有机胺基氨基酸盐吸收剂的沼气CO_2分离特性  

Performance of CO_2 Removal from Biogas by Using Amine-based Amino Acid Salts

作　　者：晏水平[1] 贺清尧 蔡凯[1] 艾平[1] 王媛媛[1] 张衍林[1] 

机构地区：[1]华中农业大学工学院,武汉430070

出　　处：《农业机械学报》2014年第6期199-205,共7页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家自然科学基金资助项目(51006044;51376078);中央高校基本科研业务费专项资金资助项目(2011PY007)

摘　　要：在鼓泡式CO2吸收和再生装置中对有机胺基氨基酸盐吸收剂的沼气CO2吸收和再生特性进行了研究,并与乙醇胺(MEA)和哌嗪(PZ)进行了对比。试验中,气相为典型的模拟沼气氛围(CO2与CH4体积分数比为4∶6,常压),液相CO2吸收温度为35℃,再生温度为75℃,并辅以纯CH4作为吹扫气。结果表明:当达到CO2吸收和再生平衡时,质量分数为30%的4种乙醇胺基氨基酸盐吸收剂对CO2的净携带容量均优于MEA,且乙醇胺基鸟氨酸盐(MEAORN)的CO2净携带容量最高(0.733 mol/mol),比第二位、质量分数为15%的PZ高82.34%。同时,综合考虑能耗与投资成本,对吸收剂CO2分离成本的对比分析表明,MEAORN和PZ的沼气CO2分离成本低于MEA,而乙醇胺基氨基乙酸盐(MEAGLY)在大规模沼气提纯上具有替代MEA进行工程应用的潜能。Amine based amino acid salts were investigated in this study by using a bubbling CO2 absorption and regeneration reactor to assess their CO2 absorption performance from the simulated biogas and regeneration characteristics. In addition, monoethanolamine （MEA） and piperazine （PZ） were also experimented to compare with these amine based amino acid salts. In the experiments, the typical biogas consisting of 40% CO2 and 60% CH4 was used under the ambient circumstance, while 35℃ and 75℃ were adopted to act as the absorption and regeneration temperatures of solvents, respectively. And pure CH4 was also used to act as the sweeping gas during CO2 regeneration stage. The results showed that when the equilibrium CO2 absorption and regeneration statuses were reached, the net CO2 cyclic capacities of all the four MEA-based amino acid salts were higher than MEA, and MEA-based L- ornithinate （MEAORN） with 30% weight fraction owned the highest value （about 0. 733 mol/mol）, which was approximate 82.43% higher than PZ with 15% weight fraction gaining the second higher CO2 cyclic capacity. Furthermore, CO2 removal costs from biogas of different absorbents were assessed and compared when considering the regeneration energy consumption and investment of absorber and desorber. Results showed that no matter the scale of CO2 absorption plant was taken into application, the CO2 removal costs of MEAORN and PZ might be less than MEA. And MEAGLY might have the potential to act as the most promising alternative to replace MEA in the large-scale biogas upgrading plants.

关 键 词：沼气提纯 CO2吸收再生 化学吸收法 氨基酸 

分 类 号：S216.4[农业科学—农业机械化工程]