Bituminous coals in the Huainan mining area of China were selected as the research object, and the organic macerals were enriched through manual separation and floatation–sedimentation experiments first. Then, the simulated biogas generation experiments were carried out by using raw coal, single vitrinite, and inertinite, respectively.
The conditions necessary for efficient, small-scale separation of coal macerals are investigated. The method developed takes advantage of known density differences of the various macerais, but unlike most separations, an isopycnic density gradient centrifugation (DGC) technique is used to isolate pure macerals.
In order to address the question of whether charring contributed to the formation of certain inertinite macerals present in these Witbank coals, vitrinite-rich and inertinite-rich samples were prepared through density-fractionation using a medium rank C bituminous coal (termed the "parent coal") from the No. 4 Seam Upper, Witbank …
Other articles where vitrinite is discussed: bituminous coal: …of coal) can be recognized: vitrinite, liptinite, and inertinite. The glassy material in most bituminous coal is vitrinite, composed of macerals derived primarily from woody plant tissue. Because of its relatively high heat value and low (less than 3 percent) moisture content, its ease of …
It is possible, for example, to have a coal with a volatile matter content of 16% ad which may appear to be a lean low volatile bituminous coal (or bituminous A ), but in fact, based upon true determination of rank, is found to be a sub - bituminous coal with high proportions of oxidised and inert inertinite macerals.
Methods by which coal can be studied and classified are described, including coal petrography, vitrinite reflection measurement, and chemical and physical characterization methods (ultimate and proximate analyses). The concept of macerals is …
In order to investigate the generation mechanism of phenols for providing the theory basis of the coal directional pyrolysis, PCXC are selected as target products to analyze the influence of swelling on the pyrolysis properties and distribution of …
Bituminous coal. Bituminous coal is an organic sedimentary rock formed by diagenetic and sub metamorphic compression of peat bog material. It is also called as black coal. It is often referred to as soft coal. However, this designation is a layman's term and has little to do with the hardness of the rock.
Comparing the molecular structure of different macerals can further help in better understanding the physical, chemical, and technological properties of coal, which is of great significance to guide appropriate processing and utilisation of coal [ [26], [27], [28]].
Bulgaria's sub-bituminous coal deposits are mostly restricted to the south-western part of the country, where numerous coal deposits belonging to Pernik and Strimon-Mesta coal provinces, were formed during the Oligocene and Miocene ( …
Here, we provide a comprehensive analysis focused on the characterization of coal composition and gas content in the entire area, with a special investigation of the vitrinite reflectance variations and its controlling effect on CBM accumulation.
High-volatile bituminous coal samples were reacted in deionized water with supercritical CO2 (ScCO2–water) under simulated in situ pressure and temperature conditions (8 MPa and 40 °C) in unconfined stress state for 14 days, in order to characterize potential CO2–water–coal reactions. Micro-structural changes were identified pre- and …
Great pressure results in the creation of bituminous, or "soft" coal. This is the type. most commonly used for electric power generation in the U.S. It has a higher heating value than either lignite or sub-bituminous, but less than that of anthracite. Bituminous coal is mined chiefly in the Midwest & Appalachia.
Semantic Scholar extracted view of "Nanoscale rock mechanical property changes in heterogeneous coal after water adsorption" by Yihuai Zhang et al.
In the present investigation, coal samples were collected from composite coal seam III–IV of the Ramagundam coalfield of Godavari Basin. Coal samples have been studied for their thermal maturity, maceral composition, chemical composition, surface micro-structures, porosity, permeability and geomechanical properties. Results have …
Bituminous coal is an organic sedimentary rock formed by diagenetic and submetamorphic compression of peat bog material. Bituminous coal has been compressed and heated so that its primary constituents are the macerals vitrinite, exinite, etc. The carbon content of bituminous coal is around 60-80%; the rest is composed of …
With the development of coal industry, more and more attention has been paid to the influence of different macerals in coal processing and utilization. It is found that the vitrinite has higher content of aliphatic chain and lower aromaticity, which is easier to be cracked in coal conversion compared with the inertinite.
Currently, bituminous coal is widely used in coking, power generation, coal gasification, fuel, and fuel cells because of its easy combustion, low ash and moisture content, and high calorific value.
Equally problematic is the use of prescriptive formulae to indicate coal 'origins'. This paper reviews some of the problems involved with coal petrology as it is usually practiced. In addition, new advances in organic geochemical techniques have led to a fuller understanding of the relationship of plants and coal macerals.
Despite recent interest in the low-temperature carbonization of coal to prepare disordered carbon materials for the anodes of lithium-ion (LIBs) and sodium-ion batteries (SIBs), the carbonization mechanism is still poorly understood. We selected bituminous coal as the raw material and investigated the chemical, microcrystal, and pore structure …
This coal is very difficult to float even at higher concentration of collector due to its oxidised surface with reduced hydrophobicity. This investigation has been carried out to study the flotation characteristics of oxidised Indian high ash sub-bituminous coal having particle size below 1 mm. Initially the flotation study was carried out ...
The ratio also increased with carbon content in vitrinites and inertinite. Maroto-Valer et al. [6] determined the structural variation within vitrinite and inertinite maceral groups separated from a bituminous coal using single pulse excitation (SPE) solid state 13 C NMR.
The growth mechanism of coal derived graphene films synthesized via chemical vapor deposition on copper substrates was investigated utilizing Raman spectroscopy, X-ray photoelectron spectroscopy, selected area electron diffraction, optical microscopy, and gas chromatography. The synthesis of coal derived graphene films is …
The activation energies of peaks 2 and 3 were found to be independent of coal type and clearly related to coal rank. The kinetic parameters (activation energy and preexponential factor) of the three peaks exhibited clear isokinetic effects.
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. Bituminous coal usually has a high heating (Btu) value ...
The coal rank from the lowest to the highest are lignite, sub-bituminous, bituminous, and anthracite. The factors that influencing of coal ranks are calorific value, volatile matter, moisture ...
The data show a steady increase in the Ha,/Ha, ratio from sub-bituminous coal to anthracite. Lignite shows a higher ratio than sub-bituminous coals, probably because of consumption of aliphatic H by oxidation".
The success of gravitational separation of coal macerals for a given coal is dependent on the liberation and distribution of macerals. On a basis of four coals of varying ranks from high-volatile bituminous coal to low-volatile bituminous coal, this article presents the maceral liberation and distribution under various crushing degrees and ...
The precise separation of macerals is the premise and foundation for the efficient utilization of coal resources, and flotation is the separation method with the greatest industrial potential. The differences in the surface hydrophobicity of macerals provide the basis for flotation, but the complexity of their surface properties makes …
This neglect was expressed by Walker et al. (2005), who described coal as an unknown or unsuspected source of PAH. In coals of low rank, such as lignite, sub-bituminous coal or brown coal, significantly lower PAH concentrations were detected (e. g. 13 mg/kg EPA-PAH, Püttmann, 1988 ).
Maceral separation is a priority for improving the deep processing and utilization efficiency of coal resources on the basis of the characteristics difference of maceals.
Semantic Scholar extracted view of "Characterization of nanoscale rockmechanical properties and microstructures of a Chinese sub-bituminous coal" by Yihuai Zhang et al.
A thermogravimetric analyzer (TGA-1000) was employed to investigate the thermal behavior and extract the kinetic parameters of Jamadoba coal and its corresponding density separated macerals.
