Influence of the Heating Rate on the Combustion of Coal with Paper Waste

Abstract

Coal consumption in heating may be decreased by switching to solid-fuel mixtures. In the present work, the influence of the heating rate on the combustion of coal with paper waste is studied. Mixtures with 25, 50, and 75% waste are considered. By thermal analysis in an oxidative medium with an air flow rate of 50 mL/min, at heating rates of 10, 20, and 30°C/min, the following combustion characteristics are determined: the maximum rate of mass loss and the corresponding temperature; the ignition temperature of the coke residue; the temperature at which combustion ends; the combustion index; and the mean reactivity of the fuel. The results show that, on increasing the heating rate, the temperature range characterized by combustion of volatiles and coke residue is shifted to higher values. The change in the temperature ranges corresponding to different stages of combustion is found to improve mixture combustion even with increase in ignition temperature of the coke residue. Threefold increase in the heating rate increases the combustion index (by 407%), while the mean reactivity increases by 134%. Increase in the mixture’s content of paper waste improves the basic combustion characteristics on account of its high content of volatiles.