Coal Analysis

What is the Coal?

 

Coal is a sedimentary rock that is included in the fossil fuels in the group of energy sources that has been used in industry for hundreds of years and has economic value. Although coal consists mostly of carbon, it contains varying amounts of different elements (mainly hydrogen, sulfur, oxygen and nitrogen). Coal containing free or compound carbon is one of the most preferred energy sources thanks to its widespread availability in the world, ease of transportation, convenience of storage facilities, reliability of use, low cost compared to other fossil fuels and similar features.

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What are the Analyzes Applied to Coal?

In areas where coal is used, certain quality standards must be met. It may also be necessary to analyze the physical properties of coal for some applications. Coal is usually tested before being use for analysis. Tests and analyzes applied to coal are determined by international standards organizations (e.g. ASTM, ISO, DIN).

 

There are tests and analyzes applied to coal:

 

· Ash Fusion Analysis: It determines how coal ash will behave when heated in an industrial furnace or bunker.

· Ash Content Analysis: It determines the amount of non-combustible material in a coal sample.

· Calorific Value Analysis: It determines the quality of the coal by measuring the calorific value of the coal. It is measured using bomb calorimeters, also known as coal analyzers.

· Fixed Carbon Analysis: It determines the amount of non-volatile carbon remaining in a coal sample after combustion.

· Float – Sink Test: It determines the relative amount of coal that can be separated from the bound rock and minerals.

· Hardgrove Grindability Index: It determines how easily the coal can be crushed.

· Analysis of major and minor elements by X-Ray fluorescence: It determines the elemental composition of coal and coal ash.

· Petrographic Analysis: It examines the microscopic components of coal.

· Proximate Analysis: It determines moisture, volatile matter, ash yield and fixed (relative) carbon content in coal.

· Sulfur Forms: It determines different types of sulfur in coal.

· Trace Element Analysis: It determines the elemental composition of coal and coal ash.

· Ultimate Analysis: The number of main elements in the coal sample, namely carbon, hydrogen, nitrogen, sulfur, and oxygen determine the amount.

 

What is the Coal Rank?

Coal rank is the name listed according to the degree of charring of the coals. Coal with the least coal rank is called peat. The type of coal with the highest coal ranking is anthracites. The exact order of coal is as follows:

 

· Turf

· Lignite

· Sub-bituminous Coal

· Anthracite Coal

· Non-bituminous

 

How to Determine the Calorific Value of Coal?

 

The calorific value of combustible materials such as coal can be determined by using a bomb calorimeter. The bomb calorimeter is a laboratory instrument used to analyze the calorific value of solid and liquid combustible materials. The calorific value of the coal refer the energy it will give when it is burned. To measure the quality of coal, its calorific value must be determined. The calorific value of a coal is also affected by many parameters such as the content of hydrogen, ash, moisture, volatile content, in addition to the oxygen and carbon contained in the coal.

 

To determine the calorific value of coal, a certain amount of coal sample is placed in the decomposition vessel of the bomb calorimeter. The decomposition vessel containing the sample is surrounded by an analysis chamber filled with water. By burning the coal sample inside the analysis chamber, heat is generated in the decomposition vessel and the water surrounding the chamber is heated. The calorific value of the coal is determined by measuring the difference between the initial temperature of the water and the heat generated as a result of combustion and the temperature after the water is heated, and the calculations made. This value is the gross calorific value of the coal.

 

What is the Gross Calorific Value?

 

It is the energy value released as a result of the complete combustion of the coal sample with the bomb calorimeter. When calculating the gross calorific value, a verification calculation should be made regarding the nitric acid, sulfur content, ignition wire energy and catalyst energy released during the combustion process during the analysis. The effect of other elements in the coal is not considered in the calculation of the gross calorific value. Therefore, the gross or upper calorific value (HCV: higher calorific value) is the calorific value of a fuel when it is fully burned. Since the effect of other parameters is not calculated, the upper calorific value is always higher than the lower calorific value. The calorific value measured by the bomb calorimeter is the gross calorific value.

 

What is the Net Calorific Value

 

It is the energy value when the water in its content turns into steam completely as a result of the complete combustion of the coal sample. When calculating the net calorific value from the gross calorific value of coal, it is necessary to know the mass ratio of total moisture, hydrogen, oxygen and nitrogen. These ratios in the coal content are analyzed using different devices and are included in the calculation after combustion process by bomb calorimeter.

 

 

Gross and Net Calorific Values of Coal

 

When calculating the calorific value of the coal, the basis of the coal sample is important. For this reason, the basis of the coal sample should be known and appropriate calculations should be made while performing the calorific value analysis with a bomb calorimeter. For accurate gross and net calorific value calculations in coal samples, you can review the "Application Note for Calculation of Gross and Upper Calorific Value of Coal Samples".


With Which Device Is Coal Heating Value Measured?

 

Coal calorific value is measured with a bomb calorimeter device. Bomb calorimeter or isoperibol calorimeter is a type of calorimeter used to determine the calorific value of samples. The calorific value of the coal sample can be easily calculated with the calorimeter bomb. The upper calorific value of a coal sample can be calculated using a bomb calorimeter. For detailed information about bomb calorimeter, you can visit our isoperibol calorimeter page. At the same time, you can contact us for detailed information about the bomb calorimeter and coal calorie analysis!

With Which Device Is Coal Heating Value Measured?

Coal calorific value is measured with a bomb calorimeter device. Bomb calorimeter or isoperibol calorimeter is a type of calorimeter used to determine the calorific value of samples. The calorific value of the coal sample can be easily calculated with the calorimeter bomb. The gross calorific value of a coal sample can be calculated using a bomb calorimeter. For detailed information about bomb calorimeter, you can visit our isoperibol calorimeter page. At the same time, you can contact us for detailed information about the bomb calorimeter and coal calorie analysis!

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