The invention provides a
hydrocyanation process for the production of
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 ethylenically unsaturated nitriles,
hydrogen cyanide, and a 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 from about 0.001 to about 0.5, and a value for Z in the range from about 0.5 / 1 to about 0.99 / 1, such that the value of quotient Q, whereinQ=X[(moles3PN+4PNinthefeed) / (molesallunsaturatednitrilesinthefeed)]-Zis in the range from about 0.2 to about 10, wherein 3PN is 3-pentenenitriles and 4PN is 4-pentenenitrile; andc) 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 from about 0.2 / 1 to about 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; andwherein the multidentate phosphorus-containing ligand gives acceptable results according to at least one protocol of the 2-Pentenenitrile
Hydrocyanation Test Method.