Releasing characteristics of chlorine and alkali metals (K AND Na) in process of biomass combustion

Aiming at the issue of high content of Cl and alkali metals (K and Na) in the biomass, which causing serious corrosion of heating surface, the releasing characteristics of chlorine and alkali metals (K and Na) in the process of biomass combustion were studied. A muffle furnace was used to burn wheat straw, rice straw and other 4 kinds of biomass at temperature of 500-900℃. X-ray fluorescence spectrometry and X-ray diffraction were adopted to analyze the ashes. The results showed that only a little chlorine and kalium was released from biomass for burning at temperature of 500-600℃; andgreatamountsofchlorineandkaliumreleasedfrombiomassforburningattemperatureof 600-800℃, mostly as KCl; When the temperature was higher than 800℃, the release rate of chlorine and kalium in biomass was very slow except rape straw. And burning at temperature of 500-900℃, the content change of sodium in biomass ash was very small.