The inherent moisture content of South African Permian coals. Int. J. Coal Geol., 17:297-311. The inherent moisture content (IM) of coals impinges on many usages but little is known about the controls on this parameter in Gondwana coals. In the Permian coals of the main Karoo Basin the chief mediator of IM (on as as-received basis) is rank ...

ADB - Air-Dried Basis. In coal sample analysis, ADB neglects the presence of moistures other than inherent moisture while DB (dry-basis) leaves out all moistures, including surface moisture, inherent moisture, and other moistures.

Conventional methods used to analyze moisture, ash, fixed carbon, and volatile content in coal samples, are time consuming and costly. Near-infrared (NIR) spectroscopy is excellently suited to determine all parameters simultaneously in less than one minute without any sample preparation.

Proximate and ultimate analysis determination: The proximate analysis is used for the estimation of coal quality, which is helpful in thermal industries. It includes the determination of moisture, volatile matter (VM), ash and fixed carbon (FC), present in coal in weight percentage.

The inherent moisture in low-rank coals should be determined by ASTM procedure D 1412 (as indicated in procedure D388). Moisture can be determined by measuring the phase shift in a guided microwave train, the phase shift being related to the amount of moisture.

1.1 This standard (Part 1 ) prescribes the methods of test for coal and coke relating to proximate analysis including determination of moisture under different conditions.

X1.3 Brown (2) further refers to ( 1) "Free" or "adherent" moisture (essentially surface adsorbed) possessing the physical properties of ordinary water, (2) physically bound or" inherent" moisture of vapor pressure lowered by the small diameter of the pores of the coal structure in which it is absorbed, and (3) chemically bound ...

1.2 Since coal can vary from extremely wet (water-saturated) to completely dry, special emphasis must be placed on the sampling, sample preparation, and the moisture determination itself to ensure total reliability of measurement. Therefore, this standard entails collection of the gross sample, sample preparation, and the method of …

Moisture percent deter- mined by this test method may be used in conjunction with the air-dry moisture loss determined in Method D 2013 and Test Method D 3302 to determine total moisture in coal. Total moisture is used for calculating other analytical results to "as received" basis using Practice D 3180.

1.2 Since coal can vary from extremely wet (water-saturated) to completely dry, special emphasis must be placed on the sampling, sample preparation, and the moisture determination itself to ensure total reliability of measurement. Therefore, this standard entails collection of the gross sample, sample preparation, and the method of …

The role of temperature and moisture content on methane adsorption is well established for higher rank coals that produce thermogenically-derived gas. These parameters are sufficiently important that laboratory determination of the gas adsorption isotherm is usually undertaken at formation temperature and using equilibrium …

Moisture content in coal powder is a critical index because it controls the difficulty of coal handling and ultimately its combustion efficiency in coal-fired power plants. A unilateral proton nuclear magnetic resonance (NMR) scanner was applied in a laboratory to nondestructively quantify moisture content in powdered samples of brown and …

Request PDF | Experimental study on the effect of inherent moisture on hard coal adsorption–desorption characteristics | Coal is a complex geological body that is composed of organic material ...

Inherent Moisture (or Bed Moisture) is the moisture remaining in coal after natural drying in air. The Inherent Moisture is held within the molecular structure of the coal which can be removed only at temperatures greater than 100 °C. The other moisture in the coal is on the surface of the coal that can be evaporated in exposed …

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Inherent or equilibrium moisture is used for calculating moist mineral-matter-free calorific values for the rank classification of high-volatile bituminous coals. It is also used for estimating free or surface moisture, since total moisture is equal to the sum of the inherent moisture and the free moisture.

Low-rank coals have high inherent moisture content, and high yield of pyrolytic water formed from the functional groups in the coal during pyrolysis. …

Indian coals contain low inherent moisture (typically 5.5 %–9.5 % with an average of around 7.5 %) and moisture addition is through the surface moisture due to external sources [Bhatt and Rajkumar (2015)]. Coal obtained from mine is often subjected to hot air or oven drying to reduce the surface moisture content. The moisture that remains in …

The aim is to quantitatively understand the evaporation of inherent moisture and its overlapping with the subsequent volatile ignition and oxidation steps during pulverised coal combustion. A wet Victorian brown coal sample with the moisture content up to 30 wt.% and a size range of 63–104 μm has been tested.

1.1 This test method covers the determination of moisture in the analysis sample of coal or coke. It is used for calculating other analytical results to a dry basis. When used in conjunction with the air drying loss as determined in accordance with Method D 2013 or Practice D 346, each analytical result can be calculated to an as-received …

Ultimate analysis provides a convenient method for reporting the major organic elemental composition of coal. For this analysis, a coal sample is combusted in an ultimate analyzer, which measures the weight percent of carbon, hydrogen, nitrogen, sulfur, and ash from a coal sample. The total carbon, hydrogen, and nitrogen are determined at …

The moisture content of low-rank coal is mainly controlled by elemental oxygen and specific surface area, whereas for medium- and high-rank coals, this is controlled mainly by minerals. Our study finds application …

PDF | On Nov 11, 2020, Nuraini A.A. and others published Effect of Coal with High Moisture Content on Boiler Operation Parameters at Thermal Coal Fired Power Plant | Find, read and cite all the ...

The moisture distribution of coal presents gradient changes from center to edge, with drying time ranging from 0 to 30 min, the moisture content of coal decreases by 2% at the edges and by 1.5% in the middle.

And it can be found that the moisture effect coefficient is dependent on the coal rank. Further analysis indicates that the influence of inherent moisture on the methane adsorption capacity is more prominent for low rank coals, which is probably due to its greater hydrophilia and water-holding capacity.

When considering the moisture in coal it is useful to use the concepts of surface moisture and inherent moisture. Surface moisture is like the drops of rain on a windshield, inherent moisture is like that in green wood, or held inside a sponge.

Two stage total moisture determination is used when the coal sample is too small mass or too wet to divide or crush without the potential of losing significant amounts of moisture.

Proximate analysis indicates the percentage by weight of the fixed carbon, volatiles matter, Ash and moisture content in coal.

Indian coals inherently contain low inherent moisture (IM) (5.5-9.5 % with an average of around 7.5 %) and moisture addition is through the surface moisture (SM) due to sources external to the coal. On the other hand imported coals contain very high IM (15-25 %) but negligible SM. Presence of surface moisture (SM) is a major liability to the ...

The proximate analysis of coal separates the products into four groups: (1) moisture, (2) volatile matter, consisting of gases and vapors driven off during pyrolysis, (3) fixed carbon, the nonvolatile fraction of coal, and (4) ash, the inorganic residue remaining after combustion. The proximate analysis of coal is presented as a group of test ...