Patent GB-670898-A (GB)
Title: Synthesis of oxygenated organic compounds
IPC: C07C45/50
Filed: 1950-01-20
Abstract: Olefinic compounds are contacted in an initial carbonylation reaction zone with carbon monoxide and hydrogen in the presence of a cobalt carbonylation catalyst under conditions of temperature and pressure conducive to production of aldehydes containing one more carbon atom than the olefinic compounds, a portion of the cobalt being converted into cobalt carbonyl and a reaction product comprising aldehydes and cobalt carbonyl being withdrawn and transferred to a catalyst decomposition and removal zone in which the product is continuously passed in contact with an indirectlyheated heat transfer surface so that the cobalt carbonyl is decomposed and a substantial quantity of metallic cobalt is deposited on the heated surface from which it is scraped and recovered.  Preferred temperatures for the cobalt removal process are in the range 300-400 DEG  F., and pressures in the range 50-150 p.s.i.g. are preferred for primary reaction products having six or more carbon atoms per molecule.  Suitable starting materials are aliphatic olefines and diolefines, cyclo-olefines, aromatic compounds with olefinic side-chains and oxygenated compounds having olefinic double bonds.  The liquid olefinic feed stock and a gas mixture containing carbon monoxide and hydrogen are introduced into a reactor.  The catalyst, preferably soluble in the feedstock, e.g. cobalt naphthenate, stearate or oleate may be added to the feed-stock in a concentration of 0.1-3 per cent by weight.  If desired, the reactor may be provided with a bed of cobalt catalyst supported on an inert carrier such as silica gel or pumice.  The reactor is operated under usual carbonylation conditions, i.e. at a temperature in the range of 300-400 DEG  F., and a pressure in the range 2500-3000 p.s.i.g.  The reaction products containing dissolved cobalt, mainly as cobalt carbonyl, are removed with unreacted gas and cooled and the gases are separated from the liquid.  The liquid product comprising mainly aldehydes and cobalt compounds (mainly cobalt carbonyl) is passed into a heater in which is a continuously rotating scraping device which scrapes deposited cobalt from the heated heat transfer surfaces.  The temperature of this decobalter is in the range 300-350 DEG  F., obtained by passing steam under pressure through a surrounding jacket.  A stream of inert stripping gas, preferably hydrogen, is passed through the decobalter and removes the carbon monoxide resulting from the decomposition of cobalt carbonyl and any water present in the decobalter feed.  The mixture of decobalted material suspended solids, substantially free of cobalt carbonyl, is separated into a cobalt free liquid aldehyde phase and a thickened cobalt sludge.  Two forms of apparatus are described-one in which the heat required for carbonyl removal is applied externally to a tube carrying the oxygenated product to be treated and the internal surface of which is continuously scraped and another in which the internal heat is supplied through a partially immersed rotating heat transfer surface which is continuously scraped.  In both cases stripping gas is introduced through a gas distributing manifold, the openings of which face downward.ALSO:Cobalt carbonyl formed when olefines are treated with carbon monoxide and hydrogen under elevated temperature and pressure in the presence of a cobalt catalyst is decomposed by passing the products of the reaction containing the carbonyl into a heated zone.  The cobalt carbonyl is decomposed and cobalt is deposited p  on the heated heat exchange surface from which it is continuously scraped.  The cobalt collects as a thickened sludge.