2109 results about "Anaerobic digestion" patented technology

An anaerobic digester system has a vertically upright vessel, a matrix arranged in the vessel supporting a microorganism biomass thereon, an input for supplying an input slurry of liquid and suspended solids at an upper portion of the vessel above the matrix, a gas output at the top of the vessel for withdrawing gas generated by anaerobic digestion of solids, and an effluent output at the bottom of the vessel for withdrawing liquid and remaining solids. The vessel has a preferred liquid height to diameter ratio of 2 to 1, and is constructed of inert fiberglass-reinforced plastic coated with a translucent blue gel pigment layer for filtering light at wavelengths that promote biomass cultivation. The matrix is formed as an array of panels mounted to a spindle with wheels fixed at spaced intervals along its vertical height, and the panel are made of a polyethylene grass matting providing a high surface area to volume ratio of at least 20 to 1. Gas from the top of the vessel is recycled to the bottom to generate bubbles for mixing the feedstock. The related method of anaerobic digestion includes comminuting input wastes with a slurry grinder into a pumpable slurry 8-10 % by weight solids, and providing as the biomass hydrolytic bacteria, and fermentative bacteria including acetogenic and methanogenic bacteria to produce a methane gas product. Other products include an organic soil additive, bacterial solids plant food, and a filtrate used as plant tonic.

A wastewater treatment system is provided including an aerobic membrane bioreactor and an anaerobic digester system connected to receive wasted solids continuously from the aerobic membrane bioreactor and also connected to return effluent from the anaerobic digester system continuously to the aerobic membrane bioreactor. Further, a process is provided for treating wastewater including the step of wasting a volume fraction of organic cell mass from an aerobic membrane bioreactor to an anaerobic digester system and maintaining a solids retention time (SRT) in the bioreactor that is (1) greater than a time needed to achieve growth of organisms suitable for converting carbonaceous biochemical oxygen demand (CBOD) into cell mass and (2) less than a time at which substantial decay of the organisms occurs. The system and process may further include optional pretreatment and/or phosphorus and/or nitrogen removal downstream of the membrane bioreactor system.

A method for an anaerobic digester system is provided that employs a cumulative data base to better monitor and control the anaerobic process, as compared with conventional anaerobic digester systems. The method includes the storing and ensiling of a feedstock, preferably a biomass, to form a digester feed material, which then processed by a digester. The process evolves a biogas and forms a digested material. The process is monitored, to collect a plurality of digester data from all stages of the process. These individual points or elements of the data are telemetered to a cumulative data base for storage and eventual retrieval and the cumulative data base is mined to compile predictive, feed forward controls and construct feedstock correlations between the metabolic activity within the digesters and an analysis of the feedstocks into the digesters. The method further includes the production of a high quality plant growth media from the digested mash, and recovery of the biogas generated within the digester. The biogas is collected with the aid of a biogas recovery system. The biogas is predominantly methane, and the anaerobic digester system is preferably operated to maximize the quantity and quality of methane generated.

Systems and methods are provided for converting organic waste materials from a municipal waste stream to useful products. Organic waste materials having a wide range of compositions such as, for example, yard waste, food waste, paper, and the organic fraction of municipal solid waste are converted into a uniform biomass that is suitable for conversion to useful products, such as fuels. Through the use of a biomixer and a hydropulper, as well as through sorting and screening, the organic waste materials are progressively reduced in size and cleaned of contamination. The resulting uniform biomass is suitable for anaerobic digestion to produce biogas and a residual solid that is suitable for producing a high quality compost.

A method for treating particulate biodegradable organic waste includes sizing the waste and adding a base prior to introducing the waste to a thermal hydrolysis reactor and hydrolyzing the waste at a temperature of about 130° C. or greater and a pressure greater than the saturated water vapor pressure to produce a slurry including solubilized organic material and residual solids. The solubilized organic material is separated from the residual solids using a liquid/solid separator and the solubilized organics are subjected to anaerobic digestion to produce a methane gas. The base is preferably potassium hydroxide (KOH) at a concentration of about 1%. The method may further include preheating the particulate biodegradable organic waste with latent heat of the separated solubilized organic material prior to thermal hydrolysis.

The invention relates to a method for comprehensively recycling the fecal sewage of large-scale livestock and poultry farms and farmland crop straws, which comprises the following steps of: (1) performing anaerobic digestion, namely regulating the solid content of the fecal sewage of livestock and poultry to be between 5 and 10 percent, adding anaerobic digestion inocula, and performing the anaerobic digestion to generate methane; (2) performing energy utilization on the methane, namely purifying the methane obtained in the step (1) to be used as fuel gas or allowing the purified methane to be used for power generation to perform energy utilization; (3) performing solid-liquid separation, namely performing the solid-liquid separation on biogas residues and biogas slurry which are obtainedin the step (1) to obtain the biogas slurry and the biogas residues of which the moisture content is about 60 percent; (4) preparing a biological organic compound fertilizer from the biogas slurry, and mixing the biogas residues and part of biogas slurry with the straws and part of excrement to perform aerobic compost; and (5) mixing and performing the aerobic compost, namely mixing part of biogas slurry obtained in the step (3) and the crushed straws, regulating the moisture content of the mixture to be between 50 and 60 percent, and performing the aerobic compost. In the method, clean resources are recovered by the anaerobic digestion, and the biogas slurry is used for producing the biological organic compound fertilizer with a high additional value.

The present invention relates to a process and apparatus for processing agricultural waste to make alcohol and/or biodiesel. The agricultural wastes are subjected to anaerobic digestion which produces a biogas stream containing methane, which is subsequently reformed to a syngas containing carbon monoxide and hydrogen. The syngas is converted to an alcohol which may be stored, sold, used, or fed directly to a reactor for production of biodiesel. The solids effluent from the anaerobic digester can be further utilized as slow release, organic certified fertilizer. Additionally, the wastewater from the process is acceptable for immediate reuse in agricultural operations.

Ar anaerobic-aerobic reactor for preparing composit is composed of fermentor, ventilation system, stirring system, and heating system. The said fermentor has a sieve plate to divided it into thepartsand a stirring axle driven by motor. Its fermenting chamber is a sealed unit with circulating water both jacket for heating it and liquid inlet and outlet, and features that the anaerobic digestion and aerobic reaction are conduted in a single equipment.

A process for improving the yield and efficiency of an ethanol fermentation plant that receives organic fermentable feedstock material, prepares the feedstock for fermentation, ferments the feedstock with yeast to produce ethanol, and produces stillage as a byproduct of ethanol fermentation. The process steps which can be operated independently or in combination, may include, but are not limited to, degrading fatty acids in the fermentable feedstock material prior to fermentation; degrading cellulose and hemicellulose present in the feedstock prior to fermentation; adding a surfactant to the fermentable feedstock; separating a liquid fraction from the stillage; recycling the liquid fraction to be combined with the fermentable feedstock; recovering a solid fraction from the stillage; and introducing at least a portion of the solid fraction to an anaerobic digester to produce methane.

A process for removal and recovery of nutrients and recycling of water from digested manure or other organic wastes. A first step involves separating waste from an anaerobic digester into digested liquids, digested solids, and biogas. A second step involves precipitating solids from the digested liquids. A third step involves stripping ammonia from the digested liquids. A fourth step involves injecting an exhaust stream of carbon dioxide drawn from the co-generator into the digested liquids to reduce the pH and raise the temperature of the digested liquid. A fifth step involves recycling the digested liquids back to the anaerobic digester for use in diluting in coming solid wastes. A sixth step involves passing the excess ammonia stripped from the digested liquid through the digested solids to recover nitrogen through aborption with the resultant digested solids being usable as a biofertilizer with a high nitrogen content. A seventh step involves capturing the biogas for use in a co-generation system.

A process for the recovery of nitrogen from anaerobically digested liquid waste and for the collection of the nitrogen as nitrate compounds that can be used to produce fertilizer and compost, includes stripping ammonia from anaerobically digested liquid waste, and converting the ammonia into nitrates via nitrification.

A controlled eutrophication system and process are disclosed. The system includes the combination of a partitioned aquaculture system in conjunction with an anaerobic digester. Wastewater containing pollutants, such as nitrogen and phosphorus, are fed to the partitioned aquaculture system. Algae within the system converts the pollutants into algal biomass. Fish populations, in turn, control the algal populations. The fish populations may then be periodically harvested for human or animal consumption. A polishing chamber is contained in the system in which aquatic organisms remove substantial amounts of the algae from batch fed additions of water. The water is then discharged to an external water source containing virtually no pollutants. In one embodiment, the biomass excreted by the aquatic organisms in the system are collected and fed to a digester. In the digester, the biomass is converted to a hydrocarbon gas and collected for its fuel value, while the liquid fraction is collected for its fertilizer value.

An apparatus for the anaerobic digestion of solid waste is disclosed. The apparatus includes a pre-digestion treatment chamber and an anaerobic digester chamber coupled to the pre-digestion treatment chamber. A liquid suspension of solid waste is pretreated under aerobic conditions by heating to a desired pre-digestion temperature. One or more chemical or biological additives are added to the suspension of solid waste to improve the anaerobic digestibility of the solid waste. This may include enzymes to destruct poorly digestible solids and/or materials to provide a desired C:N ratio in the solid waste. The apparatus may include mixers, heaters, chemical or biological additives as needed, various sensors and probes, and a control system to monitor and control the anaerobic digestion process and maintain microbial health of the digester.

The present invention is directed to aquatic systems and methods for off-shore energy production, and particularly to systems and methods for generating large amounts of methane via anaerobic digestion, purifying the methane produced, and sequestering environmentally deleterious by-products such as carbon dioxide. The energy production systems contain one or more flexible, inflatable containers supported by water, at least one of which is an anaerobic digester containing bacteria which can produce energy sources such as methane or hydrogen from aquatic plants or animals. The containers of the present invention can be large enough to provide adequate amounts of energy to support off-shore activities yet are relatively easy to manufacture and ship to remote production sites. The systems can also be readily adapted to sequester carbon dioxide or recycle nutrients for growing feedstocks on site.

The invention discloses vertical equipment for treating organic waste by dry anaerobic digestion without stirring and a method thereof. The equipment comprises that a feed port and an air outlet are arranged on the vertical digester; a discharge port is arranged on the bottom of the vertical digester; a feeding storage tank is connected with the discharge port of the vertical digester through a pipeline, an inoculation mixing tank and a delivery pump; the discharge port of the vertical digester is connected with the inoculation mixing tank through a control valve; a biogas slurry discharge pipe is arranged on the lower part of the vertical digester, and is connected with a spraying device arranged on the upper part of the vertical digester through a pH value on-line monitor, a reflux pump sequentially; and an alkali solution storage tank is connected with the reflux pump through the pipeline and the control valve. The vertical equipment for treating organic waste by dry anaerobic digestion without stirring and the method thereof overcome the defects of difficult isotrope mixing, easy isotrope acidification and the like of the prior dry anaerobic digestion system, and is applicable to treatment on household organic garbage, kitchen garbage, excrement of fowls and livestocks, agricultural waste, garden garbage, sewage sludge and other organic waste.

Disclosed is a method and equipment for treatment of polluted fluid, wherein ferrum family flocculating agents of a finite concentration are charged into the membrane bioreactor, in which they are subject to domestication and become compact biological ferrum sludge with improved property.

Anaerobic digestion system and process in which a liquor containing a digestible biomass is processed a retort vessel at a thermophilic temperature and with a vacuum pressure at the surface of the liquor. A pressurized feedstock is introduced into the vessel so that the feedstock impacts upon the surface of the liquor in a manner which serves to break up any scum on the surface and produce a mixing of the liquor.

A method of treating a mixture of microorganisms with readily biodegradable carbon compounds (RBCs) in the form of one or more volatile fatty acids (VFAs), by first inducing the mixture microorganisms to release phosphorus and magnesium which is then tapped o as the mixture is thickened, to produce a phosphorus/magnesium-nch liquid and a phosphorus/magnesium-reduced treated mixture This treated mixture is placed in an anaerobic digester where ammonia is formed, but combines very little with phosphorus or magnesium Next the high-ammonia mixture is dewatered to produce an ammonia-rich liquid, which is combined with the phosphorus and magnesium-rich liquid and reacted to form struvite In one preferred embodiment, VFAs are formed in situ via an upstream unified fermentation and thickening (UFAT) process and added to the waste sidestream to strip phosphorus and magnesium found therein In another preferred embodiment a usable struvite product is harvested.

Sludge from an anaerobic digester is treated to recover one or more of fibers, or solids or liquids with a high nutrient content. The solids or liquids can be used as a fertilizer. The fibers can be used in a plant growing medium. Solids are separated from liquids in the sludge and dried. The solids may be dried to produce a flake or pellet. Ammonia in the liquids is recovered and used to produce a concentrated acidic ammonium salt solution. This solution may be mixed with the solids to produce a nitrogen enhanced solid. The fibers and solids or liquids can also be used in combination to produce an enhanced plant growing medium. A device and process for removing ammonia from a liquid can be used in the system or separately.

A method for treating municipal solid waste and other waste is provided which comprises: introducing said waste into a rotary autoclave which is downwardly inclined towards its discharge end and has a door at the discharge end; and injecting steam through said door into said autoclave to treat the load. A method is also provided for treating waste, comprising steam autoclaving the waste, anaerobically digesting an organic-rich fraction of the autoclaved waste, recovering methane-containing gas from anaerobic digestion, internally combusting the methane-containing gas to generate power and exhaust gas, and generating steam for autoclaving using the waste heat. A plant for treating the waste may comprise at least one autoclave for steam treating the waste, at least one anaerobic digestion tank for digesting an organic-rich fraction of the autoclaved waste, a recovery system for recovering methane-containing gas from the or each digestion tank, at least one internal combustion engine for combusting the methane-containing gas and generating power, and a steam generator fed with combustion gas from the internal combustion engine for generating and accumulating steam for supply to said at least one autoclave. Also provided is a method of treating waste material in a rotary autoclave, which comprises: loading the waste material into a top opening of the autoclave whilst rotating the autoclave in a first direction in which screw flights within the autoclave convey the waste forwardly along a downwardly inclined body of the autoclave towards a base of the autoclave; rotating the autoclave in a second direction opposite to the first direction so as to establish a circulation of the loaded material between the upper and lower ends of the autoclave to facilitate vacuum and/or steam treatment thereof; and monitoring the load imparted by the autoclave adjacent upper and lower ends thereof during the reverse rotation, increase of the load adjacent the upper end of the autoclave providing an indication of effective load circulation. A door structure for a commercial-scale autoclave based on a castellated door and a locking ring with lock blocks of inwardly facing U-structure is also provided.