COMPARISON OF THE GASIFICATION BEHAVIOR OF A WEST AND EAST-GERMAN BROWN-COAL

Some experimental work has been carried out in a pressurized thermobal ance to investigate the gasification behaviour of two German brown coa ls, one stemming from the eastern part of Germany and the other one fr om the Rhine region. In order to determine their kinetics with regard to fluidized bed conditions the gasification has been investigated in the temperature range of 1073 up to 1123 K and in the pressure range o f 1 up to 20 bar. Pure steam and carbon dioxide as well as mixtures of steam and hydrogen and of carbon dioxide and carbon monoxide have bee n used as gasifying agents. Analyses of the mineral matter of both bro wn coals reveal considerable amounts of Calcium which is known for bei ng a strong catalyst in coal gasification as far as it is finely dispe rsed. Pressure dependent reactions of Calcium compounds leading to the ir catalytic deactivation are assumed to influence the gasification be haviour and hence to cause the decrease of the gasification rate with increasing burn-off.