A study on co-gasification of high ash Indian coal with petcoke in a fluidized bed gasifier

An investigation has been undertaken to study the co-gasification of high ash sub bituminous Indian coal with petcoke in a bubbling Fluidized Bed Gasifier (FBG) system. The objective of this work is to study the effect of petcoke content in coal blend feed on gasification characteristics by carrying experiments in a pilot scale 1.2 T/d FBG (I.D. 0.2m X height 4.2m) system using air and steam as gasifying agents. The gasification characteristics include cold gas efficiency, carbon conversion, calorific value and composition of synthesis gas (syngas).Reactivity study carried in High Pressure Thermo Gravimetric Analyser (HPTGA) shows that coal blend reactivity decreases with increase in petcoke content in it. Gasification results indicate that increase in petcoke content in blend leads to decrease in carbon conversion and syngas calorific value which could be attributed to low reactivity of petcoke. A very low carbon conversion and syngas calorific value for petcoke gasification indicate that it may not be viable to gasify petcoke in FBG system.