合成气直接制低碳烯烃用Fe/K/Mg-O-Al催化剂  

Fe/K/Mg-O-Al catalysts for direct production of lower olefins from syngas

作　　者：邢宇 赵晨曦 贾高鹏 田红美 高玉集 刘振新 XING Yu;ZHAO Chenxi;JIA Gaopeng;TIAN Hongmei;GAO Yuji;LIU Zhenxin(Henan Provincial Key Laboratory of Surface and Interface Science,School of Materials and Chemical Engineering,Zhengzhou University of Light Industry,Zhengzhou 450002,Henan,China)

机构地区：[1]郑州轻工业大学材料与化学工程学院,河南省表界面科学重点实验室,河南郑州450002

出　　处：《精细化工》2020年第5期968-975,共8页Fine Chemicals

基　　金：国家自然科学基金(21571161);河南省高等学校重点科研项目资助计划(20A150044);省属高校基本科研业务费专项资金项目(19KYYWF0402);郑州轻工业大学博士科研基金(2016BSJJ034/CLY20170069/LZX2016)。

摘　　要：传统费托合成着眼于制取蜡/油等长碳链饱和烃,其催化剂的"金属/酸性氧化物"界面可以极化和稳定反应中间体,从而促进加氢和C-C偶合,有助于较长链烷烃的生成。为了从合成气直接获取高附加值的低碳烯烃,催化剂设计理念应该与以制取较长链烷烃为目的的传统费托催化剂取法相异。该文着眼于"弱加氢金属/固体碱型载体"费托合成制低碳烯烃催化剂的基础研究,采用表面碱性的载体和碱性的钾助剂,逆转上述传统催化剂中"金属/酸性氧化物"之间界面的状况,削弱对加氢和C-C偶合的促进,达到抑制加氢、抑制C-C偶合的目的。所测Fe/K/Mg-O-Al系列催化剂的烯烷比取决于强碱性位的数量及其占总碱性位的比值。在1200℃钝化处理条件下,与简单MgO担载的弱碱性催化剂相比,复合氧化物MgAl2O4担载的强碱性催化剂将低碳烯烃(C2^=~C4^=)产物分布值显著提高了84%,将C2~C4烯烷比显著提高了266%。Traditional Fischer-Tropsch synthesis focuses on the production of long chain saturated hydrocarbons such as wax/oil, whose catalyst’s "metal/acidic oxide" interface can polarize and stabilize the reaction intermediates, thus promoting hydrogenation and C-C coupling, and contributing to the formation of longer chain alkanes. In order to obtain high value-added lower olefins directly from syngas, the concept of catalyst design should be different from that of the traditional Fischer-Tropsch method to produce long-chain alkanes. Therefore, the basic research of catalysts for Fischer Tropsch synthesis of low-carbon olefins with "weak hydrogenation metal/solid base support" was carried out. Base support and potassium promoter were adopted to reverse the status of above-mentioned interface between "metal/acid oxide" in the traditional catalysts, weaken the promotion of hydrogenation and C-C coupling, and achieve the purpose of inhibiting hydrogenation and C-C coupling. The ratio of olefin to paraffin(O/P) of Fe/K/Mg-O-Al series catalysts depended on the number of strong basic sites and their ratio to the total basic sites. Under the same passivation treatment at 1200 ℃, compared with those in the weak base catalyst supported by simple MgO, the hydrocarbon product distribution value of C2^=~C4^= hydrocarbon was increased by 84% in the strong base catalyst supported by composite oxide MgAl2O4, and the C2~C4 olefin/paraffin ratio was increased by 266%.

关 键 词：费托合成 CO加氢 低碳烯烃 铁催化剂 尖晶石 催化技术 

分 类 号：TQ426.64[化学工程] TQ221.2