Co-liquefaction of coal and cellulose in supercritical water

Co-liquefaction of biomass and coal in supercritical water is proposed with the intention that hydrogen matching between biomass and coal takes place, resulting in enhanced coal liquefaction and preferable liquefaction produc ts. A semi-batch packed-bed reactor is employed to co-liquefy cellulose uti lized for a model compound of biomass and Ishikari coal in supercritical wa ter at 673 K and 25 MPa. No interaction between coal and cellulose is obser ved for the production of residue and water insoluble product, judging from the yield and its composition. On the contrary, the yield of the water-sol uble product increased for the case of co-liquefaction. Both hydrogen to ca rbon ratio and oxygen to carbon ratio of the water-soluble product increase d by co-liquefaction. The mechanism for this interaction is proposed based on the addition reaction of compounds derived from cellulose with coal-deri ved compounds to increase the recoverable yield of the water-soluble produc t. (C) 1999 Elsevier Science Ltd. All rights reserved.