Deactivating species in the transformation of crude bio-oil with methanol into hydrocarbons on a HZSM-5 catalyst
Deactivating species in the transformation of crude bio-oil with methanol into hydrocarbons on a HZSM-5 catalyst
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DOI：
10.1016/j.jcat.2011.10.004
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发表时间：
2012
影响因子：
7.3
通讯作者：
Beatriz Valle;P. Castaño;M. Olazar;J. Bilbao;A. Gayubo
中科院分区：
文献类型：
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作者：
Beatriz Valle;P. Castaño;M. Olazar;J. Bilbao;A. Gayubo
采用TPO、FTIR、拉曼、~（13）C NMR、CH_2Cl_2中焦炭溶解的GC/MS等技术，研究了木质纤维素生物质（松木屑）快速热解制得的粗生物油在Ni改性的HZSM-5催化剂上转化为烃类时焦炭的性质。反应系统具有两个串联步骤。在第一种方法中，在400°C下聚合来自生物质木质素热解的粗生物油的组分。在第二种方法中，剩余的挥发性含氧化合物在450°C的流化床催化反应器中转化为烃。反应在进料中以不同的生物油/甲醇质量比（从100/0到0/100）进行。共进料甲醇显著地减弱焦炭沉积，并且焦炭组分的性质根据进料中的生物油/甲醇比率而变化。当生物油被共同进料时，沉积在催化剂上的焦炭具有显著含量的含氧化合物和氧代芳族化合物，并且由通过程序升温氧化鉴定的两个馏分组成，对应于沸石晶体中的外部焦炭和内部焦炭。外部焦炭的馏分可溶于CH 2Cl 2中，具有高含量的含氧化合物和氧代芳族化合物，并且通过由沸石酸位点活化的生物质木质素热解衍生的产物的聚合而产生。保留在沸石晶体内的焦炭部分是部分不溶的，并且通过几种途径形成：从甲醇和生物油含氧化合物转化为烃的中间体;通过其他焦炭部分的析出;从反应介质中的烃（具有高芳烃含量）。
A study has been carried out by using different techniques (TPO, FTIR, Raman,13C NMR, GC/MS of the coke dissolved in CH2Cl2) on the nature of the coke deposited on a HZSM-5 catalyst modified with Ni in the transformation of the crude bio-oil obtained by flash pyrolysis of lignocellulosic biomass (pine sawdust) into hydrocarbons. The reaction system has two steps in-line. In the first one, the components of crude bio-oil derived from the pyrolysis of biomass lignin are polymerized at 400°C. In the second one, the remaining volatile oxygenates are transformed into hydrocarbons in a fluidized bed catalytic reactor at 450°C. The reaction has been carried out with different bio-oil/methanol mass ratios in the feed (from 100/0 to 0/100). Co-feeding methanol significantly attenuates coke deposition, and the nature of the coke components varies according to the bio-oil/methanol ratio in the feed. When bio-oil is co-fed, the coke deposited on the catalyst has a significant content of oxygenates and oxo-aromatics and consists of two fractions, identified by temperature programmed oxidation, corresponding to external and internal coke in the zeolite crystals. The fraction of external coke is soluble in CH2Cl2, with a high content of oxygenates and oxo-aromatics, and is generated by polymerization of products derived from biomass lignin pyrolysis activated by the zeolite acid sites. The fraction of coke retained within the zeolite crystals is partially insoluble and is formed by several routes: from the intermediates in the transformation of both methanol and bio-oil oxygenates into hydrocarbons; by evolution of the other coke fraction; from the hydrocarbons (with high aromatics content) in the reaction medium.