Production of Alkylate Gasoline Using Methanesulfonic Acid as a Green Catalyst in the Presence of Real Refinery Hydrocarbon Mixtures

Abstract

The application of methanesulfonic acid (MSA) as a green catalyst for the production of alkylate gasoline was successfully attained in the liquid (batch pressure reactor) and gas phase (1 atm, glass reactor, with MSA supported on silica gel) using real refinery hydrocarbon mixtures containing isobutane and butenes. The product quality was monitored by gas and liquid chromatography, yielding octane (C8s) selectivity of up to 92% in the gas phase and 70% in the liquid phase. The reaction temperature and catalyst/hydrocarbon mass ratio were the most influential reaction parameters affecting the conversion and selectivity. The addition of a liquid co-catalyst to MSA negatively affects the quality of the alkylate product, as well as the conversion of butenes. The presence of the silica support, in the gas phase at continuous regime alkylations, allowed us to obtain alkylate gasoline with sustained high conversions and selectivity to C8s at a quality similar or even higher to that obtained with sulfuric acid as the commercial catalyst. Characterization of the supported MSA reveals strong dipole–dipole interactions, revealed through the protonation of the surface –OH groups.