Eq. (5.21) represents the thermal decomposition of coal; it decomposes into volatile matter such as hydrogen and hydrocarbon gas and char (residual solid content composed of fixed carbon and ash). Eqs. (5.22) and (5.23) indicate combustion and partial combustion by reaction with oxygen, and supply heat of reaction required for gasification. Eqs. (5.24) …

In-situ investigation of coal particle fragmentation induced by thermal stress and numerical analysis of the main influencing factors ... and ε is the coal particle emissivity. Here, a value of ε = 0.85 is applied for the calculation [17], which is a characteristic value for ... The heat capacity of coal normally ranges from 0.2 to 0.4 cal …

The gasifier accomplishes four principal functions in a single stage, namely: (1) decaking coal, (2) devolatilizing coal, (3) gasifying coal, and (4) agglom-erating and separating ash from char. Coal of about 0.25-in. diameter is dried and pneumatically injected into the gasifier through a lock hopper system.

DOI: 10.1016/J.TCA.2021.179011 Corpus ID: 237655010; A method for in-situ measurement of calorific value of coal: a numerical study @article{Linglong2021AMF, title={A method for in-situ measurement of calorific value of coal: a numerical study}, author={Wang Linglong and Xue-cheng Wu and Xiang Gao and Yingchun Wu and Kefa …

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 …

Calorific value is defined as the amount of calories generated when a unit amount of substance is completely oxidized and is determined using the bomb calorimeter. The calorific value of coal represents gross calorific value (H G), which contains the latent heat of water vaporization.When the latent heat of water vaporization is not included, the …

The gross calorific value (GCV), also known as the higher heating value (HHV) of coal is the amount of heat emitted upon complete combustion of coal. The …

The coal fire was burning 3 m below the surface. A vertical temperature profile for the crack is shown in Fig. 11. The measuring points for the vertical profile were taken from the edge of the crack at the following spots: surface, − 0.02 m, − 0.5 m, − 1 m, − 2 m below the surface, and at the coal fire (− 3 m) itself.

The TG-MS experimental results show that: (1) during coal pyrolysis with heating rate of 10 °C/min, methane generation started at ∼300 °C, reached its peak generation at 480 °C, and ended at ...

Heat release of coal combustion in an oxygen-lean and multi-gas environment is a common phenomenon, coalfield fires caused by it can lead to serious environmental destruction and loss of coal ...

UCG is a is a combination of mining, exploitation and gasification that eliminates the need for mining and can be used in deep or steeply dipping, …

Hence, the in-situ measurement of the coal calorific value is needed. This study developed an in-situ calorific value determination method and established the …

The macroscopic multi-physics simulation of tar-rich coal in situ pyrolysis (TCISP) is conducted, in the fractured porous zone, by coupling heat transfer, fluid flow, and chemical reaction. A novel TCISP pattern of gas injection between fractured zones is proposed by treating the fractured porous zone as a homogeneous porosity gradient …

IN-SITU PROCESSES; UNDERGROUND COAL GASIFICATION. Oxidation first takes place in the flame front, giving CO2 and H20. These are subsequently reduced to CO …

Abstract. Underground coal thermal treatment (UCTT) is a promising concept that was recently proposed for extracting high-value hydrocarbon fuels from deep coal seams, which are economically unattractive for mining. UCTT is essentially an in situ pyrolysis process that converts underground coals into synthetic liquid and gaseous …

The in situ heating stage microscope was used to observe the ash morphology change of coal char. The results show that the random pore model was …

Large reserves of low-rank coal are available, but such coal has heavy volatile matter and low heat value [4]. Consequently, achieving clean and effective application of such coal is of great importance. ... Technical scheme of in situ pyrolysis of coal by superheated water vapor to extract oil and gas. Many researchers [11, [15], ...

Heat injection strengthen desorption and relieve inhibition of water on gas. •. The in-situ heat injection test is conducted for the first time. •. Concentration and daily gas production are increased by 10 times and 100 times. •. The drainage stage after heat injection is the high yield period of gas drainage. •.

Compared with the actual values measured by the calorimeter, the value of the empirical formula is the closest, so the heat content of tar-rich coal is −23.83 MJ·kg –1, and the standard enthalpy of …

Abstract. 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 ...

The average temperature of the gas increases when the coal releases heat and reaches the peak (306 K). Then it starts to decrease at the end of coal combustion (t c = 230 s). As gas. Conclusion. Aiming at the in-situ measurement of the calorific value of coal, a method based on an open cyclic calorimeter was proposed and the related model …

A method for in-situ measurement of calorific value of coal: a numerical study | Semantic Scholar. DOI: 10.1016/J.TCA.2021.179011. Corpus ID: 237655010. A method …

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 mass of 0. 5, 1, 1. 5 and 2 g and wall thickness of 1, 10, 25 and 50 mm were numerically ...

Furthermore, the changes in chemical structure of coal components by HRTEM in situ with heating procedure were rarely reported. HRTEM in situ heat-treatment would have a significant advantage over HRTEM is that it can provide directly image-observed in different temperature stages.

Furthermore, the changes in chemical structure of coal components by HRTEM in situ with heating procedure were rarely reported. HRTEM in situ heat-treatment would have a significant advantage over HRTEM is that it can provide directly image-observed in different temperature stages. ... As seen in Fig. 4 b, the Lc values of …

This low ashing temperature was used to ensure that AAEMs are kept in the ash to facilitate the study of morphological transformations upon heating. For coal samples and coal/biomass blends, the ashing was carried out following the approach adopted by many others [3, 9, 15]. The sample was heated from room temperature to 500 °C in 30 …

The carbon content of coking coal was more than 85 % while the disordered arrangement of carbon atoms contributed to pores generation, leading to the carbon-pore two phases mesoscopic structure property of coal [16]. Based on this, a novel in-situ technique combining synchrotron radiation Small Angle X-ray Scattering (SAXS) and Wide Angle X …

In general, the major coal basins in China contain different types of coal, ranging from less thermally matured lignite coal to high thermally matured anthracite coal, with R o values ranging from 0.2% to 4.4%. The formation of multi-rank coals is the result of multi-stage evolution and the superposition of multiple heat sources for metamorphism …

The gas content is crucial for evaluating coal and gas outburst potential in underground coal mining. This study focuses on investigating the in-situ coal seam gas content and gas sorption capacity in a representative coal seam with multiple sections (A1, A2, and A3) in the Sydney basin, where the CO 2 composition exceeds 90%. The fast …

The results indicate that increasing CaO addition tends to elevate the low heating value (LHV) of the gas products, and the maximum H2/CO ratio of 4.6 was attained with coal when FeCa50 (the molar ...