US 12,345,470 B2
Process for removing CO2 from a methane-containing gas
Uwe Jordan, Worpswede (DE); Gamuret Hack, Zürich (CH); and Lukas Völlmy, Winterthur (CH)
Assigned to HITACHI ZOSEN INOVA AG, Zurich (CH)
Appl. No. 18/266,072
Filed by HITACHI ZOSEN INOVA AG, Zürich (CH)
PCT Filed Jan. 27, 2022, PCT No. PCT/EP2022/051882
§ 371(c)(1), (2) Date Jun. 8, 2023,
PCT Pub. No. WO2022/162059, PCT Pub. Date Aug. 4, 2022.
Claims priority of application No. 21154198 (EP), filed on Jan. 29, 2021.
Prior Publication US 2024/0044579 A1, Feb. 8, 2024
Int. Cl. F25J 3/06 (2006.01); B01D 53/04 (2006.01); B01D 53/047 (2006.01)
CPC F25J 3/0635 (2013.01) [B01D 53/0462 (2013.01); B01D 53/047 (2013.01); F25J 3/067 (2013.01); B01D 2256/245 (2013.01); B01D 2257/504 (2013.01); B01D 2259/40052 (2013.01); F25J 2205/40 (2013.01); F25J 2205/64 (2013.01); F25J 2245/02 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A process for obtaining a methane-enriched product gas from a methane-containing gas comprising the steps of:
a) providing a methane-containing gas containing at least CO2 as an impurity and cooling the methane-containing gas in a first heat exchanger;
b) further cooling the methane-containing gas of step a) to remove CO2 from the methane-containing gas from step a) by freezing-out;
c) further reducing the CO2 concentration of the methane-containing gas from step b) using a pressure temperature swing adsorption apparatus (PTSA) to obtain a methane-enriched product gas;
d) using at least a portion of the methane-enriched product gas from step c) as treatment gas which is passed through the PTSA for treatment of the PTSA, whereby CO2 is absorbed by the treatment gas and removed from the PTSA as a CO2-enriched treatment gas; and
e) recycling the CO2-enriched treatment gas that has been passed through the PTSA and admixing same with the methane-containing gas in step a),
wherein at least a portion of the treatment gas is initially recycled to the first heat exchanger to cool the methane-containing gas in the first heat exchanger before being passed to the PTSA for regeneration.