Impact of Process Parameters on Oxygen-Bearing Low Concentration Coal Mine Methane Enrichment by Proportion Pressure Swing Adsorption

Abstract

Conventional PSA methods with a single adsorbent can result in an explosive CH4 concentration of 5 to 15%, making low concentration coal mine methane (LCCMM) or risky in terms of safety at a concentration of 30%. Proportion Pressure Swing Adsorption (PPSA) is a new and safer enrichment method suggested for LCCMM enrichment that uses a mixture of active carbon (AC) and carbon molecular sieves (CMS) as adsorbents. The effect of adsorption Pressure, adsorption time and bed length on the PPSA process were investigated to verify the feasibility of this method. The experiment results show that the methane concentration in desorption gas and the oxygen concentration in exhaust gas increased and decreased, respectively, with an increase in adsorption pressure or bed length. And the methane concentration in desorption gas is increased with the adsorption time expanding, but the recovery of methane is reduced. So the methane concentration in desorption gas can be increased to more than 30% and the oxygen concentration in exhaust gas be decrease to less than 12% by increasing the adsorption pressure or lengthening the bed.

A review of oxygen removal from oxygen-bearing coal-mine methane

“…At standard pressure (101.3 KPa), the boiling points of CH 4 , N 2 , and O 2 are −161.5, −195.6, and −182.9°C, respectively. According to the difference in boiling point of different gas components in the oxygen-bearing CMM, the different components are evaporated consecutively, and methane is enriched (Li et al 2011b). Cui et al (2015 proposed a new liquefaction and distillation process which is used for the coal mine methane to remove the oxygen.…”