Effect of Catalyst Form and Concentration on the Reactivityof Chars from a Victorian Brown Coal

摘要

A set of Victorian brown coal samples, containing sodium mainly in theform of NaCl, were pyrolysed in argon in a thermogravimetric analyser at900°C and the char reactivity was measured at 400 °C in air. It appearsthat there existed a loading saturation level of NaCl for the coal. Theadditional NaCl loaded into the coal, was almost all volatilised duringpyrolysis, resulting in little increase in the Na concentration in the char andtherefore little improvement of char reactivity. Both concentration andform/dispersion of Na in the char seemed to be important to the charreactivity. The specific reactivity of a char is determined by the stability ofchar structure, the concentration of catalysts and the form/dispersion of thecatalysts in the char.