Alkylation of isobutane with butenes under microcatalytic conditions in pulse mode

Abstract

Alkylation of isobutane with butenes is one of few important petrochemical processes that is still implemented using liquid acids. New highly active solid alkylation catalysts are investigated for century. The development of new rapid methods for testing catalysts will contribute to progress in this area. Therefore, the aim of the work was to test the possibility of conducting a bimolecular reaction of alkylation of isobutane with butenes in a microreactor in a pulsed mode of feeding. A zeolite-containing alkylation catalyst was synthesized and characterized by X-ray diffraction analysis, temperature-programmed desorption of ammonia and low-temperature nitrogen adsorption. Catalytic studies were performed in a microreactor built into the gas chromatograph scheme, which provided online analysis of the reaction products. The isobutane /butenes mixture was fed into the helium carrier gas stream via a loop. Testing was performed at 80, 100, 135 and 1850C. It was found that a significant amount of products is not desorbed by the carrier gas and is retained by the catalyst at reaction temperatures, while an increase in desorption temperature to 3800C promotes removing the products from the catalyst surface. The highest yield of products was 27% at 800C. With increasing the reaction temperature, the yield drops to 15%. It was shown that the developed method of testing of alkylation catalysts is promising for further use in the search for efficient solid-phase alkylation catalysts.