Catalytic Fluidized-Bed Co-Combustion of Peat and Anthracite

Abstract

Results of the studies of catalytic combustion of peat, anthracite, as well as the mixture at the peat to anthracite weight percent ratio 40/60 are discussed. The degree of the mixture burning-off was shown to increase when peat evolving large quantity of volatile substances is added to anthracite. The burn-up degrees of the solid fuel particles less than 1.25 mm in size were 98.2 % of peat, 50.9 % of anthracite, 74.2 % of the peat and anthracite mixture at 700–750 °C and 1 m height bed of the industrial aluminum-copper-chromium oxide catalyst IC-12-70. In combusting coarse particles (equivalent diameter 11.6–18.6 mm) of molded peat and anthracite mixture, the burn-up degree was 80.5 % at the top of the fluidized catalyst bed. The burn-up degree of the coarse particles fed to the bottom of the fluidized bed was estimated with allowance for the burn-up degree of fine particles moving through the bed. With the coarse molded particles of the peat and anthracite mixture fed to 1 m height catalyst bed, the burn-up degree was shown to reach no less than 95 %. When the catalyst used is 2 mm in size, the peat and anthracite particles comprised in the molded fuel must be no more than 1–1.5 mm in size in order to prevent from ash accumulation in the fluidized catalyst bed.