GB731721A - Improvements in or relating to deasphalting operation - Google Patents

Abstract

Residual oils containing asphaltic constituents are purified therefrom and converted into gasolines &c. of desired boiling range by subjecting the residual oil to mild cracking, e.g. temperatures of the order of 750-920 DEG F., removing fractions boiling below 650 DEG F. from the product and treating the residuum with a deasphalting solvent to separate the asphaltic constituents. The deasphaltized residuum may then be cracked in presence of fluidized catalysts and gasloine &c. recovered from the cracked products. An asphaltic crude is fed through line 2 to a distillation zone where the crude is fractionated into (a) hydrocarbon gases recovered through line 3; (b) naphtha through line 4; (c) heavy naphtha through line 5 and gasoil through line 6. The reduced crude is fed through line 7 into a visbreaking zone 10 and the products withdrawn through line 70 to a distillation zone 71 where fractions boiling below 650 DEG F. are withdrawn through lines 72, 73, while the residual oil is fed to a deasphaltizing zone 8 where it is contacted <PICT:0731721/III/1> with a solvent, e.g. propane or butane, fed through line 9. The asphalt and solvent pass to a still 54 to recover the solvent through line 55 and the asphalt through line 56. The asphalt free fraction is fed to still 15 where residual solvent is recovered through line 50 and recycled to zone 8. The asphalt free oil, mixed if desired with the gasoil fraction from line 6 is fed through line 51 to a fluid catalytic cracking plant comprising reactor 22, regenerator 30, and product fractionator 24 where the cracked products are separated into gasoline, heating oil, recycle oil and bottoms.