Synthesis Of Cyclohexylamine

Cyclohexylamine is a widely used organic chemical raw material and a chemical immediate in fine chemical industry. Six synthesis methods for cyclohexylamine are reviewed and compared through scientific literature search, and a synthesis process, which is rational in economics and can possibly be industrialized, is put forward. Cyclohexylamine and dicyclohexylamine are gained through ammonolysis of cyclohexanol with cyclohexanol as a raw material over hydrogen and addition of excess ammonia.Hydrogenation and dehydrogenation are the key points for catalytic ammonolysis of cyclohexanol. Metal-supported oxides of Cu and Ni is used as catalysts to prepare CuO/NiO/ γ -Al2O3 catalyst, the active components ratio is Cu/Ni/Al2O3=l8/15/67. Evaluation shows that cyclohexanol catalytic ammonolysis catalyst has good catalysis performance.Mechanism for cyclohexanol catalytic ammonolysis to synthesize cyclohexylame and dicyclohexylamine is introduced, systemic analysis methods, design of small scale test device are suggested, selection of cyclohexylamine is 80%~90%, selection of dicyclohexylamine is 5%~15%,the total selection of cyclohexylamine and dicyclohexylamine is above 97%, single yield is above 90%. The best reaction conditions for cyclohexylamine are at temperature of 190 ℃,volume space-velocity at 0.3h-1, the molar ratio of cyclohexanol to ammonia of 8,pressure of 0.8MPa, the molar ratio of hydrogenation to cyclohexanol of 1. The best reaction conditions for cyclohexylamine and dicyclohexylamine are at temperature of 190 ℃,volume space-velocity at 0.4h-1, the molar ratio of cyclohexanol to ammonia of 6,pressure of 0.9MPa, the molar ratio of hydrogenation to cyclohexanol of 1.Exploring the reaction conditions to improve the ratio of dicyclohexylamine. Above 99.5% cyclohexylame and above 95% dicyclohexylamine are gained in purity through purification and separation.Primary thermodynamics analysis shows it is a heat-removing reaction, the heat of reaction is 2774cal/mol. The pilot-plant device validates small scale device, cyclohexylame and dicyclohexylamine reach 92% in a single yield, recycling of unconverted cyclohexanol and excess ammonia is explored. The process has many advantages such as high yield, available raw materials, moderate cost, mild reaction conditions, good quality and environmental protection, it is very fit to be industrialized.