真空变压吸附提浓煤矿乏风瓦斯的排放气充压过程

Pressurization with raffinate in vacuum pressure-swing adsorption for upgrading ventilation air methane

针对传统的变压吸附循环不能很好地适应乏风瓦斯提浓的问题,建立了以活性炭为吸附剂的三塔真空变压吸附实验装置,提出了一种适合煤矿乏风瓦斯提浓的三塔排放气充压流程,以此提高煤矿乏风瓦斯的提浓效果,并对该流程进行了实验研究。结果表明:在变压吸附回收重组分甲烷的过程中,采用排放气从吸附塔上端充压可以有效降低排放气中甲烷的体积分数。在排放气甲烷体积分数相同的情况下,采用排放气充压可以延长穿透时间,提高产品气中甲烷的体积分数。随着排放气充压比的增大,产品气中甲烷的体积分数先上升,后趋于平稳;排放气中甲烷的体积分数则先下降,后趋于平稳。

Pressure-swing adsorption has great advantage in upgrading ventilation air methane, but conventional PSA switching sequence is not suitable for it. An improved pressurization step with raffinate was developed and studied ex- perimentally in three-bed vacuum pressure-swing adsorption（VPSA） system with activated carbon for improving venti- lation air methane （VAM） upgrading. The results show that pressurization with raffinate from effluent end can decrease the concentration of CH4 in raffinate and extend the penetration time. For this reason,the CH4 concentration in product can be increased in case of same raffinate concentration. When the raffinate-pressurization ratio increases, the CH4 con- centration in product and raffinate increases initially, then tends to be steady. But the raffinate concentration decreases initially,then tends to be steady at the same time.