GB343286A - Improved process for cracking petroleum oils - Google Patents

Abstract

<PICT:0343286/III/1> Hydrocarbons, cracking. -- In a process for cracking petroleum oils containing heavy material which cokes easily in which the crude oil is subjected only to a short period cracking and the cracked products passed to evaporating and dephlegmating zones the reflux from the dephlegmator being subjected to a long period cracking, and the efflux from both crackings united, the short and long period cracking reactions are effected at the same temperature which does not exceed 950 DEG F. Crude oil is fed by a pump 12 through a short cracking coil 1 and the products pass to an evaporator 3 where evaporation is aided by a steam coil 15 and heavy residues are removed through a line 17. The vapours pass to a dephlegmator 5 from which the light fractions pass to a condenser 7 and receiver 8 while the condensate collecting in a surge tank 19 is returned by a pump 23 through a line 22 to a long period cracking zone which may comprise three tubular heaters 2a, 2b, 2c similar to those described in Specifications 271,601 and 277,983, [both in Class 32, Distilling &c.]. The cracked products from this zone are mixed with those from the coil 1 in the pipe 14. Part of the pressure distillate may be circulated through the cooler 6, pipe 28, and dephlegmator 5. Specification 240,339, [Class 32, Distilling &c.], is referred to.