Prediction of feasible synthesis gas compositions at three European coal deposits

2021 ◽  
Author(s):  
Christopher Otto ◽  
Thomas Kempka
Keyword(s):  
Synthesis Gas ◽  
Coal Gasification ◽  
Economic Feasibility ◽  
Gas Composition ◽  
Underground Coal Gasification ◽  
Computationally Efficient ◽  
Coal Conversion ◽  
Coal Deposits ◽  
In Situ Conditions

<p>In the present study, we apply our validated stoichiometric equilibrium model [1], based on direct minimisation of Gibbs free energy, to predict the synthesis gas compositions produced by in-situ coal conversion at three European coal deposits. The applied modelling approach is computationally efficient and allows to predict synthesis gas compositions and calorific values under various operating and geological boundary conditions, including varying oxidant and coal compositions. Three European coal deposits are assessed, comprising the South Wales Coalfield (United Kingdom), the Upper Silesian Coal Basin (Poland) and the Ruhr District (Germany). The stoichiometric equilibrium models were first validated on the basis of laboratory experiments undertaken at two different operating pressures by [2] and available literature data [3]. Then, the models were adapted to site-specific hydrostatic pressure conditions to enable an extrapolation of the synthesis gas composition to in-situ pressure conditions. Our simulation results demonstrate that changes in the synthesis gas composition follow the expected trends for preferential production of specific gas components at increased pressures, known from the literature, emphasising that a reliable methodology for estimations of synthesis gas compositions for different in-situ conditions has been established. The presented predictive approach can be integrated with techno-economic models [4] to assess the technical and economic feasibility of in-situ coal conversion at selected study areas as well as of biomass and waste to synthesis gas conversion projects.</p><p><span>[</span><span>1] </span><span>Otto, C.; Kempka, T. Synthesis Gas Composition Prediction for Underground Coal Gasification Using a Thermochemical Equilibrium Modeling Approach. </span><em><span>Energies</span></em> <span><strong>2020</strong></span><span>, </span><em><span>13</span></em><span>, 1171.</span></p><p>[2] Kapusta et al., 2020</p><p>[3] Kempka et al., 2011</p><p>[4] Nakaten and Kempka, 2019</p>

Optimization of synthesis gas heating values and tar by-product yield in underground coal gasification

Fuel ◽  
2018 ◽  
Vol 229 ◽  
pp. 248-261 ◽  
Author(s):  
Stefan Klebingat ◽  
Thomas Kempka ◽  
Marc Schulten ◽  
Rafig Azzam ◽  
Tomás Manuel Fernández-Steeger
Keyword(s):  
Synthesis Gas ◽  
Coal Gasification ◽  
Product Yield ◽  
Underground Coal Gasification ◽  
Gas Heating

Characteristics of "Three Zones" during Underground Coal Gasification

2012 ◽  
Vol 524-527 ◽  
pp. 56-62 ◽  
Author(s):  
Hong Tao Liu ◽  
Hong Yao ◽  
Kai Yao ◽  
Feng Chen ◽  
Guang Qian Luo
Keyword(s):  
Large Scale ◽  
Coal Gasification ◽  
Basic Knowledge ◽  
Gas Composition ◽  
Underground Coal Gasification ◽  
Reduction Zone ◽  
Gasification Process ◽  
Product Gas ◽  
Dry Distillation ◽  
Major Chemical

According to the temperature, major chemical reactions and gas compositions, the gasification process along the tunnel of underground coal gasification is divided into three zones, i.e. oxidation zone, reduction zone and dry distillation zone. A model test in the laboratory was carried out by using large-scale coal blocks to simulate the coal seam. The characteristics of the “three zones”, and the relation between the temperature and gas composition were also quantitative studied. It provided the necessary basic knowledge for further studying the process of underground coal gasification, including predicting compositions of product gas, life-cycle analyzing, selecting optimistic control parameters and determining suitable gasification craft.

Model Test Study of Underground Co-Gasification of Coal and Oil Shale

2013 ◽  
Vol 295-298 ◽  
pp. 3129-3136 ◽  
Author(s):  
Li Mei Zhao ◽  
Jie Liang ◽  
Lu Xin Qian
Keyword(s):  
Temperature Field ◽  
Model Test ◽  
Oil Shale ◽  
Coal Gasification ◽  
Underground Coal Gasification ◽  
Test Study ◽  
Heat Value ◽  
Occurrence State ◽  
Specification Analysis

For testing the feasibility of in-situ exploring oil shale by underground coal gasification. Based on the specification analysis of coal and oil shale, through simulating the occurrence state and characteristics of coal and oil shale, the underground Co-gasification model test was carried-out. In different gasification conditions (φ(O2) are 30%、35%、40%、45%、50% and oxygen/steam) ,The temperature-field extend rules of coal and oil shale、the separate-out rules of oil shale production and influence of oil shale on the quality of gas were studied. The results show that: when φ(O2) is 40-45%, temperature-rising rate is 7°C/min、extend rate of gasification face is 0.036m/h, the extend of temperature field is continuous and stable, the temperature change of oil shale and coal are synchronously , the high temperature of oil shale can up to 1000 °C above, that can satisfied the requirement of oil-gas collecting; and the same time , The heat-value of syngas improved 26.37%; The technological parameter was obtained in this test.

Mathematical Modeling of the Stream Method of Underground Coal Gasification

1975 ◽  
Vol 15 (05) ◽  
pp. 425-436 ◽  
Author(s):  
C.F. Magnani ◽  
S.M. Farouq Ali
Keyword(s):  
Mathematical Modeling ◽  
Carbon Dioxide ◽  
Coal Seam ◽  
Coal Gasification ◽  
Underground Coal Gasification ◽  
Hydrocarbon Gases ◽  
Underground Gasification ◽  
Performance Curves ◽  
Synthetic Gas

Abstract This investigation focuses on mathematical modeling of the process of underground gasification of coal by the stream method. A one-dimensional, steady-state model consisting of five coupled differential equations was formulated, and the solution, extracted analytically, was used to develop closed-form expressions for the parameters influencing coal gasification. The model then was used for interpreting field performance curves, predicting the results of The performance curves, predicting the results of The field tests, and ascertaining the over-all process sensitivity to the input variables. The usefulness of the model was shown by establishing the parameters influencing the success or failure of parameters influencing the success or failure of an underground gasification project. Introduction One method of eliminating many of the technological and environmental difficulties encountered during the production of synthetic gas through aboveground coal gasification involves gasifying cod in situ. This process, known as underground coal gasification, was first proposed in 1868 by Sir William Siemens and is based on the controlled combustion of coal in situ. This in-situ combustion results in the production of an artificial or synthetic gas that is rich in carbon dioxide, carbon monoxide, hydrogen, and hydrocarbon gases. Despite the fact that reaction stoichiometry is a moot element of underground coal gasification, it is nonetheless believed thatcarbon dioxide is formed by the partial oxidation of coal,carbon monoxide is generated by the subsequent reduction of carbon dioxide, andthe hydrogen and hydrocarbon gases result from the water-gas reaction and carbonization of coal, respectively. To effect the controlled combustion of coal in situ, the coal seam first must be ignited and a means must be provided for supporting combustion (through injection of a suitable gasification agent) and producing the gases generated underground. Fig. 1 presents a schematic diagram of an underground gasification system that complies with these requirements. This approach to gasifying coal is known as the stream or channel method and necessitates drilling two parallel galleries, one serving as an injection gas inlet and the other as a producer gas outlet. These wells are then linked by a borehole drilled horizontally through the coal seam. Ignition occurs in the coal seam at the gas inlet and proceeds in the direction of flow. The combustion front thus generated moves essentially perpendicular to the direction of gas flow. perpendicular to the direction of gas flow.Since the technological inception of underground gasification, over 1,500 publications have appeared in the literature that bear testimony to the absence of a complete, legitimate, theoretical analysis of the underground gasification process. Given this observation, it is the basis of this paper that progress in underground coal-gasification research progress in underground coal-gasification research has suffered from the absence of "interpretative theory"; that is, it has suffered from a lack of logical, physical, and mathematical analysis of the governing and underlying aerothermochemical principles. The difficulties in formulating a principles. The difficulties in formulating a mathematical model adequately describing the numerous phenomena involved during coal gasification are indeed formidable. SPEJ P. 425

The Change of Structural and Thermal Properties of Rocks Exposed to High Temperatures in the Vicinity of Designed Geo-Reactor / Zmiany właściwości strukturalnych i cieplnych skał poddanych wysokim temperaturom w rejonie projektowanego georeaktora

2013 ◽  
Vol 58 (2) ◽  
pp. 465-480 ◽  
Author(s):  
Piotr Małkowski ◽  
Zbigniew Niedbalski ◽  
Joanna Hydzik-Wiśniewska
Keyword(s):  
Physical Properties ◽  
High Temperatures ◽  
Laboratory Tests ◽  
Coal Gasification ◽  
Underground Coal Gasification ◽  
Specific Density ◽  
Temperature Conductivity ◽  
Underground Gasification ◽  
Coal Deposits ◽  
Heat Diffusivity

Among the main directions of works on energy acquisition, there is the development and application of the technology of underground gasification of coal deposits (UCG). During the process of deposit burning and oxidation, there is also impact of temperatures exceeding 1000°C on rocks surrounding the deposit. As a result of subjecting carboniferous rocks to high temperatures for a prolonged period of time, their structure will change, which in turn will result in the change of their physical properties. Due to the project of underground coal gasification, as performed in Poland, laboratory tests are currently under way to a broad extent, including physical properties of carboniferous rocks subjected to high temperatures. The article presents results of laboratory tests of rocks surrounding the designed geo-reactor: changes to bulk density, specific density and porosity due to high temperature, and confronts the above results with the results of tests of thermal conductivity, specific heat and heat diffusivity (temperature conductivity) of the rocks. The mineralogical investigations were presented too.

scholarly journals Underground coal gasification technology impact on coal reserves in Colombia

2013 ◽  
Vol 22 (35) ◽  
pp. 9
Author(s):  
John William Rosso Murillo
Keyword(s):  
Energy Production ◽  
Coal Gasification ◽  
Underground Coal Gasification ◽  
World Energy ◽  
The World ◽  
Coal Reserves ◽  
Gasification Technology ◽  
Available Volume

<p>In situ coal gasification technology (Underground Coal Gasification–UCG–) is an alternative to the traditional exploitation, due to it allows to reach the today’s inaccessible coal reserves’ recovery, to conventional mining technologies. In this article I answer the question on how the today’s reserves available volume, can be increased, given the possibility to exploit further and better the same resources. Mining is an important wealth resource in Colombia as a contributor to the national GDP. According with the Energy Ministry (Ministerio de Minas y Energía) [1] mining has been around 5% of total GDP in the last years. This is a significant fact due to the existence of a considerable volume of reserves not accounted for (proved reserves at year 2010 were 6.700 million of tons. Source: INGEOMINAS and UPME), and the coal future role’s prospect, in the world energy production.</p>

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