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Gabruś E, Wojtacha-Rychter K, Aleksandrzak T, Smoliński A, Król M. The feasibility of CO 2 emission reduction by adsorptive storage on Polish hard coals in the Upper Silesia Coal Basin: An experimental and modeling study of equilibrium, kinetics and thermodynamics. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 796:149064. [PMID: 34328898 DOI: 10.1016/j.scitotenv.2021.149064] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 07/12/2021] [Accepted: 07/12/2021] [Indexed: 06/13/2023]
Abstract
Carbon dioxide storage in unmineable coal seams is advantageous in the highly industrialized areas, such as the Upper Silesia Coal Basin (USCB), Poland, where heavy industry constitutes the source of huge CO2 emissions and coal mines will be closed in the future, due to unprofitability. The paper presents the results of experimental and theoretical research of CO2 capture on medium rank C and B bituminous coals coming from three mines located in the USCB. The porous texture of the investigated adsorbents was analyzed using SEM images and the N2 and CO2 isotherms at -196 °C and 0 °C, respectively. Qualitative studies using DRIFT spectroscopy showed that band intensity attributed to the functional groups of coals changed after CO2 adsorption. The analyses encompassed the equilibrium, kinetics and thermodynamics of CO2 adsorption on coals at 25, 50 and 75 °C (up to 2000 kPa). The adsorption isotherms were obtained by the static gravimetric method and described by means of the Langmuir, Freundlich, Dubinin-Radushkevich and Dubinin-Astakhov models. The highest CO2 uptakes were obtained for medium rank C bituminous coals at 25 °C; the values were 1.600 mol/kg and 1.274 mol/kg. The adsorption kinetics was better characterized by the Avrami fractional-order model rather than by the pseudo-first and pseudo-second order models. The results reveal that the adsorption process is the fastest for medium rank C bituminous coals. The isosteric heats of adsorption were calculated in the following two ways: based on the multi-temperature Toth isotherm and the Clausius-Clapeyron equations. Depending on degree of coal metamorphism, the heat of adsorption ranged from 18 to 26 kJ/mol. The estimated maximum temperature increase due to heat accumulation in the insulated coalbed during CO2 adsorption was 6 °C and did not reach the self-ignition temperature in any of the tested adsorption systems.
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Affiliation(s)
- Elżbieta Gabruś
- West Pomeranian University of Technology, Szczecin, Faculty of Chemical Technology and Engineering, Department of Chemical and Process Engineering, al. Piastów 42, 70-065 Szczecin, Poland.
| | | | - Tomasz Aleksandrzak
- West Pomeranian University of Technology, Szczecin, Faculty of Chemical Technology and Engineering, Department of Chemical and Process Engineering, al. Piastów 42, 70-065 Szczecin, Poland
| | - Adam Smoliński
- Central Mining Institute, Pl. Gwarków 1, 40-166 Katowice, Poland
| | - Magdalena Król
- AGH University of Science and Technology, Department of Silicate Chemistry, Mickiewicza 30, 30-059 Kraków, Poland
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Combustion Characteristics of Mui and Taru Basin Coal in a Fluidized Bed Combustor. JOURNAL OF COMBUSTION 2021. [DOI: 10.1155/2021/6647875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Coal reserves at Mui and Taru in Kitui and Kilifi counties in Kenya are estimated to provide over 400 million tons. Being new discoveries, their properties were investigated using the ASTM standards, while the combustion characteristics were studied in a fluidized bed combustor (FBC). Proximate analyses of the Mui1, Mui2, and Taru coal samples were as follows: moisture content 3.75, 5.48, and 3.53%; volatile matter 59.25, 58.05, and 55.10%; ash content 9.25, 11.48, and 24.63%; and fixed carbon 27.80, 25.00, and 16.75%, respectively. Ultimate analysis for Mui1, Mui2, and Taru coal samples is as follows: sulphur wt.% 1.94, 1.89, and 1.07; carbon 65.68, 60.98, and 51.10%; hydrogen 5.97, 5.70, and 5.09%; nitrogen 0.92, 0.94, and 1.00%; and oxygen 11.62, 12.33, and 11.13%, respectively. Temperature–weight loss analysis showed that for Mui and Taru basin coal, devolatilization starts at 200°C and 250°C, and combustion was complete at 750°C and 650°C, respectively. The maximum temperature obtained in FBC was 855°C at 700 mm height, just above the point of fuel feed, while the minimum was 440°C at height of 2230 mm. Maximum pressure drop was 1.02 mbars at 150 mm, while minimum was 0.67 mbars at 700 mm from the base. Gross calorific values were Mui1 coal, 27090 kJ/kg (grade A), Mui2 coal, 25196 kJ/kg (grade B), and the Taru coal, 21016 kJ/kg (grade C). Flue gas analysis for Taru and Mui coal gave hydrogen sulfide as 20 ppm and 6 ppm, maximum carbon monoxide of 2000 ppm at 600°C, and a decrease in oxygen as combustion progressed to a minimum of 15%, followed by an increase to 20.3%, suggesting depletion of coal. Based on the findings, the coal samples were suitable for commercial use.
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Yin H, Lu J, Liu G, Niu Z, Zha X, Wu D, Feng A, Hu Y. Application of Chemometrics for Coal Pyrolysis Products by Online py-GC×GC-MS. ACS OMEGA 2021; 6:3763-3770. [PMID: 33585755 PMCID: PMC7876837 DOI: 10.1021/acsomega.0c05359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 01/14/2021] [Indexed: 06/12/2023]
Abstract
Investigations on the molecular composition of coal pyrolysis products can help us to improve nonfuel utilization of coal. Meanwhile, the molecular composition of coal pyrolysis products is also influenced by the characteristics and depositional environment of coal. However, due to the extremely complex nature of coal, direct investigation of the molecular composition of coal pyrolysis products is still a challenge. In the present work, the data of the molecular composition of bituminous coal pyrolysis products are obtained by online pyrolysis coupled to comprehensive two-dimensional gas chromatography and mass spectrometry (online py-GC×GC-MS) and are divided into nine molecular groups depending on the aromaticity of the pyrolysis products and separating power of the GC×GC-MS. Chemometric tools, hierarchical cluster analysis, and principal component analysis are employed to reveal the correlations among the molecular composition of coal pyrolysis products and coal characteristics. The results show that the nine molecular groups of bituminous coal pyrolysis products can be divided into two clusters, the "aromatic group" and the "aliphatic group", and that the eight coals are divided into three clusters, all of which can be interpreted by the depositional environments and δ13CVPDB values of coals. Moreover, a simple and empirical equation for estimation of coal tar from hydropyrolysis can be obtained depending on the chemometric results of the molecular composition of the coal pyrolysis products. By application of chemometrics, the molecular composition of coal pyrolysis products can provide preference to industrial utilization of coal.
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Affiliation(s)
- Hao Yin
- CAS Key Laboratory
of Crust-Mantle Materials and the Environments, School of Earth and
Space Sciences, University of Science and
Technology of China, Hefei 230026, China
- Mass Spectrometry Lab, Hefei National Laboratory
for Physical Sciences at Microscale, University
of Science and Technology of China, Hefei 230026, China
| | - Jie Lu
- National
High Magnetic Field Laboratory, Florida
State University, 1800
East Paul Dirac Drive, Tallahassee, Florida 32310-4005, United States
| | - Guijian Liu
- CAS Key Laboratory
of Crust-Mantle Materials and the Environments, School of Earth and
Space Sciences, University of Science and
Technology of China, Hefei 230026, China
| | - Zhiyuan Niu
- CAS Key Laboratory
of Crust-Mantle Materials and the Environments, School of Earth and
Space Sciences, University of Science and
Technology of China, Hefei 230026, China
| | - Xiangping Zha
- CAS Key Laboratory
of Crust-Mantle Materials and the Environments, School of Earth and
Space Sciences, University of Science and
Technology of China, Hefei 230026, China
| | - Dun Wu
- CAS Key Laboratory
of Crust-Mantle Materials and the Environments, School of Earth and
Space Sciences, University of Science and
Technology of China, Hefei 230026, China
| | - Airong Feng
- Mass Spectrometry Lab, Hefei National Laboratory
for Physical Sciences at Microscale, University
of Science and Technology of China, Hefei 230026, China
| | - Yanyun Hu
- Mass Spectrometry Lab, Hefei National Laboratory
for Physical Sciences at Microscale, University
of Science and Technology of China, Hefei 230026, China
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