Dolomite is used as a gasification catalyst and a desulfurization material of vacuum residue at the same temperature. Calcium sulfide was regenerated to calcium oxide for subsequent re-use of sulfided dolomite. High temperature regeneration with air was accomplished in a fluidized bed of sulfided dolomite. As a result higher temperature, higher gas velocity and lower O2 concentration increased CaO regeneration on the experi-mental conditions. However, the CaO regeneration was lower than 56%, and decreased with decreasing the initial sulfided level of dolomite. In the CaS-CaSO4 reaction CaO regenera-tion attained 90% at temperatures above 950°C. Sulfided dolomite was regenerated more easily than sulfided limestone.
