THERMAL DISSOLUTION CATALYSIS METHOD FOR PREPARING LIQUID FUEL FROM LIGNITE AND THE CATALYST AND THE SOLVENT SUITABLE FOR THE METHOD

摘要

The present invention relates to coal chemical processing, and particularly to a thermal dissolution catalysis method for preparing liquid fuel from lignite. The method comprises steps of: 1) crushing and drying lignite into coal powder; 2) stirring and mixing coal powder, a solvent and a catalyst sufficiently to form coal slurry, wherein there are 30-40% mass of coal powder, 60-70% mass of solvent, and 0.5-1% mass of catalyst relative to coal powder mass; 3) subjecting the coal slurry to thermal dissolution catalysis reaction to obtain thermal dissolution liquefied product, wherein the reaction is carried out for 30-60 minutes at a temperature 390-450° C. under a pressure 5.0-9.0 MPa; 4) separating the thermal dissolution liquefied product into gas, liquid and solid phases; and 5) upgrading the liquid product into liquid fuel. The present invention further discloses a catalyst and a solvent for use in the above method. The method according to the present invention requires moderate operation conditions and can enable organic matter in the lignite to convert at a relatively high level, the liquid fuel product, after being processed, can be used to prepare engine fuel meeting a national standard; the method requires a simple preparation apparatus, a small investment and a low cost and is a coal liquefying method meeting China's status quo.