The performance of HMCM-22 zeolite catalyst on the olefin alkylation thiophenic sulfur in gasoline

The catalytic performance of the HMCM-22 zeolites with different Si/Al-2 ratios for the olefin alkylation thiophenic sulfur (OATS) process was investigated. With the Si/Al-2 ratio decreasing, the catalytic activity of the HMCM-22 zeolite was increased clearly due to the acidity increment. Further, the thiophene alkylation activity was increased much faster than the xylene alkylation and the hexene oligomerization for the reactivity difference of thiophene, xylene and hexene. When the Si/Al-2 ratio decreased from 473 to 98, the thiophene alkylation activity first reached its quasi-plateau value and its selectivity got a maximum, while after that the increased acid sites would more transfer to the hexene oligomerization and the xylene alkylation, thus improved their activity and decreased the selectivity of thiophene alkylation. (c) 2007 Elsevier B.V. All rights reserved