GB758431A - Improvements in or relating to the hydrogenation of organic materials - Google Patents

Abstract

In a process for hydrogenation or dehydrogenation of organic materials wherein the organic materials are contacted with a fluidized bed of catalyst containing a platinum group metal and halogen in the form of chlorine or fluorine, which catalyst becomes contaminated with carbonaceous deposits, regeneration is effected by withdrawing the catalyst from the reaction zone and treating it as a fluidized bed with a gas containing free hydrogen to remove the deposits; the catalyst is then recycled to the reaction zone. The invention is particularly applicable to the hydrogenation of olefins, the hydrogenation of catalytically - cracked naphthas, hydrogenation of unsaturated alcohols to form saturated alcohols, hydrogenation of aldehydes and ketones to the corresponding alcohols, dehydrogenation and isomerization of methyl cyclopentane to benzene, dehydrogenation of butane to butene, and conversion of ethyl benzenes to styrene. Specification 745,283 is referred to.ALSO:<PICT:0758431/III/1> In a process for hydrogenation or dehydrogenation of organic materials wherein the organic materials are contacted with a fluidized bed of catalyst containing a platinum group metal and halogen in the form of chlorine or fluorine, which catalyst becomes contaminated with carbonaceous deposits, regeneration is effected by withdrawing the catalyst from the reaction zone and treating it as a fluidized bed with a gas containing free hydrogen to remove the deposits; the catalyst is then recycled to the reaction zone. The invention is particularly applicable to the hydrogenation of olefins, the hydrogenation of catalytically-cracked naphthas, desulphurization of kerosenes, hydrofining of heavy petroleum fractions or lubricating oils, hydrogenation of unsaturated alcohols to form saturated alcohols, hydrogenation of aldehydes and ketones to the corresponding alcohols, dehydrogenation and isomerization of methyl cyclopentane to benzene, dehydrogenation of butane to butene, and conversion of ethyl benzene to styrene. In the Figure, liquid feed for example, heavy catalytic naphtha (B.P. 275 to 430 DEG F.) is introduced from pipe 1 to reactor A which contains a fluidized bed of catalyst. The gaseous products leave through line 13 and pass through an oil scrubber S which removes last traces of catalyst, and on to a separator 15. The liquid products recovered from 15 pass in part to a distillation column 18 whilst the gaseous products pass via pipes 21 and 22, to be enriched in hydrogen from line 24 and are recycled through reheater 27 to the lower regenerator section of the reactor. The boiling point range of the product is the same as the initial feed but the sulphur content and bromine member are decreased. Regeneration occurs in fluidized bed B in the presence of the hydrogen fed at line 24 and the gasses gass from thence to the reactor A. Catalyst is withdrawn from A to B by line 30 and returned to A by a elutriation from bed B. The regeneration bed B is maintained at a higher temperature than the reaction bed A due to the preheating of the gases in 27 and the carbonaceous deposits are thus removed. The bed A may be cooled by the introduction of cold feed and by recycling a part of the liquid from separator 15 by line 33 to feed pipe 1. For low pressure hydrogenation the pressure of the system may be 100 to 500 p.s.i.g., the temperature of the reactor A may be 500 to 900 DEG F. and that of reactor B, 800 to 1100 DEG F. The catalyst is preferably composed of platinum or alumina prepared by impregnating alumina with chloroplatinic acid to give a 0.2 to 1 per cent platinum content, followed by treatment with hydrogen sulphide. Other suitable carriers are silica-alumina magnesia, activated carbon and zirconia; if palladium is employed the content should be 2 to 3 times the amount specified above for platinum. The catalyst may contain 0.5 to 5 per cent of hydrogen fluoride which may be incorporated by impregnation of the catalyst or by adding it to the recycle gas in line 28 through pipe 36 or by adding it to the feed to the system through line 1a. Specification 745,283 is referred to.