Catalytic combustion of sulfur-containing liquid fuels in the fluidized bed: Experiment and modeling

Abstract

Environmentally safe fuel combustion is an actual worldwide problem. The alternative technology of combustion in fluidized bed of catalyst was developed in the Boreskov Institute of Catalysis. The technology allows one to conduct the process at 400–700 оC and significantly reduce outlet concentrations of toxic compounds. However, the use of sulfur oils as fuel demands solving a problem of the decreasing the outlet SO2 concentration because the oils contain small amount of ash to absorb SO2. The work is devoted to study features of sulfur light oil and high-sulfur heavy oil combustion in the fluidized bed of the Al–Cu–Cr-oxide catalyst. Reduction of SO2 emission at conserving oxidation degree of oils within range of 99.5–99.8% might be reached by using a non-isothermal temperature profile in the reactor as well as a use of CaCO3 or CaO at Ca/S > 2 to absorb sulfur oxides. The non-isothermal temperature profile in the reactor consisted of an oxidation zone with the temperature in the fluidized bed of 700 оC and a catalytic oxidation of SO2 to SO3 zone with equilibrium shift to reducing SO2 concentration because of the temperature change from 700 оC to 585 оC.