Impact analysis of the oxidant in the process of underground coal gasification

Kačur, Ján; Durdán, Milan; Laciak, Marek; Flegner, Patrik

doi:10.1016/j.measurement.2014.01.036

Cited by 30 publications

(18 citation statements)

References 2 publications

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“…The calorific value of the product gas recovered by UCG is usually low (3~4 MJ/Nm 3 ) when air is injected as a gasification agent, meaning that the usage of the gas is limited because of its low calorific value. On the other hand, researchers have obtained results to improve the quality of the product gas by using a mixture of air and oxygen due to an increase of the reaction temperature in the underground reactor [10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Effect of Injection Flow Rate on Product Gas Quality in Underground Coal Gasification (UCG) Based on Laboratory Scale Experiment: Development of Co-Axial UCG System

Hamanaka

Itakura

et al. 2017

Energies

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Underground coal gasification (UCG) is a technique to recover coal energy without mining by converting coal into a valuable gas. Model UCG experiments on a laboratory scale were carried out under a low flow rate (6~12 L/min) and a high flow rate (15~30 L/min) with a constant oxygen concentration. During the experiments, the coal temperature was higher and the fracturing events were more active under the high flow rate. Additionally, the gasification efficiency, which means the conversion efficiency of the gasified coal to the product gas, was 71.22% in the low flow rate and 82.42% in the high flow rate. These results suggest that the energy recovery rate with the UCG process can be improved by the increase of the reaction temperature and the promotion of the gasification area.

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Section: Introductionmentioning

confidence: 99%

Effect of Injection Flow Rate on Product Gas Quality in Underground Coal Gasification (UCG) Based on Laboratory Scale Experiment: Development of Co-Axial UCG System

Hamanaka

Itakura

et al. 2017

Energies

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“…This set of competitive reactions plays an important role in determining the hydrogen-to-carbon monoxide ratio in the synthesis gas. To sustain the process, the conversion reactions must generate sufficient heat to provide the required activation energy as well as to overcome the heat losses due to water evaporation and the endothermic gasification reactions at appreciable rates [45].…”

Section: Reaction Name Stoichiometrymentioning

confidence: 99%

Synthesis Gas Composition Prediction for Underground Coal Gasification Using a Thermochemical Equilibrium Modeling Approach

Otto

Kempka

2020

Energies

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Underground coal gasification (UCG) is an in situ conversion technique that enables the production of high-calorific synthesis gas from resources that are economically not minable by conventional methods. A broad range of end-use options is available for the synthesis gas, including fuels and chemical feedstock production. Furthermore, UCG also offers a high potential for integration with Carbon Capture and Storage (CCS) to mitigate greenhouse gas emissions. In the present study, a stoichiometric equilibrium model, based on minimization of the Gibbs function has been used to estimate the equilibrium composition of the synthesis gas. Thereto, we further developed and applied a proven thermodynamic equilibrium model to simulate the relevant thermochemical coal conversion processes (pyrolysis and gasification). Our modeling approach has been validated against thermodynamic models, laboratory gasification experiments and UCG field trial data reported in the literature. The synthesis gas compositions have been found to be in good agreement under a wide range of different operating conditions. Consequently, the presented modeling approach enables an efficient quantification of synthesis gas quality resulting from UCG, considering varying coal and oxidizer compositions at deposit-specific pressures and temperatures.

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“…Lignitic deposits are developed on an area of about 70 km 2 . In the next part of the article risk of leakage of emissions of hazardous gases to the surface (e.g., missing pipes) as well as potential risks to the population from the others already mentioned influences while using the underground coal gasification technology are more particularised [25].…”

Section: Risk Analysis -Environmental Impact Of Ucg On the Populationmentioning

confidence: 99%

Analysis of Risk Factors for Underground Coal Gasification

Škvareková

Tomašková

Wittenberger

et al. 2019

Management Systems in Production Engineering

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The purpose of this article is to determine the environmental impacts of underground gasification on the population and to analyze the risk of underground coal gasification (UCG) activities using selected risk assessment methods. Coal gas is a regular part of coal deposits and its extraction also allows the use of coal deposits that cannot be extracted by traditional methods. These technologies bring both positive and negative aspects. The paper points out the risk analysis, hazard identification and assessment during the operation of UCG technology using a risk graph and a risk matrix. Identified risks to workers that cannot be reduced should be taken into consideration and appropriate safeguard should be used. For each risk, it is necessary to inform employees about regular education and training. From worldwide experience with this technology, it is possible to analyze risks in Slovakia. Actual gasification produces polluting gases such as carbon dioxide, carbon monoxide, hydrogen sulphide, hydrogen sulphide, nitrogen oxides, tar and ash, and creates a risk that may occur on and under the surface of the site depending on the geological and hydrogeological structure of the deposits. Possible measures to mitigate the adverse effects are proposed for the implementation of this technology. Coal is still one of the main domestic primary energy sources. Currently, only 5 out of 19 deposits in the Slovak Republic are used. Underground gasification could increase the use of Slovak coal and brown coal deposits.

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Impact analysis of the oxidant in the process of underground coal gasification

Cited by 30 publications

References 2 publications

Effect of Injection Flow Rate on Product Gas Quality in Underground Coal Gasification (UCG) Based on Laboratory Scale Experiment: Development of Co-Axial UCG System

Effect of Injection Flow Rate on Product Gas Quality in Underground Coal Gasification (UCG) Based on Laboratory Scale Experiment: Development of Co-Axial UCG System

Synthesis Gas Composition Prediction for Underground Coal Gasification Using a Thermochemical Equilibrium Modeling Approach

Analysis of Risk Factors for Underground Coal Gasification

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