IMPROVEMENT OF LOW RANK COAL PROPERTIES BY VARIOUS ...

The use of domestic (high-ash) low rank (sub-bituminous and lignite) coal reserves contributes to the security of energy supply, and therefore high-ash coal is expected to remain as a key energy source in several countries (e.g. India, Turkey, Greece) for at least the next 30-40 years. However, the use of high-ash coals for energy production,

Biological degradation and solubilisation of coal ...

Coal beneficiation upgrades low-rank coals that have high moisture content and low BTU value through the application of heat, and in one process pressure and heat, thereby reducing moisture content leading to a boost in BTU value of the coal.

What are the types of coal? - USGS

Feb 01, 2011· Coal rank is the measure of the degree of organic metamorphism (coalification) of a coal, ranging from low-rank peat to high-rank meta-anthracite (Table 3.1.5).Rank can be determined through a number of chemical and physical parameters. In general, no single parameter can be used throughout the entire rank range.

GLOBAL COAL BENEFICIATION SCENARIO AND …

Low-rank coals are high in moisture or ash content and susceptible to spontaneous combustion. Since low-rank coals are high in moisture, using them as fuel in energy-producing facilities like power plants increases coal consumption, emitting more CO 2 and lowering power generation efficiency. This chapter introduces upgrading and advanced ...

Low-Temperature Oxidation Reactivity of Low-Rank Coals and ...

Coal classification, any of various ways in which coal is grouped. Most classifications are based on the results of chemical analyses and physical tests, but some are more empirical in nature. Coal classifications are important because they provide valuable information to commercial users (e.g., for power generation and coke manufacturing) and to researchers studying the origin of coal.

Recent advances in beneficiation for ... - sciencedirect

The distribution of wettability of as-received and oxidized coal particles was determined by film flotation with a series of aqueous methanol solution of different surface tensions. The mean critical wetting surface tension of coal particles (y¯) obtained from the distribution shows that in general the hydrophobicity of coal particles decreases upon oxidation and that low-rank coals are more ...

Gasification of low rank coal

Low-rank coals, such as lignite and subbituminous coal, usually contain relatively large quantities of water (i.e., about 10 to 50% by weight), which makes the economics of transporting and combusting these coals considerably more expensive than higher rank coals.

Factors Affecting Quality of Dried Low-Rank Coals: Drying ...

Dec 10, 2007· The chemical and physical properties of coal are strongly affected by the upgrading process employed. For high-moisture coals, upgrading involves thermal dehydration to improve the calorific value of the coal on mass basis. This study evaluates the feasibility of upgrading a low-rank/grade coal using the oven drying method. The objective of this research work is to study the …

Method for beneficiation of low-rank coal

Development of Low Rank Coal Upgrading and Upgraded Brown Coal Water Mix- ture Preparation Technologies, Kobe University, Doctoral Dissertation. Usui, H., Mahidin, T. and Umar, D. F., 2004. Upgrading by Kobe University Process and Control of Spon- taneous Combustion of Low Rank Coals, Proc. 21st International Pittsburgh Coal Conference, Osaka ...

Chapter 7 COAL - Pennsylvania State University

Low-rank coals, such as lignite and subbituminous coal, usually contain relatively large quantities of water (i.e., about 10 to 50% by weight), which makes the economics of transporting and combusting these coals considerably more expensive than higher rank coals.

Extraction of Low Rank Coals by Coal Derived Oils at 350 ...

However, low-rank coal as a substitute for high-rank coal has several limitations, such as low calorific value and high moisture and oxygen content (Rao et al., 2015).

Recent advances in beneficiation for ... - ScienceDirect

They are to increase the kinds and amounts of usable coal and to develop the technologies for upgrading low rank coals such as subbituminous coal and brown coal into coking coal substitutes ...

Coal Rank - an overview | ScienceDirect Topics

Anthracite: The highest rank of coal. It is a hard, brittle, and black lustrous coal, often referred to as hard coal, containing a high percentage of fixed carbon and a low percentage of volatile matter. Bituminous: Bituminous coal is a middle rank coal between subbituminous and anthracite.

Low-Temperature Oxidation Reactivity of Low-Rank Coals and ...

Through the oxidation of coal at low temperatures and the resulting petrographic analysis, this study aims to predict spontaneous combustion, which has emerged as an industrial problem. Low-temperature oxidation analysis and the corresponding petrographic characteristics of four different coals treated under low temperatures of 25, 50, and 75 °C, which was set as the reactor temperature, were ...

Biological degradation and solubilisation of coal ...

Sep 22, 2012· This review focuses on ligninolytic fungi, soil bacteria, plants and root exudates in the degradation and solubilisation of low grade and waste coal and the interaction between these mutualistic biocatalysts. Coal represents a considerable portion of the total global fossil fuel reserve and continued demand for, and supply of this resource generates vast quantities of spoil and low grade waste.

Effect of fluidizing characteristics on upgrading of ...

In general, the beneficiation process of low rank coals is more difficult to achieve than that of bituminous and/or anthracite coals. However, about 50% of the world's total coal deposits are low ...

Low-rank Coals for Power Generation, Fuel and Chemical ...

Dec 10, 2007· The chemical and physical properties of coal are strongly affected by the upgrading process employed. For high-moisture coals, upgrading involves thermal dehydration to improve the calorific value of the coal on mass basis. This study evaluates the feasibility of upgrading a low-rank/grade coal using the oven drying method. The objective of this research work is to study the …

an overview - ScienceDirect | Science, health and ...

Coal beneficiation is one of the most effective methods for removing minerals (such as gangues and pyrite) and pollutants (such as sulfur) before the burning of coal. In general, the beneficiation process of low rank coals is more difficult to achieve than that of bituminous and/or anthracite coals. However, about 50% of the world's total coal ...

Mineral Processing Technology : GLOBAL COAL BENEFICIATION ...

A method of improving the calorific value and preventing autogenous heating of low-rank coals is disclosed which comprises crushing the coal into a particle size range from 0.1 cm to 3 cm, immersing the particles in a distillation residuum of petroleum crude oil at a temperature between 240° C. and decomposition temperature of the coal, and draining excess residuum from the particles to give ...

5.2.5 Gasifiers and Impact of Coal Rank and Coal ...

Feb 25, 2009· Their high moisture content, greater tendency to combust spontaneously, high degree of weathering, and the dusting characteristics restrict widespread use of such coals. The price of coal sold to utilities depends upon the heating value of the coal. Thus, removal of moisture from low-rank coals (LRC) is an important operation.

coal classification | Types & Facts | Britannica

Jun 01, 2015· In general, the beneficiation process of low rank coals is more difficult to achieve than that of bituminous and/or anthracite coals. However, about 50% of the world's total coal deposits are low rank coals. It is urgently required to develop effective beneficiation technologies for low rank coals.

A Modified Godbert Apparatus for Determining Optimum …

Sep 22, 2012· This review focuses on ligninolytic fungi, soil bacteria, plants and root exudates in the degradation and solubilisation of low grade and waste coal and the interaction between these mutualistic biocatalysts. Coal represents a considerable portion of the total global fossil fuel reserve and continued demand for, and supply of this resource generates vast quantities of spoil and low grade waste.