水合物法连续分离煤层气实验研究

摘要

A continuous gas mixtures separating device via forming hydrate was designed and established. Hydrate can form and decompose successively by the device:hydrate forms in the hydration reactor and then is sent to decompose in the decomposer. During the whole process, the working solution is recycling. Based on the device, the separation experiments of Coal Bed Methane (CBM) simulation gas (CH4 50.44%(mol)+N2) were carried out in 6%(mol) tetrahydrofuran (THF) solution under the following conditions: temperature 278.15~281.15 K, pressure 0.7~1.1 MPa, feed gas flow rate 1~5 L×min-1 (standard condition), respectively. Experimental results show that the higher pressure, lower temperature and lower feed gas flow rate facilitate CH4 enrichment in hydrate and CH4 recovery. The fractions of CH4 in hydrate and residual gas are 52.53%~64.24%(mol) and 45.33%~49.63%(mol), respectively. The recovery of CH4 is between 3.0% and 19.4%. Among all the experimental conditions, the best are T=279.15 K, P=1.1 MPa and feed gas flow rate=1 L×min-1. The results show that the continuous hydration process is suitable for CBM separation both in theory and in practice.%　　基于水合物法分离技术建立了一套能够连续分离混合气体的实验装置，可以同时实现水合物的生成和化解，即水合物在反应器中生成之后被输送至化解器中立刻化解，且化解后的工作液能够循环利用。利用此装置对模拟煤层气(CH450.44%(mol)+N249.56%(mol))进行了水合分离实验研究，工作液为6%(mol)的四氢呋喃(THF)水溶液，实验条件为温度278.15~281.15 K，压力0.7~1.1 MPa，原料气流量1~5 L×min-1(标况下)，工作液流量60 L×h-1。结果表明：低温、高压、低原料气流量有利于水合物中CH4的富集和CH4回收。水合物相CH4含量在52.53%~64.24%(mol)；剩余气中CH4含量在45.33%~49.63%(mol)；CH4回收率介于3.0%~19.4%。其中，279.15 K，1.1 MPa，原料气流量1 L×min-1为较好的操作条件。结果表明连续性水合分离过程在理论上和实际应用中均适用于煤层气的分离。