摘要 |
An improved delayed coking process utilizing a coking unit and a coking unit product fractionating column which includes the steps of: heating a mixture of a fresh whole crude oil feedstream and the bottoms from the coking unit product fractionator in a furnace to a coking temperature in the range of 480° C. to 530° C./896° F. to 986° F.; introducing the heated mixed whole crude oil and bottoms feedstream directly into the delayed coking unit; optionally passing the vaporized liquid and gaseous coking unit product stream into a flash unit; recovering a light product gas stream that includes H2S, NH3 and C1 to C4 hydrocarbons from the flash unit; transferring the bottoms from the flash unit to the coking unit product fractionating column; recovering as separate side streams from the fractionating column naphtha, light gas oil and heavy gas oil; recycling a portion of the heavy gas oil by introducing it into the fractionating column optionally with the bottoms from the flash unit; mixing the fractionating column bottoms with the whole crude oil feedstream to form the mixed feedstream; and introducing the mixed whole crude oil and fractionating column bottoms feedstream into the furnace.
|