Anaerobic-aerobic integrated fermentation process for high solid content organic solid waste

Abstract

The present invention provides an integrated anaerobic-aerobic fermentation process for high-solid content organic solid waste, which includes processes such as raw material compounding, anaerobic fermentation, biogas treatment, and aerobic composting to obtain high-quality biogas and organic fertilizer products. The present invention can carry out the coordinated treatment of multiple organic solid wastes by coupling anaerobic fermentation with aerobic fermentation. The anaerobic fermentation residue does not require solid-liquid separation and can be directly aerobically composted in full, avoiding the production and treatment of biogas slurry. The biogas produced by anaerobic fermentation can be directly used to generate electricity to supply the integrated system, and the high-temperature tail gas produced by aerobic composting can be used for anaerobic fermentation heating, thereby reducing the energy consumption and cost of organic waste treatment and realizing the coordinated utilization of energy and fertilizer.

Description

Technical Field

[0001] The present invention relates to the technical field of organic waste utilization, in particular to an anaerobic-aerobic integrated fermentation process for organic solid waste with a high solid content. Background Art

[0002] Currently, my country's annual production of organic solid waste in urban and rural areas reaches 5 billion tons (wet basis). The treatment of this organic solid waste has always been a key issue hindering sustainable development. In fact, organic solid waste is also a valuable resource rich in nutrients [nitrogen (N), phosphorus (P), potassium (K)] and trace elements [copper (Cu), iron (Fe), zinc (Zn)] as well as organic matter, requiring effective treatment technologies for resource recovery and utilization.

[0003] Anaerobic fermentation is an effective, multi-faceted organic solid waste treatment and resource utilization technology. It transforms organic matter into methanogens and reduces their volume through the growth and metabolism of anaerobic microorganisms. Aerobic composting is an effective biotransformation technology that humifies organic matter and removes phytotoxic substances such as pathogens, VFAs, and risk pollutants. It has become a research hotspot in the field of organic solid waste resource utilization.

[0004] However, although anaerobic fermentation and aerobic composting can recycle target products, they still have disadvantages that cannot be ignored. This has become a bottleneck problem restricting the treatment of organic solid waste and a pain point for the industry’s low efficiency. For example, anaerobic fermentation treatment inevitably produces a large amount of biogas slurry and biogas residue, which contain a large amount of phytotoxic substances, including volatile fatty acids (VFAs), ammonia nitrogen (NH4 + -N), active heavy metals, incompletely degraded organic matter, pathogenic bacteria and other components are difficult to be directly applied to farmland for use, and further treatment is required to avoid secondary pollution; and the sludge and liquid manure contain a lot of water, which increases the transportation cost and limits people's further treatment and utilization. For example, the aerobic composting process is a simple energy-consuming process that requires continuous energy input to maintain the operation of the system, and the bioheat generated during the composting process is difficult to be utilized. Therefore, the aerobic composting process, especially the high-temperature aerobic composting process in the reactor, is relatively expensive; and a large amount of organic matter is oxidized into polluted gas and dissipated during the high temperature period, and the remaining part can be converted into effective components of organic fertilizers such as humus, which will cause a certain amount of energy and organic matter waste.

[0005] Therefore, the current mainstream organic solid waste treatment process has two key bottleneck problems: 1. Single process, single product, waste of resources. The mineralization of organic matter not only fails to be converted into usable products as much as possible, but also causes secondary pollution; 2. The resource recovery rate is low, and a large amount of organic matter is mineralized into gas emissions and wasted; 3. The by-products are difficult to handle, and the upstream treatment units are not coordinated with the downstream treatment units, resulting in waste of resources and poor treatment effects, which has become a serious obstacle to the development of the organic solid waste resource utilization industry.

[0006] In view of this, this patent is applied for. Summary of the Invention

[0007] To address the problems of low resource recovery and secondary pollution in organic solid waste, the present invention provides an anaerobic-aerobic coupled fermentation technology for organic solid waste, combining high-solids anaerobic fermentation with aerobic composting to form an integrated treatment process. Simultaneously, a focus is placed on the conversion of organic matter during the fermentation process, establishing process parameters that balance methanogenesis during anaerobic fermentation and humification during aerobic fermentation. This achieves the coordinated utilization of organic solid waste as both energy and fertilizer, avoiding resource waste and secondary pollution to the environment.

[0008] The present invention provides an organic solid waste anaerobic-aerobic integrated fermentation process, wherein the organic solid waste high solid content anaerobic-aerobic integrated fermentation process comprises the following steps:

[0009] The organic solid waste is precisely compounded according to its organic component composition and anaerobically fermented to obtain methane-rich biogas and anaerobic fermentation residues; the organic components include protein, oil, easily degradable carbohydrates and lignocellulose;

[0010] The entire amount of the anaerobic fermentation residue is mixed with auxiliary materials for aerobic fermentation to form organic fertilizer.

[0011] The present invention aims to fully utilize organic solid waste for resource utilization, with minimal pollution and low energy consumption. The products of the entire high-solids anaerobic-aerobic integrated fermentation process are only biogas and organic fertilizer. Solid-liquid separation is not required, and the anaerobic fermentation residues produced by anaerobic fermentation are fully consumed and used in subsequent aerobic fermentation. No other unnecessary waste (such as biogas slurry or biogas residue) is generated during the production process.

[0012] The process is simple. The anaerobic fermentation products of organic solid waste do not require solid-liquid separation and no additional inoculum (fermentation bacteria or substances containing fermentation bacteria) is required. The aerobic fermentation process can be completed by directly adding auxiliary materials and introducing oxygen.

[0013] Through the precise compounding of the organic components in organic solid waste, the continuous operation of anaerobic fermentation and aerobic fermentation is achieved, the methane yield of the anaerobic fermentation process and the humus quality of the aerobic fermentation process are simultaneously improved, the production efficiency is significantly improved, and the goal of coordinated utilization of organic solid waste as energy and fertilizer is achieved.

[0014] The biogas produced by anaerobic fermentation is converted into electrical energy to provide power for aerobic fermentation or anaerobic fermentation process; the tail gas of aerobic fermentation is collected to provide heat for anaerobic fermentation, thereby realizing the material and energy cycle of the anaerobic-aerobic integrated fermentation process of organic solid waste, saving energy consumption and reducing production costs.

[0015] In some embodiments, the organic solid waste is degradable organic waste. Preferably, the organic solid waste is degradable organic waste generated in urban and rural production processes. More preferably, the organic solid waste includes crop straw, kitchen waste, livestock and poultry manure and / or dewatered sludge, and other urban and rural organic solid wastes rich in organic matter.

[0016] In some embodiments, organic solid waste is compounded according to an organic component composition to form an organic solid waste mixture, wherein the organic component composition includes a mass ratio of protein: oil: easily degradable carbohydrates: cellulose = (2.2-7.3): (1.4-4.4): (1.1-2.5): (2.5-3.0); more preferably, protein: oil: easily degradable carbohydrates: cellulose = 2.8:3.7:1.3:2.8.

[0017] The appropriate organic component ratio enriches more Methanosaeta and Methanosarcina in the organic waste gas, thereby strengthening the key factors of the acetic acid trophic methanogenesis pathway, thereby alleviating the accumulation of VFAs and maintaining a stable CH4 production pathway and organic fertilizer production pathway. An unsuitable organic component ratio will lead to the accumulation of volatile fatty acids (VFAs) and ammonia nitrogen (NH4 + -N) production capacity is improved, while CH4 and organic fertilizer production are reduced. Limiting the added ratios of protein, oil, easily degradable carbohydrates, and lignocellulose ensures the optimal balance of nutrients required for aerobic and anaerobic fermentation, preventing fermentation system instability caused by excessively rapid or slow organic matter degradation, and increasing gas production. Simultaneously, regulating the organic composition of anaerobic fermentation residues promotes subsequent aerobic fermentation, achieving optimal energy and fertilizer benefits while reducing the production of by-products.

[0018] In some embodiments, the solid content of the solid waste mixture is 15-25 wt %, more preferably, the solid content of the solid waste mixture is 20-25 wt %; further preferably, the solid content of the anaerobic fermentation residue is 13-19 wt %.

[0019] Selecting the solid content of the mixture not only increases biogas and organic fertilizer production but also facilitates the progression of both anaerobic and aerobic fermentation. Using a high-solids anaerobic fermentation process in the early stages of production also reduces the solids content of the anaerobic fermentation residue to 13-19% by weight, eliminating the need for solid-liquid separation before subsequent anaerobic fermentation. This allows for continuous operation of both anaerobic and aerobic fermentation, improving production efficiency.

[0020] In some embodiments, the organic solid waste is compounded according to the organic components, functional materials are added, and then anaerobic fermentation is performed;

[0021] Preferably, the functional material includes biochar, iron slag, etc.;

[0022] More preferably, the added amount of the functional material is 7-10% of the total dry weight of the compounded organic solid waste.

[0023] Generally, anaerobic fermentation is a wet fermentation process, and the solid content of the fermented material needs to be adjusted to below 10wt%, which will produce a large amount of biogas slurry and need to be treated. If high-solid content anaerobic fermentation is adopted, the system is prone to instability, which reduces the methane yield, and produces more biogas residues. The humus content in the formed biogas residues is low, and it also contains more pathogens, VFAs and risk pollutants, etc., and cannot be directly utilized. The present invention compounds the fermentation materials according to the organic components of the organic solid waste, and adds functional materials to achieve stable operation of high-solid content anaerobic fermentation and efficient methanation of organic matter. The pathogens, VFAs and risk pollutants are reduced through conversion and decomposition in the subsequent aerobic fermentation process, and the humus content in the product is increased. Direct aerobic fermentation also eliminates the need for solid-liquid separation of the residues after high-solid content anaerobic fermentation, and does not generate other waste.

[0024] The addition of functional materials not only regulates the moisture content of organic solid waste but also promotes microbial implantation and reproduction, optimizes the synergistic interaction between hydrolytic and methanogenic microorganisms, provides system buffering capacity, promotes the anaerobic fermentation process, and increases methane production. Meanwhile, functional materials remaining in the biogas residue continue to function during the aerobic composting process. For example, the addition of biochar can promote microbial activity during both aerobic and anaerobic fermentation. Specifically, it can act as a conductive material to transfer electrons during anaerobic fermentation, thereby increasing the fermentation rate. In aerobic fermentation, it can also enrich humifying microorganisms in a targeted manner, improving fertilizer quality.

[0025] The purpose of controlling the solid content of the anaerobic fermentation substrate is to avoid the solid-liquid separation process before aerobic fermentation, but at the same time it is also necessary to ensure sufficient fermentation in the anaerobic stage, ensure the stable growth of methanogens, promote methane production, and ensure that the methane content in the biogas is high, usually reaching more than 65%.

[0026] The auxiliary materials include high-carbon source agricultural and forestry wastes. Preferably, the high-carbon source agricultural and forestry wastes include planting wastes with a certain bulky spatial structure such as corn straw, rice straw and / or waste mushroom matrix; more preferably, the added amount of the auxiliary materials is 15-30% (wet weight) of the total weight of the compounded organic solid waste.

[0027] The solid content of the anaerobic fermentation residue produced after anaerobic fermentation is 13-19% by weight. The residue produced from the anaerobic fermentation process of the present invention does not require solid-liquid separation and can be guaranteed to contain a solid content of 13%-19% by weight. The anaerobic fermentation residue can be mixed with auxiliary materials to meet the nutritional requirements of aerobic fermentation. The humidity of the material to be aerobic fermented can also be controlled, and the structure of the aerobic fermentation pile can be adjusted to ensure normal oxygen flow, which is more conducive to the progress of aerobic fermentation.

[0028] In some embodiments, the bacterial species in the anaerobic fermentation include firmicutes and symbiotic bacteria; preferably, the bacterial species in the anaerobic fermentation include macromolecular hydrolysis, acidification bacteria and acetic acid-producing methanogenic archaea;

[0029] More preferably, the macromolecular hydrolysis and acidification bacteria include Christensenellaceae_R_7_group, Fastidiosipila and Thermovirga, and the acetic acid-trophic methanogenic archaea include Methanosaeta and Methanosarcina;

[0030] Christensenellaceae R7 and Fastidiosipila, members of the Firmicutes family, can drive the hydrolysis and acidification of organic matter during anaerobic fermentation. Christensenellaceae R7 promotes the decomposition of macromolecular organic matter, particularly cellulose and oils, inducing pentose phosphate and glycerolipid metabolism to enhance the biodegradation of polysaccharides and oils, while also reducing the presence of VFA-oxidizing bacteria, such as Synergistes and Acinetobacter. Petrimonas, a member of the Bacteroidota family, is known for its ability to consume VFAs and produce acetic acid, and is believed to promote CH4 production. An appropriate organic component ratio can promote the growth of Petrimonas. However, increasing the oil content and reducing the protein and cellulose additions inhibits their growth. Thermovirga, a member of the Synergistota family, exhibits strong tolerance to the various stages of anaerobic fermentation. It promotes the acidification of acetic and lactic acids, promotes anaerobic fermentation, provides nutrients for methanogens, and increases methane production. Acetate-trophic methanogens such as Methanosaeta and Methanosarcina are able to rapidly utilize large amounts of acetic acid to produce methane under high-solids anaerobic fermentation conditions, playing an important role in maintaining fermentation system homeostasis and increasing gas production.

[0031] More preferably, the organic solid waste includes dewatered sludge; the dewatered sludge itself contains Firmicutes and syntrophic bacteria and can be directly used for anaerobic fermentation without adding other inoculants.

[0032] During the anaerobic fermentation, the anaerobic fermentation residues of the previous batch, dewatered sludge and / or anaerobic fermentation residues of other projects are used as inoculum for anaerobic fermentation; the anaerobic fermentation residues of other projects include biogas slurry and / or biogas residue produced by anaerobic fermentation of other projects;

[0033] And / or, the high solid content anaerobic-aerobic integrated fermentation process is a continuous sequencing batch fermentation process;

[0034] Preferably, the first anaerobic fermentation uses dewatered sludge and / or anaerobic fermentation residues from other projects as inoculum, and the Nth anaerobic fermentation uses the anaerobic fermentation residues from the previous batch as inoculum, N≥2, so that continuous anaerobic fermentation can be achieved;

[0035] During continuous sequencing batch fermentation, the inoculum for the first anaerobic fermentation can be dewatered sludge or anaerobic fermentation residues from other projects. The anaerobic fermentation bacteria such as Firmicutes and Syntrophic bacteria contained in them can promote the production of methane and organic fertilizer.

[0036] More preferably, the solid content of the anaerobic fermentation residue from the other processes is 10-20 wt%; and the amount of the inoculum added is 50-100% (wet weight) of the total weight of the compounded organic solid waste. During the first anaerobic fermentation, the solid content of the added inoculum needs to be limited to ensure that the solid content of the anaerobic fermentation residue produced after anaerobic fermentation is 13-19 wt%. Otherwise, solid-liquid separation is required before aerobic fermentation.

[0037] To achieve continuity throughout the entire anaerobic-aerobic integrated fermentation process, reduce the introduction of exogenous substances, and save costs, the present invention recycles previously generated anaerobic fermentation residues. During the engineering fermentation process, a portion of the anaerobic fermentation residue, approximately 1 / 2-2 / 3 of the total volume, is directly pushed through a plug-flow agitator into the aerobic fermentation tank, where it is mixed with auxiliary materials for aerobic fermentation. The remaining anaerobic fermentation residue remains in the anaerobic fermentation tank and is mixed with the newly mixed organic solid waste as an inoculum to initiate a new round of anaerobic fermentation.

[0038] The present invention uses the residue after anaerobic fermentation to inoculate organic solid waste raw materials for cyclic fermentation, which not only saves energy and reduces the loss of residue, conforms to the concept of material and energy limit utilization, but also has a better fermentation effect (higher methane and humus production), shortens the fermentation cycle, reduces the production cost of fermentation, and improves production efficiency.

[0039] The first anaerobic fermentation can use biogas slurry or biogas residue produced by other engineering anaerobic fermentation, which contains more anaerobic fermentation bacteria, which can promote the anaerobic fermentation process of the present invention, effectively utilize methane production, and reduce production costs.

[0040] In some embodiments, microaerobic aeration is performed in the early stage of anaerobic fermentation, and the microaerobic aeration is 0.5-1.0 L / min per liter of pre-anaerobic fermentation material, and the microaerobic aeration time is 1 min / d; based on the anaerobic fermentation properties of organic solid waste, the present invention uses a microaerobic aeration-assisted anaerobic fermentation device in the early stage of anaerobic fermentation to microaerate the pre-fermentation material, which helps to quickly start anaerobic fermentation and accelerate the process of anaerobic fermentation.

[0041] The rate of microaerobic aeration is regulated to ensure ventilation, as excessive ventilation will hinder anaerobic fermentation, while too little ventilation will have an insignificant effect on anaerobic fermentation. During microaerobic aeration, the present invention selects and determines a ventilation rate of 0.5-1.0 L per minute per liter of pre-anaerobic fermentation material (air is introduced, and ventilation is performed for 1 minute per day). This results in better anaerobic fermentation, low energy consumption, improved organic solid waste treatment, and increased methane production.

[0042] Preferably, the anaerobic fermentation temperature is 33-37°C and the anaerobic fermentation time is 20-45 days; more preferably, the anaerobic fermentation temperature is 34-36°C and the anaerobic fermentation time is 25-35 days. Further preferably, the anaerobic fermentation time can be 35 days to obtain the maximum net energy value of operation.

[0043] Adjust the temperature and time of anaerobic fermentation to achieve more thorough fermentation in the shortest possible time, maximize net energy value, and save production costs. During the controlled anaerobic fermentation process, some residues can be discharged at the appropriate time and retained as inoculum for the next batch of feed, ensuring the raw materials and inoculum volume for the cyclic fermentation.

[0044] In some embodiments, during the aerobic fermentation process, forced aeration is performed;

[0045] Preferably, the forced aeration rate is 0.12-0.24 L / min per kilogram of pre-aerobic fermentation material.

[0046] The ventilation rate is selected to be 0.12-0.24L of air per minute per kilogram of pre-aerobic fermentation material. This can just meet the needs of aerobic fermentation. If the ventilation rate is too high, the air residence time is short, resulting in incomplete aerobic fermentation. If the ventilation rate is too low, it cannot meet the oxygen required for aerobic fermentation.

[0047] More preferably, the aerobic fermentation time is 7-15 days.

[0048] The fermentation products of the organic solid waste anaerobic-aerobic integrated fermentation process are biogas and organic fertilizer; preferably, the volume content of methane in the biogas is more than 65%, and the CH4 volumetric gas production is 35m 3 / m 3 ; The humus content in the organic fertilizer is more than 75g / kg;

[0049] The organic solid waste anaerobic-aerobic integrated fermentation process is a continuous fermentation process. Preferably, the organic solid waste anaerobic-aerobic integrated fermentation process is a continuous sequencing batch fermentation process.

[0050] In some embodiments, part of the biogas is used to heat the water tank to ensure the temperature of the anaerobic fermentation substrate; the rest is used to generate electricity, and the electricity generated provides power for the aerobic and anaerobic fermentation processes;

[0051] The waste heat gas generated during the aerobic fermentation process is connected to a constant temperature water tank through a pipeline for heat exchange and serves as a water circulation heat supply for the anaerobic fermentation reactor.

[0052] Converting biogas generated by anaerobic fermentation into electrical energy; preferably, the biogas is converted into electrical energy after being purified, stored, and generated electricity;

[0053] After aerobic fermentation, organic fertilizer is formed through aging, drying, screening and granulation.

[0054] The anaerobic fermentation process requires continuous heat supply, and the heat source is biogas combustion; or the waste heat from the conversion of biogas into electricity.

[0055] The waste heat generated during the aerobic fermentation process is collected and supplied to anaerobic fermentation.

[0056] The waste heat generated during the conversion of biogas into electricity is used to power the anaerobic fermentation process. The waste heat generated during the conversion of biogas into electricity can be used to heat the anaerobic fermentation reactor to maintain anaerobic fermentation performance. The electricity generated provides power for both aerobic and anaerobic fermentation processes, primarily supplying the mixing process, microaerobic aeration, or forced ventilation aeration. This enables a self-sufficient, integrated anaerobic and anaerobic fermentation cycle for organic solid waste, eliminating the need for external energy sources, reducing pollution, and saving energy and production costs.

[0057] The organic solid waste is pretreated and then precisely compounded according to the composition of the organic components. Preferably, the pretreatment includes magnetic separation, sorting and / or crushing.

[0058] If the organic solid waste contains a large amount of metal impurities, it needs to be removed by magnetic separation to avoid the generation of pollutants; if the organic solid waste contains a large amount of other impurities (such as glass, etc.), it needs to be removed by sorting; if the organic solid waste contains large particles, it is not conducive to fermentation and needs to be crushed before fermentation, which can not only save fermentation time, but also make the fermentation more thorough and avoid waste.

[0059] In some embodiments, the anaerobic fermentation residue is mixed with the auxiliary material to form an auxiliary material mixture, the functional material is added again to the auxiliary material mixture, and then aerobic fermentation is carried out; preferably, the added amount of the functional material is 1-3% of the dry weight of the auxiliary material mixture. Further preferably, the added amount of the functional material is 2% of the dry weight of the auxiliary material mixture.

[0060] The anaerobic compost residue already contains the functional materials added during the anaerobic fermentation process. Aerobic composting units can be prepared without these materials, or they can be supplemented with functional materials such as biochar at a rate of 1-3% by dry weight of the mixture. Controlling the amount of functional materials added improves aerobic fermentation efficiency and the quality of the compost product (organic fertilizer).

[0061] In some embodiments, the organic solid waste anaerobic-aerobic integrated fermentation process comprises the following steps:

[0062] (1) Raw material compounding: organic solid waste is collected and precisely compounded according to the composition of organic components to form a mixed material; the bacterial species in the organic solid waste include firmicutes and mutualistic bacteria; preferably, the bacterial species in the anaerobic fermentation include macromolecular hydrolysis and acidification bacteria such as Christensenellaceae_R_7_group, Fastidiosipila and Thermovirga, and acetic acid-producing methanogenic archaea such as Methanosaeta and Methanosarcina;

[0063] (2) Pre-fermentation material preparation: adding functional materials to the mixed material obtained in step (1) to form a pre-fermentation material;

[0064] (3) Anaerobic fermentation: adding the anaerobic fermentation residues of the previous batch or the anaerobic fermentation residues of other projects as inoculum to the pre-fermented material obtained in step (2) to carry out a new round of anaerobic fermentation to obtain biogas and a new round of anaerobic fermentation residues;

[0065] (4) Aerobic composting: The residue from the new round of anaerobic fermentation obtained in step (3) is mixed with auxiliary materials to form an aerobic fermentation material, and the compost is aerobic fermented.

[0066] In the process of converting the biogas produced by anaerobic fermentation into electricity, the waste heat generated is supplied to the anaerobic fermentation process; the electricity generated by power generation provides power for aerobic fermentation or anaerobic fermentation process; the tail gas of aerobic fermentation is collected to provide heat for anaerobic fermentation, thus realizing the cycle of anaerobic-aerobic integrated fermentation process of organic solid waste, which is self-sufficient, does not need to borrow external energy, reduces pollution, saves energy consumption, and saves production costs.

[0067] In the prior art, air is introduced into the tank through blowers, aeration pipes and other equipment to increase the oxygen content in the water. The present invention uses a forced ventilation static composting reactor for forced ventilation and aeration, which increases the oxygen content of the material, allowing aerobic fermentation to occur and improving the efficiency of aerobic fermentation.

[0068] The aerobic fermentation time is 7-15 days. The anaerobic fermentation residue after anaerobic fermentation directly enters the high-temperature aerobic composting process for secondary fermentation, and high-quality organic fertilizer can be obtained after the fermentation is completed. The organic fertilizer produced by the present invention fully meets the standard requirements of "Organic Fertilizer" (NY / T525-2021).

[0069] In some embodiments, the anaerobic fermentation is carried out in a micro-aerobic aeration-assisted anaerobic fermentation device, and the micro-aerobic aeration anaerobic fermentation device includes a horizontal or vertical anaerobic fermentation reactor;

[0070] The bottom of the anaerobic fermentation reactor is provided with an aeration port, the interior of the reactor is provided with an automatic stirring device, and the top of the reactor is provided with an exhaust port, a safety valve and a feed port.

[0071] Preferably, the anaerobic fermentation reaction device is further provided with a temperature sensor, and the probe extends into the interior of the anaerobic fermentation reaction device to detect the temperature of the material inside the anaerobic fermentation device.

[0072] More preferably, the anaerobic fermentation reaction device further comprises an air pump with adjustable flow rate, and the outlet of the air pump is connected to the aeration port located at the bottom of the reactor.

[0073] During operation, the temperature sensor automatically measures the temperature and initiates heating of the material in real time, ensuring optimal fermentation conditions. A flow-controlled air pump provides oxygen to the material through an aeration port located at the bottom of the reactor. A check valve is installed at the aeration port to control the aeration volume.

[0074] The present invention provides an integrated anaerobic-aerobic fermentation process for organic solid waste. By constructing a coupled fermentation system, this process directly integrates high-solids anaerobic fermentation and aerobic composting into a single process, eliminating the need for solid-liquid separation. Furthermore, the process focuses on the conversion of organic matter during the fermentation process to optimize energy (methanization) and fertilizer (humification) utilization, while avoiding the generation of byproducts. This approach addresses the issues of low resource recovery, complex procedures, and high secondary pollution associated with organic solid waste.

[0075] After a series of parameter optimization, the degree of methanation and humification in the fermentation process was greatly improved, with the methane yield increased by more than 4 times and the humic acid content increased by 1-1.5 times. -1 / kg VS (unit L·d -1 / kg VS represents the high methane production (converted to volumetric gas production of 35m3 / day) per kilogram of volatile solids. 3 / m 3 ), and a humic acid carbon content of more than 75g / kg dry matter.

[0076] The biogas produced in the anaerobic process can be used for power generation and for anaerobic and aerobic fermentation. The anaerobic fermentation residue does not require solid-liquid separation and can be directly subjected to aerobic fermentation. The heat generated in the aerobic fermentation process can be used to heat the anaerobic process tank, reducing energy consumption. This truly realizes the coordination and continuity of materials and energy in the entire integrated fermentation process, avoiding the transfer of materials and energy waste between the traditional anaerobic and aerobic fermentation processes.

[0077] The process parameters for the entire anaerobic and aerobic integrated fermentation process, which take into account the coordinated methanation and humification of organic components, are clarified to achieve the coordinated production of energy and fertilizer.

[0078] The present invention optimizes the process parameters in anaerobic fermentation and aerobic fermentation to obtain good fermentation effect and superior product performance. The parameter regulation process includes raw material source allocation, fermentation matrix inoculation adjustment, aerobic end carbon source auxiliary material conditioning, anaerobic → aerobic switching node optimization and functional material mediation (biochar) to optimize product performance.

[0079] The present invention aims to treat multiple organic solid wastes through this multi-link technical means, avoid the addition of exogenous energy and water, save water and electricity, do not produce by-products, recycle resources, and achieve the goals of synergistic recovery of organic solid waste energy and fertilizer, less secondary pollution, and high resource recovery rate, greatly reducing costs, increasing benefits, and improving the treatment efficiency of organic solid waste, with broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0081] Figure 1 This is a schematic diagram of the process of the anaerobic-aerobic integrated fermentation process for organic solid waste provided by the present invention;

[0082] Figure 2 This is the simulation result of the annual net energy value output of multiple batches of anaerobic fermentation processes with different anaerobic fermentation cycles provided in Test Example 1 of the present invention;

[0083] Figure 3 are the (A) daily and (B) cumulative CH4 production and (C) CH4 concentration of the organic component ratios in different raw materials during the anaerobic fermentation process of Experimental Example 2 of the present invention;

[0084] Figure 4 It is the molecular weight and quality effect of humic acid in different proportions of organic components in raw materials during anaerobic fermentation in Test Example 2 of the present invention;

[0085] Figure 5 This is the effect of solid content on methane yield in anaerobic fermentation process in Experiment 3 of the present invention;

[0086] Figure 6 This is the effect of different auxiliary materials of anaerobic fermentation residue on humus content in aerobic fermentation stage in Test Example 4 of the present invention;

[0087] Figure 7 is a schematic diagram of the amount and method of biochar addition in Experimental Example 5 of the present invention;

[0088] Figure 8 This is a comparison of methane production performance during anaerobic fermentation with different biochar addition amounts in Experimental Example 5 of the present invention;

[0089] Figure 9 This is the effect of different biochar addition methods on the humic acid content of compost during the aerobic fermentation stage in Experimental Example 6 of the present invention;

[0090] Figure 10 is the effect of inoculum size on the methane production performance of anaerobic fermentation process;

[0091] Figure 11 is the effect of inoculum size on the humic acid content of compost during the aerobic fermentation stage; DETAILED DESCRIPTION

[0092] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0093] The organic solid waste used in this invention includes crop straw, restaurant waste, livestock and poultry manure, and dewatered sludge. The crop straw and livestock and poultry manure were purchased from farms and livestock farms in Hebei and Beijing, respectively. The dewatered sludge and restaurant waste were sourced from municipal sewage treatment plants and domestic waste treatment plants in Beijing, respectively. Unless otherwise specified, the raw materials used in this invention are all commercially available products.

[0094] In the following experiments, biogas collection containers (including air bags, etc.) were used to collect biogas products daily, and the methane content in the biogas was detected at the same time.

[0095] The following combination Figures 1-11 The present invention describes the organic solid waste anaerobic-aerobic integrated fermentation process.

[0096] In some specific embodiments, an organic solid waste anaerobic-aerobic integrated fermentation process is provided, comprising the following steps (process flow chart as follows Figure 1 shown):

[0097] (1) Raw material compounding: organic solid waste is collected and pre-treated and compounded to form a mixed material; in the mixed material, protein: oil: easily degradable carbohydrate: lignocellulose = (2-3): (3-4): (1-2): (2-3); the solid content of the mixed material is 10-20 wt%;

[0098] adding 6-8% of biochar by weight of the mixed material to the mixed material to form a pre-fermented material;

[0099] (2) Anaerobic fermentation: adding a portion of the anaerobic fermentation residue from the previous batch as an inoculum to the pre-fermented material obtained in step (1) to carry out anaerobic fermentation at a temperature of 33-37° C. for 20-45 days; obtaining biogas and anaerobic fermentation residue;

[0100] (3) Biogas treatment: converting the biogas produced by anaerobic fermentation in step (2) into electrical energy;

[0101] (4) Aerobic composting: The remaining anaerobic fermentation residue produced by the anaerobic fermentation in step (2) is mixed with auxiliary materials to form aerobic fermentation material, and the aerobic fermentation material is composted for aerobic fermentation; after the aerobic fermentation is completed, the aerobic fermentation product is screened and granulated to form organic fertilizer; the waste heat generated during the aerobic fermentation process is collected and supplied to the anaerobic fermentation.

[0102] Example 1

[0103] The organic solid waste anaerobic-aerobic integrated fermentation process provided in this embodiment includes the following steps:

[0104] (1) Raw material compounding: Crop straw and kitchen waste were collected and magnetically separated and sorted, and then crushed into materials with a particle size of less than 1 mm, compounded and put into a material pit to form a mixed material; in the mixed material, the ratio of protein: oil: easily degradable carbohydrate: lignocellulose = 2.8:3.7:1.3:2.8; the solid content of the mixed material was 20 wt%; the bacterial species included macromolecular hydrolysis and acidification bacteria such as Christensenellaceae_R_7_group, Fastidiosipila and Thermovirga, and acetic acid-trophic methanogenic archaea such as Methanosaeta and Methanosarcina;

[0105] adding 7% biochar by weight of the mixed material to the mixed material to form a pre-fermented material;

[0106] (2) Anaerobic fermentation: adding anaerobic fermentation residues (80% by weight of the pre-fermentation material) as inoculum (biogas residue from other projects, with a solid content of 20 wt%) to the pre-fermentation material obtained in step (1) to carry out anaerobic fermentation to obtain biogas and anaerobic fermentation residues with a solid content of 18 wt%; the anaerobic fermentation temperature is 35° C., and the anaerobic fermentation time is 35 days; microaerobic aeration is carried out during the first 9 days of anaerobic fermentation, the microaerobic aeration rate is 0.5 L / min / LR, and the aeration time is 1 minute per day;

[0107] (3) Biogas treatment: The biogas generated by the anaerobic fermentation in step (2) is converted into electrical energy after purification, storage, and power generation; the generated electrical energy provides power for the aerobic fermentation process.

[0108] (4) Aerobic composting: The remaining anaerobic fermentation residue from step (2) is mixed with corn straw to form an aerobic fermentation material, with the corn straw added in an amount of 15% of the weight of the aerobic fermentation material. The aerobic fermentation material is placed in a forced ventilation static composting reactor and composted for 15 days, with air introduced at a rate of 0.18 L / min per kilogram of aerobic fermentation material to complete the aerobic fermentation process. After the aerobic fermentation is completed, the aerobic fermentation product is screened and granulated to form organic fertilizer. The waste heat generated during the aerobic fermentation process is collected and supplied to the anaerobic fermentation.

[0109] Example 2

[0110] The organic solid waste anaerobic-aerobic integrated fermentation process provided in this embodiment includes the following steps:

[0111] (1) Raw material compounding: Dewatered sludge (the effective viable bacteria count of dewatered sludge is 100,000 to 200,000 / g) and livestock and poultry manure are collected, magnetically separated, sorted, and then crushed into materials with a particle size of less than 1 mm. The materials are compounded and put into the material pit to form a mixed material; in the mixed material, the ratio of protein: oil: easily degradable carbohydrate: lignocellulose is 2.8:3.7:1.3:2.8; the solid content of the mixed material is 20wt%;

[0112] adding 7% biochar by weight of the mixed material to the mixed material to form a pre-fermented material;

[0113] (2) Anaerobic fermentation: The pre-fermented material obtained in step (1) was subjected to anaerobic fermentation to obtain biogas and an anaerobic fermentation residue with a solid content of 19%; the anaerobic fermentation temperature was 35° C., and the anaerobic fermentation time was 40 days. Microaeration was performed during the anaerobic fermentation at a rate of 1 L / min (1.0 L / min per liter of anaerobic fermentation material) and the aeration time was 1 minute per day;

[0114] (3) Biogas treatment: The biogas generated by the anaerobic fermentation in step (2) is converted into electrical energy after purification, storage, and power generation; the generated electrical energy provides power for the aerobic fermentation process.

[0115] (4) Aerobic composting: The remaining anaerobic fermentation residue produced by the anaerobic fermentation in step (2) is mixed with corn straw to form an aerobic fermentation material, and the amount of corn straw added is 25% by weight of the aerobic fermentation material; 2% by weight (dry weight) of biochar is added to the aerobic fermentation material; the aerobic fermentation material is loaded into a forced ventilation static composting reactor for composting to complete the aerobic fermentation process; the aerobic fermentation time is 15 days, and a ventilation rate of 0.24 L / min of air is adopted per kilogram of dry material for aerobic fermentation.

[0116] After aerobic fermentation is completed, the aerobic fermentation products are screened and granulated to form organic fertilizer; the waste heat generated during the aerobic fermentation process is collected and supplied to anaerobic fermentation.

[0117] Part of the biogas is used to heat the water tank to ensure the temperature of the anaerobic fermentation substrate; the rest of the biogas is used to generate electricity, which provides power for the aerobic and anaerobic fermentation processes.

[0118] The waste heat gas generated during the aerobic fermentation process is connected to a constant temperature water tank through a pipeline for heat exchange and serves as a water circulation heat supply for the anaerobic fermentation reactor.

[0119] After testing, the organic fertilizers produced in Example 1 and Example 2 fully meet the standard requirements of "Organic Fertilizer" (NY / T525-2021).

[0120] Test Example 1

[0121] The organic solid waste anaerobic-aerobic integrated fermentation process of this test example is basically the same as that of Example 1, with the only difference being that the time of anaerobic fermentation is different. The time of anaerobic fermentation is selected to be 5 days, 10 days, 15 days, 20 days, 25 days, 30 days, 35 days, 40 days, and 45 days, respectively.

[0122] The annual operating energy value simulation method (formula, energy consumption unit, energy consumption parameters, etc.) refers to the method given in the paper "Effects of digestion duration on energy efficiency, compost quality, and carbon flow during solid state anaerobic digestion and composting hybrid process" (Science of the Total Environment 811 (2022) 151363). The annual operating net energy value simulation results of the fermentation process with different anaerobic fermentation times are obtained as follows Figure 2 As shown, the anaerobic fermentation time is preferably 20-45 days, and the preferred anaerobic fermentation time is 35 days.

[0123] Test Example 2

[0124] The organic solid waste anaerobic-aerobic integrated fermentation process provided in this test example is basically the same as that in Example 1, with the only difference being that the organic component ratios of the mixed materials are different, and the ratios of protein: oil: easily degradable carbohydrates: lignocellulose are as shown in Table 1 below. The daily methane production and cumulative methane production were detected.

[0125] Table 1 Organic components of mixed materials

[0126]

[0127] The effects of different ratios of organic components in the mixture on daily methane production and cumulative methane production and the molecular weight of humic acid in the substrate are as follows: Figure 3 and Figure 4 As shown in the results, by comparison, when the mass ratio of protein: oil: easily degradable carbohydrates: cellulose = (2.2-7.3): (1.4-4.4): (1.1-2.5): (2.5-3.0), a better methanogenesis effect is achieved; selecting the organic component ratio of Example 1 has a better methanogenesis and humus quality enhancement effect.

[0128] Test Example 3

[0129] The organic solid waste anaerobic-aerobic integrated fermentation process provided in this test example is basically the same as that in Example 1, with the only difference being that the solid content of the mixed material is set at a gradient of 10 wt%, 15 wt%, 20 wt%, 25 wt% or 30 wt%, respectively, to observe the effect of the solid content of the mixed material on the cumulative methane yield during anaerobic fermentation.

[0130] The results are as follows Figure 5 As shown, the results show that the solid content is preferably 15-25wt%, preferably 20-25wt%, which has better methane production and organic fertilizer effects.

[0131] Test Example 4

[0132] The organic solid waste anaerobic-aerobic integrated fermentation process provided in this test example is basically the same as that in Example 1, the only difference is that the auxiliary materials added in the aerobic fermentation stage are replaced by waste mushroom substrate and sugarcane bagasse instead of corn straw. Figure 6 As shown in the figure, the results show that in the aerobic stage, auxiliary materials with good supporting structure and capable of ensuring the bulking of the fermentation material, such as corn straw and waste mushroom matrix, are suitable, while auxiliary materials with poor bulking effect, such as sugarcane bagasse, are not conducive to the production of humic acid.

[0133] Test Example 5

[0134] The organic solid waste anaerobic-aerobic integrated fermentation process provided in this test example is basically the same as that in Example 1, the only difference is that the amount of biochar added in the anaerobic stage is 0%, 3%, 7%, and 10%; no biochar is added or not added in the aerobic stage. Figure 7 shown.

[0135] Comparison of methane production performance in anaerobic fermentation process with different biochar addition amounts Figure 8 As shown in the results, considering factors such as methane production and biochar cost, adding 7% biochar before anaerobic fermentation has a better methane production effect.

[0136] Test Example 6

[0137] The integrated anaerobic-aerobic fermentation process for organic solid waste provided in this experimental example was essentially the same as that in Example 1, with the only difference being the addition of biochar at different stages of the fermentation process. Three scenarios were described: no biochar addition during both aerobic and anaerobic fermentation, addition during the aerobic phase, and addition during the anaerobic phase only. The humic acid content of the resulting organic fertilizer was observed and compared.

[0138] The results are as follows Figure 9 The results showed that adding biochar only during the anaerobic process and continuing to use the residue of anaerobic fermentation with biochar as raw material in the aerobic stage had a better effect on humic acid production.

[0139] Comparative Example 1

[0140] The organic solid waste anaerobic-aerobic integrated fermentation process provided in this comparative example is essentially the same as that in Example 1, with the only difference being that the amount of anaerobic fermentation residue added as inoculum is lower, only 50% of that in Example 1 (40% by weight of the pre-fermentation material added). The methane production and humic acid content in the organic fertilizer were observed and measured.

[0141] The results of methane production were as follows: Figure 10 As shown in Figure 2, by comparing with Example 1, the inoculum amount of Example 1 has a better methane production effect; the determination results of the humic acid content in the organic fertilizer are as shown in Figure 2. Figure 11 As shown, continuing to use the anaerobic fermentation residue in the inoculum amount described in Example 1 as raw material in the aerobic stage has a better effect of producing humic acid.

[0142] Through the above test, it was found that the organic solid waste anaerobic-aerobic integrated fermentation process described in Example 1 and based on the preferred parameters can obtain 350-600 L·d -1 / kg VS (converted to volumetric methane production, it is 35m 3 / m 3 ) high methane yield. The volume content of methane in the biogas is more than 65%; the humic acid carbon content in the organic fertilizer is more than 75g / kg.

[0143] Therefore, it can be seen that the organic solid waste anaerobic-aerobic integrated fermentation process provided by the present invention has the following advantages:

[0144] (1) No solid-liquid separation is required, and anaerobic fermentation products other than biogas are consumed during the fermentation process, avoiding the treatment of biogas slurry and biogas residue;

[0145] (2) It significantly improves the environmental friendliness of organic matter utilization and the efficient use of resources, avoids inefficient utilization methods such as anaerobic residue incineration, avoids the mineralization and pollution emissions caused by the rapid decomposition of a large number of organic components by simply using aerobic composting, and realizes the dual recovery of methane and humic acid;

[0146] (3) The biogas production / operating energy value is greatly improved. The control parameters of the anaerobic fermentation part of the present invention can increase the methane production by up to 4 times; after the anaerobic fermentation time is optimized, the annual net energy value of the system is greatly improved;

[0147] (4) Producing organic fertilizer rich in humic acid. The present invention can achieve the pre-generation of humic acid substances (carboxyl, alicyclic, aromatic compounds, etc.) during the anaerobic fermentation process through the regulation of optimal parameters. It can further promote the synthesis of humic acid during the aerobic composting process. Through the optimization of a series of parameters such as organic component adjustment, inoculation amount optimization and continuous strengthening of the whole process of biochar, the humic acid content can be increased by more than 1-1.5 times.

[0148] (5) Save water addition and adopt high solid content fermentation. The water content of the raw materials themselves can be used to complete the fermentation, and generally no additional water is needed; the energy is self-sufficient to meet the needs of the system, and both energy and fertilizer are recycled.

[0149] In the above embodiments, anaerobic fermentation is carried out in a micro-aerobic aeration anaerobic fermentation device, and the anaerobic fermentation is carried out in a micro-aerobic aeration anaerobic fermentation device, and the micro-aerobic aeration anaerobic fermentation device includes a horizontal or vertical anaerobic fermentation reactor;

[0150] The bottom of the anaerobic fermentation reactor is provided with an aeration port, the interior of the reactor is provided with an automatic stirring device, and the top of the reactor is provided with an exhaust port, a safety valve and a feed port.

[0151] Preferably, the anaerobic fermentation reaction device is further provided with a temperature sensor, and the probe extends into the interior of the anaerobic fermentation reaction device to detect the temperature of the material inside the anaerobic fermentation device.

[0152] More preferably, the anaerobic fermentation reaction device further comprises an air pump with adjustable flow rate, and the outlet of the air pump is connected to the aeration port located at the bottom of the reactor.

[0153] During operation, the temperature sensor automatically measures the temperature, enabling real-time heating of the material based on the temperature, ensuring optimal fermentation conditions. A flow-controlled air pump provides oxygen to the material via an aeration port located at the bottom of the reactor. A check valve is provided at the aeration port to regulate the aeration rate. The micro-aerobic aeration anaerobic fermentation device of the present invention provides quantitative and uniform aeration.

[0154] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. An anaerobic-aerobic integrated fermentation process for organic solid waste with high solid content, characterized in that: The high solid content anaerobic-aerobic integrated fermentation process comprises the following steps: The organic solid waste is precisely compounded according to its organic component composition and anaerobically fermented to obtain methane-rich biogas and anaerobic fermentation residues; the organic components include protein, oil, easily degradable carbohydrates and lignocellulose; Mixing the entire amount of the anaerobic fermentation residue with auxiliary materials for aerobic fermentation to form organic fertilizer; The organic components include protein: oil: easily degradable carbohydrate: lignocellulose in a mass ratio of (2.2-7.3): (1.4-4.4): (1.1-2.5): (2.5-3.0); The solid content of the organic solid waste mixture obtained by compounding is 15-20wt%.

2. The anaerobic-aerobic integrated fermentation process for organic solid waste with high solid content according to claim 1, characterized in that: After compounding, functional materials are added and then anaerobic fermentation is carried out.

3. The anaerobic-aerobic integrated fermentation process for organic solid waste with high solid content according to claim 2, characterized in that: The functional material includes biochar and / or iron slag; The added amount of the functional material is 7-10% of the total dry weight of the compounded organic solid waste.

4. The anaerobic-aerobic integrated fermentation process for organic solid waste with high solid content according to claim 3, characterized in that: The auxiliary materials include high-carbon source agricultural and forestry wastes.

5. The anaerobic-aerobic integrated fermentation process for organic solid waste with high solid content according to claim 4, characterized in that: The high-carbon source agricultural and forestry waste includes corn straw, garden prunings and / or waste mushroom substrate; the added amount of the auxiliary material is 15-30% of the weight of the anaerobic fermentation residue.

6. The high solid content anaerobic-aerobic integrated fermentation process for organic solid waste according to claim 5, characterized in that: The bacterial species in the anaerobic fermentation include firmicutes and symbiotic bacteria.

7. The high solid content anaerobic-aerobic integrated fermentation process for organic solid waste according to claim 6, characterized in that: The bacterial species in the anaerobic fermentation include macromolecular hydrolysis and acidification bacteria and acetic acid trophic methanogenic archaea.

8. The high solid content anaerobic-aerobic integrated fermentation process for organic solid waste according to claim 7, characterized in that: The macromolecular hydrolysis and acidification bacteria include Christensenellaceae_R_7_group, Fastidiosipila and Thermovirga , the acetic acid trophic methanogenic archaea include Methanosaeta, Methanosarcina; The organic solid waste includes dewatered sludge; During the anaerobic fermentation, the anaerobic fermentation residues of the previous batch, dewatered sludge and / or anaerobic fermentation residues of other projects are used as inoculum for anaerobic fermentation; the anaerobic fermentation residues of other projects include biogas slurry and / or biogas residue produced by anaerobic fermentation of other projects; The high solid content anaerobic-aerobic integrated fermentation process for organic solid waste is a continuous sequencing batch fermentation process; The first anaerobic fermentation uses dewatered sludge and / or anaerobic fermentation residues of other projects as inoculum, and the Nth anaerobic fermentation uses the anaerobic fermentation residues of the previous batch as inoculum, N≥2, and continuous anaerobic fermentation can be achieved.

9. The high solid content anaerobic-aerobic integrated fermentation process for organic solid waste according to claim 8, characterized in that: The solid content of the anaerobic fermentation residues of the other projects is 10-20wt%; the amount of the inoculum added is 50-100% of the total weight of the compounded organic solid waste.

10. The high solid content anaerobic-aerobic integrated fermentation process for organic solid waste according to claim 9, characterized in that: During the anaerobic fermentation process, microaerobic aeration is performed, wherein the microaerobic aeration is performed at a rate of 0.5-1.0 L / min per liter of anaerobic fermentation material, and the microaerobic aeration time is 1 min / d; The temperature of the anaerobic fermentation is 33-37° C., and the anaerobic fermentation period is 20-45 days; forced ventilation and aeration are performed during the aerobic fermentation process; The forced aeration rate is 0.12-0.24 L / min per kilogram of aerobic fermentation material; The aerobic fermentation time is 7-15 days.

11. The anaerobic-aerobic integrated fermentation process for organic solid waste with high solid content according to claim 10, characterized in that: The temperature of the anaerobic fermentation is 34-36° C., and the anaerobic fermentation period is 25-35 days.

12. The anaerobic-aerobic integrated fermentation process for organic solid waste with high solid content according to claim 11, characterized in that: The fermentation products of the high-solid-content anaerobic-aerobic integrated fermentation process for organic solid waste are biogas and organic fertilizer.

13. The anaerobic-aerobic integrated fermentation process for organic solid waste with high solid content according to claim 12, characterized in that: The volume content of methane in biogas is more than 65%, and the methane volumetric gas production is 35 m 3 / m 3 ; The humic acid content in the organic fertilizer is more than 75 g / kg.

14. The high solid content anaerobic-aerobic integrated fermentation process for organic solid waste according to claim 13, characterized in that: Part of the biogas is used to heat the water tank to ensure the temperature of the anaerobic fermentation substrate; the remaining biogas is used to generate electricity, and the electricity generated provides power for the aerobic and anaerobic fermentation processes; The waste heat gas generated during the aerobic fermentation process is connected to a constant temperature water tank through a pipeline for heat exchange and serves as a water circulation heat supply for the anaerobic fermentation reactor.

15. The high solid content anaerobic-aerobic integrated fermentation process for organic solid waste according to claim 2, characterized in that: The anaerobic fermentation residue does not need to be separated into solid and liquid, and can be mixed with auxiliary materials in full to form an auxiliary material mixture. The functional material is added to the auxiliary material mixture again, and then aerobic fermentation is carried out.

16. The high solid content anaerobic-aerobic integrated fermentation process for organic solid waste according to claim 15, characterized in that: The functional material is added in an amount of 1-3% of the dry weight of the auxiliary material mixture; The organic solid waste is degradable organic waste.

17. The anaerobic-aerobic integrated fermentation process for organic solid waste with high solid content according to claim 16, characterized in that: The organic solid waste is degradable organic waste generated in urban and rural production processes.

18. The anaerobic-aerobic integrated fermentation process for organic solid waste with high solid content according to claim 17, characterized in that: The organic solid waste includes crop straw, kitchen waste, livestock and poultry manure and / or dewatered sludge.

19. The anaerobic-aerobic integrated fermentation process for organic solid waste with high solid content according to claim 1, characterized in that: The anaerobic fermentation is carried out in a micro-aerobic aeration anaerobic fermentation device, which includes a horizontal or vertical anaerobic fermentation reactor; The bottom of the anaerobic fermentation reactor is provided with an aeration port, the interior of the reactor is provided with an automatic stirring device, and the top of the reactor is provided with an exhaust port, a safety valve and a feed port.

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