脂肪酸甲酯和甲醇催化共裂化制备可再生芳烃和烯烃

• 作 者: 刘森 国玉倩 孙培永 张胜红 姚志龙
• 机 构: 北京石油化工学院化学工程学院,恩泽生物质精细化工北京市重点实验室,北京102617;安阳工学院化学与环境工程学院,河南安阳455000;北京石油化工学院化学工程学院,恩泽生物质精细化工北京市重点实验室
• 出 处: 燃料化学学报
• 发表日期: 2021年12期
• 关键词: catalytic cracking fatty acid methyl ester methanol aromatic olefin

甘油三酸酯及其衍生物(如脂肪酸甲酯,FAMEs)催化裂化是制备可再生芳烃和烯烃的潜在途径,但该路径严重受限于HZSM-5分子筛催化剂的积炭失活.为调控FAMEs裂化产物分布并减缓催化剂的失活速率,本研究发展了FAMEs和甲醇催化共裂化的反应策略.结果表明,FAMEs和甲醇催化共裂化能够提高烯烃的选择性并降低芳烃的选择性,在原料中甲醇含量为60％时芳烃和烯烃的总选择性高达70.9％.甲醇的引入不仅能够提高烯烃的收率,而且有助于抑制单环芳烃持续脱氢形成多环芳烃,进而减少积炭的生成并延长HZSM-5/Al2O3催化剂的使用寿命.在温度为450℃、压力为0.16 MPa、FAMEs空速为4 h-1和反应时长为12 h的条件下,引入与FAMEs等质量的甲醇能够将催化剂的积炭量从17.8％降低为10.1％.此外,FAMEs和甲醇共裂化反应中部分失活的HZSM-5/Al2O3可以通过简单焙烧进行再生,再生催化剂的结构、酸性和反应活性与新鲜催化剂相比无明显改变.“,”Catalytic cracking of triglycerides and their derivatives(e.g.,fatty acid methyl esters,FAMEs)by HZSM-5 zeolite offers a promising route to produce renewable aromatics and olefins,but it is primarily hindered by the rapid catalyst deactivation caused by coke.In this work,the co-cracking of FAMEs and methanol over HZSM-5/Al2O3 composites was developed to regulate the product distribution and slower the catalyst deactivation.Co-feeding methanol with FAMEs enhanced the olefin selectivity at the expense of aromatics,and the total selectivities of aromatics and olefins added up to 70.9％with an optimized methanol content of 60％.The co-feeding of methanol not only promoted the olefin yield but also retarded the consecutive H-elimination of aromatics to polycyclic aromatics,thus reducing the coke formation and prolonging the catalyst lifespan.Under the conditions of 450℃,0.16 MPa and a space velocity of FAMEs at 4 h-1,increasing the methanol blending ratio in FAMEs from zero to 50％reduced coke from 17.8％to 10.1％after reaction for 12 h.Besides,the spent catalyst for the co-cracking reaction could be easily regenerated by coke combustion,yielding similar structure,acidity and activity to those of the fresh one.