非常规天然气未来可以作为常规天然气的有效补充,其中低浓度煤层气和生物质燃气分别需要脱除大量的N2和CO2以达到富集和纯化CH4的目的。本研究针对CH4/N2这一对较难分离的气体组合,选取了具有一维菱形孔道的MOFs材料Cu(INA)2作为吸附剂,将合成的样品做了XRD和TG表征,测试了纯气体CO2、CH4和N2的吸附曲线,利用巨正则系综蒙特卡罗(GCMC)分子模拟和理想吸附溶液理论(IAST)计算了气体的吸附热和该材料对于CH4/N2和CO2/CH4的吸附选择性系数;3 MPa压力下制备的颗粒样品填装吸附分离装置,进行了混合气体CH4/N2(50%/50%)和CO2/CH4(50%/50%)的穿透试验,分离的结果显示,Cu(INA)2不仅高选择性地吸附CH4/N2混合物中的CH4(SCH4/N2=10),而且对CH4/N2的分离效果优于CO2/CH4。
As powerful and effective supplement to conventional natural gas in future, the unconventional gas including low concentration coalbed methane and biomass need to remove a large amount of N2 and CO2 to achieve enrichment and purification of CH4. To separate N2 and O2, Cu(INA)2 with pores of a one-dimensional rhombus was chosen as an adsorbent. The synthesized sample was characterized with XRD and TG. Combined with CO2, CH4 and N2 adsorption curves, the grand canonical ensemble Monte Carlo (GCMC) molecular modeling and the ideal adsorbed solution theory (IAST) were used to calculate the adsorption heat of gas and adsorption selectivities for binary mixtures (CH4/N2 and CO2/CH4), separately; For breakthrough separation experiments, powder samples of Cu(INA)2 were pelletized into particles of a certain size under pressure of 3 MPa. The result revealed that Cu(INA)2 has not only high selective adsorption of CH4 in mixture of CH4/N2 (SCH4/N2=10), but also better separation for CH4/N2 than CO2/CH4.