Effects of zeolite morphologies on CO conversion to aromatics via a modified Fischer-Tropsch synthesis pathway
Effects of zeolite morphologies on CO conversion to aromatics via a modified Fischer-Tropsch synthesis pathway
复制标题
沸石形态对通过改进的费托合成途径将 CO 转化为芳烃的影响
DOI：
10.1002/jctb.7216
复制
发表时间：
2022
影响因子：
3.4
通讯作者：
Tsubaki Noritatsu
中科院分区：
文献类型：
--
作者：
Zhang Baizhang;Yao Jie;Wang Yang;Gao Weizhe;Kugue Yasuharu;Guo Xiaoyu;He Yingluo;Yang Guohui;Tsubaki Noritatsu
背景通过费托合成（FT）路线将合成气转化为烯烃，然后转化为芳烃（合成气-烯烃-芳烃（SOA））被认为是一种有前途的工业化路线，因为它能够匹配合成气到烯烃（300–400°C）和烯烃到芳烃（300–500°C）之间的反应温度。在该反应路线中，合成气制烯烃过程可以通过铁基费托催化剂高效、轻松地实现。然而，由于沸石复杂的拓扑结构、多变的形貌和难以捉摸的酸性特性，在沸石催化剂上发生的芳构化过程仍然被认为是一个巨大的挑战。 结果成功合成了一系列不同形貌的ZSM-5沸石，包括纳米椭球、纳米立方体、纳米聚集体、纳米珠和纳米堆。系统研究了ZSM-5沸石的形貌和反应温度对改进的FTs路线合成气合成芳烃的影响。结论在所有研究的ZSM-5沸石中，纳米立方ZSM-5沸石（Z5-NC）沸石具有最好的芳构化能力。 FeMnK&Z5-NC复合催化剂组合获得的二甲苯选择性最高为12%（2.8%±9.2%），其总芳烃选择性也最高（42.5%）。对反应温度的研究表明，较高的反应温度（320-360°C）可以有效阻止CO2的形成。然而，在较高温度下芳烃选择性被限制在44%左右，因为高温有利于高级烃的加氢裂化，导致较轻的CH4和石蜡的选择性增加。 © 2022 化学工业协会 (SCI)。
BACKGROUNDSyngas conversion to olefinsviaFischer‐Tropsch Synthesis (FTs) route and then subsequently into aromatics (syngas−olefins−aromatics (SOA)) was considered a promising industrialization route due to its ability to match reaction temperatures between syngas to olefins (300–400 °C) and olefins to aromatics (300–500 °C). In this reaction route, the syngas to olefin process can be efficiently and easily realized by Fe‐based FTs catalysts. However, the aromatization process occurring over the zeolite catalyst was still considered a big challenge due to zeolites' complex topology, variable morphology, and elusive acidic properties.RESULTSA series of ZSM‐5 zeolites with different morphologies, including nano ellipsoid, nano cube, nano aggregate, nano bead, and nano pile were successfully synthesized . The effects of the ZSM‐5 zeolite's morphology and reaction temperature on the aromatics synthesis from syngas based on a modified FTs route were systematically studied.CONCLUSIONIn all the studied ZSM‐5 zeolites, the nano cube ZSM‐5 zeolite (Z5‐NC) zeolite had the best aromatization ability. The hybrid catalyst combination of FeMnK&Z5‐NC obtained the highest xylene selectivity of 12% (2.8% + 9.2%), and its total aromatics selectivity was also the highest (42.5%). The study on reaction temperature suggested that a higher reaction temperature (320–360 °C) could efficiently impede the formation of CO2. However, the selectivity of aromatics was restrained to around 44% at higher temperatures because a high temperature facilitated the hydrocracking of higher hydrocarbons, leading to the increase of the selectivity of lighter CH4and paraffin. © 2022 Society of Chemical Industry (SCI).