Design and modification of zeolite capsule catalyst, a confined reaction field, and its application in one-step isoparaffin synthesis from syngas
Design and modification of zeolite capsule catalyst, a confined reaction field, and its application in one-step isoparaffin synthesis from syngas
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DOI：
10.1021/ef700682y
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发表时间：
2008-05-01
期刊：
影响因子：
5.3
通讯作者：
Tsubaki, Noritatsu
中科院分区：
文献类型：
--
作者：
Yang, Guohui;He, Jingjiang;Tsubaki, Noritatsu
制备了4种不同晶化条件的分子筛胶囊催化剂，并将其用于费托合成（FTS）反应中异构烷烃的直接合成。表征结果表明，这些胶囊催化剂具有致密、完整的H-ZSM-5壳层。在这些沸石胶囊催化剂上的FTS反应中，C11+烃被完全抑制，伴随着尖锐的反Anderson-Schultz-Flory（ASF）定律产物分布。轻质异构烷烃的选择性明显提高，但随着烯烃选择性的增加而增加。在单釜双床催化剂中，采用分子筛胶囊催化剂与Pd/SiO2加氢催化剂的组合，进行了两段异构烷烃合成反应，以转化单分子筛胶囊催化剂产生的残余烯烃。依靠钯的加氢作用和氢溢流，第一段沸石胶囊催化剂流出的烯烃几乎全部加氢，大部分转化为异构烷烃。最终产物中异构烷烃的选择性显著提高。
Four kinds of zeolite capsule catalyst with different crystallization conditions were prepared and utilized for the middle isoparaffin direct synthesis via Fischer-Tropsch synthesis (FTS) reaction. Characterization results exhibited that these capsule catalysts had a compact, integral H-ZSM-5 shell. In FTS reactions on these zeolite capsule catalysts, hydrocarbons of C11+ were totally suppressed, accompanied by a sharp anti-Anderson-Schultz-Flory (ASF) law product distribution. The selectivity of light isoparaffin was improved obviously, but with the increase of the olefin's selectivity. Two-stage isoparaffin synthesis reaction, using the combination of zeolite capsule catalyst with hydrogenation catalyst of Pd/SiO2 in a single reactor as dual-bed catalyst, was also conducted for converting the residual olefins produced by the single zeolite capsule catalyst. Dependent on the palladium role of hydrogenation and hydrogen spillover, almost all the olefins effused from the first stage of zeolite capsule catalyst were hydrogenated, mostly converted to isoparaffin. The selectivity of isoparaffin in the final products was increased markedly as expected.