The invention provides a method for preparing clean diesel oil by mixing and gasifying cellulosic
biomass and pulverized
coal. The method comprises the following steps: carbonizing
cellulose biomass to obtain
biomass coal, mixing the biomass
coal with pulverized coal, feeding the mixture into a gasification furnace, introducing
water vapor and
oxygen for gasification to obtain raw gas, and then sequentially carrying out conversion, purification, Fischer-Tropsch reaction, intermediate
fractionation, hydrorefining, hydrocracking and product
fractionation to obtain the clean diesel oil. By combining the characteristics that biomass pulverized coal is rich in
hydrogen and less in carbon and the pulverized coal is rich in carbon and less in
hydrogen, biomass and pulverized coal are mixed, and a clean diesel oil product with a relatively low
condensation point is prepared through indirect
coal liquefaction; the co-gasification of the cellulosic biomass and the pulverized coal overcomes the defects of independent gasification, complementary advantages can be realized after the cellulosic biomass and the pulverized coal are mixed, the
energy consumption of pulverized
coal gasification and shift reaction is reduced, the cost is saved, a clean diesel oil product with a lower
condensation point can be prepared through the Fischer-Tropsch synthesis reaction, and the preparation ways and methods of the clean diesel oil are increased. And the dependence on fossil energy can be reduced.