GB798019A - Integrated process for manufacture of gasoline and lubricating oils - Google Patents

Abstract

In a process for producing gasoline and lubricating oils from crude oil, the crude oil is distilled to separate a distillate, boiling between 500 DEG and 1200 DEG F., and a bottoms fraction; the distillate subjected to catalytic cracking, the cracked products are fractionated to separate a fraction boiling between 700 DEG and 1100 DEG F. which is of relatively low aromatic content, and this fraction is submitted to solvent extraction, e.g. with phenol, to remove the aromatic constituents whereby a product is obtained which may be worked up to produce a lubricating oil. Due to the low aromatic content of the feed to the extraction unit, only a relatively small volume of solvent has to be used. A higher boiling aromatic-rich fraction, separated from <PICT:0798019/III/1> the cracked products, is used as a wash material in conjunction with the propane-de-asphalting of the bottoms fraction from the initial distillation, for it enables a de-asphalted oil of very low metallic-ash content to be obtained. Crude oil is fed through line 11 into still 10 from which a fraction boiling in the range of 500-1200 DEG F. is taken off through line 14, and cat. cracked in unit 15. The cracked products are fractionated in fractionator 17; and naphtha is withdrawn through line 19, while heating oil is withdrawn through line 20. A fraction having a boilingrange of about 600-900 DEG F. is taken off through line 21 and is mixed with the bottoms which leave fractionator 17 through line 22. The mixture is fractionated in fractionator 24, from which all material boiling below 650-700 DEG F. is taken overhead. A low aromatic fraction boiling between about 700 DEG and about 1100 DEG F. is taken off through line 26; part of this fraction is recycled through line 27 to the cracking unit 15, but the major portion of the fraction is treated in tower 30 with phenol, which is introduced through line 31 and extracts the aromatic constituents from the fraction. The raffinate phase from tower 30 is removed via line 40, and the phenol is recovered therefrom. The dephenolized raffinite is then subjected to dewaxing and decolorizing to produce a finished lubricating oil. After the phenol has been separated from the aromatic extract, withdrawn from tower 30 through line 32, the extract is combined with the aromatic bottoms from fractionator 24; and the mixture is fed through line 34 into unit 33, where the crude residuum from still 10 is de-asphalted with liquid propane. The addition of the aromatic oil effects a precipitation from the residuum of salts of iron, nickel and vanadium in unit 33. The deasphalted oil is taken off through line 37, and propane is recovered therefrom. All or a portion of the non-metallic, de-asphalted oil may be used as a feedstock for the manufacture of a lubricating oil, or it may be passed to cracking unit 15. Other solvents which may be used in tower 30, in place of phenol, are furfural, nitrobenzene and liquid sulphur dioxide.