No.10 Tar Emission during Pyrolysis of Low Lank Coal Under Enhancement of Volatile-char Interaction

Abstract

A circulating fluidized bed (CFB) reactor was prepared to examine reduction of tar emission by utilizing volative-char interaction. A bubbling bed pyrolyzer was interconnected with a combustor in the CFB reactor. Two kinds of coal were independently fed to over bed (top feeding) or in-bed (bottom feeding) of the pyrolyzer. The volatiles (heavy tar, light tar, and gas) emitted from the pyrolyzer were quantitatively determined by several methods. The emission of heavy tar as well as light tar in case of bottom feeding was much lower than that of top feeding. Volatile-char interaction and thermal decomposition of tar in gas phase were important reactions for reduce the tar emission. Contribution of each reaction on the tar reduction was varied with reaction temperature.