Coal Classification,composition & basis
- 4. CONTENTS What is Coal? Origin of Coal Reservoir of Coal in Pakistan Classification on the basis of rank of Coal Classification on the basis of Proximate Analysis Classification involving both Proximate analysis and Calorific value Basis for Coal Conclusion
- 5. WHAT IS COAL? Coal is a non-renewable solid fossil fuel comprising of black to brownish sedimentary rock with a high amount of carbon and hydrocarbons.
- 6. ORIGIN OF COAL Coal is called fossil fuel because it was formed from the remains of vegetation that grew on as long as 400 million years ago. Most of our Coal was formed 300 million years ago. As plants and trees died, physical and chemical alteration of plant material started. The plant debris accumulated in various wet environments and buried by sand, silt and mud. As a result of temperature and pressure, metamorphosis occurs to produce various types of coal.
- 8. RESERVOIR OF COAL IN PAKISTAN Sindh 186.5 Billion tonnes Thar Desert 175 billion tonnes The Thar coalfield is TharParkar, 6th largest Coal reservoir in the World, and discovered by Geological survey of Pakistan (GSP) & United State Agency for International Development Punjab 235 million tonnes Balochistan 217 million tonnes KPK 90 million tonnes
- 10. STATISTICS OF COAL CONSUMPTION IN PAKISTAN
- 11. CLASSICATION ON THE BASIS OF BURNING CHARACTERISTICS OF COAL This is the oldest classification based on the visual observations and the burning characteristics of Coal. According to this Coal is classified into; 1. Peat 2. Lignite 3. Bituminous 4. Sub-Bituminous 5. Anthracite
- 12. PEAT • Peat is also known as turf. • First stage of transformation. • Contains less than 40 to 50 % Carbon. • Contains sufficient volatile matter and lot of moisture.
- 13. LIGNITE • Lower grade coal. • Moisture content is High. • 40 to 55 % carbon content. • Contains brown to black woody substances. • It undergoes spontaneous reaction when it is burnt.
- 14. BITUMINOUS • Derived its name after a liquid called bitumen • Soft Coal ; Most widely available and used Coal. • It is usually black in colour. • It burns with flame & smoke • Fixed carbon content is 45 to 75%
- 15. SUB- BITUMINOUS • Transition state between Bituminous and Anthracite • Lower oxygen and moisture content • No traces of any vegetation matter • Carbon is 70 to 80%
- 16. ANTHRACITE • Hardest coal • Black in colour and lustrous • Very little volatile matter • Negligible amount of moisture • 80 to 95 % carbon • Burns with smokeless flame
- 19. CLASSIFICATION BASED ON PROXIMATE ANALYSIS • Frazer’s classification: • In 1887, he used fuel ratio to classify coal as given: • Fuel Ratio is defined as ratio of fixed carbon to volatile matter • Coals of lower rank than bituminous were not considered
- 20. CLASSIFICATION INVOLVING BOTH PROXIMATE ANALYSIS AND CALORIFIC VALUE Parr’s classification: It is the simplest method for determining the amount of mineral matter present in a coal is to determine the ash and sulfur contents and to make corrections for the changes taking place in these during combustion.
- 21. CLASSIFICATION INVOLVING BOTH PROXIMATE ANALYSIS AND CALORIFIC VALUE The Parr’s formula for Classification is: Total inorganic matter = Moisture +1.08 Ash +0.55 Sulfur, where moisture, ash, and sulfur represent the percentages of these substances found by analysis of the coal.
- 22. BASIS FOR COAL ASTM made standards for the analysis of solid fuel i.e coal. The different analysis of coal can also reported in terms of some arbitrary basis which are described below:
- 23. 1) RUN-OF-MINE (ROM) • When the coal directly obtained from a mine is analyzed by elemental or proximate analysis. • This type of data are called run-of-mine
- 24. 2) AS-RECEIVED • After extraction from mine, coal is transported to the receiver. • The analysis data obtained at this point is called as- received.
- 25. 3) AIR-DRIED • When analytical data are collected after air drying the coal at a standard condition of 400oC and 60% relative humidity, • The data are called at air-dried basis.
- 26. 4) DRY • When the effect of moisture content is removed from the analytical data. • After this step coal is said as dry basis.
- 27. 5) DRY AND ASH-FREE (D.A.F) • When the data are reported excluding the effect of ash content, then it is said d.a.f basis
- 28. 6) DRY AND MINERAL MATTER FREE (D.M.M.F) • When effects of both moisture and mineral matter are removed from the analytical data, then it is reported as d.m.m.f basis. This is the data of pure coal only.
- 29. 7) MOIST-MINERAL-MATTER-FREE • This is the basis where the effect of mineral matter is excluded, only pure coal and moisture are taken to report the data.
- 30. CONCLUSION From the above discussion, it is concluded that coal is an economical solid fuel which can be classified into many types and composition. Moreover, we can decide after that which basis is used for Coal.