田相龙,王之婧,刘晓勤,马正飞

• 1:南京工业大学化工学院材料化学工程国家重点实验室

摘要(Abstract)：

采用真空变压吸附工艺(VPSA)从组成为60%(V)CH_4、30%(V)CO_2和30%(V)N2的沼气中获得纯度大于95%的CH_4,以满足车用燃料的要求。通过测定CH_4、CO_2及N2在13X分子筛和碳分子筛(CMS)吸附剂上的吸附性能,将提纯CH_4的VPSA工艺分为两个阶段:第一阶段以13X分子筛为吸附剂,采用六床七步法以脱除CO_2;第二阶段以CMS为吸附剂,采用三床六步法以脱除N2。选择数学模型分别对CH_4、CO_2及N2混合气在13X和CMS上的穿透曲线计算,并与实验值进行对比,以验证其可靠性。基于所选数学模型,对两段VPSA工艺进行模拟,可获得CH_4纯度为99%,总回收率为65%;考察第一段工艺的操作压力及第二段工艺的吸附动力学参数对CH_4纯度和回收率的影响。结果表明:吸附压力升高,脱附压力降低有利于提高CH_4的纯度,但其回收率会降低;当CMS具备对CH_4吸附速率较低、N2吸附速率较高的吸附特性时,可获得纯度大于99%的CH_4,这对CMS吸附剂的研发有一定的指导作用。

关键词(KeyWords)： 沼气提纯;CO2及N2脱除;真空变压吸附;吸附剂

Abstract:

Keywords:

基金项目(Foundation): 国家重点基础研究发展计划(2013CB733504)

作者(Author): 田相龙,王之婧,刘晓勤,马正飞

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