Fundamentals of Petroleum Residue Cracking Gasification for Coproduction of Oil and Syngas

Abstract

Vacuum residue (VR) was stepwise converted via catalytic cracking for liquid and coke gasification for hydrogen-rich syngas in a fluidized bed reactor. Silica sand and spent equilibrium FCC (E-FCC) catalyst were used as the catalysts for VR cracking. The liquid yield was about 89 wt % at 568 °C using silica sand as catalyst and the conversion ratio of heavy fractions was only 55%. About 60 wt % VR was converted into gas and coke over the E-FCC catalyst at 480 °C, showing that the catalyst had too strong acidity for VR cracking. The E-FCC catalyst was thus modified (aged) with both hydrothermal treatment and impregnation of alkali and alkaline-earth metals (K and Mg) to weaken its acidity and facilitate the liquid oil production. The aged FCC (A-FCC) catalyst exhibited appropriate cracking activity to allow both the expected liquid yield of about 80 wt % and heavy fraction conversion ratio of up to 98 wt %. Steam gasification of the deposited coke on the surface of the A-FCC catalyst resulted in the production of syngas containing CO and H 2 content to be about 45 and 42 vol %, respectively.