Patent ID: 7625480

Claim:
A process comprising: (a) mixing a feed stream comprising an asphaltene-containing crude oil or condensate, or fraction thereof, with a final boiling point-increasing high boiling hydrocarbon containing low-to-nil asphaltenes which provide the high boiling hydrocarbon with a CCR as high as 0.05 wt %, to obtain a hydrocarbon mixture; (b) cracking said hydrocarbon mixture in a pyrolysis furnace comprising a convection section comprising high pressure superheater exchanger tubes located between an upper convection section tube bank directly communicating with a lower convection section tube bank, and a radiant section; (c) recovering a cracked effluent from said pyrolysis furnace; and (d) decoking said convection section using an air/steam decoking mixture without shutting down the pyrolysis furnace; wherein the high boiling hydrocarbon is mixed with the feed stream in an amount sufficient to lower to the lower convection section tube bank, the location at which foulant deposits form in the convection section of the pyrolysis furnace and/or cause foulant deposits to form at higher temperatures in the convection section of the pyrolysis furnace, as compared to the feed stream alone.