COAL LIQUEFACTION PRODUCTS UNDER MECHANO-CHEMICAL ACTION

摘要

The effects of mechano-chemical action in the liquefaction of coal have been investigated in the present study. The planetary Szego Mill was adapted as a grinder-reactor to operate at temperatures up to 673K and hydrogen pressures up to 20 MPa. The mill fits a modified 2-liter autoclave. Bituminous Devco coal from Nova Scotia, tetralin and hydrogen are used. Mechano-chemical action enhances the total conversion of Devco coal to tetrahydrofuran solubles over the temperature range of 613K to 653K and pressures of ～13.8 MPa. Gas evolution upon grinding is likely a kinetically induced phenomenon. It is believed that over ～50% of the initial sulphur in Devco coal is converted to H_2S, and about 30% of the initial oxygen in Forestburg coal is converted to CO_2 and CO. The H_2S produced vanishes from the gas phase as the reaction proceeds. Increased production of preasphaltenes, C1-C4 hydrocarbons and olefins and gases are obtained as a result of mechano-chemical action, probably due to the build-up of free radicals prior to and during the softening of the coal particles, and chemical decomposition after the scission of linkages between clusters in the coal.