Aqueous extractions for efficient catalyst recovery

One such method can be the separation of the catalyst and products (plus unreacted starting material and inert components of the feed) by extraction. 

The same general principles and the same phosphines (18) can be used for still another variation of catalyst recovery which was demonstrated in the hydroformylation of 1-tetradecene [143], The reaction, catalyzed by the Rh/18 catalyst, was run in a homogeneous methanolic solution and gave slightly better results than the Rh/PPh3 catalyst under identical conditions. After the reaction most of the methanol was distilled off and the remaining solution was extracted with water. The catalyst-containing aqueous phase was evaporated to dryness, the catalyst was taken up in methanol and reused. No loss of activity and selectivity was observed in three recycles. 

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