1993 Volume 72 Issue 8 Pages 778-786
Gas evolution from coal heated at a fairly low temperature in the presence of SeO2 and liquefaction behavior of the treated coal were examined for different coals. During atmospheric pyrolysis of coal with SeO2, gas evolution was observed at extremely low temqeratures below 473 K. The gas was shown to consist of CO, CO2 and H2O. Combined with the gas evolution characteristics with gas composition from various aromatic model compounds, those gases were supposed to be originated mostly from carboxyl and methyl groups in coal and oxygen from SeO2. The solid residue after the pyrolysis was liquefied using a sufficient amount of tetralin as a solvent under 10MPa of nitrogen at 723K. The results clearly showed that the SeO2-treated coals give higher yields of pyridineand benzenesolubles than their parent coal due to improved coal reactivity and catalytic effects of SeO2 and/or Se formed during pyrolysis.