Patent ID: 6652739
Filing Date: 2003-11-25
Classification: C10G

Abstract:
Process for deasphalting an asphalt-containing feedstock in a deasphalting process unit comprised of:(i) a heating zone wherein solids containing carbonaceous deposits are received from a stripping zone and heated in the presence of a heating gas which may contain oxygen for partial combustion purposes; (ii) a short vapor residence time reaction zone containing a horizontal moving bed of stirred hot solids recycled from the heating zone and feed, which reaction zone is operated at a temperature from about 450Â° C. to about 700Â° C. and operated under conditions such that the solids residence time and the vapor residence time are independently controlled, which vapor residence time is less than about 5 seconds, and which solids residence is from about 5 to about 60 seconds; and (iii) a stripping zone through which solids having carbonaceous deposits thereon are passed from the reaction zone and wherein lower boiling additional hydrocarbon and volatiles are recovered with a stripping gas; which process comprises: (a) feeding the asphalt-containing feedstock to the short vapor residence time reaction zone wherein it contacts the fluidized and/or stirred hot solids thereby resulting in high Conradson Carbon components and metal-containing components being deposited onto said hot solids, and a vaporized fraction; (b) separating the vaporized fraction from the solids; and (c) passing the solids to said stripping zone where they are contacted with a stripping gas, thereby removing volatile components therefrom; (d) passing the stripped solids to a heating zone where they are heated to an effective temperature that will maintain the operating temperature of the reaction zone; (e) recycling hot solids from the heating zone to the reaction zone where they are contacted with fresh feedstock; (f) passing the vaporized fraction from step (b) above to a soaker drum where it is quenched to produce a vapor fraction boiling less than about 450-600Â° C. and a high boiling fraction condensate having an initial boiling point in the range of about 450Â° C. to 600Â° C. (g) providing sufficient residence time and reactor severity in the soaker drum to permit molecular weight growth reactions to occur; (h) recycling said high boiling fraction to the short vapor residence time reaction zone; and (i) recovering the vapor fraction having a lower concentration of contaminants from step (h).