Analysis Procedures of Coal

In coal fired power plants coal is a main fuel for combustion purpose. Before use of coal different tests are to be carried out to analysis the constituent elements and some undesirable contamination in the coal. Discuss the analysis procedures of the coal.

The analysis of coal is as follows C=82%, H=6%,O2=4% and remaining is ash. Determine the amount of theoretical air required for complete combustion. If the actual air supplied is 40% in excess and 80% of given carbon is burnt to CO2 and remaining is CO. Conduct the volumetric analysis of dry products of combustion.

1. PBL Case Study Presentation in Group for the Mid-Semester Examination of Thermodynamics-II Teacher:- Prof. Dr. Abdul Fatah Abbasi Group:- A Subgroup:- A1 Dated: 27-07-2020 Group Members 18ME01 Muhammad Taha 18ME02 Usama Kaleem 18ME05 Umama Qureshi 18ME06 Awais Ali Memon 18ME07 Saad- ud -din 18ME08 Wahid Dino 18ME09 Syed Muhammad Hassan

2. Problem Statement In coal fired power plants coal is a main fuel for combustion purpose. Before use of coal different tests are to be carried out to analysis the constituent elements and some undesirable contamination in the coal. Discuss the analysis procedures of the coal. The analysis of coal is as follows C=82%, H=6%,O2=4% and remaining is ash. Determine the amount of theoretical air required for complete combustion. If the actual air supplied is 40% in excess and 80% of given carbon is burnt to CO2 and remaining is CO. Conduct the volumetric analysis of dry products of combustion.

3. What is a Fuel? Any material that can be burned and give us thermal energy for our useful work those materials is known as FUEL. Mostly organic compounds are being used as best thermal energy producers ,so we often choose hydrocarbon ( carbon and hydrogen subsuming compounds) as fuel. Types of Fuels There are three types of fuels . Solid ( mostly coal) Liquid ( mostly gasoline) Gas (mostly sui gas) Now , actually we are discussing about coal as mention in our given question.

4. Analysis Procedures of Coal

5. Coal Coal is an organic rock (as opposed to most other rocks in the earth's crust, such as clays and sandstone, which are inorganic); it contains mostly carbon (C), but it also has hydrogen (H), oxygen (O), sulfur (S) and nitrogen (N), as well as some inorganic constituents (minerals) and water (H2O)

6. Properties of Coal Because of wide variations in the composition and properties of coals, a classification system is needed to describe the different kinds available for use in homes and power plants

7. Need For Analysis Worldwide, coals are used for various purposes such as generation of electricity, iron and steel making, cement production, paper manufacturing and chemical and pharmaceutical productions. However, the application of coals in manufacturing industries depend on its types, grades and quality, which are function of temperature and pressure and the length of time of its formation . There are two classes of coals: low rank coals (the lignite and subbituminous) and hard coals (the bituminous and anthracite).

8. Need For Analysis Rank refers to steps in a slow, natural process called “coalification,” during which buried plant matter changes into an ever denser, drier, more carbon rich, and harder material. Low rank coals are characterized with high moisture content and hard coals with high carbon/energy content. Both low rank and hard coals can be used in railway transportation, power generation and cement manufacturing because high quality coals is not pre-requisite. Thus, little or no laboratory analysis may be required after exploration and prior to the usage. However, in iron and steel making industries, smokeless fuel manufacturing industries and town gas supply, high quality coal is needed This implies that there is a need for coal analysis to meet the desire objectives.

9. Types of Analysis of Coal.

10. Ultimate Analysis The determination of the percentage of constituent elements of a chemical substance. In case of coal and coke, the determination of carbon and hydrogen in the material as found in the gaseous products of its complete combustion the determinations of Sulphur, nitrogen and ash in the material as a whole, and the calculation of oxygen by difference The principal reason for the ultimate analysis of coal is the classifications of coals according to rank, although it is often used for commercial and industrial purposes when it is most desirable to known the Sulphur content of coal also known as total analysis of coal.

11. Ultimate Analysis (contd.) 1) Carbon and Hydrogen :  

12. Ultimate Analysis (contd.) 2) % of Nitrogen  

13. Significance of Coal

14. Proximate Analysis of Coal. It subsumes quantitative determination of :- 1. % Moisture Higher percentage of moisture , lower the caloric value in outcome. Increase the cost of transport. Considerable amount of heat is lost in evaporation. 2. % Volatile Matter Higher value causes smoke ,long flame and decrease the caloric value. 3. % Ash High ash content decease the calorific value. 4. % Carbon High carbon percentage gives good quality coal, increase its calorific value.

15. Determination of moisture:- About 1g of finely powdered coal is weighed in silica crucible. The crucible is placed without lid an electric hot-air-oven , maintained at 105C for an hour . The crucible is then taken out , cooled in a desiccator and weighed for loss in weight. % moisture = ×100  

16. Determination volatile matter The coal in the crucible in in covered with a lid and placed in a muffle furnace maintained at 925 ± 20 C for 7 minutes. The crucible is cooled in air, then in desiccator and weighed again. % of volatile matter = × 100  

17. Determination of Ash The residual coal in the crucible in is then heated without lid in muffle furnace at 700 ± 50 C for half-an-hour. The crucible is then taken out , cooled first in air , then in desiccator and weighed. The residual is reported as ash on percentage basis. % of Ash =   Determination of Carbon Percentage of fixed carbon = 100 -% of ( moisture + volatile matter + ash)

18. Problem The analysis of coal is as follows C=82%, H=6%,O2=4% and remaining is ash. Determine the amount of theoretical air required for complete combustion. If the actual air supplied is 40% in excess and 80% of given carbon is burnt to CO2 and remaining is CO. Conduct the volumetric analysis of dry products of combustion. Data C = 82% H = 6% = 4% Ash = 8% Excess air = 40% Theoretical Air= ??  

19. Solution As we know 80% of carbon is burnt into and remaining into So for Carbon dioxide, C = 0.82 x 0.8 = 0.656 And for Carbon monoxide C = 0.82 - 0.656 = 0.164  

20. Solution(contd.) Now theoretical air can be found out by Theoretical Air 100/23[(8/3 C+8H2+S)-O2] C + O 2 = CO 2 1kg + 8/3kg = 11/3  

21. Solution(contd.) required for is 2H 2 + O 2 = 2H 2 O 1kg + 8 kg = 9 kg H = 8 x 0.06 = 0.48 kg So total oxygen required will be  

22. Solution(contd.) So , theoretical air will, Theoretical air = Since, 3.326  

23. Solution(contd.) Thus, mass of supplied with excess air will Masses of the product will kg kg  

24. Solution(contd.) Products Mass (kg) Molecular Mass No of Mole %Volume 2.40533 44 0.05466 47.575% 0.382667 28 0.013667 11.895% 0.54 28 0.0192 16.711% 0.87568 32 0.02736 23.814% Total 100% Products Mass (kg) Molecular Mass 2.40533 44 0.05466 47.575% 0.382667 28 0.013667 11.895% 0.54 28 0.0192 16.711% 0.87568 32 0.02736 23.814% Total 100% Volumetric Analysis

25. Thank You