Hydroformylation process

#1. Field of the Invention

#This invention relates to an improved rhodium-organophosphite complex catalyzed hydroformylation process.

#2. Background Art

#Accordingly, the subject invention encompasses reversing or minimizing the intrinsic catalyst deactivation of solubilized rhodium-bisphosphite complex catalyzed, continuous hydroformylation processes for producing aldehydes, by carrying out the hydroformylation in the presence of added water and/or certain weakly acidic additives as disclosed herein.

#Illustrative rhodium-bisphosphite complex catalyzed continuous hydroformylation processes in which such intrinsic catalyst deactivation may occur include hydroformylation processes such as described, e.g., in U.S. Pat. Nos. 4,668,651; 4,774,361 and 4,769,498, and U.S. patent application Ser. No. 911,518 filed Jul. 16, 1992 which is a continuation-in-part of U.S. patent applications, Ser. Nos. 748,111 and 748,112, both filed Aug. 21, 1991, wherein the bisphosphite ligand is a ligand selected from the class consisting of Formulas (I) and (II) above, the entire disclosures of said patents and applications being incorporated herein by reference thereto. Thus such hydroformylation processes and the conditions thereof are well known and it is to be understood that the particular manner in which the hydroformylation reaction is carried out and particular hydroformylation reaction conditions employed may be varied widely and tailored to meet individual needs and produce the particular aldehyde product desired.

#In general, such hydroformylation reactions involve the production of aldehydes by reacting an olefinic compound with carbon monoxide and hydrogen in the presence of a solubilized rhodium-bisphosphite complex catalyst in a liquid medium that also contains a solvent for the catalyst. The process may be carried out in a continuous single pass mode or more preferably in a continuous liquid catalyst recycle manner. The recycle procedure generally involves withdrawing a portion of the liquid reaction medium containing the catalyst and aldehyde product from the hydroformylation reaction zone, either continuously or intermittently, and distilling the aldehyde product therefrom in one or more stages under normal, reduced or elevated pressure, as appropriate, in a separate distillation zone in order to recover the aldehyde product and other volatile materials in vaporous form, the non-volatilized rhodium catalyst containing residue being recycled to the reaction zone. Condensation of the volatilized materials, and separation and recovery thereof, e.g., by distillation, can be carried out in any conventional manner, the aldehyde product being passed on for further purification if desired and any recovered reactants, e.g., olefinic starting material and syn gas recycled in any desired manner to the hydroformylation zone. Likewise, the recovered non-volatilized rhodium catalyst containing residue can be recycled with or without further treatment to the hydroformylation zone in any conventional manner desired. Accordingly, the processing techniques of this invention may correspond to any known processing techniques such as heretofore employed in conventional liquid catalyst recycle hydroformylation reactions, for instance.