Patent ID: 7544852
Filing Date: 2009-06-09
Classification: C10G

Abstract:
1. A process for cracking a heavy hydrocarbon feedstock in a furnace having a convection section and a radiant section, said radiant section having radiant section burners which provide hot flue gas in said furnace, said furnace further having draft, said process comprising: (a) heating said heavy hydrocarbon feedstock to form a preheated heavy hydrocarbon feedstock; (b) mixing said preheated heavy hydrocarbon feedstock with a fluid stream and a primary dilution steam stream to form a mixture stream; (c) heating said mixture stream in said convection section of said furnace to form a hot mixture stream, said hot mixture stream having a vapor phase and a liquid phase; (d) separating said vapor phase and said liquid phase of said hot mixture stream; (e) cracking said vapor phase in said radiant section of said furnace to produce an effluent containing olefins; and (f) periodically controlling the temperature of at least one of said hot mixture stream and said vapor phase by adjusting the draft in said furnace and at least one of the flow rate of said fluid stream and the flow rate of said primary dilution steam stream.