Solvent refined coal process with retention of coal minerals

Claim 1

A PROCESS FOR PREPARING DEASHED SOLID AND LIQUID HYDROCARBONACEOUS FUEL FROM HYDROCARBONACEOUS FEED COAL CONTAINING ASH COMPRISING CONTACTING THE FEED COAL WITH HYDROGN AND A SOLVENT FOR THE HYDROCARBONACEOUS MATERIAL IN THE COAL TO FORM A COAL-SOLVENT SLURRY IN CONTACT WITH HYDROGEN, PASSING THE SLURRY AND HYDROGEN THROUGH A PREHEATER FOR A RESIDENCE TIME BETWEEN 0.01 AND 0.25 HOURS, SAID PREHEATER HAVING A LENNGTH TO DIAMETER RATIO OF AT LEAST 100 TO INHIBIT BACKMIXING SO THAT AN INCREMENT OF SAID SLURRY GRADUALLY INCREASES IN TEMPERATURE IN PASSAGE THROUGH THE PREHEATER FROM A LOW INLET TEMPERATURE TO A MAXIMIUM TEMPERATURE AT THE PREHEATER OUTLET, THE MAXIMUM TEMPERATURE AT THE PREHEATER OUTLET BEING 400* TO 525*C., THE VISCOSITY OF AN INCREMENT OF THE SLURRY IN PASSAGE THROUGH THE PREHEATER INCREASING INITIALLY TO A VALUE AT LEAST 20 TIMES THE VISOSITY OF THE SOLVENT ALONE WHEN EACH IS MEASURED AT A TEMPERATURE OF 99*C., THE VISCOSITY OF THE SLURRY WHEN MEASURED AT 99*C. IN CONTINUED PASSAGE TO A VALUE LOWER THAN 10 TIMES THE VISCOSITY OF THE SOLVENT ALONE WHEN EACH IS MEASURED AT 99*C. IN CONTINUED PASSAGE THROUGH THE PREHEATER, THE VISCOSITY OF SAID SLURRY FINALLY TENDING TO INCREASE TO A VALUE GREATER THAN 10 TIMES THAT OF THE SOLVENT ALONE WHEN EACH IS MEASURED AT 99*C. AT THE EXIT TEMPERATURE OF SAID PREHEATER BUT THE SLURRY AND HYDROGEN BEING REMOVED FROM SAID PREHEATER AFTER THE RELATIVE VISCOSITY DROPS TO A VALUE BELOW 10 BUT BEFORE THE RELATIVE VISCOSITY FINALLY INCREASES TO A VALUE OF 10, PASSING THE SLURRY TO A DISSOLVER MAINTAINED AT A TEMPERATURE BETWEEN 350* AND 475*F. AND WHICH IS BELOW THE TEMPERATURE AT THE OUTLET OF THE PREHEATER, THE RESIDENCE TIME OF THE SLURRY IN THE DISSOLVER BEING GREATER THAN IN THE PREHEATER, SELECTIVELY RETAINING IN THE DISSOLVER A PORTION OF THE ASH REMOVED FROM THE COAL RELATIVE TO FLOW OF FUEL THROUGH THE DISSOLVER, REMOVING DISSOLVER EFFLUENT AND SEPARATING SAID EFFLUENT INTO A GASEOUS STREAM, A FRACTION WHICH IS LIQUID AT ROOM TEMPERATURE AND A DEASHED FRACTION WHICH IS SOLID AT ROOM TEMPERATURE, RECYCLING HYDROGEN CONTAINED IN SAID GASEOUS STREAM TO THE PREHEATER, AND RECYCLING AT LEAST A PORTION OF SAID LIQUID AND/OR SOLID FRACTION AS SOLVENT FOR SAID PREHEATER STEP.