Ruhrchemie Aktiengesellschaft

Hoechst Aktiengesellschaft

Ernest Wiebus

Boy Cornils

Hanswilhelm Bach

Werner Konkol

Helmut Bahrmann

Wolfgang Lipps

Wilhelm Gick

Gehard Diekhaus

A process for separating rhodium from mixtures thereof, comprising extracting said rhodium with an aqueous solution of a rhodium complexing agent and a solubilizer. A process for preparing aldehydes in the presence of both the complexing agent and the solubilizer is also set forth. The solubilizer is generally selected from salts of carboxylic acids having 8-20 carbon atoms, alkyl sulfonates, alkyl aryl sulfonates, amines and quaternary ammonium compounds of Formula II ##STR1## wherein A is alkyl, alkoxy, hydroxyalkyl, aryl having 6-25 carbon atoms, or R.sup.7 CONHCH.sub.2 CH.sub.2 CH.sub.2 --wherein R.sup.7 is alkyl having 5-11 carbon atoms; B is an alkyl having 1-25 carbon atoms, an aryl having 6-25 carbon atoms, or an .omega.-hydroxy alkyl having 1-4 carbon atoms; C and D are each independently an alkyl or .omega.-hydroxy alkyl having 1-4 carbon atoms or form, together with each other and the bridging N, a 5 or 6 membered heterocyclic ring; E is a halide, sulfate, borate, sulfonate, lactate or citrate; and p is the number of charges on E. The rhodium complexing agent is preferably a triaryl phosphine carboxylate or sulfonate.

Process for hydroformylation with rhodium catalysts and the separation

In a hydroformylation process for the preparation of aldehydes by reacting aliphatic olefins of 2 to 12 carbon atoms with carbon monoxide and hydrogen at temperatures of 20.degree. to 150.degree. C. and pressures of 0.1 to 20 mPa in the liquid phase and in the presence of an aqueous solution containing 50 to 800 wt. ppm of rhodium and 25 to 30 wt. % of phosphines, in each case based on the aqueous solution as a catalyst system and in addition the transformation products of the phosphines, the improvement comprising draining off a portion of the aqueous solution of the catalyst system together with the reaction product and replacing the same by fresh aqueous solution of the catalyst system whereby the original catalyst selectivity for formation of n-aldehydes is maintained.

Hydroformylation process

Growing community of inventors

Oberhausen, Germany

Ernest Wiebus