Effects of Mild Treatment on the Properties of the Char Product by the Flash Pyrolysis of Wandoan coal

Abstract

The effects of mild acid and/or tetralin treatments on the flash pyrolysis reactivity of Wandoan coal were investigated in order to improve the product distribution as well as to modify the properties of the char. The reactivity of Wandoan coal at 590°C for 5sec by Curie-point pyrolyzer was improved by hydrogen chloride or acetic acid aq./20 vol% alcohol pretreatment, the char yield being decreased with increased yields of gas and tar. Impregnation of tetralin also reduced the char yield to 63.5%. A combination of acid and tetralin pretreatments slightly reduced further the char yield.
The porosity (area) of the pyrolyzed char was influenced very much by the acid treatment. The macropores of which areas ranging from 205 to 411μm² were increased significantly by the acetic acid pretreatment. These results revealed that such acid pretreatments may enhance the gasification and the volatilization of tar fraction and improved the fusibility of coal to enlarge the porosity.