GB539383A - Improvements in or relating to the conversion of hydrocarbon oils in the presence of powdered contact materials - Google Patents

Abstract

539,383. Reforming gasolines. STANDARD OIL DEVELOPMENT CO: Feb. 13, 1940, No. 2732. Convention date, Feb. 16, 1939. [Class 2 (iii)] [Also in Group III] Crude petroleum oil is converted into motor fuel of high anti-knock value by distilling the crude to separate it into a plurality of fractions of different boiling range, suspending catalysts in the different fractions and submitting the separate fractions to catalytic conversion in independent reaction zones through which the suspensions are passed. The catalyst is suspended in a gas and is injected into the oil stream so that the powdered catalyst is maintained in suspension therein while passing through the reaction zone. The catalyst is separated from the conversion products in a cyclone separator, regenerated by treatment with oxidizing gases and returned to the cycle. The unvaporized residues of the crude are catalytically converted to coke. Crude stock fed through line 10 is vaporized by heating to incipient cracking temperatures in a tubular heater 12 and the products are fractionated in a tower 15 into (a) a gasoline fraction recovered through line 19 and condenser 20 to receiver 21, (b) a naphtha fraction collected on plate 27, (c) a gas oil fraction collected on plate 16 and (d) unvaporized residues withdrawn through line 17. The naphtha is revaporized at 700-1,000‹ F. in coil 29 and mixed with catalyst in an injector 32 the suspension thus formed being passed through a tubular coil 42 heated to 900-1,000‹ F. The products are separated from catalyst wholly or in part in a cyclone separator 45 from which the catalyst falls down a tower 46 to a receiver (against a current of steam to remove residual oil) into a receiver 47, while the mixed vapours and steam are condensed together in a condenser 51 and passed through a gas separator 52 to a separator 55 where water is decanted off carrying with it any catalyst that has remained in suspension in the vapours. The condensate is removed through line 57, re-distilled in heater 59 and fractionated in tower 58 to recover overhead gasoline fractions in receiver 63 while the heavier fractions are removed through line 60 and may be recycled for further conversion. The gas oil fraction is catalytically converted in a similar series of reaction and fractionating zones to that described above and comprising heaters 76, 85, catalyst-injector 82, cyclone separator 88, re-distillation coil 104 and final fractionation tower 103, the gasoline product being collected in receiver 121 and the heavier oils re-cycled through line 112. The residues removed through line 17 are converted to coke and vapours in a similar plant to that described above comprising heater 132 (to which steam is admitted through line 134), catalyst injector 136, reactor 139, where conversion to coke and vapours takes place, and cyclone separator and catalyst removal tower 142, 143. The separated vapours are fed through lines 147, 148, 157 to combine with the gas oil passing to coil 76, or are condensed and recovered separately by passage through condenser 152 and separators 153, 156. Alternatively the vapours may be combined with those passing overhead in line 93 from cyclone separator 88. The apparatus for mixing the catalyst, gases and hydrocarbon vapours to form a suspension comprises a hopper 34 from which powdered catalyst is fed by a conveyer 35 to a chamber 37 so as to impinge against a steam of gases admitted through nozzle 38. The dispersion of gases and catalyst is fed through nozzle 39 and conduit 40 into an injector 32 where it is mixed with the hydrocarbons. The gases may comprise steam, nitrogen, hydrogen or hydrocarbons, e.g. those produced in the conversion processes described which are separated from the various separators 52, 63, 121, 153 &c. and collected in a common line 66, 67 from which they are passed to the various injectors. Catalysts specified for the various reaction stages comprise mixed oxides of silica and alumina or of metals of the 3rd and 6th groups of the Periodic System particularly a coprecipitated mixture of chromium and aluminium oxides ; sodium aluminium chloride ; " Superfiltrol," pumice, spent clay, kieselguhr. Regeneration apparatus for the catalysts (Fig. 2) comprises a collector 160 placed at the bottom of the catalyst separating towers from which the catalyst is removed by a star conveyer 161 to a line 162 through which hot oxidizing gases are injected by a blower 166 to convey the catalyst through a tubular regenerating zone 163, located in a waste heat boiler 164. The regenerated catalysts are passed through a separator 168 and fall down a tower 169 in counter-current to steam or other gases. The Specification as open to inspection under Sect. 91 comprises also the subject-matter of Specification 542,989, [Group III]. This subject-matter does not appear in the Specification as accepted.