— In situ coal fires significantly pollute the environment in many countries of the world. Monitoring these pollutants is challenging due to extensive area coverage and spatial variations. Thus, the present study demonstrates the method of deriving the spatial and temporal profiles of columnar density of three major greenhouse gases (carbon …
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The gross calorific value (GCV), also known as the higher heating value (HHV) of coal is the amount of heat emitted upon complete combus-tion of coal. The GCV of coal is used to estimate various technoeco-nomic parameters such as boiler efficiency, combustion values, and production costs. This study seeks to examine the methods that are ...
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— Performing online evolution analysis of tar in actual pyrolysis process is a major challenge. In this work, the effects of heating rate (HR) on evolution curves of in-situ tar for low-rank coals pyrolysis were investigated in a novel laboratory bench. The escape law of volatiles was obtained, the influence of HR on secondary reactions was analyzed, …
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— The heating value in a standard condition refers to the quantity of energy produced by a certain amount of coal. Higher heating value (HHV) or lower heating …
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— By igniting in the coal seam and injecting gas agent, underground coal gasification (UCG) causes coal to undergo thermochemical reactions in situ and, thus, to be gasified into syngas for power generation, hydrogen production, and storage. Compared with traditional mining technology, UCG has the potential sustainable advantages in …
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— Three vitrinite samples of different rank, denoted as V-YJL, V-AW, and V-J15, were investigated by in situ heating while in a High resolution transmission electron microscope (HRTEM) to study the aromatic structural transformations from 200 to 800 °C. Thermogravimetry coupled with Fourier transform infrared spectroscopy and mass …
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— A multi-physics numerical method coupling fluid flow, heat transfer, and a chemical reaction was used to determine the temperature distribution and the conversion rate of a coal seam during ...
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Anthracite Coal is very shiny, hard black coal, high carbon content and energy density, repels moisture, for domestic industrial uses, including smokeless fuel; Bituminous Coal …
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— 1. Introduction. The shortage of oil resources and high proportion and low utilization rate of coal are the general utilization landscape of China's energy [1].The low-rank coal accounts for more than 55% of coal resources in China [2].Pyrolysis is one of the effective ways to alleviate the shortage of crude oil resources and improve energy …
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— The procedures for the in-situ measurement of the GCV of coal in a power plant are illustrated in Fig. 1. First, the coal sample is collected into a metal crucible from …
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— Another key point of in-situ pyrolysis is the migration of heat-carrying mediums and volatile products, which is in connection with the pore structure of coal. During the in-situ pyrolysis, the coal close to the mining tunnels or artificial passages is first heated by the heat-carrying medium, and then a semicoke layer is formed following ...
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— Moisture content is an important parameter in coal analysis. It is needed for determining the calorific (heating) value and handling properties of a coal. The moisture value given for a proximate analysis is …
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— Underground coal thermal treatment (UCTT) technology converts deep-buried coal into syngas or liquid fuel with low carbon content and high calorific value through in situ heating (Kelly et al. 2016; Zhang et al. 2017). As UCTT is an in situ pyrolysis process conducted in a nonoxidizing environment, the carbon matrix left after pyrolysis is ...
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— In situ underground pyrolysis of tar-rich coal is significant for alleviating the scarcity of oil and gas resources and realizing the green and efficient development and utilization of coal in China. Tar-rich coal is often subjected to high axial pressure, surrounding pressure, and pore pressure in the in situ underground pyrolysis …
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— The actual production process of the in situ pyrolysis of oil-rich coal is shown in Fig-ure 1. Nitrogen gas is heated and injected into the fractured zone to heat the coal seam. The coal seam starts pyrolysis when the temperature exceeds 573 K, and oil and volatile gas are then generated. The products flow out with the high-temperature nitrogen
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insitu.--Refers to coal "in place" in the ground. in situ mining.--Utilization of coal by burning in place and extracting the gases, tars, and heat. joule (J).--The basic metric unit of work …
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— The O2 content with a value of 19.43% for the Fracture Type sample and 4.94% for the In-Situ type sample. Fracture Type and In-situ Lignite Coal produced fewer syngas products due to UCG testing ...
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— ABSTRACT. Hydrogen production via in-situ injection of supercritical water into underground coal seams is a new coal conversion technology. This study proposes a solid-fluid-heat coupling mathematical model for the heating stage of the injection of supercritical water into the coal seam and studies the evolution law of the temperature …
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— Tar-rich coal in situ pyrolysis (TCISP) refers to the technology that upgrades oil and gas products by heat transfer through heat carriers (such as high-temperature nitrogen) under formation pressure without mining, as shown in Figure Figure1 1. The products are expelled through pores and fractures in the coal layer and finally flow out …
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— Coal calorific value is an important indicator in the combustion optimization of power plants and the calculation of operating efficiency. Hence, the in-situ measurement …
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Anthracite Coal is very shiny, hard black coal, high carbon content and energy density, repels moisture, for domestic industrial uses, including smokeless fuel; Bituminous Coal is softer and shiny, moisture content is 8 -20%, possible for coking coals, volatile matter from 16% - 40%, can be used for thermal or metallurgical applications; Sub-bituminous Coal …
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— In-situ pyrolysis is a new, efficient and environmentally friendly coal utilization technology by heating and pyrolyzing coal underground through thermal carrier such as high-temperature nitrogen, CO 2, supercritical water and so on (Ozowe et al., 2020, Omari et al., 2022, Jin et al., 2017) without mining just like oil shale recovery (Wang et ...
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The idea of recovering the energy values of coal by in-situ processes, without the intervention of human effort below ground and without bringing waste to the surface, is one which has exceptional appeal to the public. For this reason alone, a careful analysis of the possibilities is desirable, regularly renewed in the light of developing technology and …
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HEATING VALUE Depending on the heating values of the resultant synthesis gases produced by gasifi-cation processes, product gases are typically classified as three types of gas mixtures3: 1. Low-Btu gas consisting of a mixture of carbon monoxide, hydrogen, and some other gases with a heating value typically less than 300 Btu/scf. 2.
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1. Introduction. The entrained flow gasification technology has become one of the essential technologies for the clean utilization of coal due to its high gasification strength and wide adaptability, which is now widely used in chemical and energy production [1].The thermal evolution characteristics of coal particles in the gasifier are closely related to the …
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— 1. Introduction. The integrally structural arrangement of coal increases with proceeding coalification up to the formation of organic macromolecules of flat shape with carbon atoms in the central part [1 – 3].During coalification, the size of coal molecules increases as well as the degree of their ordering and macromolecules arrange …
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— In this study, a method for in-situ determination of the coal calorific value was developed based on a flow calorimeter. The temperatures of gas and walls and energy distributions in the calorimeter at gas flow rates of 0 . 1, 0 . 5, 1 . 5 and 3 m 3 / h, coal …
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Types of coal according to increasing rank (in terms of hardness, purity and heating value) are peat, lignite, subbituminous, bituminous and anthracite. ... As of 31 December 2020, our in-situ coal reserves amount to 315 million metric tons or 13.29% of the country's total coal resource potential of 2.37 billion metric tons. ...
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— Calorific value is a measure of the amount of energy produced from a unit weight of coal when it is combusted in oxygen. A measured sample of coal is completely combusted in a bomb …
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— Traditional coal mining and utilisation patterns are severely detrimental to natural resources and environments and significantly impede safe, low-carbon, clean, and sustainable utilisation of coal resources. Based on the idea of in situ fluidized coal mining that aims to transform solid coal into liquid or gas and transports the fluidized resources …
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