass from biogas generation can be converted into charcoal, which can be released back into the soil as organic fertilizer.

Thus, the present invention has as its starting point the utilization of organic waste, wherein a mechanical-thermochemical decomposition takes place, in particular, a mechanical shredding followed by a two-stage process of chemical hydrolysis. In a particular aspect, the first stage of the process according to the present invention consists of grinding to reduce the particle size, which increases the surface area of the organic material and makes it more accessible for thermochemical treatment, by minimizing the size, polymerization chains are broken, and crystallinity of lignin and cellulose structure is reduced. The next step in the process is heat treatment, which has the purpose of disintegrating the cell wall and the membrane to increase the solubilization of organic matter. Due to the limitations of organic matter natural degradation, using chemical reagents that promote hydrolysis not only reduces the degradation time significantly but also makes the process less complex and more efficient.

In another specific aspect of the process disclosed herein, an additional stage of recalcitrant carbon or biochar takes place. That is, once the waste is shredded, recalcitrant carbon is added and mixed to generate a homogeneous substrate before the start of hydrolysis.

The above-described steps provide the following advantages:

• Reduced degradation time for organic matter, which helps prevent organic matter from attracting undesirable wildlife or producing foul odors.

• Decreased release of greenhouse gases by achieving CO2 solubilization and the absence of methane (CH4) generation from open-air landfills. Additionally, it reduces the degradation time of organic waste in landfills, which, in turn, attracts undesirable wildlife and causes foul odors.

• Increased availability of essential macronutrients.

• Reduced space requirements for organic waste processing.

• Chemical hydrolysis outperforms enzymatic hydrolysis with higher yields in the conversion process for complex molecules like carbohydrates to simpler sugars.

• Promotion of proper separation of organic and inorganic waste.

• Utilization of food waste through the production of a biofertilizer, benefiting soil nutrition and plant growth.

• To avoid the use of chemical fertilizers that can create chemical compound complexes that affect soil and crop quality.

• Reduction of environmental impact and air pollution.

• Employing more simple structures with low molecular weight, highly soluble in water, and of easier degradation in subsequent treatments.

These and other advantages will be apparent to those skilled in the art from the detailed description provided below. Brief description of the figures of the invention

Figure 1 shows an image of the organic material during the grinding stage in the process disclosed herein.

Figure 2 shows a flowchart for one embodiment of the process from the present invention.

Figures 3A to 3E show examples of equipment that can be used during the process in accordance with the present invention. Figures 3A and 3B depict three-hole flasks with oil and with inlets for acid and an industrial thermometer, a laboratory stirrer and an oven intended for temperatures up to 500 °C, wherein the feedstock is placed and undergoes the hydrolysis step; Figure 3C depicts an example of the resultant product after grinding, Figure 3D depicts an industrial blender (which can be replaced by a kitchen blender) and Figure 3E shows an oven with a dehydrating function.

Figure 4 shows a further embodiment of the process of the present invention.

Detailed description of the invention

The present invention will be described with reference to the attached drawings and examples, which depict embodiments of the invention. This description is not intended to be a detailed catalog of all the different ways in which the invention can be implemented or all the features that can be added to the present invention. For example, features illustrated regarding one embodiment can be incorporated into other embodiments, and features illustrated with respect to a particular embodiment can be omitted from that embodiment. Therefore, the invention disclosed herein contemplates that in some embodiments of the invention, any feature or combination of features set forth in this document may be excluded or omitted. Furthermore, numerous variations and additions to the various embodiments suggested herein will be apparent to those skilled in the art in light of the present description, which by no means deviant from the essence of the present invention. Therefore, the following descriptions are intended to illustrate some embodiments of the invention and are not intended to specify exhaustively all permutations, combinations, and variations thereof.

For a person skilled in the art, it will be evident that various embodiments of the invention can be expressed differently and should not be interpreted as limited to the embodiments described herein; rather, these exemplary embodiments are provided to make this invention clear and complete and to fully convey the scope of the invention to experts in the field. For example, unless otherwise indicated, when a step is described as first, second, or similar should not be interpreted as a particular order. As used in the description and in the accompanying claims, singular forms "a, one", "an" and "the" include plural referents unless the context clearly indicates otherwise. In this sense, the present invention relates, in a first general aspect, to a process for obtaining biofertilizers or other agricultural products. The product obtained by the process of the present invention is useful even as an additive in the construction industry, packaging, and industrial molds by utilizing the organic fibers obtained. In other words, the process of the present invention is an alternative for the final disposal of the organic fraction of special management waste and is specifically focused on minimizing its volume; therefore, is a suitable alternative to be used in landfills and has applications in the waste management industry, helping to reduce environmental pollution.

Furthermore, the process of the present invention aims to function as a pretreatment that allows the generation of energy and the production of biofuels. Due to its physicochemical characteristics, the biomass obtained from the thermochemical process can be fed to biodigesters for biogas production and contribute to the CO2 emissions balance. Even the residual mass from biogas generation can be converted into charcoal, which can be returned to the soil as organic fertilizer.

Thus, in a preferred embodiment, the process disclosed herein uses organic waste as feedstock, such as waste obtained from fruit and vegetable scraps (including their peels and juice residues), meat and bone remnants, fish bones and remnants, eggshells, dairy products, coffee and tea residues, cereal and flour products (bread or tortillas), any derivatives, related waste, and combinations thereof. The mentioned feedstock is then subjected to a mechanical- thermochemical decomposition stage, particularly mechanical grinding followed by a two-stage chemical hydrolysis process.

Specific, non-limiting examples of organic waste used in accordance with the present invention are selected from squash, carrots, apples, melons, dragon fruit, tangerines, oranges, bell peppers, green beans, watermelons, whole corn, pineapples, corn husks, lemons, tortillas, radishes, cooked chicken, plantains, boiled beans, tomatoes, cooked beef, papayas, mole sauce with oil, bananas, boiled rice, combinations thereof, and their derived residues.

The first stage of the process according to the present invention consists of a grinding/crushing pretreatment stage (as shown in Figure 1), which aims to reduce the particle size, increasing the surface area of the organic matter for better accessibility to the thermochemical treatment. By minimizing the size, polymerization chains are broken, and the organic waste's structure crystallinity, such as lignin and cellulose, is reduced.

In alternative embodiments, a disinfection stage may precede the grinding stage. Disinfectants used to treat organic waste play a crucial role in the proper management of these materials. These products eliminate pathogenic microorganisms such as bacteria and viruses, thereby preventing the spread of diseases. In addition, they contribute significantly to reducing unpleasant odors associated with organic decomposition, thus improving the work environment and the quality of the surrounding air. By preparing waste for subsequent processes such as composting or hydrolysis, disinfectants ensure the effectiveness of these treatments and the safety of the final products. In addition, they comply with local regulations by ensuring that waste is managed in accordance with established standards; these disinfectants are essential to protect public health and the environment, as they help prevent cross-contamination and minimize the risks associated with the handling and disposal of treated organic waste.

The biocide active substance is the main component of the disinfectant and is responsible for eliminating or inactivating pathogenic microorganisms present on surfaces or treated materials. These biocidal substances can vary in their effectiveness against different types of microorganisms, such as bacteria, viruses, fungi and spores. The choice of the active substance or the appropriate combination of substances depends on the type of pathogens that are expected to be found and eliminated in the specific application environment.

Some common examples of biocidal active substances include chlorine, sodium hypochlorite, hydrogen peroxide, ammonium quaternaries, and peracetic acid, among others. Each of these substances has its own properties and levels of effectiveness, and it is crucial to select the appropriate one based on the context of use, such as hospitals, food industries, public facilities, among others.

Sodium hypochlorite is highly effective at killing a wide range of microorganisms, including bacteria, viruses and fungi. It acts by destroying cellular structures and denaturing the proteins of microorganisms.

The process of disinfecting organic waste using sodium hypochlorite involves a series of crucial steps to ensure effective and safe disinfection. In a most preferred embodiment, a sodium hypochlorite solution is prepared with a suitable concentration, usually between 2% and 5%. This solution is sprayed or poured over the organic waste, making sure to completely cover all the waste. After an adequate contact time, which is usually at least 30 minutes, the residue can be rinsed with softened water to remove excess sodium hypochlorite. Once disinfected, the waste is crushed to create smaller particles that facilitate decomposition and subsequent treatment.

The next step in the process is the thermal treatment, which is intended to disintegrate the cell wall and membrane to increase the solubilization of organic matter. Due to the limitations of organic matter natural degradation, using chemical reagents that promote hydrolysis not only reduces the degradation time significantly but also makes the process less complex and more efficient. In a preferred embodiment, the mechanical shredding generates a particle size of 4 mm which helps to increase the specific surface area and thus facilitates the hydrolysis process.

The above-mentioned mechanical shredding is carried out in industrial shredding equipment, preferably of the hammer mill shredder type, which is intended to fragment the organic matter by the impact and the operating speed of the shredder. In a more preferred embodiment, this stage can be carried out in mills of the ball, knife, or roller type.

In another embodiment of the present invention, drying, extrusion, or chemical processes (using oxidative pretreatments) or biological processes (using enzymes) can also be employed. However, the choice of pretreatment type is based on operational cost, energy cost, and process effectiveness. Mechanical crushing is one of the most common and efficient techniques for promoting increased interaction of organic matter with reagents, in addition to obtaining a uniform particle size to homogenize the reaction mixture for the subsequent process. A particle size of not less than 2 mm and not more than 10 mm should be considered; the selection of the particle size will depend on the reduction of the volume of the fibrous materials, to increase the reaction speed and facilitate the interaction with the chemical solvents of the hydrolysis reaction.

On the other hand, the chemical hydrolysis process aids in the obtention of monomeric sugars by directly affecting lignocellulosic compounds and starches. Chemical hydrolysis involves the use of solutions with sulfuric acid (H2SO4), nitric acid (HNO3), or hydrochloric acid (HCI) at various concentrations and conversion temperatures. However, concentrated acids can generate undesirable by-products, affecting the physicochemical characteristics of the final product. Concentrated acids are powerful agents for hydrolyzing for example cellulose, but they are toxic, corrosive, and hazardous, requiring corrosion-resistant operating equipment. This is why diluted acids are used at temperatures not exceeding 160°C, preferably at temperatures between 60 to 80°C. On the other hand, alkaline hydrolysis is carried out with sodium hydroxide NaOH, potassium hydroxide KOH, or calcium hydroxide (Ca(OH ) at temperatures between 90 to 110°C or at room temperature. Some unwanted salt compounds may form within the biomass, but alkaline hydrolysis removes lignin from lignocellulosic material without significant effects on other components, resulting in reduced crystallinity and, consequently, alteration of lignin structure.

Preferably, the chemical hydrolysis process begins with acid hydrolysis at normal atmospheric pressure conditions, with the addition of 1.0 N HCI at a temperature of 75°C, under constant agitation at 150 rpm for 30 minutes. Consequently, a second hydrolysis stage takes place by adding 0.5 N KOH, creating an alkaline environment. The reaction temperature is increased to 100°C for 30 minutes under the same conditions of agitation. The resulting sludge from hydrolysis undergoes a drying process at 80°C for 8 hours in a rotary dryer. The final product is a brittle residue that is pulverized to achieve a homogeneous product.

The process disclosed herein includes both an initial acidic hydrolysis stage and a subsequent alkaline hydrolysis stage. Acidic hydrolysis aims to decompose and depolymerize cellulose and hemicellulose, especially in complex, polymeric, and high-fiber-carbohydrate compounds. This reaction breaks the glycosidic bonds of polysaccharides, leading to the release of soluble oligomers and monomers from the cell wall matrix. However, it is not highly effective in lignin removal, requiring additional treatments to achieve it. Consequently, the main purpose of alkaline hydrolysis is delignification to obtain monosaccharides from macromolecules such as cellulose and hemicellulose, increasing their reactivity and promoting the depolymerization of polysaccharides. This treatment results in the degradation of ester and glycosidic bonds, along with the removal of acetyl and uronic acid substitution in hemicellulose, which promotes the structural binding of lignin and cellulose in the cell wall.

In alternative embodiments, after the hydrolysis process, the residual sludge undergoes a separation process into its liquid and solid phases, giving rise to two valuable components. The liquid phase, known as leachate, is rich in essential plant nutrients. This leachate constitutes a concentrated liquid biofertilizer, ready to be applied directly to crops, providing them with the nutritional elements necessary for healthy growth. On the other hand, the solid phase, containing less liquid due to previous separation, becomes the base of the solid biofertilizer. This phase is directed to the drying process, where the reduction in the amount of water optimizes drying efficiency. By having less liquid to evaporate, the process becomes faster and requires less energy, which in turn makes the production of solid biofertilizer more sustainable and effective.

In further embodiments, after the hydrolysis process, the residual sludge will undergo phase separation through physical methods.

1. Centrifugation is a highly efficient process that harnesses centrifugal force to perform precise separation between solids and liquid in a mixture. During this process, the mixture is placed in a rotor that rotates at high speed, generating a centrifugal force that pushes the solid particles outward, while the liquid is kept in the center of the rotor due to its lower mass. This action results in a clean and effective separation, producing a clear liquid and a more concentrated sludge. The phase separation obtained through centrifugation stands out for its efficiency and precision, which ensures that the nutrients and other valuable components present in the liquid are preserved, while the concentrated sludge is prepared for transformation into a high-quality biofertilizer. 2. After chemical hydrolysis of organic materials, a separation process is carried out for solids from the residual liquid. During this step, a suitable separation method is applied that allows the solids to be retained while the leachate, containing the nutrients and soluble compounds released during hydrolysis, is filtered and collected in a suitable container. This filtered liquid constitutes the final liquid biofertilizer, which is ready for processing and use in fertilization activities. Subsequently, the solids obtained are subjected to a drying process to eliminate moisture, giving rise to the dry solid biofertilizer.

2.1. After chemical hydrolysis, the resulting mixture is transferred to an oblique sieve, which is specialized equipment for the separation of solids and liquids. The inclination of the oblique sieve is adjusted to optimize the separation of solids from the residual liquid. The tilt allows solids to move upward while liquid is filtered through the screen. Collecting the filtered liquid, which contains the nutrients and soluble compounds released during hydrolysis, in a suitable container for subsequent processing and use as liquid biofertilizer.

2.2. After chemical hydrolysis, transferring the resulting mixture to a vibrating sieve with specific mesh size, particularly from 10 to 20 mm, to separate the solids from the liquid. Activating the vibrating sieve to allow solids to be retained on the mesh surface while the filtered liquid passes through the mesh openings. Collecting the filtered liquid in a suitable container for subsequent processing and use as liquid biofertilizer.

In another aspect, the drying process occurs in a rotary dryer at approximately 80°C for 8 hours, allowing the removal of moisture from the final product to meet the required specifications for commercialization and use. The drying process can be carried out in fluidized bed dryers, flash dryers, with the aid of solar panels, or even by direct solar drying on the product. The rotary dryer removes moisture through a mass transfer fluid, such as air or another gas. The operating conditions vary significantly in this process depending on the amount of fluid or gas and its temperature. Its main advantage is the continuous drying of large quantities of hydrolyzed material at a stable drying rate, even at moderate temperatures, while preventing the degradation of thermally sensitive compounds.

In an additional aspect, the inventors of the present invention have found that once the residues are crushed, and before the hydrolysis, they are mixed with 100 grams of recalcitrant carbon or biocarbon (biochar) for every kilogram (Kg) of waste. This functions as a pH stabilizer by neutralizing the reaction medium and as a catalyst for the degradation of macromolecules present in the medium, resulting in an improved C:N ratio and a better nitrogen-phosphorus- potassium (NPK) ratio. Furthermore, the reaction temperatures in both hydrolysis stages are not sufficiently high to alter the surface structure of the carbon or for the reagent concentrations to be abrasive enough to cause a radical change in its surface. However, due to the presence of functional groups on the recalcitrant carbon's surface, it can effectively hydrolyze cellulose, hemicellulose, xylan, and lignin structures. This is due to the presence at the adsorption sites of carboxylic acid (COOH) and hydroxyl (OH) groups from the phenolic groups in the carbon mixture, thus releasing simple carbohydrates from the polysaccharide matrix. Additionally, any CO2 and other gases generated during hydrolysis will be sequestered in the reaction medium due to the recalcitrant carbon's ability to capture carbon; therefore, this eliminates the need for adding a trap or filter to the reactor to capture greenhouse gases. The addition of recalcitrant carbon also serves to neutralize the pH of the resulting product, creating a liquid fertilizer from the leachate generated after the hydrolysis stage. This avoids the need to treat leachate water as waste.

According to the present invention, the recalcitrant carbon or biocarbon used herein can be obtained from various sources, such as but not limited to, woody waste from trees and pines; orange peels; pineapple peels and crowns; corn husks and cobs; coconut or nutshells; sugarcane tops and bagasse; organic waste (rural and urban); residual sludge (from beer manufacturing, for example); seaweed or other types of marine algae; sawdust and wood compounds; oak and pine residues; water hyacinth; coffee and rice husks; livestock manure; vanilla waste; materials composed primarily of hemicellulose, cellulose, and lignin.

Likewise, different types of biocarbon can be used based on the pore size according to the IUPAC classification, i.e., Macropores (> 50 nm diameter); Mesopores (2-50 nm diameter); and Micropores (> 2 nm diameter).

In this sense, biocarbon can exhibit external porosity for the pores between biocarbon particles, with size and shape dependent on the size and morphology of the particles; residual porosity inherited from the structure of the feedstock with a pore size distribution centered in the range of 1 pm to 100 pm, these pores are derived from plant cell structures, such as pine wood tracheids, which make up most of the volumetric porosity of biocarbon; and pyrogenic nanopores, ranging from less than 2 nm to 50 nm, which are internal pores produced at higher carbonization temperatures. The contribution of pyrogenic porosity to liquid absorption is minimal.

The resulting products from the process disclosed herein are biofertilizers, liquid fertilizers, fibers, and additives useful in the agricultural, materials, or construction industry, in addition to being an alternative to promote the recycling, separation, and final disposal of organic waste. In a further embodiment, the biofertilizers according to the present invention can be enriched with other ingredients, such as mycorrhizal fungi. Mycorrhizae are symbiotic associations between fungi and plant roots, offering several benefits. These include improved nutrient absorption, resistance to disease and stress, and the creation of an interconnected network between plants called mycomedia. In addition, mycorrhizae play a key role in carbon capture, helping to fix carbon in the soil through the transfer of organic compounds from plants to fungi, forming glomalin that stabilizes the soil and improves its structure. This process contributes significantly to the mitigation of climate change and the maintenance of the health of terrestrial ecosystems. By integrating mycorrhizae into the biofertilizer, an additional beneficial component is added to the product. These microorganisms, being part of the biofertilizer, not only contribute to improving the absorption of nutrients in plants, but also help store carbon in the soil, contributing to carbon capture and improving soil structure. The combination of mycorrhizae, biocarbon and the organic base of the product represents an eco- friendly strategy to promote soil fertility and support healthy plant growth. In the context of the present invention, the biofertilizer may include commercial strains supplied e.g. Glomus Clarum; Glomus SP1; Glomus SP2; Glomus SP3; Paraglomus Occultum; Aucalospora Morrowiae; Aucalospora SP1, A. Geosporum-Hke, G. Rubiformis, A. Aggregatum, A. Mellea, A. Scrobiculata, A. Miniscrubiculata, A. Delicada-like, A. Bireticulata-like, A. Spinosa G. Fuegianun, Scutellospora, Entrophospora colombiana, Gigaspora. These commercial strains have been developed and cultivated specifically for use in agricultural and gardening applications. These commercial strains have been selected and tested for their effectiveness in providing the benefits mentioned above, making them a reliable choice for enriching biofertilizers and promoting sustainable agricultural practices.

EXAMPLES

The following examples are non-limited with respect to the scope of the present invention. They are included to offer a better understanding to an expert in the field regarding the various possibilities and advantages provided by the present invention.

Example 1. The process according to the present invention.

Figure 2 depicts a diagram of one embodiment of the process of the present invention. In stream 1, the feedstock is introduced, with a batch of 250 kg transferred to the crusher (B- 101), where it is necessary to add water (stream 17) to facilitate the process. 100 kg/ton of recalcitrant carbon (biochar) is added, and the mixture is homogenized to neutralize it. Subsequently, stream 2 is conveyed to the reactor to complete 1 ton of feedstock (R-101), where it reacts in the presence of an acid (1 M HCI) (stream 3) and a base (0.5 N KOH) (stream 4). As mentioned earlier, the reactor requires a heating system, and for this purpose, thermal oil (stream 7) is used and heated first within a temperature range of 60 to 80°C for 30 minutes and then between 90 and 110°C for 30 minutes with the assistance of a boiler (H-101) that operates with natural gas (stream 13) and air (stream 12). The product exiting the reactor is a biofertilizer with a high moisture content (stream 8), which is conveyed to a sieving process (S-101) to remove the leachates present in the product (stream 10). Finally, stream 9 is taken to a rotary dryer for 8 hours at a temperature of 80 to 100°C (D-101), where, with the help of combustion gases (stream 14) coming from equipment H-101, the moisture percentage is reduced. After this, the biofertilizer product flows through stream 15 and is stored in a tank for later packaging. The humid gas exits through stream 16.

In Figure 4 a further embodiment of the process is shown. Here, the process described includes three additional stages: disinfection prior to crushing, solid-liquid separation after hydrolysis and storage of the product obtained (biofertilizer). These changes are relevant to ensure that the biofertilizer obtained is of high quality and complies the necessary standards for its application in agriculture and gardening.

Disinfection prior to crushing. Disinfection before crushing is crucial to ensure the safety and hygiene of the process. Eliminating harmful and pathogenic microorganisms present in the raw material contributes to the production of a safe final product for use as a biofertilizer. Prior disinfection helps to prevent contamination of the product with bacteria or other undesirable microorganisms, which could affect the quality of the biofertilizer and its effectiveness in agriculture.

Solid-liquid separation after hydrolysis. In the solid-liquid separation stage after hydrolysis, the process generates two different products. On the one hand, a solid part is obtained that contains the degraded solid waste; this solid part is subjected to a drying process using a rotary dryer to reduce its moisture content. The result is a dry and concentrated biofertilizer, easily manageable and ready for storage and subsequent use. On the other hand, the liquid resulting from the separation, known as leachate, preserves essential nutrients with great nutritional value. The leachate is used as a valuable liquid fertilizer that is applied directly to agricultural crops, enriching the soil with beneficial nutrients and contributing to healthy plant growth. Thus, this separation process ensures effective use of the valuable components of the original organic material for the benefit of agriculture and gardening.

Storage of biofertilizer. Proper storage of biofertilizer is essential to maintain its quality over time. Proper storage involves controlled conditions to avoid the proliferation of unwanted microorganisms, oxidation of nutrients and degradation of the product. Storing the biofertilizer properly ensures that it retains its composition and effectiveness until its use in agriculture or gardening. Example 2. Tests applied to the biofertilizer product obtained through the process of the present invention.

The physicochemical analysis of the biofertilizer (Table 1) was carried out in the "FERTILAB" Soil and Nutrition Analysis Laboratory, said analysis indicates that the values obtained may be ideal for the application of the product to agriculturally significant soils. A nearneutral pH was obtained, ranging between 6 and 7, preferably closer to 6.80. This indicates better nutrient availability in the soil, which can be more easily assimilated by plants in a shorter time. This value is related to the percentage of organic matter, which represents the total bioavailable material that can be utilized by microorganisms in the soil. These microorganisms break down these bioavailable compounds to provide benefits to the soil and, consequently, promote plant growth. The percentage of organic matter falls between 80 and 85, preferably at 84.2%. Material degradation will be controlled and slow, resulting in soil stability and improvement. This value is also correlated with the C:N content since 22.7% is sufficient to stimulate soil microorganisms and release available nutrients for plants, causing the present CO2 to mineralize in the medium. This leads to a decrease in the amount of organic carbon in the decomposing residue, while the nitrogen is retained within the biomass of the microorganisms. Furthermore, the product of the present invention has a moisture content between 4 and 6%, more preferably at 4.8%, demonstrating a stable product resistant to external microbial attack due to limited water availability. The NPK (nitrogen, phosphorus, and potassium) content promotes the growth of roots, stems, and fruits, and the values obtained are in line with the necessary requirements for plants. In general, the analysis indicates that the thermochemical process with the addition of recalcitrant carbon helps degrade organic matter sufficiently to obtain simple compounds that enrich soils and stimulate crop or plant growth.

Table 1

Values Values with Parameters Typical Values without biocarbon biocarbon Sodium (Na) % < 0.03 0.17 0.35

As shown in the table above, for normal composting, a somewhat high percentage of moisture would be expected, however, a very low (favorable) moisture was obtained due to the addition of the biochar. The resulting moisture content after drying indicates that the product obtained by the process of the present invention can be packaged without the risk of it suffering any type of alteration during storage until it comes into contact with the soil and fulfills its function.

The percentage of organic matter is also an effect of the addition of biochar, i.e. there are more active compounds that can be used for plant growth and benefit the soil.

In another test applied to the fertilizer (see Table 2 below) it can be observed that the leachate has a notable concentration of essential plant nutrients, such as potassium, calcium and nitrogen, making it a valuable biofertilizer. The potassium present in the leachate improves the growth and resistance of plants, promoting flowering and fruiting. On the other hand, calcium strengthens cellular structures and facilitates the transport of nutrients within the plant. In addition, nitrogen stimulates foliar growth and increases protein content in plants, being essential for early crop development. The presence of humic and fulvic acids in the leachate contributes to the retention of nutrients in the soil and improves its structure, promoting root growth and beneficial microbial activity. With proper management, this biofertilizer in liquid form can offer multiple benefits by promoting healthy and sustainable plant growth, as well as improving soil quality. Table 2

Claims

1. A process for obtaining biofertilizers, said process comprising the steps of: a) Preprocessing organic waste by milling and/or crushing it to reduce the particle size; b) Submitting the resulting product from step a) to an acid hydrolysis to decompose and depolymerize the cellulose and hemicellulose from the organic waste; wherein, during the acid hydrolysis step, a thermal treatment is carried out to disintegrate the cell wall and increasing the solubilization of the organic matter; c) Submitting the resulting product from step b) to basic hydrolysis in order to delignify the obtained product; and d) Drying the resulting product from step c); wherein the process further comprises mixing, the milled and/or crushed organic waste resulting product, before the step b) with an appropriate amount of recalcitrant biocarbon.

2. The process of claim 1, wherein the organic waste is selected from the group comprising fruit and vegetable residues, including their peels and pulps (juice residues), meat and bone remnants, fish bones and remnants, eggshells, dairy products, coffee and tea residues, cereal and flour products (bread or tortillas), any derivatives, related waste, and combinations thereof.

3. The process of claim 1, wherein the particle size in step a) is not less than 2 mm and not greater than 10 mm.

4. The process of claim 1, wherein step a) is carried out in ball, blades, or roller mills.

5. The process of claim 1, wherein before the step a), the organic waste is disinfected with biocidal active substances.

6. The process of claim 5, where the biocidal active substances are selected from chlorine, sodium hypochlorite, hydrogen peroxide, ammonium quaternaries, and peracetic acid.

7. The process of claim 1, wherein the acid hydrolysis in step b) is carried out in a medium containing sulfuric acid (H2SO4), nitric acid (HNO3), or hydrochloric acid (HCI), at a temperature between 60 and 80°C.

8. The process of claim 1, wherein the basic hydrolysis in step c) is carried out in a medium containing sodium hydroxide (NaOH), potassium hydroxide (KOH), or calcium hydroxide (Ca(OH)2), or any combination thereof, at a temperature between 90 and 110°C.

9. The process of claim 1, wherein the drying in step d) is carried out at a temperature ranging from 80°C to 100°C.

10. The process of claim 1, wherein after the hydrolysis process, the residual sludge undergoes a separation process into its liquid and solid phases.

11. The process of claim 10, wherein the separation is carried out by centrifugation, by an oblique sieve and by a vibrating sieve with a mesh size from 10 to 20 mm.

12. The process of claim 1, wherein the recalcitrant carbon is added in a ratio of 100 g of carbon for every kilogram of organic waste.

13. A biofertilizer product obtained from the process of claims 1 to 12, wherein said product has a pH between 6 and 7, preferably 6.80; an organic matter percentage ranging from 80 to 85%, preferably 84.2%; a C:N content of 22.7%; and moisture between 4 and 6%, preferably 4.8%.

14. The biofertilizer product of claim 13, wherein the product is enriched with mycorrhizal fungi, such as Glomus Clarum; Glomus SP1; Glomus SP2; Glomus SP3; Paraglomus Occultum; Aucalospora Morrowiae; Aucalospora SP1, A. Geosporum-Hke, G. Rubiformis, A. Aggregatum, A. Mellea, A. Scrobiculata, A. Miniscrubiculata, A. Delicada-like, A. Bireticulata-like, A. Spinosa G. Fuegianun, Scutellospora, Entrophospora colombiana, Gigaspora.

15. A process for obtaining biofertilizers, said process comprising the steps of: conveying feedstock (stream 1) to a crusher (B-101); wherein water (stream 17) is added; adding an appropriate amount of recalcitrant carbon and homogenizing it to neutralize the mixture; transporting stream 2 to a reactor to complete an appropriate amount of feedstock (R- 101), wherein it reacts in the presence of an acid (stream 3) and a base (stream 4); wherein the reactor includes a heating system with thermal oil (stream 7), which is heated first in a temperature range between 60 and 80°C for 30 minutes and then between 90 and 110°C for 30 minutes with the assistance of a boiler (H-101) that operates with natural gas (stream 13) and air (stream 12); transporting the biofertilizer with high moisture content obtained at the reactor outlet (stream 8) to a sieving process (S-101) in order to remove leachates present in the product (stream 10); finally, feeding stream 9 to a rotary dryer for 8 hours at a temperature of 80 to 100°C (D- 101), wherein, in combination with the combustion gases (stream 14) from equipment H-101, the moisture percentage is reduced and the biofertilizer is recovered through stream 15, stored in a tank, and later packaged, meanwhile humid gas exits through stream 16.

16. The process of claim 15, wherein the acid is sulfuric acid (H2SO4), nitric acid (HNO3), or hydrochloric acid (HCI).

17. The process of claim 16, wherein the acid is HCI at a concentration of IM.

18. The process of claim 15, wherein the base is sodium hydroxide (NaOH), potassium hydroxide (KOH), or calcium hydroxide (CafOH ), or any combination thereof.

19. The process of claim 18, wherein the base is KOH at a concentration of 0.5 N.

20. The process of claim 15, wherein the recalcitrant carbon is added in a ratio of 100 g of carbon for every kilogram of organic waste.