Abstract: This specification describes a system and process for treating waste, for example municipal solid waste (MSW) or post-recycling municipal solid waste. The system includes a press and a pulper. The press is adapted to provide a wet fraction of the waste suitable for anaerobic digestion and rejects. The pulper is adapted to receive the rejects and produce pulp. The pulper may be, for example, a drum pulper. In the process, waste is separated into a press into an organic fraction and rejects. The organic fraction is treated by way of anaerobic digestion. The rejects are separated, optionally in a drum pulper, to produce a fraction containing pulp. The pulp can be re-used to make paper or other products. In some case, 70% or more or 80% or more of MSW can be diverted from landfill.

Abstract: A system and process for separating organic material from solid waste such as material recovery facility (MRF) fines is disclosed. The fines are treated in a press, in which the fines are compressed against a wall having a set of holes. The fines are mixed with a substantial amount of water before being pressed. The water increases the amount of organic matter that is recovered from the fines. A wet fraction, extruded through the holes of the press, may be treated in an anaerobic digester.

Abstract: Organic solid waste is pressed at a high pressure to separate the solid waste into a dry fraction and a wet fraction. The wet fraction is diluted and floatables (i.e. pieces of plastic and/or paper) in the wet fraction are comminuted. The wet fraction is then de-gritted before being sent to an anaerobic digester. Digestate is withdrawn from the digester from a free liquid surface of the digester. The digestate is filtered to extract comminuted floatables. The resulting filtrate is then composted or directly applied to land. A corresponding system comprises a press, a grinder, a hydrocyclone, an anaerobic digester, a filter and a dewaterer.

Abstract: Solid waste, for example source separated organics (SSO) or commercial and industrial (C&I) waste or both, are treated by first pressurizing the waste against a screen to produce a solids fraction and a liquid fraction. The liquid fraction can be treated in an anaerobic digester. The solids fraction is pulverized or milled, for example with a hammer mill, preferably after being diluted. The pulverized or milled waste is separated again to provide a second solids faction and a second liquid fraction. The liquid fraction can be treated in an anaerobic digester. The solids fraction is primarily inert and can be landfilled, preferably after being washed.

Abstract: In a system and process, sludge from a wastewater treatment plant is treated in a high solids digester, optionally a mechanically mixed wet digester. Sludge (i.e. digestate) from the anaerobic digester is thickened or dewatered. Part of the thickened or dewatered digestate is thermally hydrolysed. The hydrolysed digestate may be, or may be further treated to produce, Class A biosolids. The hydrolysed digestate can be dewatered producing a liquid fraction that is recycled to the digester. Another part of the thickened or dewatered digestate is returned to the digester. The return of thickened or dewatered digestate to the digester allows for a smaller tank to be used (compared to a system without a recycle of thickened or dewatered digestate) while maintaining the same solids residence time (SRT) and volatile solids reduction (VSR). In some examples, the hydraulic residence time (HRT) of the digester is 10 days or less.

Abstract: An anaerobic digester is fed a feedstock, for example sludge from a municipal wastewater treatment plant, and produces a digestate. The digestate is dewatered into a cake. The cake may be dried further, for example in a thermal drier. The cake is treated in a pyrolysis system to produce a synthesis gas and biochar. The gas is sent to the same or another digester to increase its methane production. The char may be used as a soil enhancer.

Abstract: Waste, such as municipal solid waste (MSF), is separated into a wet fraction and refuse derived fuel (RDF). For example, the waste may be separated in a press. The wet fraction is treated in an anaerobic digester. The RDF is further separated into a cellulosic fraction and a non-cellulosic fraction. The cellulosic fraction is treated by pyrolysis and produces a pyrolysis liquid. The pyrolysis liquid is added to the anaerobic digester.

Abstract: This specification describes a system and process for treating waste, for example municipal solid waste (MSW) or post-recycling municipal solid waste. The system includes a press and a pulper. The press is adapted to provide a wet fraction of the waste suitable for anaerobic digestion and rejects. The pulper is adapted to receive the rejects and produce pulp. The pulper may be, for example, a drum pulper. In the process, waste is separated into a press into an organic fraction and rejects. The organic fraction is treated by way of anaerobic digestion. The rejects are separated, optionally in a drum pulper, to produce a fraction containing pulp. The pulp can be re-used to make paper or other products. In some case, 70% or more or 80% or more of MSW can be diverted from landfill.

Abstract: Organic solid waste is pressed at a high pressure to separate the solid waste into a dry fraction and a wet fraction. The wet fraction is diluted and floatables (i.e. pieces of plastic and/or paper) in the wet fraction are comminuted. The wet fraction is then de-gritted before being sent to an anaerobic digester. Digestate is withdrawn from the digester from a free liquid surface of the digester. The digestate is filtered to extract comminuted floatables. The resulting filtrate is then composted or directly applied to land. A corresponding system comprises a press, a grinder, a hydrocyclone, an anaerobic digester, a filter and a dewaterer.

Abstract: This specification describes a system and process for treating waste, for example municipal solid waste (MSW) or post-recycling municipal solid waste. The system includes a press and a pulper. The press is adapted to provide a wet fraction of the waste suitable for anaerobic digestion and rejects. The pulper is adapted to receive the rejects and produce pulp. The pulper may be, for example, a drum pulper. In the process, waste is separated into a press into an organic fraction and rejects. The organic fraction is treated by way of anaerobic digestion. The rejects are separated, optionally in a drum pulper, to produce a fraction containing pulp. The pulp can be re-used to make paper or other products. In some case, 70% or more or 80% or more of MSW can be diverted from landfill.

Abstract: A system and process for separating organic material from solid waste such as material recovery facility (MRF) fines is disclosed. The fines are treated in a press, in which the fines are compressed against a wall having a set of holes. The fines are mixed with a substantial amount of water before being pressed. The water increases the amount of organic matter that is recovered from the fines. A wet fraction, extruded through the holes of the press, may be treated in an anaerobic digester.

Abstract: Waste, such as municipal solid waste (MSF), is separated into a wet fraction and refuse derived fuel (RDF). For example, the waste may be separated in a press. The wet fraction is treated in an anaerobic digester. The RDF is further separated into a cellulosic fraction and a non-cellulosic fraction. The cellulosic fraction is treated by pyrolysis and produces a pyrolysis liquid. The pyrolysis liquid is added to the anaerobic digester.

Abstract: 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.

Abstract: Organic waste is treated by pyrolysis or by anaerobic digestion followed by pyrolysis of the digestate. The pyrolysis is performed in two staged reactors. The second stage reactor treats char produced in the first stage. The temperature of the first stage reactor is preferably 450 degrees C. or less. The temperature of the second stage reactor is higher than the temperature of the first stage, for example by 50 degrees C. or more. Optionally, there may be a char cooler, a water sprayer, or both downstream of the char outlet of the second reactor. In an exemplary system, a digestate outlet is connected to the inlet of the first pyrolysis reactor. A pyrolysis liquid outlet of the first pyrolysis reactor is connected to the digester. Char produced in the second pyrolysis reactor may be used as a soil amendment.

Abstract: A process and apparatus for the anaerobic digestion of organic wastes, preferably to also produce a useful biogas, is described. The waste may have a total solids (TS) concentration of 6% or less while a digester is operated at a higher solids concentration, for example with a feed TS concentration of 8-12%. One or more separation stages downstream of the digester separate active bacteria and undigested organics from the digestate, and return separated matter to the digester. Optionally, a feed thickening apparatus and step may be provided upstream of the digester. The upstream thickener and recycle from the downstream separation stages are operated such that the TS of the combined inputs to the digester is within a desired range.

Abstract: This specification describes a system and process for treating waste, for example municipal solid waste (MSW) or post-recycling municipal solid waste. The system includes a press and a pulper. The press is adapted to provide a wet fraction of the waste suitable for anaerobic digestion and rejects. The pulper is adapted to receive the rejects and produce pulp. The pulper may be, for example, a drum pulper. In the process, waste is separated into a press into an organic fraction and rejects. The organic fraction is treated by way of anaerobic digestion. The rejects are separated, optionally in a drum pulper, to produce a fraction containing pulp. The pulp can be re-used to make paper or other products. In some case, 70% or more or 80% or more of MSW can be diverted from landfill.

Abstract: Waste, such as municipal solid waste (MSF), is separated into a wet fraction and rejects. For example, the waste may be separated in a press. A cellulosic fraction is separated from the rejects. In a wet method the rejects are treated in a pulper to extract the cellulosic fraction. In a dry method, the rejects are treated with an optical sorter. The cellulosic fraction is treated in an anaerobic digester, optionally with the wet fraction.

Abstract: Low strength wastewater such as municipal sewage is treated using an anaerobic digester. In some examples, a wastewater stream is separated into a solids rich portion and a solids lean portion. The solids lean portion is treated, for example to remove nitrogen. The solids rich portion is treated in an anaerobic digester, preferably with influent or recuperative thickening. In another example, the wastewater stream is fed to an anaerobic digester and solid-liquid separation stages downstream of the digester return active bacteria and undigested organics to the digester. Both cases may use a process train comprising treatment in an anoxic tank followed by a nitritation tank with a portion of the effluent from the nitritation tank recirculated to the anoxic tank to provide nitritation and denitritation.

Abstract: A waste stream is treated by anaerobic digestion. A process is described involves a step of separating solids from digestate, and returning separated solids to a digester. Optionally, there may be a step of solids separation in which larger solids are removed from the digester. A process and apparatus are described for treating waste sludge from a wastewater treatment plant in an anaerobic digester. Feed sludge is thickened or solids are separated from digestate and returned to the digester. Additional co-digestion waste may be added to the digester. The process and apparatus may be used in a retrofit of an existing wastewater treatment plant.

Abstract: An anaerobic digester is fed a feedstock, for example sludge from a municipal wastewater treatment plant, and produces a digestate. The digestate is dewatered into a cake. The cake may be dried further, for example in a thermal drier. The cake is treated in a pyrolysis system to produce a synthesis gas and biochar. The gas is sent to the same or another digester to increase its methane production. The char may be used as a soil enhancer.