GB702224A - Improvements in or relating to the production of oxygen-containing organic compounds - Google Patents

Abstract

In an OXO synthesis using a "cobalt carbonyl" catalyst part of the reaction mixture, consisting at least in part of liquid phase material, is withdrawn from a point remote from the point of entry of the reactants, cooled and returned without phase separation to the reactor at a point nearer to the point of entry of the reactants and at a temperature not less than the minimum required for the synthesis. The term "cobalt carbonyl" covers true carbonyls such as Co(CO)8 and carbonyl hydrides such as Co(CO)4H. Temperatures specified are 80-180 DEG C. Recycled material may be withdrawn and returned at a plurality of points. Cooling may be effected by heat exchangers. Preferably the recycling rate should be high, e.g. at a volume flow rate of 5-50 times the rate at which fresh feed is passed to the reactor. Preferably the Reynolds number of the liquid in the heat exchanger is 10,000-30,000. Preferably the temperature drop during circulation is relatively low, e.g. below 50 DEG C., preferably below 20 DEG C. Preferred inlet and outlet temperatures vary with the olefine used and a table is provided giving these temperatures for a number of olefines. The withdrawn stream may comprise gas and liquid or using upflow conditions through the reactor especially with C2-C4 olefines, liquid streams and gas streams are removed from different points and recombined before cooling. The liquid phase product stream may be combined with fresh CO and H2 before cooling. Olefine hydrocarbons are preferred feedstocks but olefines containing such groups as ester, halogen, aldehyde and acetal may also be used. Lower olefines, e.g. ethylene, propylene and butenes, are especially preferred. It is particularly preferred that cobalt catalysts are not introduced in the solid phase. Diagrams are provided of apparatus used when a single product stream is withdrawn and when separate gas and liquid streams are removed. Specifications 647,363, 702,191, 702,192, 702,195, 702,196, 702,197, 702,201, 702,203 and 702,204 are referred to.