1266
Energy & Fuels 2003, 17, 1266-1276
Combustion Characteristics of Coal Briquettes. 1. Thermal Features N. Emre Altun,† Cahit Hicyilmaz,*,† and A. Suat Bagci‡ Departments of Mining Engineering and Petroleum and Natural Gas Engineering, Middle East Technical University, 06531 Ankara, Turkey Received December 13, 2002. Revised Manuscript Received April 28, 2003
In this study, the influence of some of the most important briquetting parameters on the combustion and thermal properties of coal briquettes were studied in detail. For this purpose, briquettes with various organic (molasses, sulfide liquor, carboxyl methyl cellulose, Peridur XC3, and Peridur C10) and inorganic agents (cement and bentonite) were prepared, to be combusted in a reaction cell that was complemented with a continuous gas analyzer unit. Furthermore, using the binding agent that provided the most favorable thermal features, the effect of the binder quantity, as well as the amount of water addition, was successfully determined with fractions of 5%, 10%, and 15%. The influence of the relevant variables on the thermal behavior of the coal briquettes were expressed and investigated, using the effluent gas analysis method, by considering (i) the changes in the amounts of evolved CO and CO2 and consumed O2 gases, as a function of temperature and time; (ii) the O2 peak temperatures and times; and (iii) the residue that remained at the end of each run. The binder type, as well as the amount of binder agent and water addition, had a significant effect on the thermal behavior and combustion efficiency of the coal briquettes.
Introduction In today’s coal industry, one of the most severe problems is the huge amount of coal fines that are accumulating very rapidly, because of the easily friable characteristic of most of the coals, tough transportation and prolonged storage periods, new-generation coalmining techniques, and slime formation in the coal washeries. These and similar reasons lead to a greater degree of particle disintegration and pulverization of coal than ever observed previously. Being a nonrenewable fossil fuel, coal is one of the most important energy sources from which utilization at the highest possible extent is still a critical objective. However, undesired coal fine production at extremely large amounts (the amount of particles 2 2-1.41 1.41-0.841 0.841-0.589 0.589-0.420 0.420-0.297 0.297-0.250 0.250-0.208 0.208-0.149 0.149-0.105 0.104-0.074 0.074-0.053 0.053-0.044
