Comparison of Pyrolysis Products between Coal, Coal/CaO, and Coal/Ca(OH)_2 Materials

摘要

Products from coal, coal/CaO, and coal/Ca(OH)_2 pyrolysis under various pressures were examined and compared experimentally. A high-pressure flow-type reactor with a rapid cooling system was used for the pyrolysis experiment, and it was found that the amount of gas products increased in response to CaO and Ca(OH)_2 addition. The total volume of gas product from pyrolysis was in the order of coal/Ca(OH)_2 > coal/CaO > coal at extremely high pressure. H_2 products in coal/CaO and coal/Ca(OH)_2 pyrolysis peaked in the temperature range of 923―973 K. At this H_2 peak temperature, the H_2 content in product gas was approximately 80%, while there were little CO, CO_2, and CH_4. One reason for this is that the H_2O contained in coal can be brought to a higher temperature by the reactions of Ca(OH)_2 formation and decomposition. H_2O reacted with coal at high temperature, producing H_2 and CO. It was also found that CO can shift to CO_2, and that CO_2 can be fixed by CaO to CaCO_3 in the temperature range of the H_2 peak.