Patent ID: 7709674

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 a catalyst precursor composition, by continuously feeding the ethylenically unsaturated nitriles, the hydrogen cyanide, and the catalyst precursor composition; 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 0.001 to 0.5; and a value for Z in the range of 0.5 to 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 0.2 to 10, wherein 3PN is 3-pentenenitriles and 4PN is 4-pentenenitrile; and c) withdrawing a reaction product mixture comprising adiponitrile; wherein the ratio of the concentration of 2-pentenenitriles to the concentration of 3-pentenenitriles in the reaction mixture is in the range from 0.2/1 to 10/1; wherein the catalyst precursor composition comprises a zero-valent nickel and at least one multidentate phosphorus-containing ligand; wherein the multidentate 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 members; and wherein the multidentate phosphorus-containing ligand gives acceptable results according to at least one protocol of the 2-Pentenenitrile Hydrocyanation Test Method.