Effects of Experimental Conditions on the Conversion of Coal-N during the Gasification of a Victorian Brown Coal

摘要

The purpose of this study is to investigate the reaction mechanisms for the conversion of coal-N during gasification. A Victorian brown coal was gasified in O_2 and H_2O in a novel fluidised-bed/fixed-bed reactor. Our experimental results indicate that both hydrogen originally present in coal substrate and hydrogen introduced as an element in gasifying agent (e.g. H_2O) can play important roles in the formation of HCN and NH3. Gasifying agents such as O_2 and CO_2 not containing hydrogen can also change the way in which the hydrogen in coal is utilised to activate and hydrogenate the nitrogen in coal. Experimental conditions such as coal feeding rate and gas flow rate can affect the yields of NO_x precursors such as HCN and NH_3. These results indicate that the interaction between the volatiles and char can change the char structure and reactivity at least in terms of coal/char-N conversion.