US 12,239,939 B2
Methods and apparatus for recycling tail gas in syngas fermentation to ethanol
John D. Winter, Houston, TX (US); and Jerrod Hohman, Louisville, CO (US)
Assigned to LanzaTech, Inc., Skokie, IL (US)
Filed by LanzaTech, Inc., Skokie, IL (US)
Filed on Dec. 27, 2023, as Appl. No. 18/397,263.
Application 18/397,263 is a continuation of application No. 17/457,156, filed on Dec. 1, 2021, granted, now 11,857,923.
Application 17/457,156 is a continuation of application No. 16/751,981, filed on Jan. 24, 2020, granted, now 11,202,989, issued on Dec. 21, 2021.
Application 16/751,981 is a continuation of application No. 15/876,198, filed on Jan. 21, 2018, granted, now 10,603,632, issued on Mar. 21, 2020.
Claims priority of provisional application 62/518,295, filed on Jun. 12, 2017.
Prior Publication US 2024/0123401 A1, Apr. 18, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. B01D 53/84 (2006.01); B01D 53/52 (2006.01); B01D 53/96 (2006.01); C10J 3/48 (2006.01); C10J 3/72 (2006.01); C10K 1/00 (2006.01); C12P 7/08 (2006.01); B01D 53/047 (2006.01); B01D 53/62 (2006.01)
CPC B01D 53/84 (2013.01) [B01D 53/52 (2013.01); B01D 53/96 (2013.01); C10J 3/482 (2013.01); C10J 3/723 (2013.01); C10K 1/005 (2013.01); C12P 7/08 (2013.01); B01D 53/047 (2013.01); B01D 53/62 (2013.01); B01D 2251/10 (2013.01); B01D 2251/95 (2013.01); B01D 2256/16 (2013.01); B01D 2256/20 (2013.01); B01D 2256/22 (2013.01); B01D 2257/304 (2013.01); C10J 2300/0916 (2013.01); C10J 2300/1618 (2013.01); C10J 2300/1621 (2013.01); C10J 2300/1665 (2013.01); C10J 2300/1823 (2013.01); Y02E 50/10 (2013.01); Y02P 20/145 (2015.11); Y02P 20/151 (2015.11)] 23 Claims
OG exemplary drawing
 
1. A method of converting a carbonaceous feedstock to a syngas-fermentation product, said method comprising:
a) passing the carbonaceous feedstock and an oxidant to a gasifier to gasify the feedstock and produce a raw syngas stream comprising CO, H2, and CO2;
b) passing the raw syngas stream to a syngas cleanup unit to produce a first treated syngas stream, wherein the cleanup unit is selected from a cyclone, a centrifuge, a filter, a membrane, and a solvent-based system;
c) feeding at least a portion of said first treated syngas stream to an acid-gas removal unit selected from a solvent removal unit or a pressure-swing adsorption (PSA) removal unit, to remove at least some of said CO2 and produce a conditioned syngas stream;
d) feeding at least a portion of said conditioned syngas stream to a fermentor, under suitable fermentation conditions and in the presence of suitable microorganisms and nutrients to biologically convert one or more of CO, H2, or CO2 to a fermentation product and generate a product stream comprising at least the fermentation product and a tail gas stream comprising at least CO2 and unconverted CO and/or H2; and
e) recycling at least a first portion of the tail gas to the fermentor, at least a second portion of the tail gas to the acid-gas removal unit, or both.