Orthogonal Design and Optimization of Na_2WO_4·2H_2O Catalysts for Cyclohexanol/Cyclohexanone to Adipic Acid

Na_2WO_4·2H_2O catalyst for cyclohexanol/cyclohexanone to adipic acid and its operation condition were screened by orthogonal experiments designed upon basis of selected variables. Variance analysis was made on the results, the major influential factors were obtained: the kind of ligands, the amount of ligand, reaction time and amount of the catalyst and reaction condition optimised. Adipic acid yield of 76.6 % was attained under the optimum condition: the amount of sulphosalicylic acid is 1.8 mmol, cyclohexanol/cyclohexanone is 1/2, the amount of catalyst is 2.0 mmol and reaction time is 8 h.