Effect of core-shell structuring of chabazite zeolite with a siliceous zeolite thin layer on the separation of acetone-butanol-ethanol vapor in humid vapor conditions
Effect of core-shell structuring of chabazite zeolite with a siliceous zeolite thin layer on the separation of acetone-butanol-ethanol vapor in humid vapor conditions
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DOI：
10.1016/j.cej.2019.01.106
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发表时间：
2019-05
影响因子：
15.1
通讯作者：
M. Miyamoto;H. Iwatsuka;Y. Oumi;S. Uemiya;Stijn Van den Perre;G. Baron;J. Denayer
中科院分区：
文献类型：
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作者：
M. Miyamoto;H. Iwatsuka;Y. Oumi;S. Uemiya;Stijn Van den Perre;G. Baron;J. Denayer
窄孔沸石分子筛具有择形性能，可选择性捕集丙酮、乙醇和丁醇混合物中的乙醇，是从ABE(丙酮-丁醇-乙醇)发酵液中分离提纯1-丁醇的理想材料。为了改善沸石在潮湿条件下的分离性能，我们合成了一种核壳结构的沸石，在沸石的铝硅酸盐核心上包覆了一层纯的硅沸石。该材料在1-丁醇的气相分离中用ABE模型蒸气混合物进行了评价。出乎意料的是，乙醇在涂层沸石上获得了更广泛的突破轮廓，导致了较低的正丁醇回收率。结果表明，纯硅沸石涂层降低了正丁醇的吸附速率。在突破性实验中，与母体材料相比，涂层沸石对正丁醇的排除更加明显，导致乙醇的分离系数比正丁醇更大。纯硅砂包覆层对正丁醇而不是乙醇起扩散阻挡作用，增强了分子筛分效果。
Due to its shape selective properties, the narrow pore chabazite zeolite is an interesting material for the separation and purification of 1-butanol from ABE (acetone-butanol-ethanol) fermentation broth, as it selectively traps ethanol from the mixture of acetone, ethanol and butanol. In order to improve the separation performance of chabazite zeolite in humid conditions, we synthesized a core-shell structured chabazite type zeolite, with a chabazite aluminosilicate core coated with a pure silica chabazite layer. This material was evaluated in the vapor phase separation of 1-butanol using a model ABE vapor mixture. Unexpectedly, a broader breakthrough profile of ethanol was obtained on the coated chabazite, resulting in a lower 1-butanol recovery. It was found that the adsorption rate of 1-butanol was decreased by the pure silica chabazite coating. In breakthrough experiments, the coated chabazite showed an even more pronounced exclusion of 1-butanol as compared to the parent material, resulting in a larger separation factor of ethanol over 1-butanol. The pure silica chabazite coating layer acts as a kind of diffusion barrier against 1-butanol rather than ethanol, enhancing the molecular sieving effect.