METHOD OF PRODUCING A METHANE-RICH GAS MIXTURE FROM MINE GAS

摘要

A pressure-swing adsorption system is used to enrich the methane content of mine gas obtained from bores around mine shafts or galleries from the customary 25 to 45% by volume to a product gas quality of 50% by volume. Using a carbon molecular sieve adsorbent, the adsorption is carried out at 5 to 8 bar and is followed by a uniflow expansion to an intermediate pressure and a counterflow expansion to a flushing pressure of 1.1 to 2 bar. Counterflow flushing is carried out with waste gas and the product gas is a mixture of the gases obtained by counterflow expansion and flushing.