Study On Purification Process Of Caprolactam Produced With Toluene

The purpose of this paper is to study technics of purifying caprolactam from amide oil produced with toluene.This paper study the effect of operation condition of crystallization (use isopropyl ether and methyl tert-butyl ether)and Hydrogenation(use amorphous alloy catalyst)on the value of potassium permanganate(PM).When use isopropyl ether as crystallization solvent,the effects of dissolve temperature, solvent volume and crystallization temperature on the value of potassium permanganate (PM) and yield were studied by using orthogonal experimental method. The best condition of crystallization is that dissolve temperature is 55℃, solvent volume is 60ml isopropyl ether /10g caprolactam and crystallization temperature is 20℃. Repeated crystallization can significantly improve caprolactam's value of potassium permanganate(PM).It is easy to recover crystallization mother liquor.When use methyl tertiary butyl ether as crystallization solvent, the effects of crystallization temperature,crystallization time,volume of solvent and cooling rate on the value of potassium permanganate (PM) and yield were studied and optimised by using orthogonal experimental method .The best condition of crystallization is that crystallization temperature is 5℃,crystallization time is 80min,volume of solvent is 75ml methyl tertiary butyl ether/10g caprolactam,cooling rate is 0.2℃/min. Amorphous alloy catalyst were used in the reaction of cyclohexanonehydrogenation based on the orthogonal experimental method.The effects of reaction temperature,reaction pressure,mass of catalyst and reaction time on the conversion of cyclohexanone were studied.The best operation condition is that reaction time is 1.5h,reaction temperature is 110℃,reaction pressure is 1.2MPa,catalyst amount is 4 g/200ml.Then it is used in the reaction of caprolactam hydrogenation with different concentrations.