Liquefaction behavior and chemical structure of Alberta coal, Canada have been evaluated by semicritical gas extraction and conventional autoclave experiment. The effects of catalyst (ZnCl2, SnCl2·2H2O) and solvent (toluene, CH3OH, C2H5OH, C3H7OH) on the gas extraction have been observed using a small high pressure flow apparatus near critical conditions with or without hydrogen. Conversion to gas and liquid increased strikingly in the presence of hydrogen up to 43wt% and the weight ratio of liquid to gaseous product also increased with the addition of catalyst and solvent.
Autoclave experiments were carried out in a 300ml conventional autoclave equipped with a stirring device at 420°C under 51Kg/cm2⋅G of hydrogen in the presence of 5 parts of tetralin. Conversion calculated on the basis of tetralin insoluble were observed up to 85wt%.
The structural parameters of the extracts obtained from both types of reactions were evaluated by the modified Brown-Ladner's equation. From average fa of 0.6 and Hau/Ca of 0.9, an average unit cluster has been estimated to be the mixture of one or two aromatic rings which are joined together with some saturate groups.