Development of High-performance Coal Gasification Technology for High Ash Fusion Coals : Study on Determination Method of Flux Adding Rate and Coal Blending Ratio

Coal gasification performances of the entrained-flow coal gasifiers tend to be the lower for coal with higher ash fusion temperature because of higher air ratio required to elevate the combustor gas temperature in order to get the stable slag discharging state. Addition of flux and blending of coals with different characters, known effective to reduce the ash fusion temperature, have been investigated with a gasification test fasility (2t/d Process Development Unit) to confirm them in actual gasifiers. This paper reports the proposition of a correlation to predict the ash fluid temperature on the ash acid rate and presents a procedure to decide the suitable rate of flux addition and coal blending. This report also presents the proper selection guidelines of these methods based on the difference in the effects on gasification performance improvements when these methods are applied.