【作者】 晏水平； 陈竞翱； 艾平； 王媛媛； 张衍林；

【Author】 Yan Shuiping,Chen Jing’ao,Ai Ping,Wang Yuanyuan,Zhang Yanlin(College of Engineering,Huazhong Agricultural Universtiy,Wuhan 430070,China)

【机构】 华中农业大学工学院；

【摘要】 以常用疏水性聚丙烯中空纤维膜接触器作为反应器,以提纯后气体中CH4浓度、系统CO2传质速率和能耗因子为主要指标,研究了乙醇胺(MEA)、二乙醇胺(DEA)和三乙醇胺(TEA)等CO2吸收剂对模拟沼气的净化性能。研究中,吸收剂溶液在膜管程内流动,模拟沼气在接触器壳程内逆向流动。结果表明,新型膜CO2吸收技术可应用于沼气净化,净化气中CH4浓度最高可达到97.8%,系统CO2传质速率可达到18mol.m-2.h-1,且吸收剂对沼气净化性能的排序为:MEA>DEA>TEA>H2O。同时,能耗因子分析结果表明,MEA应选择较高的浓度、02～0.22mol.mol-1贫液负荷、较低的液相流量和30～35℃反应温度,而DEA应选择较高的浓度、16.7L.L-1的气液比和40～50℃反应温度。另外,降低气相流速和初始CO2浓度,净化气中CH4浓度升高,但系统CO2传质速率却出现下降。因而在设计膜吸收系统时,需要综合考虑CO2脱除效率与CO2的传质总量。更多还原

【Abstract】 Taking CH4 concentration in the treated gas,mass transfer rate of CO2 for membrane absorption system and energy consumption factor as the main indicators,the simulated biogas purification performance of monoethanolamine(MEA),diethanolamine(DEA)and triethanolamine(TEA)was experimented in this study by using the conventional hydrophobic polypropylene hollow fiber membrane contactor as the CO2 absorber.In the experiments,solvents flowed in the tube side of membrane contactor,while the simulated biogas countercurrently flowed in the shell side of contactor.The results showed that the new membrane CO2 absorption can be successfully used for biogas purification,and CH4 concentration can be elevated from 60% to up to 97.8% and mass transfer rate of CO2 can reach approximate 18 mol.m-2.h-1.In addition,biogas purification performance of three absorbents can be ranked as:MEA>DEA>TEA.The operating conditions were also optimized by using the energy consumption analysis.Based on the calculation of energy consumption factor,higher concentration,0.2～0.22 mol.mol-1,lower liquid flow rate and 30～35 ℃ absorption temperature may be recommended for MEA,and higher concentration,16.7 L.L-1 gas-liquid ratio and 40～50 ℃ absorption temperature should be suitable for DEA.Finally,the effect of gas flow rate and CO2 concentration in the raw biogas was also studied.Results showed that CH4 concentration in the treated gas increases with the decrease of gas flow rate and CO2 concentration in the raw biogas,however mass transfer rate of CO2 decreases.Therefore,both CO2 removal efficiency and mass transfer rate of CO2 should be taken into consideration for the design of membrane absorption system.更多还原