The origin of aliphatic hydrocarbons in brown coal liquefaction - Reactions of a model acid, alcohol and ester

A model long-chain alcohol (n-C-22), carboxylic acid (n-C-20) and ester (n-C-20 + n-C-22) have been reacted under coal liquefaction conditions at 320 and 405 degrees C with both hydrogen and carbon monoxide-water as reducing systems. The products of these reactions were characterized by g.c., g.c.-m.s. and mass spectroscopy. In addition to materials with the same carbon number as the starring compounds, lower-molecular-weight materials arising from fragmentation and higher-molecular-weight compounds arising from radical recombination reactions were detected. Reactions with CO-H2O gave different product distributions from reactions with H-2-SnO2 and H-2-tetralin, and these differences have been correlated with differences observed in reactions of low-rank coals. Reactions of eicosanoic (C-20) acid with hydrogen at temperatures from 320 to 415 degrees C showed an unexpected formation of the ester CH3(CH2)(18)CO2(CH2)(19)CH3, especially for H-2-SnO2 reactions at 365 degrees C. Copyright (C) 1996 Elsevier Science Ltd.