GB455505A - Improvements in and relating to processes and apparatus for splitting hydrocarbons - Google Patents

Abstract

<PICT:0455505/III/1> Oils, coal and lignite tars &c., are cracked by vaporizing the oil, passing the vapours to a fractionating column, withdrawing condensate from a number of levels in the column, and subjecting each condensate in its own tubular heating system to cracking under conditions which are optimum for the said condensate, returning the cracked products to the column and removing light end fractions from the top of the column. The cracked condensates are preferably returned to the column at a point above the point of their withdrawal. Crude tar is pumped from a storage tank a through a coil heated in a furnace c into a fractionating tower d, where the heated tar is separated into vapours and liquid residues which are removed through a line o and cooler p to storage. The tower is provided with a number of bubble trays e<1>, e<2>, e<3>, e<x> on which condensates are collected. These condensates are passed through descending pipes g into tubular cracking units m located in a furnace l and the cracked products are returned to the tower through ascending pipes n. The speed at which the condensates pass through the units m may be increased by the use of pumps or by introducing gases or liquids through injectors. Part of the liquid residues may similarly be withdrawn through lines q, cracked, and recirculated. Vapours pass off through a line k to a dephlegmator s from which reflux is recycled by a pump i and line h, with or without cracking in a coil w, to the tower d. U.S.A. Specification 1,934,049 is referred to.