GB328649A - Improvements in the manufacture and production of hydrocarbons of low boiling point from those of higher boiling point - Google Patents

Abstract

328,649. Johnson, J. Y., (I. G. Farbenindustrie Akt.-Ges.). Feb. 1, 1929. Hydrocarbons, cracking and distilling; hydrogenation, destructive.-In a process of cracking high boiling point hydrocarbons, such as tars, mineral oils &c., in the presence of a solid catalyst, which maintains its shape under the conditions of working, e.g. bauxite, silica gel &c., the deterioration of the catalyst by the deposition of carbonaceous material thereon is minimized by the intermittent or continuous withdrawal of some of the liquid being treated together with its contained catalyst, separating this from the liquid, which may be returned to the reaction chamber, and regenerating the catalyst for further use. Separation from the catalyst may be effected bv distillation, filtration, extraction by a solvent, by centrifuging or by a combination of these methods. Removal may be effected by a valve at the bottom of the reaction chamber or, when the cracking is carried out under pressure, removal and re-introduction are effected by means of a pressure lock, the withdrawal being made before there is any substantial deposition of coke on the catalyst. Reduced or increased pressure may be employed, e.g. 10 to 100 atmospheres or more, and extraneous gases, such as hydrogen, nitrogen, water vapour and gaseous hydrocarbons such as methane, may be introduced at temperatures between 350‹ and 650‹ C. In an example, gas oil with 3.5 per cent of finely ground bauxite is preheated to 420‹ or 430‹ C. at a pressure of 50 atmospheres and introduced into a reaction vessel from which the volatile products are withdrawn. A part of the liquid with its contained bauxite is intermittently or continuously withdrawn through a vertical tube. The volatile constituents of this portion are distilled off, or the liquid is separated by filtration &c., and the adherent matter removed from the bauxite by combustion, the heat so generated being used for preheating the oil. The regenerated bauxite, ground if necessary, is returned to the reaction chamber. Specifications 5245/13, 189,200, 326,157, and 326,184 are referred to.