Mesoporous HBeta zeolites application in the desulfurization of 2-methylthiophene

Abstract

The generation of mesoporosity in Beta zeolite through desilication promoted an increase in the formation of H2S in the transformation of 2-methylthiophene in an n-hexane stream. The desilication approach was studied using statistical analyses, through which it could be observed that, among the studied process variables (NaOH concentration, temperature, and time), concentration was the only variable significant to the mesoporosity generation response variable. Every catalyst subjected to alkaline treatment had an increase in mesopore volume. The thus generated mesoporosity improved 2-methylthiophene intracrystalline diffusion and this, consequently, enhanced the accessibility to the strong internal Bronsted acid sites. Therefore, the yield to H2S was increased from 35% on the precursor zeolite to 71% on the desilicated zeolite. The latter presented the greatest H2S formation. This result clearly demonstrates the potential mesoporous HBeta zeolites have. It shows they can be applied as additives in fluid catalytic cracking catalysts for sulfur reduction in fuel feedstocks.