Development of nanoporous structured catalysts for xylenes production

Five zeolites-based catalysts were evaluated in a fixed-bed reaction system. All five catalysts exhibited increase in C₉ conversion and xylene selectivity with increase in temperature and decrease in space velocity. High molybdenum loading (HMo-MOR) provided higher C₉ conversion as compared to low molybdenum loading (LM0-MOR). Mordenite-based catalysts offered a number of advantages over the USY-based catalysts, which include higher C₉ conversion, higher xylenes selectivity, and reduced C₁₀+ and ethylbenzene production, whereas the disadvantages were higher yield of benzene and toluene. Very high loadings of metals on the catalysts decreased C₉ conversion. For the conversion of C₉ aromatics to xylenes, mordenite zeolite based catalysts performed better than USY. Mo loaded mordenite based catalysts performed better in terms of higher C₉ conversion as compared to Re loaded catalyst. The EB concentration increased with rise in temperature for USY-based catalysts while decreased for mordenite-based catalysts with increase in temperature. EB concentration was lower for mordenite-based catalysts compared to USY-based catalysts. Benzene and toluene concentrations were higher for mordenite-based catalysts as compared to USY-based catalysts. This is an abstract of a paper presented at the 17th Annual Saudi-Japanese Symposium on Catalysts in Petroleum Refining and Petrochemicals 2007 (Dhahran, Saudi Arabia 11/11-12/2007).