Effect of Coal Properties on the Generation of
By-Products

Abstract

Heating of a coal under anaerobic condition is called carbonization or destructive distillation.Carbonization produces solid (coke) and gas (coke oven gas), by-product of coke making process. Generally one ton of coal produces 0.24 ton of crude coke oven gas (COG) and 0.76 ton of coke. Because of higher calorific value of COG, global demand is increasing day by day.It possess high energy content due to the presence of more percentage of hydrogen.Furthermore, COG calorific value and its generation while carbonization greatly depends upon the type, seam, rank and aromaticity of coal. The aim of carbonization process is to produce the quality coke which is used in the blast furnace for the reduction of iron from iron ore. Once again the quality of coke depends upon the coking ability of coal but in India the availability of coking coal is decreasing with the time so it is important to study the characteristics of weakly and non-coking coal to fill the void of coking coal and to satisfy the demand of blast furnace. In this work, it is focused more on the quality and quantity of coke making by-products from different type of coals and paid less attention the quality and quantity of coke. In this study different types of coals were selected based on their rank, type and volatile content. Effect of different coal properties on the generation of by-products was studied. Chemical and petrographic properties are considered to study their effect on by-products such as COG, coal tar, ammonia and hydrogen sulphide. For the above study, Thermogravimetric mass spectrometry (TG-MS) and Jenkner apparatus was used. FTIR of coals has been done to gain the insight of functional groups present in the structure.TG–MS technique was used to study the thermal analysis of coals followed by the analysis of gas compounds based on the mass to charge ratio (m/z). TG-MS carried out under inert atmosphere, 11000C and at the heating rate of 3 and 50C/min. Jenkner test was conducted to study the quantitative analysis of by-products.Results are suggesting that decrease in rank of the coal increased the generation of by-products and vice versa. Yield of coke oven gas (COG), coal tar and ammonia (NH3) is more in top charging compared stamp charging but hydrogen sulphide(H2S) is more in stamp charging compared to top charging because less inter particle distance.