Fixed sulfur petroleum coke fuel and method for its production
AssigneeMobil Oil Corporation
InventorsNai Y. Chen, Dennis E. Walsh
Life of this patent
Estimating the term…
Abstract
A fixed-sulfur, solid fuel product is obtained by an improved coking process wherein petroleum fractions are coked in the presence of added alkaline earth metal oxides. The fixed-sulfur, solid fuel product comprises coke and from about 3 to 30 weight percent, preferably from about 5 to 15 weight percent, "ash" (calculated as calcium oxide) derived from the alkaline earth additive. The quantity alkaline earth metal oxide or precursor thereof added to the coking zone is dependent on the sulfur content of the product coke and on the desired ash content of the solid fuel product. The coking zone may comprise delayed, fluid bed, or moving bed cokers.
Claims17
A process of producing a fixed-sulfur petroleum coke fuel which comprises coking a heavy petroleum coker feedstock in the presence of an added alkaline earth metal oxide or precursor thereof, the amount of added alkaline earth metal oxide being within the range from about 1 to 10 times the amount theoretically necessary to completely fix the sulfur contained in the coke produced from the petroleum coker feedstock, and recovering coker products including a fixed-sulfur petroleum coke fuel byproduct comprising coke and about 3 to 30 weight percent ash (calculated as calcium oxide) derived from the alkaline earth additive.
In a continuous process of coking a heavy petroleum coker feedstock wherein at least a portion of the coke produced in the coking zone is burned to raise its temperature above the coking zone temperature and is then recycled to the coking zone to provide heat for the coking reactions, the improvement which comprises:
- a. coking the heavy petroleum coker feedstock in the presence of an added alkaline earth metal oxide or precursor thereof, the amount of added alkaline earth metal oxide being within the range of about 1 to 10 times the stoichiometric amount necessary to completely fix the sulfur contained in the coke produced from the petroleum coker feedstock;
- b. recovering normally liquid and gaseous hydrocarbons and solid particles comprising coke and about 3 to 30 weight percent ash (calculated as calcium oxide) derived from the alkaline earth additive from the coking zone;
- c. partially combusting at least a portion of said particles to raise the temperature thereof above the coking zone temperature, the heated solid particles comprising coke and about 4 to 40 weight percent ash (calculated as calcium oxide) derived from the alkaline earth additive from the coking zone;
- and returning said heated solids to the coking zone;
- and
- d. recovering the remaining solid particles as a fixed-sulfur petroleum coke fuel byproduct.
Dependencies are inferred from the claim text.