Syngas biomethanation process and anaerobic digestion system
AssigneeAnaergia Inc.
InventorsJuan Carlos Josse, Andrew Benedek
Life of this patent
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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.
Claims14
A process for converting a feedstock to biogas comprising steps of,
- a) producing a synthesis gas from pyrolysis of the feedstock;
- b) separating organic compounds from the synthesis gas and returning the separated organic compounds to step a) as additional feedstock;
- and,
- c) adding the synthesis gas to an anaerobic digester.
An apparatus for transferring syngas to digestate comprising,
- a) a pipe between a source of digestate and a digester;
- b) a pump to create a flow of digestate in the pipe;
- c) an ejector, microbubble pump or gas transfer membrane in communication with the pipe and having an inlet connected to a source of the syngas;
- and,
- a heat exchanger between the inlet and the source of the syngas.
A process and apparatus for treating wastewater comprising,
- a) treating the wastewater to generate a sludge;
- b) feeding the sludge to an anaerobic digester to produce biogas and digestate;
- c) dewatering the digestate to produce a cake;
- d) thermally drying the cake to produce a dried cake;
- e) pyrolysing the dried cake to produce char, organic compounds and syngas;
- f) feeding the syngas to the anaerobic digester;
- and,
- g) pyrolysing at least some of the organic compounds to produce additional syngas and feeding the additional syngas to the anaerobic digester.
Dependencies are inferred from the claim text.