GB815566A - Oxo process for the preparation of oxygenated organic compounds - Google Patents

Abstract

Oxygenated organic compounds are prepared by a process comprising preheating a stream of hydrogen, carbon monoxide and a hydroformylation catalyst to a temperature between 140 DEG and 250 DEG C. and mixing this stream with a stream of an olefinically unsaturated organic compound preheated to the same temperature and in amount no greater than in equimolar porportion to the carbon monoxide present in the first stream, conducting the mixture through an externally cooled reactor having a length to diameter ratio of at least 2000 to 1, the reactor operating at a temperature between 140 DEG and 250 DEG C. and at a pressure between 200 and 1000 atmospheres at a rate such that turbulent flow conditions are achieved within the reactor and the total residence time within the reactor is not greater than 10 minutes. Suitable olefinic hydrocarbons having not more than 5 carbon atoms and esters of olefinically unsaturated acids and alcohols having 1 to 4 carbon atoms such as ethyl acrylate, ethyl crotonate, ethyl sorbate and allyl crotonate. For high yields it is necessary to have present in the reaction mixture about 5 to 50 per cent (by weight) of a liquid which may be a catalyst suspendant such as glycol, ether, ester, alcohol or a liquid hydrocarbon such as benzene, toluene and mineral oil; liquid olefines; or reaction products such as the crude products or the crude products after stripping off low-boiling fractions. In some cases high efficiency is obtained in a single pass but in others it is desirable that part, at least, of the liquid products should be recycled. Suitable catalysts are, for example, cobalt metal, cobalt oxide, cobalt carbonate, cobalt acetate, cobalt carbonyl, cobalt naphthenate, stearate and 2-ethyl hexanoate. They may be introduced in solution in a hydrocarbon or an oxygen-containing solvent or in water. The reactor is externally cooled, for example, by jacketing it in a vessel containing cooling fluid. It is advantageous to maintain a nearly constant reaction temperature throughout the tube and this may be done by having the cooling zone divided into sections controlled at different temperatures. In the examples: (a) propylene is treated with carbon monoxide and hydrogen in the presence of a cobaltous acetate catalyst slurried in mineral oil or propanol, fifty per cent of the liquid products being recycled, to give butyraldehyde; (b) propylene is similarly treated without recycling any of the product; (c) ethylene is treated with carbon monoxide and hydrogen in the presence of a cobaltous acetate catalyst slurried in propanol, with and without recycle of reaction products, to give propionaldehyde; and (d) ethyl crotonate containing dissolved cobalt acetate is treated with carbon monoxide and hydrogen to give ethyl 4-formyl butyrate and delta-valero lactone.