GB470035A - Improvements in or relating to the conversion of hydrocarbon oils - Google Patents

Abstract

In a process for cracking and re-forming oils, of the kind in which the crude oil is cracked cyclically under mild temperature conditions, e.g. 800--950 DEG F., and a selected low-boiling fraction of the product is reformed at higher temperatures, e.g. 900--1050 DEG F., in the first stage which comprises a cracking coil 13 and separator 9 surmounted by a dephlegmator 6 from which reflux is recycled to the coil 13 through pipes 18, 21, the crude oil is supplied through lines 4, 7 to the separator 9 so that the oil is vaporized by heat of the cracked products and the vaporous and non-vaporous products are mixed with corresponding products of the cracking operation. Vapours pass off through a line 23 to a condenser 25 and the condensate is collected in a receiver 28. This condensate when not of the required anti-knock value, or a fraction taken off through a line 46, is reformed in the coil 41 the products passing to a separator 52 <PICT:0470035/III/1> surmounted by a dephlegmator 58. The temperature of the cracked products is controlled (1) by passing them through a heat-exchanger 43 in heat exchange with part of the products passing from the first stage through a line 39, (2) by mixing directly therewith in a line 55 predetermined reflux condensate collected at the bottom of the column 58, the reflux passing through lines 75, 77 and branch lines 79, 80 situated on opposite sides of the pressure reduction valve 56. The reflux may be cooled in a cooler 85 and the remainder thereof is passed through a line 75 for further conversion in the coil 13. The reformed product passes off through a line 62 and condenser 64 to a receiver 67. Specifications 424,050, and 472,594, are referred to.