Retorting and coking of bituminous solids

Claim 1

IN A PROCESS FOR RECOVERING LIQUID HYDROCARBONS FROM PARTICULATE-FORM BITUMINOUS SOLIDS, WHICH COMPRISES PASSING A MOVING BED OF SAID SOLIDS THROUGH A RETORTING ZONE, RETORTING SAID SOLIDS IN SAID RETORTING ZONE IN COUNTERCURRENT CONTACT WITH A HEATED COMBUSTION GASEOUS RETORTING MEDIUM, WITHDRAWING FROM SAID RETORTING ZONE HYDROCARBONS RETORTED FROM SAID SOLIDS, SEPARATING THE WITHDRAWN HYDROCARBONS RETORTED FROM SAID SOLIDS TO RECOVER COMBUSTIBLE PRODUCT GASES AND A LIQUID HYDROCARBON PRODUCT, AND RECYCLING AT LEAST A PORTION OF THE RECOVERED COMBUSTIBLE PRODUCT GASES TO A LOWER PORTION OF SAID RETORTING ZONE FOR COMBUSTION THEREIN, THE IMPROVEMENT WHICH COMPRISES PREHEATING A HEAVY PORTION OF SAID LIQUID HYDROCARBON PRODUCT TO A TEMPERATURE IN THE RANGE OF ABOUT 600* TO 900* F., FURTHER DECOMPOSING SAID PREHEATED HEAVY PORTION TO PRODUCE THEREFROM LIGHTER LIQUID AND GASEOUS PRODUCTS AND COKE BY RETURNING TO SAID BED AND DISTRIBUTING SAID PREHEATED HEAVY PORTION IN A DISTRIBUTION ZONE IN SAID BED OVER MOVING PARTICLES OF SAID BITUMINOUS SOLIDS PRIOR TO PASSAGE OF SAID SOLIDS THROUGH SAID RETORTING ZONE, MAINTAINING SAID PARTICLES OF BITUMINOUS SOLIDS PASSING THROUGH SAID DISTRIBUTION ZONE AT A TEMPERATURE OF AT LEAST 900* F., MAINTAINING IN SAID DISTRIBUTION ZONE A RATIO OF AT LEAST SEVEN POUNDS OF BITUMINOUS SOLIDS PER POUND OF SAID PREHEATED HEAVY PORTION, AND WITHDRAWING FROM SAID RETORTING ZONE HYDROCARBON PRODUCTS OF DECOMPOSITION OF SAID PREHEATED HEAVY PORTION ALONG WITH SAID HYDROCARBONS RETORTED FROM SAID SOLIDS.