三塔VSA富集低浓度煤层气实验研究

Experimental study of the low-concentration coal mine methane enrichment by three-bed vacuum swing adsorption

采用常压吸附真空解吸的方法对体积分数为12%的低浓度抽排瓦斯开展富集研究.理论分析了吸附塔升压方式和解吸步骤对分离效果的影响,并对原料气充压、排放气充压及抽排3个工艺流程开展了对比实验研究.结果表明:三塔VSA流程可有效地将低浓度煤矿瓦斯富集,在吸附压力为110kPa、解吸压力为10kPa的情况下,可将12%的瓦斯气体富集到26.7%以上;排放气充压流程可以有效地延长气体的穿透时间,在排放气浓度相同的情况下可提高吸附剂的利用效率,提高产品气浓度;抽排工艺流程可以显著地提高产品气浓度,在实验条件不变的情况下抽排步骤由0s增大到6s时产品气体积分数提高了18.7%.

The enrichment of low-concentration coal mine methane （LCMM） with volume concentration of 12% was studied with three-bed vacuum swing adsorption tests. Effects of the pressurization mode and the desorption step on separation were analyzed theoretically, along with experimental comparison investigations on three processes： feed gas pressurization, effluent gas pressurization and vacuum exhaust. The results show that the LCMM can be enriched up to 26.7vol% at adsorption and desorption pressures of 110 kPa abs. and 10 kPa abs. , respectively. The process of effluent gas pressurization can efficiently extend the break through time, increasing the utilization efficiency of adsorbents as well as the concentration of the product gas with effluent methane concentration remaining unchanged. The process of vacuum exhaust enhanced the concentration of the product gas by 18.7% when the vacuum exhaust time was increased from 0 to 6 s.