FIELD: technological processes.
SUBSTANCE: invention relates to a method for liquefying biomass. Method of direct liquefaction of biomass includes stages of: (1) mixing biomass, hydrogenation catalyst and hydrogen donor solvent to prepare biomass suspension, stage (1) includes the following steps: (a) the biomass is dried to obtain dried biomass, which is crushed to obtain crushed material; (b) ground material is mixed with a hydrogenation catalyst to form a mixture; and (c) the mixture is mixed with a hydrogen donor solvent to prepare a suspension of biomass; (2) performing first liquefaction reaction with a suspension of biomass and gaseous hydrogen to obtain the first reaction product; (3) second liquefaction reaction is performed with the first reaction product and hydrogen gas to obtain a second reaction product; (4) second reaction product is subjected to the first separation into gas and liquid at a temperature of 290–460 °C to obtain the first liquid phase and the first gas phase; (5) first gas phase is subjected to a second separation into gas and liquid at a temperature of 30–60 °C to obtain the second liquid phase and mix the first liquid phase with the second liquid phase to obtain a mixture of the liquid phase; (6) first distillation of the mixture of the liquid phase is performed to obtain a light fraction and a heavy fraction; (7) second distillation of the heavy fraction is performed to separate the distillate oil and residue, with the light fraction and the distillate oil being the final liquefaction liquid; method further includes the steps in which carry out the reaction of hydrogenation of the final liquid to obtain a hydrogenation product, which is subjected to fractionation to obtain a light oil and heavy oil; heavy oil is returned to step (1) for use as a hydrogen donor solvent, and the hydrogenation reaction is carried out under the following conditions: the reaction temperature is 300–430 °C; reaction pressure is 13–25 MPa; gas-to-liquid ratio is 800–1,500 nl/kg; volume flow is 0.5–2 hours-1; and fractionation is carried out at a temperature of 280–390 °C.
EFFECT: when using the method of direct liquefaction of biomass, a high yield of products and a low content of solid residue are obtained.
7 cl, 2 dwg
