GB569185A - Catalytic conversion of hydrocarbon oils - Google Patents

Abstract

<PICT:0569185/IV/1> In a process for the catalytic conversion of hydrocarbon oils into motor fuels of the kind in which higher boiling hydrocarbons are cracked in one reaction zone while lower boiling fractions are refined, reformed, polymerized in another reaction zone at substantially lower temperatures than those used for converting the higher boiling hydrocarbons, the contaminated catalysts from the reaction zones are mixed and passed to a common regenerating zone while part of the catalyst from the high temperature reaction zone is passed directly to the low temperature zone. The lower boiling fractions may be those obtained from the conversion of the high boiling oil or extraneous fractions introduced separately to the system. In operation, crude heavy oils are converted while flowing upwardly, admixed with catalyst through reactor 28 while lower boiling fractions are reformed, refined or polymerized in the lower temperature reactor 45, the catalysts being separated in separators 31, 47 and returned through line 32, 83 and 48, 84 to the regenerator 82; part of the unregenerated catalyst from separator 31 being passed direct to the reactor 45. The regenerated catalyst passes to separator 86 and thence through line 23 in part to mix with the vapours passing in line 22 to reactor 28 and in part through line 43 to mix with fractions flowing through line 44 to reactor 45. When feeding low boiling fractions produced in the process to the second stage, these are obtained from top of fractionating tower 39 and are fed direct through line 41, 44 to reactor 45 or may be first treated to separate gasoline or light gases for polymerisation, by treatment in absorption plant 68, 75. Extraneous fractions are fed through line 98. The crude is vaporized in coil 12 and superheated in coil 21; vaporization may also be effected by heat from the regenerated catalyst. Temperatures of 800-950 DEG F. in zone 28 and 400-700 DEG F. in zone 45 are specified. 0.5 to 10 parts of catalyst may be used per weight of the fluids. Specification 552,334, [Group III], is referred to.