分子筛改性在工业富氢尾气变压吸附提纯燃料电池氢中的应用研究

Application of molecular sieve modification in purification of fuel cell hydrogen from industrial hydrogen-rich tail gas by PSA

由于燃料电池质子交换膜上的贵金属催化剂对CO、CO_(2)、CH_(4)和硫等杂质较为敏感,从而要求燃料电池氢中相关杂质的含量需小于10^(-6)甚至10^(-9),而目前成熟的常规变压吸附(PSA)制氢技术提纯燃料电池氢存在收率低、占地面积大和投资大等不足,研发高收率、高收益的新型吸附剂迫在眉睫。通过分子筛吸附剂改性研究发现,以Ca^(2+)改性的低硅铝比分子筛的比表面积比5A分子筛提高了15%以上,对N_(2)的吸附容量提高了20%左右,单位吸附剂产氢量是5A复合床的2倍以上,因此,改性型分子筛是替代PSA制燃料氢技术中常规5A分子筛的较好选择。最后,介绍了适合改性分子筛应用的氯乙烯精馏尾气和焦炉煤气这两种工业富氢尾气制燃料电池氢工艺。

As the precious metal catalyst on the proton exchange membrane of the fuel cell is sensitive to impurities such as CO,CO_(2),CH_(4) and sulfur,the content of relevant impurities in the hydrogen of the fuel cell is required to be less than 10^(-6) or even 10^(-9).However,the mature conventional pressure swing adsorption(PSA)hydrogen production technology for purifying the hydrogen of the fuel cell has the disadvantages of low yield,large land occupation and large investment,the research and development of new adsorbents with high yield and high profit are imminent.Through the study on the modification of molecular sieve adsorbent,it is found that the specific surface area of low silicon aluminum specific molecular sieve modified with Ca^(2+) is more than 15%higher than that of 5A molecular sieve,the adsorption capacity of N_(2) is about 20% higher than that of the 5A molecular sieve,and the hydrogen production per unit adsorbent is more than 2 times that of 5A composite bed.Therefore,the modified molecular sieve is a better choice to replace the conventional 5A molecular sieve in PSA fuel hydrogen production technology.Finally,the hydrogen production process of fuel cell from vinyl chloride rectification tail gas and coke oven gas were introduced,which are suitable for the application of modified molecular sieve.