Solid waste treatment with conversion to gas and anaerobic digestion

Patent metadata

Field	Value
Publication number	US-2016230193-A1
Application number	US-201615015479-A
Country	US
Kind code	A1
Filing date	Feb 4, 2016
Priority date	Feb 6, 2015
Publication date	Aug 11, 2016
Grant date	—

Abstract

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.

First claim

We claim:

1 . A process comprising steps of,
a) producing a gas containing hydrogen and carbon monoxide from pyrolysis of a feedstock at a temperature of over 700 degrees, or over 750 degrees C., preferably 800 degrees C. or more; and, b) adding the gas to an anaerobic digester.

2 . The process of claim 1 wherein the feedstock comprises non-biogenic material.

3 . The process of claim 1 wherein the feedstock comprises a mixture of biogenic and non-biogenic material.

4 . The process of claim 1 wherein the anaerobic digester is coupled with or part of a municipal wastewater treatment plant.

5 . An apparatus for transferring syngas to digestate comprising a diffusion cone in a sidestream loop.

6 . The apparatus of claim 5 having an eductor in the sidestream loop downstream of the diffusion cone and connected to a headspace of the digestor.

7 . 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 at a temperature of over 700, or 750, or 800 degrees C. or more to produce char and syngas; f) feeding the syngas to the anaerobic digester.

Assignees

• Anaergia Inc

Inventors

• Josse Juan Carlos
• Scherson Yaniv D

Classifications

• C02F9/00

  Multistage treatment of water, waste water or sewage · CPC title

• C12P5/023 Primary

  Methane · CPC title

• B01L3/56

  Labware specially adapted for transferring fluids · CPC title

• C02F2303/06

  Sludge reduction, e.g. by lysis · CPC title

• C02F11/04

  Anaerobic treatment; Production of methane by such processes · CPC title