Patent GB-539297-A (GB)
Title: An improved manufacture of saturated branched-chain hydrocarbons
IPC: C07C5/27
Filed: 1939-12-15
Abstract: 539,297. Acyclic hydrocarbons. ARNOLD, C. (Standard Oil Co.). Dec. 15, 1939, No. 32288. [Class 2 (iii)] Saturated straight chain normally liquid paraffin hydrocarbons are converted into saturated branched chain paraffin hydrocarbons by treatment, at elevated temperature and pressure with one or more normally gaseous saturated paraffin hydrocarbons containing at least 2 carbon atoms in the molecule, in presence of a catalyst comprising aluminium chloride or bromide or a hydrocarbon complex thereof and cf a halogen-containing promoter for such catalyst. Specified normally gaseous hydrocarbons are ethane, propane, butane and isobutane; isobutane recovered from the reaction products or a mixture containing at least 85 per cent. of propane may advantageously be employed. Specified promoters are hydrogen chloride or bromide, carbon tetrachloride and methyl, ethyl,propyl or butyl chloride or bromide. In the arrangement shown diagrammatically in Fig. 1 a straight-run petroleum naphtha, containing C 8  and higherboiling hydrocarbons and having an initial boiling point above about 235‹ F. enters the system at A and is forced by pump 10 through line 11 into the heated reaction zone 17. Similarly the gaseous paraffins are supplied from B by pump 12, a mixture of a slurry or solution of aluminium chloride or bromide and light mineral oil is supplied from a mixing vessel 13 by pump 14 through lines 15, 16, and the promoter is supplied from C by pump 29. The reaction zone is preferably maintained at 300-475‹ F. and under a pressure of 200-4,000 lb. per square inch. The products from reaction zone 17 are passed, if necessary, by way of cooler 23, to a separator 22, all or a part of the naphtha feed stock being supplied, if desired, through line 24, as a quenching medium. The aluminium halide-hydrocarbon complex from the lower part of separator 22 is returned to the reaction zone 17 by pump 26 through line 25 and either through line 27 or by way of mixer 13, or all or a part may be withdrawn through valved line 30. The hydrocarbons from the top of separator 22 pass by line 32 and pressure regulator 33 to a fractionator 34 from the bottom of which the heavier products are withdrawn by pump 41 through line 38, tank 39 and line 40 for return to the zone 17, while the lighter products from the top are passed by line 35 and cooler 36 to reflux drum 37 from the bottom of which liquefied products are recycled by pump 49 through line 48 to the top of the fractionator 34. The products from the top of the drum 37 are passed to a fractionator 50 from the bottom of which products of high anti-knock value are withdrawn, while the gases pass through line 52 and either through valve 52a for recycling by way of line 64 or through condenser 53 to reflux drum 54. Liquid hydrocarbons are withdrawn from the bottom of this drum and supplied to the top of fractionator 50 or a portion may be recycled through line 62 to the zone 17. The gases from the top of drum 54 may be recycled through line 64 or passed through line 65 to an absorber 66 serving to remove the hydrogen halide promoter whereupon the remaining gases are recycled through lines 69, 64 or withdrawn at 70. The reaction zone 17 may be fitted with a revolving blade mixer, especially for liquid phase reactions, in which case provision may be made for recycling of gases through the zone before the products are passed to the fractionating system. For vapour phase reaction the feed naphtha, gases and promoter may be sprayed into the bottom and the catalyst slurry into the top of the reaction zone 17, in which case the aluminium halidehydrocarbon complex is withdrawn from the bottom of the zone and the use of the separator 22 is eliminated.