Determination of proximate analysis and calorific value of coal by thermal analysis

This thesis examines the use of the thermogravimetric analyzer (TGA) and differential scanning calorimeter (DSC) in coal analysis. One foreign coal and seven local coal samples, of different ranks, were used. The Shimadzu Thermogravimetric Analyzer (TGA-50) and Differential Scanning Calorimeter (DSC-50) were used in determining the proximate analysis and calorific value of coals, respectively. Reproducibility and repeatability of the experimental data were determined by statistical analysis. The effect of heating rates, specifically 10, 20 and 50 C/min., was also studied. The proximate analysis of three local coal samples obtained from the TGA were compared to the data obtained from the Department of Energy. The results of 50 C/min. showed the least percentage error with an average value of 7.58%. Based on statistical analysis, it was also found that the data obtained from the TGA experiment were repeatable. Results obtained at 10, 20 and 50 C/min. showed that proximate analysis varies at different heating rates. The calorific values of three local coal samples obtained from the DSC were compared to the data obtained from the Department of Energy. A correction coefficient was calculated to account for the different conditions in atmosphere and equipment. After introduction of the correction coefficient, it was found that the results at 10 C/min. showed the least percentage error with an average value of 4.79%. The results from the DSC experiment were repeatable and no significant differences were observed between heating rates of 10 C/min and 20 C.min