Enrichment of low-grade methane by dual reflux vacuum swing adsorption

Abstract

Methane (CH4) has been recognized as a clean energy resource and crucial chemical feedstock. However, low-grade CH4 gases (<30%) such as coal mining gas are often released directly to the atmosphere due to limited economic values and technical challenges in enrichment, transportation and utilization, resulting in significant greenhouse gas (GHG) emissions and energy waste. In this work, a non-isothermal model of the dual reflux vacuum swing adsorption (DR-VSA) was developed on the Aspen Adsorption platform to numerically study the enrichment of low-grade CH4 from N2 gas by activated carbon (AC) and ionic liquidic zeolites (ILZ). Since the low-grade methane source was often at atmospheric pre..