Thermal decomposition kinetics of three anthraquinone hazardous waste

Anthraquinone nitro compounds are the important intermediate and hazardous waste in dye production. In order to understand the thermal decomposition characteristics of three typical dye wastes: 1-nitroanthraquinone, 1,5-dinitroanthraquinone and 1,8-dinitroanthraquinone, the dynamic and isothermal experiments were conducted by differential scanning calorimeter. The dynamic results indicate that these substances are decomposed after melting except for 1,5-dinitroanthraquinone and the specific heat release of these substances is higher than 800 J/g. Calculated by Friedman kinetic analysis, the activation energy of first step decomposition of 1,8-dinitroanthraquinone is consistent with 1-nitroanthraquinone, and the second step decomposition is consistent with the third step of 1,5-dinitroanthraquinone. Refer to the two kinetic models of 1-nitroanthraquinone (autocatalytic) and 1,5-dinitroanthraquinone (n-order + autocatalytic + autocatalytic), the model of autocatalytic + autocatalytic were established for 1,8-dinitroanthraquinone. The prediction of the self-accelerating decomposition temperature indicates that coupling of phase transition and decomposition does not increase the thermal risk.

Automated summary

This study investigated the thermal decomposition characteristics of three typical dye wastes by conducting dynamic and isothermal experiments using a differential scanning calorimeter. The results showed the different kinetic features and autocatalytic mechanisms during the decomposition process of these substances.