초록 |
In order to study the performance of aromatization using acetylene, two types of zeolites, the conventional and hierarchical zeolites, were used as catalysts. For conventional MCM-22 zeolites, we scrutinized the effects of Si/Al ratio on the performance of aromatization. The analysis was based on the acetylene conversion, the aromatics selectivity, and coke formation. For preparing hierarchical zeolites, namely MCM-36, the interlayers in the MCM-22 precursor were swollen and the resulting spaces were pillared. The resultant MCM-36 zeolites were characterized and measured for aromatization. The effects derived from structure difference and Si/Al ratio were investigated. The selectivity of aromatics through MCM-36 was substantially increased from the catalytic performance tests. Furthermore, the amount of carbon deposition was significantly reduced. Both results presumably occur because of the increased concentration of external Brønsted acid sites. |