Patent GB-506785-A (GB)
Title: Process for the conversion of hydrocarbon oils
Filed: 1937-11-30
Abstract: 506,785. Cracking and reforming oils. UNIVERSAL OIL PRODUCTS CO. Nov. 30, 1937, No. 37209 /38. Convention date, Nov. 30, 1936. Divided out of 501,560. [Class 32] Hydrocarbon oils are cracked and the cracked vapours are subjected to fractionation in two successive stages to recover gasoline fractions of desired boiling range, the fractionation in the second stage being carried out in presence of gasoline fractions introduced from an extraneous source so as to separate a gasoline fraction of desired boiling range and a heavier fraction which is-subjected to reforming and subsequent fractionation to produce a gasoline of high antiknock value. The cracking stage may comprise a single cracking coil but preferably heavy and light fractions are isolated in the primary fractionating tower 6 of the system as a side cut taken off through line 26 and as reflux taken off through line 18 from the bottom of the tower respectively and these fractions are cracked separately in coils 31, 20 under conditions of temperature and pressure suitable to the respective fractions. The products of both conversions are passed into the top of a reactor 25, preferably so that the cracked products are sprayed over the reactor walls, and the total reaction products are removed from the bottom of the reactor and, after the addition if desired of cooling oil supplied through lines 233, are passed with reduction of pressure into' an evaporator 38, from which vapours pass through lines to the primary fractionating tower 6. Vapours from this tower pass through line 48 in part to condenser 53 and separator 56 from which condensate is returned as reflux through line 60, the remaining vapours passing to the secondary tower 52 through line 50 where, with the aid of an extraneous gasoline fraction fed through line 104, they are fractionated to give gasoline of desired end point which is recovered through line 65, condenser 67 and separator 70, and a higher boiling condensate is collected at the bottom of the tower 52. This condensate is led through lines 85, 107 to a heating coil 110 where it is reformed at temperatures of 510-566‹ C. and the products are passed into the lower part 44 of a combined evaporator and fractionating tower 44, 45, from which the reformed products of desired boiling range are recovered through line 220, condenser 222 and separator 225. In the evaporator 44 the products from the coil 110 are preferably mixed with liquid residues from the evaporator 38 led through line 42, while a condensate collected on pan 117 is fed through line 194, 197 iuto the tower 6. The crude stock for the cracking stage is fed by a pump 9 through line 10 direct or through a heat exchanger 12 to the tower 6. The extraneous gasoline fraction is supplied by a pump 3 to the line 104 and may also be fed in part in admixture with the crude to the tower 6. Gaseous and vaporous fractions remaining uncondensed in the separators 56, 70, 225 are united through lines 62, 76, 231 and subjected to further cooling in subcooler 64 in order to recover condensible constituents, which are separated from gases in separator 80.