WO2019102364A1 - Système de digestion anaérobie à vitesse élevée pour déchets organiques solides - Google Patents

Système de digestion anaérobie à vitesse élevée pour déchets organiques solides Download PDF

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WO2019102364A1
WO2019102364A1 PCT/IB2018/059163 IB2018059163W WO2019102364A1 WO 2019102364 A1 WO2019102364 A1 WO 2019102364A1 IB 2018059163 W IB2018059163 W IB 2018059163W WO 2019102364 A1 WO2019102364 A1 WO 2019102364A1
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reactor
plug flow
hydrolyzed
organic
liquid
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Piyush PATIL
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Patil Piyush
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    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12M—APPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS
    • C12M21/00—Bioreactors or fermenters specially adapted for specific uses
    • C12M21/04—Bioreactors or fermenters specially adapted for specific uses for producing gas, e.g. biogas
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12M—APPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS
    • C12M1/00—Apparatus for enzymology or microbiology
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12M—APPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS
    • C12M23/00—Constructional details, e.g. recesses, hinges
    • C12M23/58—Reaction vessels connected in series or in parallel
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12M—APPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS
    • C12M45/00—Means for pre-treatment of biological substances
    • C12M45/03—Means for pre-treatment of biological substances by control of the humidity or content of liquids; Drying
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12M—APPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS
    • C12M45/00—Means for pre-treatment of biological substances
    • C12M45/06—Means for pre-treatment of biological substances by chemical means or hydrolysis
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E50/00—Technologies for the production of fuel of non-fossil origin
    • Y02E50/30—Fuel from waste, e.g. synthetic alcohol or diesel

Definitions

  • the present invention generally relates to the field of waste treatment and energy generation, more particularly to an improved anaerobic digestion system and treatment method for solid organic wastes, soluble organic matter, by-products and residues; with special consideration on treatment of lignocellulosic wastes, for energy production.
  • Solid organic wastes such as straw, alcohol stillage, vegetable refuse, energy crops and lignocellulosic crop residues, animal wastes, i.e., manure and others have been, since long, considered a potential resource for the production of methane gas. Substantial amounts of money and effort have been directed towards providing a practical process for utilization of this resource. Typical methods involve anaerobic digestion of the waste within a complex system.
  • Anaerobic digestion has been recognized to be able to stabilize sludge and other predominantly organic wastes, and produce usable product gas of varying concentration.
  • Anaerobic digestion is a processes by which microorganisms break down biodegradable material in the absence of oxygen. The process is used for industrial or domestic purposes to manage waste or to produce fuels.
  • Anaerobic digestion uses a consortium of natural bacteria working synergistically to convert organic waste to carbon dioxide and methane in the absence of oxygen, which involves four steps, namely hydrolysis, acidogenesis, acetogenesis, and methanogenesis, of which hydrolysis is the rate-limiting step for most of the complex organic substrates stated earlier.
  • Organic wastes utilized include primary and secondary activated sludge obtained from sewage treatment plants, cattle manure, energy crops, lignocellulosic crop residues, waste vegetable and fruits, household and municipal food wastes, concentrated sanitation wastes, brewery wastes, textile industry waste, food processing industry effluents and others.
  • Special attention on AD of lignocellulosic waste is imparted because it being readily available in abundant amounts and otherwise is openly incinerated in most of the developing countries; leading to huge amounts of green-house gas emissions.
  • This type of biomass/substrate/organic waste is typically a more complex type of organic waste wherein the cellulose contained in the biomass is bonded to and covered by an almost inert layer of lignin which makes the degradable matter difficult to be completely accessed for any chemical or microbial process/ reacti on/ degradati on .
  • the numbers expressing quantities or dimensions of items, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term “about.” Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the invention may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.
  • the present invention generally relates to the field of waste treatment and energy generation, more particularly to an improved anaerobic digestion system and method for solid organic wastes, soluble organic matter, by-products and residues; with special consideration on treatment of lignocellulosic wastes, for energy production.
  • the methanogeic bacteria have an optimum growth condition as: pH: 6.8-7.2, temperature: 35-38C etc. and the hydrolysis and acidogenesis bacteria perform their best at ph: 5.5- 6.5 and temperature 32-35C.
  • Majority of the conventional reactor systems carry out the anaerobic digestion of solid organic waste at one set of conditions, temp: 37C and ph: 7- 7.2 which represent best conditions for methanogenesis phase but not quite the optimum for hydrolytic and acidogenetic microbes. There is a huge difference observed in treatment efficiency or microbial action at conditions deviating from the optimum.
  • the current invention addresses this issue by carrying out Hydrolysis, acidogenesis in a different reaction vessel at optimum process conditions.
  • the reactor configuration is defined in such a way that maximum utilization of substrate solids is carried out in the hydrolysis reactor. Avoiding bypass of unreacted solids, appropriate growth conditions for microbes and enzymes, alkalinity, periodic mixing and maintaining appropriate solid to liquid ratio, gas generation and its composition etc. are some of the important factors that have been kept in mind while defining the reaction mixture composition, dosing, recirculation, solid dosing and reactor design.
  • An aspect of the present disclosure relates to a system for treatment of organic material in a two-stage anaerobic biochemical reactor configuration with occasional recirculation between the two reactors.
  • the system can include, a pre- treatment reactor, a hydrolysis reactor, and a high rate digester.
  • the first reactor receives the organic material to perform pre-treatment, wherein heat and moisture and pre-treating agents penetrate through the inert layer on substrates and exposes the biodegradable matter for further treatment resulting in formation of a pre-treated slurry material.
  • the first reactor may be employed in case of usage of very tough substrates like lignocellulosic crop residue and bio-energy crops etc.
  • the second reactor can receive the pre-treated slurry material from the first reactor or from the size reduction unit, depending on the substrate type, to automatically execute hydrolysis and acidogenesis of the pre-treated slurry or the size reduced material, using a pre- determined dose of mixture of enzymes and microbes secreted by the set of grown anaerobic microbes in the second reactor, resulting in formation of a hydrolyzed slurry material.
  • the plug flow digester receives a hydrolyzed liquid having dissolved organic acids to anaerobically generate biogas by the action of anaerobic microbes present in the plug flow digester, wherein the hydrolyzed liquid having dissolved organic acids is obtained by passing the hydrolyzed slurry material from the second reactor through one or more material separating techniques.
  • the first reactor can be a pretreatment reactor for providing thermal treatment to the received organic material.
  • the second reactor can be a plug flow reactor (PFR), and wherein the plug flow reactor (PFR) is a jacketed horizontal plug flow reactor having radially mixing mechanism.
  • PFR plug flow reactor
  • the anaerobic treatment can be methanogenesis, hydrolysis, acetogenesis, and acidogenesis.
  • the organic material received in the first reactor can be a size reduced organic material obtained from a shredder/grinder.
  • the organic material received in first reactor can include a particle size between 1 mm - 10 mm.
  • the organic material received can be pre-treated with a dilute acid-thermal pretreatment to reduce lignin content in the organic material.
  • the size reduced substrates can be directly fed to the hydrolysis reactor, bypassing the pre-treatment reactor.
  • the substrate can be simpler organic substrates(SOS) including primary and secondary activated sludge obtained from sewage treatment plants, cattle manure, vegetable and household food wastes, concentrated sanitation wastes, brewery wastes, textile industry waste, food processing effluents and others [0035]
  • the organic material can be Complex organic substrates
  • COS lignocellulosic crop residues
  • agro wastes agro wastes
  • yard clippings agro wastes
  • bioenergy crops agro wastes
  • the first reactor can receive fresh water along with the organic material and the second reactor can receive fresh water along with the pre- treated slurry material.
  • the solids separating arrangements can be selected from any or combination of bar screens, vibrating screens, rotary drum screens, and a basket centrifuge.
  • the plug flow digester can include a clarifier to maintain a pre-determined concentration of the second set of grown anaerobic microbes in the plug flow digester.
  • the plug flow digester can include a solid-liquid-gas separator for efficient separation.
  • the first reactor, pre-treatment reactor may or may not be utilized for simpler substrates.
  • first reactor and the second reactor may function in batch mode or in the continuous mode.
  • the first set of grown anaerobic enzymes and the second set of grown anaerobic enzymes can be selected from any or combination of cellulase, xylase, amylase, arabinose, glucanase, b-glucosidase enzymes and other such species [0043]
  • An aspect of the present disclosure relates to a method for treating organic material in a two-step anaerobic biochemical reactor configuration with recirculation between the two reactors.
  • the method include the following steps: thermal or chemical pretreatment of size reduced organic material obtained from a shredder, resulting in formation of a pre-treated slurry material at a first reactor of a system; an anaerobic treatment and digestion of the pre-treated slurry material received from the first reactor using a pre-determined dose of enzymes secreted by a first set of grown anaerobic microbes in the second reactor, resulting in formation of a hydrolyzed slurry material at a second reactor and a plug flow digester of the system can receive a hydrolyzed liquid having dissolved organic acids to automatically generate biogas by the action of anaerobic microbes present in the plug flow digester, wherein the hydrolyzed liquid having dissolved organic acids is obtained by passing the hydrolyzed slurry material from the second reactor through one or more material separating techniques to automatically separate unreacted solids, the hydrolyzed liquid having dissolved organic acids and formed gases from the hydrolyzed slurry material, and wherein the plug flow digester
  • the process can be completed within a hydraulic retention time of 9-13 days with a methane yield of 245-250ml CH4/gVS fed.
  • a Volatile solids utilization between 70-90% has been achieved in the process with the combination of techniques as discussed.
  • the biogas volume (NTP) generated observed is 3.5-5 times the total reactor volume as per the methodologies displayed in certain examples mentioned in the disclosure.
  • the liquid digestate generated may be selectively and occasionally recycled to an extent of 50 to 80% of the fresh water demand for mixture preparation.
  • phase 1 and phase 2 reactors when commissioned to continuous process do not require any neutralizing agents as per the proposed procedures.
  • the process according to the present invention when applied for organic food waste or simpler organic waste can help to reduce the hydraulic retention time drastically.
  • anaerobic digestion of food waste can be completed within a retention time of 5-8 days with a methane yield of 280-300ml CH4/gVS fed.
  • the biogas (65-70% methane) volume generated/cu.m was 3.5-5.5 times the total reactors volume.
  • the proposed process and the respective system enables to achieve a reduction in capital cost by a factor of 50% and reduction in production cost by a minimum of 40% for anaerobic digestion of simpler and complex solid organic wastes.
  • FIG. 1 illustrates a block diagram of a proposed improved anaerobic digestion system, in accordance with the embodiments of the present disclosure.
  • FIG. 2 illustrates a detailed block diagram of the proposed improved anaerobic digestion system, in accordance with an exemplary embodiment of the present disclosure.
  • FIG. 3 illustrates an exemplary flowchart of the proposed improved anaerobic digestion system, in accordance with the embodiments of the present disclosure.
  • FIG. 4 illustrates a flowchart for the exemplary accelerated anaerobic digestion system, in accordance with an exemplary embodiment of the present disclosure.
  • the present invention generally relates to the field of waste treatment and energy generation, more particularly to an improved and accelerated anaerobic digestion system and method for organic wastes.
  • Main substrates employed include, primary and secondary sludge obtained from sewage treatment plants, cattle manure, energy crops including lignocellulosic crop residues, vegetable and household food wastes, concentrated sanitation wastes, brewery wastes, textile industry waste, food processing industry effluents and others.
  • the substrate type can be divided into two different categories; the simple organic substrates (SOS) in which the lignin content is negligible.
  • SOS simple organic substrates
  • the others which can be broadly categorized as complex organic substrates (COS) which mainly constitute bioenergy crops, agricultural wastes, lignocellulosics or residues.
  • COS complex organic substrates
  • Anaerobic digestion is a four step process comprising of Hydrolysis
  • Acidogenesis, Acetogenesis and Methanogenesis are carried out by different set of micro-organisms which perform various functions. Different set of micro-organisms survive well and perform best at different environmental/process conditions.
  • One major problem with most of the conventional anaerobic digestion process methodologies is that the whole process is carried out at specific conditions, without keeping in mind the microbial activity and favorable conditions for various microbial groups that perform the four individual functions. Hence limiting the ability of certain microbes to perform efficiently.
  • the methanogeic bacteria perform best in process conditions where pH: 6.8-7.2, temperature of mixture: 35-38C etc.
  • the hydrolytic and acidogenetic bacteria perform their best at ph: 5.5-6.5 and temperature 32-35C.
  • the current invention addresses this issue by carrying out Hydrolysis, acidogenesis in a different reaction vessel at process conditions favorable for these processes.
  • the reactor configuration is defined in such a way that maximum utilization of substrate solids is carried out in the hydrolysis reactor (second reactor). Avoiding bypass of unreacted solids, appropriate growth conditions for microbes and enzymes; alkalinity, periodic mixing and maintaining appropriate solid to liquid ratio, gas generation and its composition etc. are some of the important factors that have been kept in mind while defining the reaction mixture composition, dosing, recirculation and solid dosing.
  • the high rate digester is fed with the liquid separated from the hydrolyzed mixture by using separating techniques like bar screen, vibrating screens, rotary drum screens or a basket centrifuge.
  • the hydrolyzed liquid obtained is rich in Volatile fatty acids (VFA) and has a dissolved COD content ranging from 2000mg/ltr to 60,000mg/ltr.
  • VFA Volatile fatty acids
  • the waste solids obtained after filtering the liquid is subjected to composting to ensure 100% treatment of organic solids.
  • the unreacted substrates may or may not be recycled depending on the strength of the hydrolyzed liquid obtained.
  • the present method or process proves helpful in-case of treating organic waste with non-biodegradable impurities in the range of 5-10% of substrate weight, since the filtration mechanism filters out maximum number of solids allowing only liquid to enter into the digester. This keeps away unwanted and un-useful material from entering the digestion reactor and occupying the active reaction volume. This is one of the highlights that distinguished the proposed methodology conventional systems.
  • the proposed advantage makes the process idea for treatment of Organic fraction of Municipal solid waste (OFMSW) obtained post segregation from automated systems and techniques.
  • Physical pretreatment such as size reduction increases the internal surface area and exposes the easily biodegradable material to hydrolyzing microbes and enzymes.
  • Dilute-acid pretreatment helps to enhance the dissolution of complex compounds like cellulose which can be easily consumed by the microbes in hydrolysis stage.
  • Thermal pretreatment can help to rupture the inert lignin wall exposing the cellulose to be consumed by microbes.
  • the alkalinity of the recycled digestate as the pretreatment medium helps to reduce and at large diminish the need of addition of external neutralizing agents.
  • the selectively recycled digestate fraction may vary between 0-0.8 as per the requirement of the process. Part of the digestate may or may not be required to dilute the digester influent.
  • the use of digestate alkalinity against alkali like NaOH and NaHC03 helps to save in the cost of neutralization agents thus contributing to the savings in operation costs.
  • the rate of utilization of volatile solids poses a major challenge in anaerobic digestion of SOS and agricultural wastes.
  • the total residence time required for satisfactory reduction of substrates by anaerobic digestion process ranges between 25-45 days using conventional techniques.
  • the changes in the conditions in the reactor proposed by the current technique, the use of pretreatments coupled with reactor configuration enables to greatly reduce the time required for hydrolysis for the same amount of reduction.
  • the reduction in volatile solids (VS) fed to the reactor ranges between 50-90% at the end of the hydrolysis process.
  • the time required by the hydrolysis process ranges between 12 hours to 6 days. Maximum amount of solids are utilized in case of simple organic substrates (SOS), whereas the hydrolysed solids for agricultural waste may or may not be selectively recycled.
  • the conventional processes carry out methanogenesis or the methane generation in the same reactor as the hydrolysis and other stages. These reactors are stirred at regular intervals of time and all the sets of microbes exist in the reactor suspended in the slurry. As the mixing keeps the reaction mixture homogenous a fraction of microbes is washed out of the system with the outgoing material. Thus keeping the microbial population limited. Such equilibrium supports a limited amount of material degradation and thus the conventional processes are slower and can bear lesser material load. In-case of excess organic load, the acid generation process dominates and the reaction mixture turns acidic hindering the growth of microbes. This is one of the biggest limitations of the conventional processes. The proposed technique approaches this limitation with a number of changes in process.
  • the hydrolyzed liquid (VF A/COD rich liquid) is fed to the anaerobic digester.
  • the digester with influent COD ranging from lOkg COD/cu.m to l5kg COD/cu.m.
  • the periodic stirring is omitted and natural setting of microbe flocks and granules is encouraged by change in reactor configuration.
  • a high rate digester with the granulation of sludge, higher settling velocity and addition of necessary in-organic nutrients is advocated.
  • Organic loading of l0-20kg COD/cu.m/day result in a removal efficiency of 89.6% to 91.2% when temperature of reaction mixture is maintained at mesophilic conditions, 35-37C.
  • a gas yield approximately in the range of 0.32-0.36 cu.m CH4/kg COD utilized can be obtained.
  • the biogas composition ranges from 55.3% methane to 71.6% in terms of methane content at various stages of the methanogenesis reactor.
  • This technique of methanation has been previously employed for reduction or treatment of highly concentrated liquid effluents, having high concentration of dissolved impurities, no solids, from textile, food processing, pharmaceutical, hospitality industries.
  • a decrease in the overall time required for digestion is observed.
  • devising a process for faster hydrolysis of solids and its liquefaction with a good efficiency remains the backbone of the proposed technique.
  • the division of the conventional process into two stages and the use of separation techniques gives a good hold on the unbalanced process and helps to broaden the threshold toxicity values adhering to which the conventional reactors functioned.
  • the present disclosure provides an accelerated process for biogas generation using a combination of techniques for pretreatment, hydrolysis, bacterial intensification in two phase anaerobic digestion without generating any liquid effluent and without utilizing any neutralization chemicals.
  • the subject matter in general, relates to anaerobic digestion systems, and in particular, to an accelerated and efficient process for biogas generation by incorporation of a compact two-phase digestion system.
  • a system according to the present disclosure incorporates a two-phase anaerobic digestion process, wherein the process includes a combination of techniques such as e.g. waste pre-treatment, hydrolysis, bacterial intensification, and methogenesis.
  • the system produces biogas without utilizing neutralization chemicals and generates negligible amount of liquid effluent in a much lower hydraulic retention time.
  • an organic dry agricultural waste/biomass that includes lignocelluloses material is reduced in size (preferably having a particle size of less than 3 mm).
  • lignocelluloses material is reduced in size (preferably having a particle size of less than 3 mm).
  • a rupture of the lignin cover takes place and the cellulosic material is exposed.
  • the material is then subjected to thermal or acid/alkali pretreatment followed by hydrolysis, solid-liquid separation with re- circulation and anaerobic digestion.
  • system and method enables to ensure complete digestion of biodegradable organic matter fed to the system and thereby achieves/provides maximum yield in gas production nearing theoretical values.
  • a process as proposed according to the present disclosure has an ability to work at zero liquid discharge rates.
  • the digestate is passed through a solid liquid separation mechanism and the liquid obtained is partially or completely recycled so as to maintain the concentration of nutrient, microbes, enzymes or inhibitory ions.
  • An aspect of the present disclosure relates to a unique process for biogas generation from solid organic wastes.
  • the process can use a combination of one or more techniques such as physical pretreatment, enzymatic hydrolysis, simple solid-liquid separation, bacterial intensification and anaerobic digestion etc.
  • the process can disengage the retention time of bio-solids, substrate-solids and the liquid medium.
  • the process demonstrates a procedure for anaerobic digestion (AD) of solid organic waste and generating negligible amounts of waste liquid and sludge, while ensuring satisfactory utilization of solid waste.
  • AD anaerobic digestion
  • This technique of biogas generation can be adopted for various types of solid organic wastes including agricultural residues, lignocellulosic wastes, domestic food waste, slaughter house waste, municipal sewage and waste from food industry etc.
  • the process can be a combination of three main stages, pretreatment, hydrolysis and digestion. This result in a faster and efficient rate of degradation at every stage.
  • the digestion of domestic food waste/municipal organic waste by this methodology provides a methane yield of 280-300ml CH4/gVS fed in a retention time of 5-8 days with‘the amount of biogas produced/ltr of total reactor volume to be 3.5-5.5 (60-65% methane)’. Similar results are applicable in case of treatment of agricultural waste. Com stover digestion yields 245-250ml CH4/gVS fed after retention time of 9- 13 days with amount of biogas produced/ltr of total reactor volume to be 3.5-5 (60-65% methane).
  • the main highlight of the process is reduction in the capital cost and the operation cost by a minimum of 40% due to reduction in retention time of the process and bio-digesters without stirring mechanism.
  • FIG. 1 a block diagram of a proposed improved anaerobic digestion system 100, and FIG. 2 a detailed block diagram of the proposed improved anaerobic digestion system, in accordance with an exemplary embodiment of the present disclosure is provided.
  • the present invention involves four major stages viz. a size reduction treatment(s) stage 102, a pre-treatment stage 103, a hydrolysis stage 104, an anaerobic digestion stage 106, and the final product is stored in biogas storage 107.
  • the proposed improved anaerobic digestion system 200 receives a biomass 202 as an input and the system 200 includes a size reduction stage 204, a first reactor 206 to receive the sized reduces biomass, a second reactor 208 to perform anaerobic digestion phase and generate a biogas 210 at a plug flow digester 209.
  • the treatment methodology of the substrates may vary significantly.
  • the complex substrates require undergoes size reduction followed by chemical/thermal pretreatment and then enzymatic-microbial hydrolysis for efficient and faster conversion of complex compounds into simpler organic acids, C1-C6 carboxylic acids.
  • the simpler organic substrates do not require chemical/thermal pre-treatment.
  • a physical size reduction treatment s) 204 are applied on the biomass 202 received as input.
  • the size reduction of dry biomass preferably having 14-16% moisture content, is done to approximately ⁇ 3mm particle size.
  • size reduction pretreatment is adopted by to get a particle size less than 5 mm, this in turn helps to rupture the lignin cover and expose the cellulosic material to a good extent, in lignocellulosic substrates.
  • the size reduction of dry biomass also increases the internal surface area and exposes the biodegradable material to hydrolyzing microbes and enzymes.
  • a dilute-acid pretreatment helps to enhance the dissolution of complex compounds like cellulose which can be easily consumed by the microbes in hydrolysis stage.
  • Thermal pretreatment can help to rupture the inert lignin wall exposing the cellulose to be consumed by microbes and enzymes.
  • the alkalinity of the recycled digestate as the pretreatment medium helps to reduce and at large diminish the need of addition of external neutralizing agents.
  • the selectively recycled digestate fraction may vary between 0-0.8 parts of the fed liquid, as per the requirement of the process. Part of the digestate may or may not be required to dilute the digester influent.
  • the size reduction for can be achieved by shredding/grinding, the material to a particle size less than 5mm. Once shredded, the material is then mixed in fresh/recycled water in the ratio varying from 1 : 1 to 1 :3 by weight to undergo thermal or chemical pretreatment depending upon the composition of waste stream.
  • a substrate containing lignin more than 5-8% of the total solid weight is categorized as the complex organic substrate and needs to undergo dilute acid pretreatment.
  • Sulphuric acid 0.5-1% by weight of the total dry solids needs to be mixed with the slurry and is heated to 100-120C for 20-60 minutes with maintaining reaction pressure at 1.2-1.5 bar.
  • the pretreatment takes place in a batch reactor (first reactor 206) with external heating.
  • hydrolysis phase 104 a hydrolysis and acidogenesis of the biomass takes place.
  • Post acid pre-treatment the material is cooled and hydrolyzed after neutralizing (by NaOH or NaHC03) it to ph: 6-6.5
  • the cooling is done by natural air circulation and periodic mixing.
  • the material is then added to the enzymatic-microbial hydrolysis and further diluted by fresh water to obtain a resultant solid content ranging from 5% to 8%.
  • the hydraulic retention time for mixture for hydrolysis is between 12 hours to 6 days.
  • the temperature in the hydrolysis is maintained at 32-35C.
  • the mixture is stirred occasionally and the second reactor 208 is operated in continuous mode.
  • the hydrolysis reactor or the second reactor is a horizontal plug flow reactor with a height to diameter (H/D) ratio about 5-8 and provided with a radial mixing mechanism.
  • the pH in the reactor is maintained between 5.5-6.5.
  • the outgoing material is fairly hydrolyzed with a reduction in volatile solid content by 50-80%.
  • the ph in the hydrolysis mixture is observed to around 5.5-6.5 at appropriate loading conditions.
  • the hydrolyzed mixture having a solid content from 1-4% is filtered through a solid-liquid separating mechanisms.
  • the liquid obtained has a pH ranging in 5.5-6.5 with a COD content of l0,000mg/ltr to 60,000mg/ltr.
  • the liquid obtained is further fed to a high rate digester operated on a continuous mode performing acetogenesis and methanogenesis.
  • a high rate digester is designed considering the concentration of COD and Volatile fatty acids in the influent. Important components of the digester being the Gas-Solid-liquid separator the digestion chamber and the inorganic sludge collection chamber.
  • the high rate digester is designed to work with the use of granulated sludge having high methane activity for efficient methanation of dissolved COD. The amount of granulated sludge and the activity are dependent on various factors like the up-flow velocity, the COD fed/cu.m/day and the temperature of reaction mixture.
  • the digester has a Gas-solid-liquid separator for separating the biosolids, liquid and gas formed (biogas 210) effectively, maintaining the concentration of microbes is accomplished by the use of a solid retaining mechanism at the top.
  • the reactor has a vertical plug flow arrangement, with a height to diameter ratio ranging between 5 to 8. A part of the digestate is wasted in the form of sludge which can be used as organic fertilizer on dewatering.
  • the flow of the influent into the digester is a regulated gravitational flow.
  • the mixing in the digester is induced by the flow of influent.
  • the granulated sludge is in a fluidized state due to the continuously up-flowing influent this leads to higher interfacial contact between the dissolved COD and the granulated sludge resulting to higher rate of degradation.
  • a reduction of 89.6-91.2% of the dissolved COD is observed at the optimum hydraulic retention time of 24-48 hours and a recycle ratio of 0-0.9.
  • a gas yield ranging from 0.32-0.36 cu.m of methane/kg of VFA utilized is obtained.
  • Granules of sludge ranging from l-4mm are present in the digester with a settling velocity in the range 40-60 m/hour which have a higher methane activity per kg of VS S.
  • biogas storage 107 the gas produced (biogas) in the bioreactor is stored.
  • an anaerobic digestion process is two stage high rate processes for the anaerobic digestion of solid organic waste, which uses enzymatic hydrolysis for liquefaction of waste in the first stage and digestion of liquefied waste in the second stage by a high rate anaerobic digester.
  • the hydrolysis can be carried by a predefined dose of enzymes, secreted by anaerobic microbes, added with the waste in each batch.
  • the anaerobic digestion process can be applicable for all types of solid organic wastes, including cooked/uncooked food waste, agricultural wastes including lignocellulosic material, slaughter house waste, municipal organic waste, garden clippings etc.
  • the process defines waste by the percentage of lignin present in the waste.
  • a dilute acid thermal pretreatment can be employed post size reduction and prior to enzymatic/microbial hydrolysis.
  • the particle size of material can be hydrolyzed should be less than 3mm, irrespective of the category of waste.
  • a biogas generated/cu.m of total reactor volume of 3.5-5.5 for organic food waste/municipal solid waste is achieved as per the methodologies displayed in certain examples mentioned in the disclosure.
  • a reduction in capital cost by a factor of 50% and the production cost by a minimum of 40% can be achieved by the implementation of methodology for degradation of solid organic wastes.
  • the phase 1 (first reactor) and phase 2 (plug flow digester) reactors when commissioned to steady state continuous process do not require any chemicals or neutralization.
  • the liquid digestate generated may be selectively recycled to an extent of 50 to 80% and fresh water demand for mixture preparation is significantly less.
  • Example 1 Food waste hydrolysis at various concentrations keeping batch time constant:
  • the treatment is carried out for a period of 18 hours.
  • the mixtures Sl and S2 developed a very low pH between 3.5-3.8 whereas S3, S4, S5 had a pH within the range 4.3 to 5.2.
  • the COD content nearby for all the mixtures ranging between 22600mg/ltr to 36200 mg/ltr.
  • the gas produced by mixtures S4 and S5 was the maximum and slightly flammable.
  • Example 2 Variation of COD with solids constant and varying time.
  • Another set of samples of mixed food waste was analyzed for hydrolysis by mixing with enzyme and microbe rich liquid mixed with water.
  • the samples having a waste to liquid ratio (1 :6) was hydrolyzed for different time durations.
  • the time duration was l2(S6), 24(S7), 36(S8), 48(S9), 60(Sl0), 72(S 11) hours.
  • temperature and mixing as per example 1. It was observed that after a reaction period of 48 hours the change in soluble COD was not significantly high, referring towards the end digestion/hydrolysis.
  • the ph and COD content observed can be as follows:
  • Example 3 Com stover hydrolysis at various solid loading and COD concentration of Hydrolysate liquid.
  • Agro-waste in the form of com stover was used for experimentation, wherein waste collected from a nearby field was shredded to a particle size below 3mm.
  • the material was mixed with freshwater in the ratio from 1 : 1 to 1 :3.
  • 0.5M sulphuric acid was added in the amount equivalent to 1% the weight of Solid waste, the mixture was stirred well and subjected to thermal treatment for 30-60 minutes at a temperature of 120C with pressure maintained between 1 to 1.2 bars.
  • the mixture was air cooled and then neutralized to ph 6.5 by using neutralizing agents like NaOH and NaHC03, 100 ml of pre-prepared enzymatic and microbial solution was added as an inoculum.
  • the final dry solid content in the mixture was maintained in the range 4 to 10%.
  • the mixture was then hydrolyzed in a plug flow rector with a H:D ratio of 8-10 and maintained at a 32-35C.
  • the retention time of the mixture varies from 3 days to 10 days.
  • the mixture was mixed periodically at 100-150 RPM.
  • the soluble COD generated was in the range 20,000mg/ltr to 30,000mg/ltr.
  • the pH of the mixture ranged from 5.1 to 5.9.
  • the amount of reduction in the total dry solid content can be observed to be 50-70%.
  • Settling techniques for the separation of hydrolyzed material with vertical reactor and high H:D ratio can be employed. Enzymatic hydrolysis of com stover resulted into effective liquefaction of complex compounds like cellulose, hemicellulose, and lipids.
  • Example 4 Corn Stover hydrolysis of a fixed mixture with varying time frame: Gounded com stover with particle size less than 3mm was mixed with water, pretreated with dilute acid pretreatment as per example 3. The cooled and neutralized solution was mixed with pre-prepared enzyme and microbe rich solution. The dry solids content was maintained in the range 7-10% by dilution with water. Three batch reactors set up in parallel were for a duration of 5 days (S12), 7 days(Sl3) and 10 days(Sl4) each. Temperature for the subjected anaerobic microbes and enzymes was maintained at 35- 37C. The reactors had a configuration equivalent to a horizontal plug flow with diagonally opposite inlet and outlet. A sampling and pH recording was done at regular intervals of time. Neutralizing chemicals were added from the top of the reactor whenever necessary to maintain pH between 5.5-6.5. The reactor was maintained at anaerobic conditions. The gas formed was stored and checked for inflammability.
  • the hydrolyzed com Stover slurry was filtered using a vibrating screen, mounted with a PP filter cloth having mesh size 120, the filtered liquid was then fed to a high rate digester operated on continuous mode, inoculated with granulated sludge.
  • the digester was fed with a hydrolyzed liquid with COD (5,000mg/ltr); the initial hydraulic retention time of the digester was 5 days and was gradually reduced.
  • the hydraulic retention of the digester was reduced after a specific time span observing the amount of gas generated, pH of digested liquid and the change in COD content of the effluent.
  • the COD loading was gradually increased in a stepwise manner, with initial loading of 3kg COD/cu.m then 5, 9, 12, 15, 18, 20 and 23.
  • the amount of gas generated per day was observed to be proportional to the COD loading, the maximum gas yield formation was observed at the COD loading around 20-22kgCOD/cu.m. Day.
  • the methane yield was observed to range from 0.32 to 0.36 cu.m of methane per Kg COD fed compared to the theoretical yield of 0.35cum/kg.
  • the COD reduction efficiency obtained was between 89 to 91.2% of COD.
  • the pH of influent was regulated between 6.0 to 6.5 whereas the pH of digestate obtained, fluctuated between 7.1 to 7.4.
  • the effluent COD can be observed to be between 500 to 3500mg/ltr.
  • influent can be diluted by the effluent with a fraction of 0-0.8 carefully maintaining the COD loading per day and the hydraulic retention time.
  • VSS generated can be dewatered and excess effluent liquid can be further treated using a constructed wetland system.
  • the amount of methane generated is estimated to be 0.l05cu.m CH4, equivalent to 280-300ml CH4/gVS fed.
  • the hydraulic retention time for hydrolysis is 2-3 days and the hydraulic retention time for Digestion to be 3-5 days.
  • the total retention time for the system turns out to be in the range of 5-8 days with the amount of biogas produced/ltr of total reactor volume to be 3.5-5.5 (65-70% methane).
  • the filtered solids were dried; moisture content, VS content and ash content was recorded. The results indicated a 65-68% reduction in the total solids.
  • the amount of total COD obtained is approximately 560gms, which implied an estimated 0.196 cu.m of CH4 generation, equivalent to 245- 250ml CH4/gVS fed.
  • the hydrolysis was completed in 4-8 days of retention time, whereas the hydraulic retention time for the liquid methanation by high rate AD process was 3-5 days.
  • the total retention time in the range of 7-12 days with amount of biogas can be produced/ltr of total reactor volume to be 3.5-5 (65-70% methane).
  • FIG. 3 illustrates an exemplary working of the proposed improved anaerobic digestion system (300), in accordance with the embodiments of the present disclosure.
  • raw material storage (102) can store the raw materials (a).
  • raw materials (a) substrates from which biogas production is possible and the amount of gas and the amount of methane content in biogas is solely dependent on the process that is followed for production and the type of substrate.
  • the raw material (a) can be passed through a shredder
  • the shredder (104) can shred/ground the raw material (a).
  • the size reduction for the raw material can be achieved by shredding/grinding by using the material to a particle or shredded solids (b).
  • the shredded solid (b) size can be less than 5mm.
  • shredded solid (b) can be mixed with fresh/recycled water (c) in the ratio varying from 1 : 1 to 1 :3 by weight to undergo thermal or chemical pretreatment depending in a thermal pretreatment reactor or first reactor (hereinafter interchangeably referred as“first reactor”) (106) upon the composition of waste stream.
  • the first reactor (106) can automatically execute hydrolysis and dissolution of the organic material, resulting in formation of a pre-treated slurry material (d).
  • the jacketed horizontal plug flow reactor or plug flow reactor or a second reactor (hereinafter interchangeably referred as“plug flow reactor” or a“second reactor”) (108) can receive the pre-treated slurry material (d) from the first reactor (106) and automatically execute an anaerobic treatment of the pre-treated slurry material (d) (hereinafter interchangeably referred as“pre-treated slurry”) using a pre- determined dose of enzymes secreted by a first set of grown anaerobic microbes in the second reactor, resulting in formation of a hydrolyzed slurry material (hereinafter interchangeably referred as“hydrolyzed slurry” or“hydrolysed slurry solid”) (e).
  • a substrate containing lignin more than 5-8% of the total solid weight is categorized as the complex organic substrate and needs to undergo dilute acid pretreatment.
  • Sulphuric acid 0.5-1% by weight of the total dry solids needs to be mixed with the slurry and is heated to 100-120C for 20-60 minutes with maintaining reaction pressure at 1.2- 1.5 bar.
  • the pretreatment takes place in a batch reactor with external heating.
  • Post acid pre-treatment the material is hydrolysed by cooling and neutralizing (by NaOH or NaHC03) it to ph: 6-6. The cooling is done by natural air circulation and periodic mixing.
  • the material or pretreated slurry (d) is then added to the enzymatic-microbial hydrolysis and further diluted by fresh water or digestate to a solid content ranging from 5% to 8%.
  • the hydraulic retention time for mixture for hydrolysis is between 12 hours to 6 days.
  • the temperature in the hydrolysis is maintained at 32-35C.
  • the mixture is stirred occasionally and the reactor is operated on a continuous mode.
  • the hydrolysis reactor is a horizontal plug flow reactor (108) with a height to diameter (H/D) ratio about 5-8 and provided with a radial mixing mechanism.
  • the pH in the reactor (108) can be maintained 5.5-6.5.
  • the outgoing material or hydrolysed slurry solid (e) is a fairly hydrolyzed with a reduction in volatile solid content by 50-80%.
  • the ph in the hydrolysis mixture or hydrolysed slurry solid (e) is observed to around 5.5-6.5 at proper loading conditions.
  • the hydrolysed slurry solid (e) can have a solid content from 1-4% as per the extent of solids hydrolyzed, this mixture is filtered through solid-liquid separating mechanisms.
  • the liquid obtained has a pH ranging in 5.5-6.5 with a COD content of l0,000mg/ltr to 60,000gm/ltr.
  • the liquid obtained is further fed to a high rate digester operated on a continuous mode in methanogenic stage.
  • a digester or liquid plug flow digester (hereinafter interchangeably referred as “liquid plug flow digester” or“high rate digester”) can be fed with the liquid separated from the hydrolyzed mixture by using separating techniques like bar screen, vibrating screens (110), rotary drum screens (110) or a basket centrifuge (114).
  • the high rate digester (120) can be designed considering the concentration of COD and Volatile fatty acids in the influent.
  • the major components of the digester (120) being the Gas-Solid-liquid separator, the digestion chamber and the inorganic sludge collection chamber.
  • the high rate digester (120) is designed to work with the use of granulated sludge having high methane activity for efficient methanation of dissolved COD.
  • the amount of granulated sludge and the activity are dependent on various factors like the up flow velocity of the influent, the COD fed/cu.m/day and the temperature of reaction mixture.
  • the digester (120) can receive a hydrolyzed liquid
  • the screened liquid will contain dissolved organic acid that is obtained by passing the hydrolyzed slurry (e) from the second reactor (108) through one or more material separating techniques.
  • the digester (120) can have a Gas-solid-liquid separator for separating the bio solids, liquid and gas generated effectively; maintaining the concentration of microbes is accomplished by the use of a clarifier at the top.
  • the digester (108) can have a vertical plug flow arrangement, with a height to diameter ratio ranging 5 to 8. A part of the digestate (h) can be wasted in the form of sludge which can be used as organic fertilizer on dewatering.
  • the flow of the influent into the digester (120) is a regulated gravitational flow.
  • the mixing in the digester (120) is induced by the flow of influent.
  • the granulated sludge is in a fluidized state due to the continuously up-flowing influent this leads to higher interfacial contact between the dissolved COD and the granulated sludge resulting to higher rate of degradation.
  • a reduction of 89.6-91.2% of the dissolved COD is observed at the optimum hydraulic retention time of 24-48 hours and a recycle ratio of 0-0.8.
  • a biogas gas yield ranging from 0.32-0.36 cu.m of methane/kg of VFA utilized is obtained.
  • Granules of sludge ranging from l-4mm are observed with a settling velocity in the range 40-60 m/hour which have a higher methane activity per kg of VSS.
  • the biogas (11) can be stored in the biogas storage (124).
  • a Gas flow-meter (122) can be post moisture removal.
  • sewage pump (116, 116’ and 116”) can be mono-block for pumping liquid slurry.
  • FIG. 4 illustrates a flowchart for the exemplary accelerated anaerobic digestion system, in accordance with an exemplary embodiment of the present disclosure.
  • step 402 executing automatically, at a first reactor of a system, thermal and chemical pre-treatment of a size reduced organic material obtained from a shredder, resulting in formation of a pre-treated slurry material.
  • step 404 executing automatically, at a second reactor of the system, hydrolysis and acidogenesis of the pre-treated slurry material received from the first reactor using a pre-determined dose of enzymes secreted by a first set of grown anaerobic microbes in the second reactor, resulting in formation of a hydrolyzed slurry material.
  • step 406 receiving, at a plug flow digester of the system hydrolyzed liquid having immersed organic acids to automatically generate a biogas using a pre determined dose of enzymes secreted by a second set of grown anaerobic microbes in the plug flow digester, wherein the hydrolyzed liquid having dissolved organic acids is obtained by passing the hydrolyzed slurry material from the second reactor thorough solid liquid separating techniques to automatically separate unreacted substrate solids, and the hydrolyzed liquid having dissolved organic acids.
  • the plug flow digester comprise of a solid liquid gas separator to maintain a pre-determined concentration of the second set of grown anaerobic microbial granules in the plug flow digester.

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Abstract

L'invention concerne un système (300) pour la digestion anaérobie (DA) à vitesse élevée, compact et efficace de déchets organiques solides. Il comprend un premier réacteur (106), qui pré-traite un matériau déchiqueté/broyé générant une suspension pré-traitée ; un second réacteur, (108) dans lequel un ensemble indépendant de microbes et d'enzymes anaérobies, hydrolyse une suspension pré-traitée générant une suspension hydrolysée ; un digesteur à écoulement à bouchon (120) qui effectue une bio-méthanation à vitesse élevée sur le liquide hydrolysé obtenu à partir de la suspension hydrolysée pour générer du biogaz. Le procédé désengage SRT, HRT et temps de rétention de substrat. Il permet également d'optimiser le procédé selon la complexité du substrat. Des substrats plus simples et complexes peuvent subir une dégradation anaérobie dans une HRT de 5 à 13 jours avec un volume (NTP) de biogaz (65 à 70 % de méthane) généré de 3,5 à 5,5 fois le volume de tous les réacteurs combinés. Le procédé global fonctionne avec un besoin négligeable en eau douce et en agents de neutralisation, une génération de sous-produit minimale et entraîne une réduction de 30 à 50 % et des coûts d'investissement et de fonctionnement.
PCT/IB2018/059163 2017-11-23 2018-11-21 Système de digestion anaérobie à vitesse élevée pour déchets organiques solides WO2019102364A1 (fr)

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JP2021020169A (ja) * 2019-07-29 2021-02-18 サイエンスシード株式会社 有機物処理設備管理装置及び有機物処理設備管理方法
US11193104B2 (en) * 2020-01-08 2021-12-07 Tongji University System for high-value utilization of organic solid waste
US20220119746A1 (en) * 2019-08-26 2022-04-21 Tongji University Anaerobic digestion device based on self-sustained air flotation
CN114395466A (zh) * 2022-01-18 2022-04-26 西安建筑科技大学 一种体外瘤胃仿生系统
WO2022096517A1 (fr) * 2020-11-04 2022-05-12 Renescience A/S Procédé de désinfection de déchets
WO2022096406A1 (fr) * 2020-11-04 2022-05-12 Renescience A/S Procédé de traitement enzymatique et/ou microbien de déchets comprenant la recirculation d'eau de traitement
CN115304226A (zh) * 2022-09-15 2022-11-08 昆明学院 一种尾菜垃圾处理方法
CN116395923A (zh) * 2023-03-21 2023-07-07 哈尔滨工业大学 一种水解纳米酶材料及利用其强化污泥厌氧消化产甲烷的方法

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WO2003011771A1 (fr) * 2001-08-01 2003-02-13 Board Of Supervisors Of Louisiana State University And Agricultural And Mechanical College Fermenteur anaerobie a ecoulement piston
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US4274838A (en) * 1979-10-01 1981-06-23 Energy Harvest, Inc. Anaerobic digester for organic waste
WO1995018072A1 (fr) * 1993-12-28 1995-07-06 Institute Of Gas Technology Digestion anaerobie en deux phases de matieres organiques carbonees
WO2000039036A1 (fr) * 1998-12-23 2000-07-06 Norsk Hydro Asa Procede de traitement de matiere organique dans un reacteur biochimique anaerobie a deux etapes
WO2003011771A1 (fr) * 2001-08-01 2003-02-13 Board Of Supervisors Of Louisiana State University And Agricultural And Mechanical College Fermenteur anaerobie a ecoulement piston
WO2010014919A1 (fr) * 2008-07-31 2010-02-04 Stewart William C Système et procédé de digestion anaérobie à plusieurs phases et en trois étapes

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2021020169A (ja) * 2019-07-29 2021-02-18 サイエンスシード株式会社 有機物処理設備管理装置及び有機物処理設備管理方法
JP7038417B2 (ja) 2019-07-29 2022-03-18 サイエンスシード株式会社 有機物処理設備管理装置及び有機物処理設備管理方法
US20220119746A1 (en) * 2019-08-26 2022-04-21 Tongji University Anaerobic digestion device based on self-sustained air flotation
US11618872B2 (en) * 2019-08-26 2023-04-04 Tongji University Anaerobic digestion device based on self-sustained air flotation
US11193104B2 (en) * 2020-01-08 2021-12-07 Tongji University System for high-value utilization of organic solid waste
WO2022096517A1 (fr) * 2020-11-04 2022-05-12 Renescience A/S Procédé de désinfection de déchets
WO2022096406A1 (fr) * 2020-11-04 2022-05-12 Renescience A/S Procédé de traitement enzymatique et/ou microbien de déchets comprenant la recirculation d'eau de traitement
CN114395466A (zh) * 2022-01-18 2022-04-26 西安建筑科技大学 一种体外瘤胃仿生系统
CN115304226A (zh) * 2022-09-15 2022-11-08 昆明学院 一种尾菜垃圾处理方法
CN115304226B (zh) * 2022-09-15 2023-12-22 昆明学院 一种尾菜垃圾处理方法
CN116395923A (zh) * 2023-03-21 2023-07-07 哈尔滨工业大学 一种水解纳米酶材料及利用其强化污泥厌氧消化产甲烷的方法

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