| 摘要 |
1495025 Recovering the rhodium and triphenyl phosphine components of a hydroformylation catalyst MONTEDISON SpA 23 Jan 1975 [23 Jan 1974] 3046/75 Headings C2P and C2C Rhodium and triphenyl phosphine are recovered from crude hydroformylation products obtained by hydroformylation of olefins in the presence of a catalyst complex comprising rhodium and triphenyl phosphine, or from the tails left after distillation of the crude products to remove the desired hydroformylation products, by treating the said crude products or the tails at 60‹ to 150‹ C. with an aqueous solution of a C 1 -C 4 aldehyde and of a strong mineral acid, the molar ratio for each of the aldehyde and the acid being from 1 : 1 to 1 : 3 with respect to triphenyl phosphine, separating the solid rhodium complex formed by filtration and decanting the aqueous solution containing triphenyl phosphine. Specified aldehydes for use in the process are formaldehyde and isobutyraldehyde and specified mineral acids are hydrochloric, sulphuric and perchloric acids. The process may be conducted in the presence of air but is preferably carried out under an inert atmosphere, e.g. a nitrogen or carbon monoxide atmosphere. When the aldehyde used is formaldehyde and the acid used is HCl and the molar ratio of each of the aldehyde and HCl to the phosphine is substantially one the rhodium complex separated by filtration comprises the compound: Rh(CO)Cl(PPh 3 ) 2 (where Ph is phenyl) and this may either be re-used as hydroformylation catalyst in the presence of an organic base which is added to bind the Cl atom or it may be converted into a monovalent hydride or carboxyl complex for subsequent use as catalyst. Solid triphenyl phosphine containing traces of rhodium compounds may be obtained from the decanted aqueous solution by adding an alkali, e.g. sodium carbonate, to the solution, and the resulting solid may be re-used in a subsequent hydroformylation reaction. Examples are given for the application of the process to a mixture of crude products formed by hydroformylation of propylene and from which n and iso-butyraldehydes have first been recovered by distillation, the aldehyde used being formaldehyde and the acids used being HCl and H 2 SO 4 respectively. |
