Thermal studies of wood impregnated with ZnCl2

In this work the thermal behavior of wood impregnated with ZnCl2 is studied. Impregnation of wood with ZnCl2 is a treatment used in activated carbon production, and liquefaction and fast pyrolysis of biomass. Frequently, the impregnated wood is dried for several hours at temperatures above 370 K and then it is carbonized. Catalytic pyrolysis occurs, giving rise to a complex set of reactions. A TG/DTA study was done on the raw material, the activated carbon, the pure ZnCl2 and the intermediate products in order to study the mass and thermal changes occurring. Elemental analysis and SEM analysis were also carried out. An exothermic torrefaction develops during the drying step; the torrefied product is carbonized in an endothermic process that involves ZnCl2 volatilization. The washed impregnated wood carbonizes through an exothermic process that may involve the decomposition of cellulose, lignin and the solid product of hemicellulose torrefaction.