scholarly journals Investigation of thermochemical process of coal particle packed bed reactions for the development of UCG

2020 ◽  
Author(s):  
Tata Sutardi ◽  
Linwei Wang ◽  
Nader Karimi ◽  
Manosh C Paul

Abstract In this study, a packed bed reactor is developed to investigate the gasification process of coal particles. The effects of coal particle size and heater temperature of reactor are examined to identify the thermochemical processes through the packed bed. Three different coal samples with varying size, named as A, B, and C, are used, and the experimental results show that the packed bed with smaller coal size has higher temperature, reaching 624oC, 582oC, and 569oC for coal A, B, and C respectively. In the case of CO formation, the smaller particle size has greater products in the unit of mole fraction over the area of generation. However, the variation in the porosity of the packed bed due to different coal particle sizes affects the reactions through the oxygen access. Consequently, the CO formation is least from the coal packed bed formed by the smallest particle size A. A second test with the temperature variations shows that the higher heater temperature promotes the chemical reactions, resulting in the increased gas products. The findings indicate the important role of coal seam porosity in UCG (underground coal gasification) application, as well as temperature to promote the syngas productions.

2020 ◽  
Vol 7 (3) ◽  
pp. 476-492
Author(s):  
Tata Sutardi ◽  
Linwei Wang ◽  
Nader Karimi ◽  
Manosh C. Paul

Abstract In this study, a packed bed reactor was developed to investigate the gasification process of coal particles. The effects of coal particle size and heater temperature of reactor were examined to identify the thermochemical processes through the packed bed. Three different coal samples with varying size, named as A, B, and C, are used, and the experimental results show that the packed bed with smaller coal size has higher temperature, reaching 624 °C, 582 °C, and 569 °C for coal A, B, and C, respectively. In the case of CO formation, the smaller particle size has greater products in the unit of mole fraction over the area of generation. However, the variation in the porosity of the packed bed due to different coal particle sizes affects the reactions through the oxygen access. Consequently, the CO formation is least from the coal packed bed formed by the smallest particle size A. A second test with the temperature variations shows that the higher heater temperature promotes the chemical reactions, resulting in the increased gas products. The findings indicate the important role of coal seam porosity in underground coal gasification application, as well as temperature to promote the syngas productions.


2020 ◽  
Author(s):  
Tata Sutardi ◽  
Linwei Wang ◽  
Nader Karimi ◽  
Manosh C Paul

Abstract In this study, a packed bed reactor is developed to investigate the gasification process of coal particles. The effects of coal particle size and heater temperature of reactor are examined to identify the thermochemical processes through the packed bed. Three different coal samples with varying size, named as A, B, and C, are used, and the experimental results show that the coal packed bed with smaller size has higher temperature, reaching 624oC, 582oC, and 569oC for coal A, B, and C respectively. In the case of CO formation, the smaller particle size has greater products in the unit of mole fraction over the area of generation. However, the variation in the porosity of the coal packed bed due to different particle sizes affects the reactions through the oxygen access. Consequently, the CO formation is least from the coal packed bed formed by the smallest particle size A. A second test with the temperature variations shows that the higher heater temperature promotes the chemical reactions, resulting in the increased gas products. The findings indicate the important role of coal seam porosity in UCG (underground coal gasification) application, as well as temperature to promote the syngas productions.


2020 ◽  
Author(s):  
Tata Sutardi ◽  
Linwei Wang ◽  
Nader Karimi ◽  
Manosh C Paul

Abstract In this study, a packed bed reactor is developed to investigate the gasification process of coal particles. The effects of coal particle size and heater temperature of reactor are examined to identify the thermochemical processes through the packed bed. Three different coal samples with varying size, named as A, B, and C, are used, and the experimental results show that the coal packed bed with smaller size has higher temperature, reaching 624 o C, 582 o C, and 569 o C for coal A, B, and C respectively. In the case of CO formation, the smaller particle size has greater products in the unit of mole fraction over the area of generation. However, the variation in the porosity of the coal packed bed due to different particle sizes affects the reactions through the oxygen access. Consequently, the CO formation is least from the coal packed bed formed by the smallest particle size A. A second test with the temperature variations shows that the higher heater temperature promotes the chemical reactions, resulting in the increased gas products. The findings indicate the important role of coal seam porosity in UCG (underground coal gasification) application, as well as temperature to promote the syngas productions.


Author(s):  
Anil N. Khadse ◽  
Mohammed Qayyumi ◽  
Sanjay M. Mahajani ◽  
Preeti Aghalayam

Underground Coal Gasification (UCG) is the process of in-situ conversion of coal into combustible products (syngas) which can be used either as fuel or as a chemical feedstock. In this study, the gasification channel is viewed as a one-dimensional packed bed reactor. The packed bed reactor model is solved incorporating chemical reactions and mass transfer effects. A pseudo-transient model is simulated for temperature and composition profiles of the gas and solid phases. The movements of the pyrolysis and the reaction front are obtained. The model results are in qualitative agreement with literature. The effects of various operating parameters are studied in detail. Steam/O2 ratio, inlet O2 and total pressure determine the solid temperature profile and hence the outlet gas composition. The simulations are performed for two sets of kinetics parameters. The solid temperature profile and outlet gas compositions change significantly with a change in kinetics parameters. The main motivation behind this study is to provide a theoretical base for understanding the critical aspects of UCG and to provide a tool which coupled with experiments will help in determining the commercial feasibility of the UCG process.


Author(s):  
Marian Wiatowski ◽  
Roksana Muzyka ◽  
Krzysztof Kapusta ◽  
Maciej Chrubasik

AbstractIn this study, the composition of tars collected during a six-day underground coal gasification (UCG) test at the experimental mine ‘Barbara’ in Poland in 2013 was examined. During the test, tar samples were taken every day from the liquid product separator and analysed by the methods used for testing properties of typical coke oven (coal) tar. The obtained results were compared with each other and with the data for coal tar. As gasification progressed, a decreasing trend in the water content and an increasing trend in the ash content were observed. The tars tested were characterized by large changes in the residue after coking and content of parts insoluble in toluene and by smaller fluctuations in the content of parts insoluble in quinoline. All tested samples were characterized by very high distillation losses, while for samples starting from the third day of gasification, a clear decrease in losses was visible. A chromatographic analysis showed that there were no major differences in composition between the tested tars and that none of the tar had a dominant component such as naphthalene in coal tar. The content of polycyclic aromatic hydrocarbons (PAHs) in UCG tars is several times lower than that in coal tar. No light monoaromatic hydrocarbons (benzene, toluene, ethylbenzene and xylenes—BTEX) were found in the analysed tars, which results from the fact that these compounds, due to their high volatility, did not separate from the process gas in the liquid product separator.


2014 ◽  
Vol 24 (1) ◽  
pp. 269-277 ◽  
Author(s):  
Ali Arshad Uppal ◽  
Aamer Iqbal Bhatti ◽  
Erum Aamir ◽  
Raza Samar ◽  
Shahid Ahmed Khan

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6533
Author(s):  
Magdalena Pankiewicz-Sperka ◽  
Krzysztof Kapusta ◽  
Wioleta Basa ◽  
Katarzyna Stolecka

One of the most important issues during UCG process is wastewater production and treatment. Condensed gasification wastewater is contaminated by many hazardous compounds. The composition of the generated UCG-derived wastewater may vary depending on the type of gasified coal and conditions of the gasification process. The main purpose of this study was a qualitative and quantitative characterization of the UCG wastewater produced during four different UCG experiments. Experiments were conducted using semi-anthracite and bituminous coal samples at two distinct pressures, i.e., 20 and 40 bar. The conducted studies revealed significant relationships between the physicochemical composition of the wastewater and the coal properties as well as the gasification pressure. The strongest impact is noticeable in the case of organic pollutants, especially phenols, BTEX and PAH’s. The most abundant group of pollutants were phenols. Conducted studies showed significantly higher concentration levels for bituminous coal: 29.25–49.5 mg/L whereas for semi-anthracite effluents these concentrations were in much lower range 2.1–29.7 mg/L. The opposite situation occurs for BTEX, higher concentrations were in wastewater from semi-anthracite gasification: 5483.1–1496.7 µg/L, while in samples from bituminous coal gasification average BTEX concentrations were: 2514.3–1354.4 µg/L. A similar relationship occurs for the PAH’s concentrations. The higher values were in case of wastewater from semi-anthracite coal experiments and were in range 362–1658 µg/L while from bituminous coal gasification PAH’s values are in lower ranges 407–1090 µg/L. The studies conducted have shown that concentrations of phenols, BTEX and PAH’s decrease with increasing pressure. Pearson’s correlation analysis was performed to enhance the interpretation of the obtained experimental data and showed a very strong relationship between three parameters: phenols, volatile phenols and CODcr.


2014 ◽  
Vol 59 (3) ◽  
pp. 677-690 ◽  
Author(s):  
Jolanta Marciniak-Kowalska ◽  
Tomasz Niedoba ◽  
Agnieszka Surowiak ◽  
Tadeusz Tumidajski

Abstract This paper presents a comparative analysis of two types of coal taken from the ZG Janina and ZG Wieczorek coalmines. The aim of this study has been to analyze the suitability of the coal in the context of the gasification process. The types of coal vary considerably in terms of their characteristics. Each of them was subjected to treatment in a ten-ringed annular jig. A particle size of 0-18 mm constituted the feed. The separated coal was divided into five layers, each of them containing material from two additional annular jigs. Analysis of their characteristics was carried out for each of the five layers and for both types of coal obtained, taking into account both their physicochemical properties as well as chemical ones. Each of these characteristics was then presented in three-dimensional surface diagrams, where the ordinate (or Y-axis) and abscissa (X-axis) was the particle size and height in which the material ended up in the jig (expressed as a percentage of the total height of the device). On the basis of observations, it was found that the types of coal have different potential for gasification, although both types are within the limits specified on the basis of previous studies. A correlation analysis between particle size and remaining characteristics of coal was carried out for each of the layers, allowing to determine which of the studied characteristics induced changes significant from the point of view of the coal gasification process. The entire research and observation was supported by conclusions and findings, which shall form the basis for further, in-depth analysis of coal.


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