Method of preparing acrylonitrile dimer

A method of preparing an acrylonitrile dimer, the method comprising:

• supplying an acrylonitrile monomer, a phosphorus-based catalyst, and a solvent to a reactor to perform a dimerization reaction to produce dimerization reaction products, wherein the solvent comprises an alcohol and does not contain an aromatic hydrocarbon solvent;
• cooling the reaction products to crystallize the phosphorus-based catalyst;
• separating the crystallized phosphorus-based catalyst from the reaction products containing an unreacted acrylonitrile monomer, the acrylonitrile dimer, and the solvent;
• and
• supplying the reaction products from which the phosphorus-based catalyst is separated to a distillation column to separate the acrylonitrile dimer,
• wherein in separating the acrylonitrile dimer, the reaction products from which the phosphorus-based catalyst is separated are supplied to the distillation column, a first fraction containing the unreacted acrylonitrile monomer and the solvent are separated to an upper portion of the distillation column from which it is collected, and a second fraction containing the acrylonitrile dimer is separated to a lower portion of the distillation column from which it is collected, and
• wherein cooling the reaction products and separating of the crystallized phosphorus- based catalyst are performed prior to separating any of the unreacted acrylonitrile monomer. the solvent, or the acrylonitrile dimer contained in the reaction products.