Anaergia Inc.

Other

International Waste Management Systems

Juan Carlos Josse

Andrew Benedek

Michael David Theodoulou

Matthew John Kuzma

Yaniv D Scherson

Zachary Scott

Hans Frederick Ouellet

Michael David Thedoulou

Christian Friedl

Diana Mourato-Benedek

Martin Bayer

Ashwani Kumar

John William Sutherlin

Sasha Rollings-Scattergood

Marcelo De Lima Vasconcellos

Warren Bruce Lee

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.

Process to recover a portion of post-recycling municipal solid waste

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.

Process for recovering organics from material recovery facility fines

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 Digestate is withdrawn from the digester from a free liquid surface of the digester.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.

Anaerobic digestion of organic fraction of solid waste with high quality digestate

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.

Organics recovery from dry fraction

The specification describes a system and process for treating a sludge or slurry to produce biochar. The sludge or in slurry may be digestate produced by an anaerobic digester that receives waste activated sludge from a wastewater treatment plant. In a process, digestate is dosed with metal ions, dewatered, and pyrolized. A corresponding system includes a reactor, a dewatering unit and a pyrolysis unit. In an example, the digestate is air stripped in the reactor and a metal salt is added to it. The metal ions form precipitates in the digestate that remain in the biochar. In some cases, a precipitate such as struvite is formed that also increases the phosphorous content of the biochar. The biochar may be used as a soil amendment, wherein the metal and phosphorous are beneficial to the soil.

Method of producing biochar from sludge

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.

Anaerobic digestion and pyrolysis system

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.

Solid waste processing with pyrolysis of cellulosic waste

In a system and process, sludge is treated by two stages of anaerobic digestion in series separated by intermediate thickening and hydrolysis. The hydrolysis product is transferred to the second digester essentially without dilution.

Two stage anaerobic digestion with intermediate hydrolysis

A multi-stage anaerobic digester is designed to treat a high solids, stackable feedstock. The system may also receive a pumpable feedstock such as a slurry or sludge. In a first stage, the digestate circulates in one direction around a raceway such that the digestate may pass a feed inlet multiple times before leaving the first tank. An optional side stream loop withdraws fibrous material from near the top of the raceway and return digestate with chopped fibers, preferably lower and further along the raceway. An outlet from the raceway located near, but upstream of, the feed inlet discharges partially digested substrate to a second stage, which is operated as a stirred tank reactor. The two stages may be provided in a single tank with an internal wall separating a ring shaped outer portion from a cylindrical inner portion. The digester may be operated in a thermophilic temperature range.

Multiple tank high solids anaerobic digester

Sewage sludge is treated to produce Class A (generally pathogen free) biosolids. Some or all of the sewage sludge is thickened or dewatered to 10 wt % dried solids and then fed to a thermophilic anaerobic digester. The thermophilic digester has multiple stages provided by way of a tank with at least one internal wall. Effluent from the thermophilic digester is treated further in a mesophilic anaerobic digester.

Sewage sludge processing with multi-stage thermophilic digester

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.

Organics and nutrient recovery from anaerobic digester residues

Waste or organic material is compressed at a pressure sufficient to burst cells, for example 50 bar or more, and separated into a dry fraction and a wet fraction. The wet fraction is treated in an anaerobic digester to produce biogas after removing grit. The wet fraction is diluted, preferably with sludge, before it is degritted. Optionally, floatables are removed from the fraction before it is added to the digester.

Production of biogas from organic materials

Waste solids are treated by pyrolysis at a temperature over 700 degrees C. to produce char and a gas. The gas is treated in an anaerobic digester. In one system, gas and digestate are brought into contact in a diffusion cone. In another option, headspace gas above the digestate is re-circulated through the digestate, for example by way of an eductor downstream of the diffusion cone.

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Mission Viejo, CA, United States of America

Juan Carlos Josse