Solvent-refining of coal

A process of the SRC type for the production of socalled "solvent-refined coal" (SRC), which comprises heating coal whilst slurried in a solvent having hydrogen-carrier characteristics and in the presence of hydrogen at a partial pressure of several times atmospheric pressure under hydrogenation conditions to substantially liquefy the coal, followed by a step of separating non-dissolved solids from the solution which is formed as a result of said liquefying and comprising the feature that the liqueform product of said liquefying, prior to the step of separating non-dissolved solids is subjected to a step of postheating at a temperature higher than the temperature during said liquefying, the condition of temperature which determines the rate of free radical formation and the condition of hydrogen partial pressure which determines the rate of radical hydrogenation being controlled during said postheating so that the rate of free radical formation exceeds the rate of radical hydrogenation, so as to chemically combine or recombine constituents of the liquefied matter to result in an increase in particle size in the non-dissolved solids which facilitates the subsequent separation of solids from liquid.

A process of the SRC type for the production of so-called solvent-refined coal (SRC), which comprises heating coal whilst slurried in a solvent having hydrogen-carrier characteristics and in the presence of hydrogen at a partial pressure of several times atmospheric pressure under hydrogenation conditions to substantially liquefy the coal, followed by a step of separating non-dissolved solids from the solution which is formed as a result of said liquefying and comprising the steps of

• a. determining for a given set of process parameters, selected for effectively liquefying the coal, the relative yields of liquefied matter and non-dissolved solids,
• b. employing essentially the parameters referred to under (a) above, to manufacture said SRC, subject to the modification that during a stage after the coal has been converted into a slurry and before said step of separating, the application of heat to the slurry is so controlled in relationship to any hydrogen partial pressure at that stage that a small percentage of the relative yield of liquefied matter as determined under (a) is consumed in thermal conversion reactions taking place in lieu of hydrogenation reactions and which cause an increase of particle sizes in the non-dissolved solids, whereby the step of separating is facilitated.