Kinetic Analysis of Depolymerization Products of Waste Nylon 6 in Subcritical and Supercritical Water

Based on previous studies,the sort of main depolymerization product of waste nylon 6 in subcritical and supercritical water was further determined. The influences of temperature,pressure and reaction time on the yield of the liquid phase products were studied. The depolymerization mechanism was proposed as well. Results showed that the main products in liquid were aminocaproic acid and caprolactam,with the maximum yield as 6.6% and 96% respectively. The reaction scheme of nylon 6 decomposition is continuous, and nylon 6 is decomposed into aminocaproic acid by hydrolysis followed by cyclodehydration to caprolactam or decomposition further to lower molecules. At each reaction condition,k values were determined and activation energy Eawas calculated.