Abstract: A process for directly liquefying coal in a reactor including a preheating section and a reaction section, each having a plurality of pressure-resistant vertical pipes, comprises introducing into the preheating section a paste consisting of finely divided coal, catalyst and heavy oil. In the preheating section the paste is heated to a temperature of 380.degree. to 410.degree. C. and preheated hydrogen is blown into each pipe to create a velocity of Reynolds number equal to at least 3.times.10.sup.3 and an axial dispersion coefficient of not more than 0.05. The preheated paste and hydrogen are forwarded to the reaction section where they are heated to a temperature of 400.degree. to 500.degree. C. and further hydrogen is introduced into each pipe of the reaction section to maintain the velocity and axial dispersion values and a high partial pressure of hydrogen. The total quantity of hydrogen introduced is 1 to 3 times the stoichiometric value.

Abstract: An apparatus for effectively making the supply of material slurry at a high pressure into a high-pressure liquefaction reaction vessel and relief of the pressure of the high-pressure product slurry to permit the discharge of the product slurry as a low-pressure slurry. At least one cylinder having a float therein is used. The material slurry is charged at a low pressure into the cylinder from one end of the latter. Then, the high-pressure product slurry after the reaction is charged from the other end of this cylinder or another cylinder so that the material slurry is pressurized and forcibly supplied to the reaction vessel by the high pressure possessed by the high-pressure product slurry.

Abstract: In a process for directly liquefying coal, a paste consisting of finely divided coal, catalyst and heavy oil can be treated for thermal cracking and hydrocracking with a high liquid/space ratio and short residence time in a preheating section and a reaction section. An apparatus threfor comprises a plural number of pipe units having apertures for hydrogen injection and apertures for the paste of a low concentration or heavy oil injection and a gas-liquid separator for removing H.sub.2 O, methane, etc., the pipe units being formed in such a manner that a Reynolds number of 3.times.10.sup.3 or greater and an axial dispersion coefficient of 0.05 or smaller are achieved for the fluid flow therein.