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New pretreatment methods were developed for separating hemicellulose, cellulose, and lignin from biomass for their efficient use in the thermo-chemical conversion of each component. One method is basically a two-step process. Biomass treated in hot water at 180 °C was extracted in a flowing stream of water/acetone mixture under 10 MPa at 230 °C. Through the hot water treatment, hemicellulose in biomass was successfully recovered as saccharides, leaving lignin and cellulose as a solid. Through the sequential extraction by the water/acetone solvent, lignin was depolymerized into the water/acetone-soluble compounds and the residual cellulose was partly dehydrated. The other method is a one-step process, in which biomass was directly extracted in 50% water/acetone solution at 200 °C using a batch reactor, and the residue was pure cellulose. The proposed methods were expected to be new routes for converting low-grade resources into valuable chemicals.

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The liquefaction of Wyoming coal (subbituminous coal) was investigated with an autoclave of 50 mL capacity, using Ketjen Black (KB)-supported NiMo catalyst, which has higher hydrogenation activity of 1-methylnaphtalene than a commercial NiMo/Al2O3. KB-supported NiMo catalyst gave the oil and oil plus asphaltene yield of 54 and 69% under reaction conditions of 440 °C, 60 min, and 13 MPa. These yields were much higher than those of a commercial NiMo/Al2O3 and synthesized FeS2 catalysts. The KB-supported NiMo catalyst was found to be recovered from the solid products using polar solvents such as THF because it is highly dispersed in liquid products due to its low specific gravity and the hydrophobic property of its surface. It was also found that KB-supported NiMo catalyst suffered the least deactivation by coke formation and mineral matter deposition because the recovered catalyst as THFI residue appeared to regenerate the activity to a level similar to the fresh catalyst.