Estimation of total carbon, hydrogen, sulfur and gross calorific value by using multi lineer regression method

Energy need in the world has been increasing with rising of human population. In the world, thermal and electricity energy are mainly produced by using hydrocarbon fossil fuels. Over the 40% of total power generation of the world is produced from coal-based power plants. The power generation forecast of all over the world shows that by the increase of the power generation, the use of coal in power generation plants is proportionally increased. 42% of total coal-based power generation of Turkey is produced by using traded coal which is mostly hard coal. In addition, the 42% of this generation is produced by using traded coal in Turkey. These coals mainly are bituminous and subbituminous coal. Also, an important part of the imported coal mainly consists of heat-based coals. In addition to being a major source of energy among fossil fuels, coal has a wide range of uses from raw material in iron and steel production to waste water purification. Coal is an organic sedimentary rock, mainly composed of carbon, hydrogen, nitrogen and oxygen elements. In addition to organic compounds in coal, coal includes inorganic structures. Carbon, hydrogen and sulfur are present in organic structure and inorganic structure in coal. Inorganic structures include mainly Fe, Si and Al and trace elements. Ash formation takes place when inorganic minerals are oxidized in coal. However, the ash content is not equal to the mineral content in the coal. Coal has been formed as a result of heat, pressure and microbiological effects during millions of years. The first phase of the coalification period is the peatification stage from the plant residue the consequences of the phsical, chemical, microbiological effects and tectonic movements. With the removal of H2O, CO2 and O2 molecules in the peat, the peat is converted into lignite, lower bituminous coal and hard coal respectively. It is also converted to anthracite by the removal of H2 from the coal. When the coal formation process stops at any stage, the process ends and is not reversible. Moisture, ash, volatile matter, fixed carbon content, carbon, hydrogen, sulfur content and thermal value analyzes are the most commonly used ones. These analyzes are carried out by national and international test methods. Moreover, there are empirical equations in the literature. The best-known equation is the estimate of the hydrogen content applied using the Seyler method which is described in the EN ISO 1928 method. However, this method is applied for hydrogen content only if there is 3% hydrogen content or more in coal. These empirical calculations were made by using the least squares method and multiple linear regression methods in the literature. Due to the fact that Turkey has been dependent on the foreign resources, it is invented in domestic resources. Even if domestic inventments are increased, the use of imported hard coal is an avoidable fact. Coals are used for a wide of industrial areas in terms of different physical and chemical properties. For this reason, the applied analysis in coal make its importance high. In this study, 84 samples of coal which has different ranks and properties are used. 41 of these coal samples are lignite, 41 of the coals are hard coals and the others are anthracite. Moisture, ash content, volatile matter, fixed carbon, carbon content, hydrogen content, sulfur content, gross calorific value and net calorific value are analysed for these coal samples. The results of these analysis are converted from original basis form to dry basis form. The correlation graphs are drawn by using the obtained results and evaluated. In the consequence of these evaluations, multilinear regression analysis is performed by the least squares method. Carbon, hydrogen and sulfur equations in dry basis are derived from the results of ash, volatile matter, fixed carbon in dry basis; also, carbon, hydrogen and sulfur equations are derived from the results of ash, fixed carbon in dry basis and volatile matter in moisture and ash free basis. In addition, gross calorific value equations in dry basis are derived from the results of ash, carbon, hydrogen, sulfur content in dry basis, the results of ash, volatile matter, carbon, hydrogen, sulfur content in dry basis, the results of ash, volatile matter, fixed carbon, carbon, hydrogen, sulfur content in dry basis and, the results of carbon, hydrogen, sulfur content in dry basis. Finally, the content carbon, hydrogen and gross calorific value are estimated by using volatile matter, all in original basis. The derived formulas are practiced for general analysis, lignite and, hard coal.