Investigation on the catalytic effect of AAEMs in Zhundong coal on the combustion characteristics of Changji oil shale and its kinetics

摘要

Changji oil shale(CJ) is characterized by high ash content, low oil content and poor combustion performance. It is widely used in local power plants to generate electricity for its abundant reserves and high transportation costs. Catalytic combustion has been considered an effective way to enhance combustion performance. In the present work, the effects of catalyst, heating rate and atmosphere on combustion performance of CJ were analyzed. Their kinetic behaviors were studied using Coats-Redfern, Flynn-Wall-Ozawa and Friedmen methods. According to the result here, the order of the catalytic effect on the ignition characteristic(C-i), burnout characteristic(C-b) and comprehensive combustion index(S) of oil shale was Zhundong coal (ZD)sodium and calcium sodium calcium. With the rise in heating rate and in oxygen content, C-i, C-b and S were improved. The mixed fuel burned in O-2/N-2 atmosphere exhibited better combustion characteristics than that burned in O-2/CO2, whereas the former had higher activation energy values (E) than the latter. The E value of mixed fuel was the lowest, and sodium acetate exhibited the best catalytic effect. The E values of Changji oil shale and mixed fuel at different conversion rates fluctuated, while the E values of Zhundong coal dropped exponentially. (C) 2019 Elsevier Ltd. All rights reserved.