Behavior of chlorine compound with combustion of RDF in fluidized bed

The combustion process in a fluidized bed has been recognized as a promisin g combustion processes for Refuse Derived Fuel (RDF). To explain the behavi or of chlorine compound during the combustion of RDF in the fluidized bed p rocess, two kinds of RDF were burnt in a 0.3x0.3 m bubbling-type fluidized bed combustor. One was model RDF produced from raw materials with controlle d combination ratios, simulating the RDF produced from municipal solid wast e (MSW), and the other was commercial RDF produced from MSW. Combustion tes t were carried out for a extended period under steady state conditions. The hydrogen chloride (HCl) concentration in the flue gas was measured on vari ous points in the process and the total weight of solid in the bed, from th e cyclone, from the gas cooler and from the bag filter was measured after e ach test run. Material balances of silica sand, ash, and chlorine were calc ulated. It was found that the material balance between feed rate and outflo w rate of chlorine compound agreesd within 10%. For the model RDF, 80% of f ed chlorine was removed by solid components during RDF combustion in the be d and only 4.1% chlorine was discharged with the flue gas in the combustor exit. The chlorine captured by calcium remaining in the bed was 46.7% and t he rest was captured by the particles entrained from the bed. For the RDF f rom MSW, 50% chlorine was removed by solid components in the bed and 21.9% chlorine was discharged with flue gas from the bed. 27.7% of the chlorine c aptured by calcium compound remained in the bed and the rest was entrained from the bed. Although potassium and sodium contained in the sand and in th e RDF are assumed to completely react with chlorine, more than 80% of chlor ine for the case of model RDF and more than 50% of chlorine for RDF from MS W are captured as CaCl2.