Features of sulfur oils catalytic combustion in fluidized bed

Environmentally safe fuel combustion is an actual worldwide problem. The alternative technology of catalytic fuel combustion in fluidized bed of catalyst was developed in the Institute of Catalysis SB RAS. The technology allows one to conduct the process at 300-700 °C 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 catalytic combustion in the fluidized bed of the Al-Cu-Cr-oxidic catalyst. It was shown that reduction of SO2 emission below the levels set by environmental regulations at conserving oxidation degree of oils within range of 99.5-99.8% may be reached by using a non-isothermal temperature profile in the reactor as well as a use of calcium carbonate or oxide 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 catalyst bed of 700 °C and a catalytic oxidation of SO2 to SO3 zone with equilibrium shift to reducing SO2 concentration because of the temperature change from 700 °C to 585 °C. The outlet NOx concentration at the catalytic combustion of the oils also corresponded to the levels set by environmental regulations.