摘要
针对CO2置换吸附分离CH4/N2过程中CO2再生困难的问题,采用少量产品气CH4真空吹扫以提高CO2的解吸效果,并以解吸得到的CH4/CO2混合气为置换步骤的置换气,通过置换来强化含氮低品质甲烷的浓缩过程。以自制椰壳活性炭为吸附剂,对CH4/CO2混合气置换强化吸附回收含氮低品质甲烷工艺过程进行了实验与模拟研究。在gPROMS软件中建立并求解固定床吸附分离模型方程,预测了CH4、N2和CO2在自制椰壳活性炭上的竞争吸附穿透曲线,通过预测结果和实验的对比,验证了数学模型方程的准确性。对比了不同置换气强化吸附分离低品质甲烷的效果,结果表明CH4/CO2混合气置换强化相对于CO2置换强化可获得更高纯度产品。进行了CH4/CO2混合气置换强化真空变压吸附循环实验,可以将14%的CH4/N2和53%的CH4/CO2联合富集到98.8%,同时获得77.8%的回收率。
To solve the problem of CO2 uncompleted desorption in the process of CO2 displacement enhancing the adsorption separation of CH4/N2,a small amount of product gas CH4 was used as purge gas to improve the CO2 desorption.CH4/CO2 mixture gas obtained from desorption step was recycled as the displacement gas to enhance the enrichment of low-grade methane in nitrogen mixture.In this work,the research conducted the experiments for CH4/N2 separation using CH4/CO2 displacement intensification adsorption and the laboratory-made coconut shell activated carbon as sorbent.The mathematical models were built in gPROMS and the accuracy of models was verified by comparison of simulations and CH4/N2/CO2 breakthrough experiments.The performance of enrichment of low-grade methane with displacement intensification using different displacer was compared.The result showed that the process with CH4/CO2 displacement had higher purity product than CO2 displacement.The CH4/CO2 mixed gas replacement enhanced vacuum pressure swing adsorption cycle experiment was carried out,which can jointly enrich 14%CH4/N2 and 53%CH4/CO2 to 98.8%,and at the same time obtain a recovery rate of 77.8%.
作者
曲冬蕾
杨颖
钱智玲
李平
于建国
QU Donglei;YANG Ying;QIAN Zhiling;LI Ping;YU Jianguo(State Key Laboratory of Chemical Engineering,School of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China)
出处
《化工学报》
EI
CAS
CSCD
北大核心
2020年第12期5599-5609,共11页
CIESC Journal
基金
国家自然科学基金项目(21978090,U1610102,51804127)
政府间国际合作重点专项(2016YFE0132500,2015DFG42220)。
关键词
活性炭
甲烷
二氧化碳
氮气
真空变压吸附
过程强化
activated carbon
methane
carbon dioxide
nitrogen
vacuum pressure swing adsorption
process intensification
