Experimental study on purification and displacement of methane in coalbed methane by PSA

LI Xiaoliang; BAI Honghao; GUO Haoqian

doi:10.3969/j.issn.1007-7677.2023.06.006

Abstract：The use of carbon dioxide to replace methane from coalbed methane can provide economic value for the storage of carbon dioxide,but the mixing of carbon dioxide can easily reduce the utilization value of coalbed methane.Therefore,it is necessary to purify methane through gas separation before entering the pipeline network and transpor-ting it to downstream users for use.In order to further achieve the capture of CO2 and the purification and utilization of coalbed methane,a self-made adsorbent was used for CH4/CO2 pressure swing adsorption separation pilot experiment.The pressure swing adsorption pilot experiment device was used to explore the effects of different process parameters on product gas concentration and adsorbent treatment capacity.Through continuous pressure swing adsorption experi-ments,a complete CO2/CH4 separation and purification process was formed.The experimental results show that after purification by two-stage pressure swing adsorption process,the CH4 concentration can be increased from 80%in the feed gas to 99.21%,the recovery rate can reach 94.93%,and the CO2 concentration can be reduced from 20%to below 1%.The use of pressure swing adsorption method can purify methane in CO2 displacement coalbed methane,thereby reducing the impact of CO2 displacement coalbed methane technology on coalbed methane concentration.Through two-stage pressure swing adsorption experiments to concentrate methane,an integrated process of gas com-pression,dehydration,oil removal,dust removal,and purification,as well as two-stage pressure swing adsorption CO2/CH4 separation and purification,has been formed.This verifies the feasibility of pressure swing adsorption puri-fication for CO2 displacement of coalbed methane.