- 作者: --
- 作者服務機構: Egyptian Petroleum Research Institute, Nasr City, P. O. Box 9540, Cairo 11787, Egypt
- 中文摘要: Toluene was methylated with methanol and disproportionated using catalysts containing different Pt contents (0.2, 0.4 and 0.6%) supported on H-ZSM-5 or H-mordenite (H-M) zeolites in a fixed-bed flow-reactor operated atmospherically at temperatures of 300-500 °C in a flow of hydrogen. Platinum dispersion in the zeolite supports and acid sites strength distribution were evaluated using hydrogen chemisorption (1:1 stoichiometry) and ammonia temperature programmed desorption (TPD) in a differential scanning calorimeter (DSC). Toluene methylation was much faster on all catalysts than toluene disproportionation (DISP). Both reactions were more acce1erated using H-ZSM-5 containing cata1ysts than H-M containing cata1ysts. The yield of xylenes, and in particular para-xylene, was significantly influenced by the yield of trimethylbenzenes (TMBs) in product. The selectivities for para-, ortho- and meta-xylenes production were found largely dependent on the Pt content in the catalysts, particularly when supported on H-ZSM5-zeolite. However, using Pt/H-M catalysts, these selectivities were not strictly controlled by Pt content in the catalysts.
- 英文摘要: --
- 中文關鍵字: Xylenes; Methylation; Toluene; Disproportionation; Platinum; ZSM-5; Mordenite; Zeolites.
- 英文關鍵字: --