Alumina supported polymolybdate catalysts utilizing tert-butyl hydroperoxide oxidant for desulfurization of Malaysian diesel fuel

Abstract

The performance of oxidative desulfurization (ODS) of commercial diesel by alumina supported polymolybdate based catalyst system was studied using tert-butyl hydroperoxide (TBHP) as an oxidizing agent. From catalytic testing, MoO 3 -Al 2 O 3 calcined at 500 o C was the most potential catalyst which gave the highest sulfur removal under mild condition. The sulfur content in commercial diesel was successfully reduced from 440 ppmw to 105 ppmw followed by solvent extraction. Response surface methodology involving Box-Behnken was employed to evaluate and optimize MoO 3 /Al 2 O 3 preparation parameters (calcination temperatures, molybdenum loading precursor and catalyst loading), and their optimum values were found to be 510 o C, 0.98 g and 11.18 g/L of calcination temperature, molybdenum loading precursor and catalyst loading, respectively. Based on results, the reaction mechanism for oxidation of sulfur compounds to the corresponding sulfones occur in the presence of MoO 3 /Al 2 O 3 catalyst was proposed.

CeO2-TiO2 catalyst prepared by physical mixing for NH3 selective catalytic reduction: Evidence about the migration of sulfates from TiO2 to CeO2 via simple calcination

“…More stringent regulations on NO x emission have been implemented due to its harmfulness to environment and human health [1]. Selective catalytic reduction (SCR) of NO x with NH 3 is the main technology for the after-treatment of NO x emission from mobile or stationary source.…”