Patent EA-001218-B1 (EA)
Title: Process for separating phosphorus acidic compounds in the presence of metal-organophosphite ligand complex catalyst
Inventor: BRYANT DAVID ROBERT
IPC: C07F9/6571
Filed: 1996-12-05
Abstract: 1. A process for separating one or more phosphorus acidic compounds from a reaction product fluid or for stabilizing an organophosphite ligand against hydrolytic degradation and/or deactivation of a metal-organophosphite ligand complex catalyst or for preventing and/or lessening hydrolytic degradation of an organophosphite ligand and/or deactivation of a metal-organophosphite ligand complex catalyst, which process comprises treating a reaction product fluid formed in the process of a hydroformylation, hydroacylation (intramolecular and intermolecular), hydrocyanation, hydroamidation, hydroesterification, aminolysis, carbonylation, isomerization or transfer hydrogenation where said reaction product fluid contains a metal-organophosphite ligand complex catalyst and optionally free organophosphite ligand and which also contains one or more phosphorus acidic compounds, with an aqueous buffer solution sufficient to neutralize and remove at least some amount of said one or more phosphorus acidic compounds from said reaction product fluid. 2. The process of claim 1 wherein at least a portion of said reaction product fluid derived after reacting of one or more reactants in the presence of a metal-organophosphite ligand complex catalyst and optionally free organophosphite ligand, and which also contains phosphorus acidic compounds, formed in said process is treated with an aqueous buffer solution sufficient to neutralize and remove at least some amount of said one or more phosphorus acidic compounds from said reaction product fluid. 3. The process of claim 2 which comprises  (i) reacting in at least one reaction zone one or more reactants in the presence of a metal-organophosphite ligand complex catalyst and optionally free organophosphite ligand to produce a reaction product fluid comprising one or more products and (ii) separating in at least one separation zone or in said at least one reaction zone the one or more products from said reaction product fluid, the improvement comprising preventing and/or lessening hydrolytic degradation of any said organophosphite ligand and deactivation of said metal-organophosphite ligand complex catalyst by (a) withdrawing from said at least one reaction zone or said at least one separation zone at least a portion of said reaction product fluid derived from said process and which also contains phosphorus acidic compounds formed during said process, (b) treating in at least one buffer treatment zone at least a portion of the withdrawn reaction product fluid derived from said process and which also contains phosphorus acidic compounds formed during said process with an aqueous buffer solution sufficient to neutralize and remove at least some amount of the phosphorus acidic compounds from said reaction product fluid, and (c) returning the treated reaction product fluid to said at least one reaction zone or said at least one separation zone. 4. The improved process of claim 2 which comprises  (i) reacting in at least one reaction zone one or more reactants in the presence of a metal-organophosphite ligand complex catalyst and optionally free organophosphite ligand to produce a reaction product fluid comprising one or more products and (ii) separating in at least one separation zone or in said at least one reaction zone the one or more products from said reaction product fluid, the improvement comprising preventing and/or lessening hydrolytic degradation of any said organophosphite ligand and deactivation of said metal-organophosphite ligand complex catalyst by treating at least a portion of said reaction product fluid derived from said process and which also contains phosphorus acidic compounds formed during said process by introducing an aqueous buffer solution into said at least one reaction zone and/or said at least one separation zone sufficient to neutralize and remove at least some amount of the phosphorus acidic compounds from said reaction product fluid. 5. The process of claim 4 further comprising separating the aqueous buffer solution from the reaction product fluid. 6. The process of any claim 1 to 5 wherein the aqueous buffer solution comprises a mixture of salts of oxyacids having a pH of 3 to 9. 7. The process of claim 6 wherein the aqueous buffer solution comprises a mixture of an anion selected from the group consisting of phosphate, carbonate, citrate and borate compounds and a cation selected from the group consisting of ammonium and alkali metals. 8. The process of claim 6 wherein the aqueous buffer solution comprises a mixture of monobasic/dibasic phosphates of an alkali metal or a mixture of citrates of an alkali metals. 9. The process of claim 8 wherein the aqueous buffer solution comprises a mixture of monobasic/dibasic phosphates of sodium or potassium and has a pH of from 4.5 to 7.5. 10. The process of claim 6 wherein the aqueous buffer solution comprises a mixture of NaH2PO4 and Na2HPO4 or a mixture of KH2PO4 and K2HPO4. 11. The process of any preceding claim 1 to 10 wherein said metal-organophosphite ligand complex catalyst is homogeneous or heterogeneous. 12. The process of any preceding claim 1 to 11 wherein said reaction product fluid contains a homogeneous or heterogeneous metal-organophosphite ligand complex catalyst or at least a portion of said reaction product fluid contacts a fixed heterogeneous metal-organophosphite ligand complex catalyst during said process. 13. The process of claim 3 or 4 wherein said separating of one or more products from the reaction product fluid occurs prior to or after treating at least a portion of the reaction product fluid derived from said process and which also contains phosphorus acidic compounds formed during said process with an aqueous buffer solution. 14. The process of any preceding claim 1 to 13 wherein said metal-organophosphite ligand complex catalyst comprises rhodium complexed with an organophosphite ligand selected from: (i) a monoorganophosphite represented by the formula:   wherein R<1> represents a substituted or unsubstituted trivalent hydrocarbon radical containing from 4 to 40 carbon atoms or greater; (ii) a diorganophosphite represented by the formula:   wherein R<2> represents a substituted or unsubstituted divalent hydrocarbon radical containing from 4 to 40 carbon atoms or greater and W represents a substituted or unsubstituted monovalent hydrocarbon radical containing from 1 to 18 carbon atoms or greater; (iii) a triorganophosphite represented by the formula:   wherein each R<6> is the same or different and represents a substituted or unsubstituted monovalent hydrocarbon radical; and  (iv) an organopolyphosphite containing two or more tertiary (trivalent) phosphorus atoms represented by the formula:   wherein X represents a substituted or unsubstituted n-valent hydrocarbon bridging radical containing from 2 to 40 carbon atoms, each R<7> is the same or different and represents a divalent hydrocarbon radical containing from 4 to 40 carbon atoms, each R<8> is the same or different and represents a substituted or unsubstituted monovalent hydrocarbon radical containing from 1 to 24 carbon atoms, a and b can be the same or different and each have a value of 0 to 6, with the proviso that the sum of a + b is 2 to 6 and n equals a + b. 15. The process of any preceding claim 1 to 14 wherein phosphorus acidic compounds present in the reaction product fluid are scavenged by an organic nitrogen compound that is also present in said reaction product fluid and wherein at least some amount of the phosphorus acidic compound of the conversion products of the reaction between said phosphorus acidic compound and said organic nitrogen compound are also neutralized and removed by the aqueous buffer solution treatment. 16. The process of claim 15 wherein the organic nitrogen compound is selected from the group consisting of diazoles, triazoles, diazines and triazines. 17. The process of claim 16 wherein the organic nitrogen compound is benzimidazole or benzotriazole.