Patent ID: 8088943

Claim:
A hydrocyanation process to produce adiponitrile and other dinitriles having six carbon atoms, the process comprising: a) forming a reaction mixture in the presence of at least one Lewis acid, said reaction mixture comprising ethylenically unsaturated nitriles having five carbon atoms, hydrogen cyanide, and at least one catalyst composition, by continuously feeding the ethylenically unsaturated nitriles, the hydrogen cyanide, and the catalyst composition; wherein the catalyst composition comprises a zero-valent nickel and at least one bidentate phosphorus-containing ligand; wherein the bidentate phosphorus-containing ligand is selected from the group consisting of a phosphite, a phosphonite, a phosphinite, a phosphine, and a mixed phosphorus-containing ligand or a combination of such ligands and the bidentate phosphorus-containing ligand gives acceptable results according to at least one protocol of the 2-Pentenenitrile Hydrocyanation Test Method; b) controlling X and Z, wherein X is the overall feed molar ratio of 2-pentenenitriles to all unsaturated nitriles; and Z is the overall feed molar ratio of hydrogen cyanide to all unsaturated nitriles; by selecting a value for X in the range of about 0.001 to about 0.5; and a value for Z in the range of about 0.5 to about 0.99; such that the value of quotient Q, wherein Q = X [ ( moles ⁢ ⁢ 3 ⁢ ⁢ PN + 4 ⁢ ⁢ PN ⁢ ⁢ in ⁢ ⁢ the ⁢ ⁢ feed ) / ( moles ⁢ ⁢ all ⁢ ⁢ unsaturated ⁢ ⁢ nitriles ⁢ ⁢ in ⁢ ⁢ the ⁢ ⁢ feed ) ] - Z is in the range from about 0.2 to about 10, wherein 3PN is 3-pentenenitriles and 4PN is 4-pentenenitrile; c) withdrawing a reaction product mixture comprising adiponitrile, 2-methyl-glutaronitrile, ethylenically unsaturated nitriles, the catalyst composition, and catalyst composition degradation products; and wherein the ratio of the concentration of 2-pentenenitriles to the concentration of 3-pentenenitriles in the reaction mixture is in the range from about 0.2/1 to about 10/1; d) extracting at least a portion of the reaction product mixture with an extraction agent selected from the group consisting of aliphatic hydrocarbons, cycloaliphatic hydrocarbons, and mixtures thereof to obtain an extract phase comprising the extraction agent and the catalyst composition and a raffinate phase comprising adiponitrile, 2-methylglutaronitrile, ethylenically unsaturated nitriles, catalyst composition degradation products, and the extraction agent; and e) distilling the extract phase to obtain a first stream comprising the extraction agent and a second stream comprising the catalyst composition.