Patent ID: 7659422

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 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; 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 about 0.2/1 to about 10/1; wherein the catalyst precursor composition comprises a zero-valent nickel and at least one bidentate phosphite ligand; and wherein the bidentate phosphite ligand is selected from a member of the group represented by Formulas I and II, in which all like reference characters have the same meaning, except as further explicitly limited: wherein each R 1 is independently selected from the group consisting of methyl, ethyl, and primary hydrocarbyl of 3 to 6 carbon atoms; each R 2 is independently selected from the group consisting of primary and secondary hydrocarbyl of 1 to 6 carbon atoms; and each R 11 , R 12 , R 13 , R 21 , R 22 , and R 23 is independently selected from the group consisting of H, aryl, and a primary, secondary, or tertiary hydrocarbyl of 1 to 6 carbon atoms.