Article
Chemistry, Physical
Krzysztof Kapusta, Marian Wiatowski, Hywel R. Thomas, Renato Zagorscak, Sivachidambaram Sadasivam, Shakil Masum, Thomas Kempka, Christopher Otto, Wioleta Basa, Marcin Szyja, Krzysztof Stanczyk
Summary: This paper presents a series of surface experimental simulations of methane-oriented underground coal gasification using hydrogen as gasification medium. The experiments demonstrated that the physicochemical properties of coal considerably affect the hydrogasification process and the feasibility of methane-rich gas production was initially demonstrated. However, further techno-economic studies are necessary to assess the economic feasibility of methane production using this process.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Review
Energy & Fuels
Shadrack Adjei Takyi, Yindi Zhang, Mengting Si, Fanjin Zeng, Yingnan Li, Paitoon Tontiwachwuthikul
Summary: Although coal mining has played a significant role in global development, its environmental impact offsets its value. The shift to net-zero CO2 emissions presents opportunities for new coal technological models. This paper reviews the current status and technology development of underground coal gasification for low carbon emission energy, discussing its modern stage, pilot operations, and market developments.
FRONTIERS IN ENERGY RESEARCH
(2023)
Article
Energy & Fuels
Wen-gang Huang, Zuo-tang Wang, Tian-hong Duan, Lin Xin
Summary: The pilot project integrating UCG with power generation in the abandoned mine Ankou aimed to optimize the gasification process, with industrial tests revealing that changes in oxygen concentration significantly affected syngas production. Increasing oxygen concentration led to higher H-2 content, combustible components, calorific value of syngas, and gasification efficiency after an initial drop. Additionally, oxygen-enriched gasification trials showed advantages in air consumption, coal consumption, and calorific value compared to oxygen-enriched steam gasification tests.
Article
Green & Sustainable Science & Technology
Wen-gang Huang, Shao-wei Zhang, Xin Lu, Shu-liang Wu, Jun Huang
Summary: This paper researched the distribution and characteristics of residual coal resources in China and its adaptability to underground coal gasification (UCG) technology. The study found that the average recovery rate of coal mines in China was low, with the majority of residual coal reserves occurring in North China at shallow burial depths. The primary coal type was bituminite. The study established a hierarchical evaluation model and applied it to industrial tests, showing that the model can provide a scientific reference for decision-making in UCG projects.
SUSTAINABLE ENERGY TECHNOLOGIES AND ASSESSMENTS
(2022)
Article
Thermodynamics
Fa-qiang Su, Xiao-long He, Meng-jia Dai, Jun-nan Yang, Akihiro Hamanaka, Yi-he Yu, Wen Li, Jiao-yuan Li
Summary: This study analyzed the impact of oxygen flow rate on the cavity of the gasification zone through two experiments and used three estimation methods to estimate the cavity volume. The results showed that the stoichiometric method had the smallest estimation error, less than 6.5%. The Delaunay triangulation approach reduced the estimation error for convex cavities to within 10%. The voxelization method reduced the overall estimation error to below 8% and accurately described the cavity shape.
Article
Mathematics
Afaq Ahmed, Syed Bilal Javed, Ali Arshad Uppal, Jamshed Iqbal
Summary: The Cavity Simulation Model (CAVSIM) is a 3D, parameterisable simulator of the Underground Coal Gasification Process (UCG) that serves as a benchmark for UCG prediction. It has limitations in graphical capabilities, parametrisation efficiency, and lack of tools to synthesise a controller. To compensate for these shortcomings, CAVSIM was integrated with MATLAB, resulting in successful integration and a controllable structure. The performance metrics further establish the efficacy of CAVLAB in designing MPC for the UCG system.
Article
Thermodynamics
Syed Bilal Javed, Ali Arshad Uppal, Raza Samar, Aamer Iqbal Bhatti
Summary: In this work, a model-based multi-variable robust control design using H-infinity technique is proposed for the underground coal gasification (UCG) process. The designed controller based on a linear model demonstrates robust stability and performance on an actual nonlinear cavity simulator, achieving adequate tracking of set points.
Article
Energy & Fuels
Jacek Nowak, Magdalena Kokowska-Pawlowska, Joanna Komorek, Marian Wiatowski, Krzysztof Kapusta, Zdzislaw Adamczyk
Summary: This study conducted coal gasification experiments under different pressures to analyze the changes in optical properties of the organic matter and determine the temperature influence on coal. The results showed that the reflectance and bireflectance of coal decreased with increasing distance from the reactor chamber inlet, and the temperature influence on coal decreased as well. Additionally, the actual temperatures during the experiment were higher than recorded temperatures, and the distance at which temperature had a significant impact depended on the pressure used.
Article
Engineering, Geological
Wen-gang Huang, Zuo-tang Wang
Summary: This study focuses on the mechanical performance evolution of coal pillars in the UCG process. A new calculation method for pillar sizing was proposed and experimentally validated, showing significant impact of high temperatures near the coal pillar surface and demonstrating the variation pattern of pillar width during UCG operation.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2021)
Article
Energy & Fuels
Krzysztof Kapusta
Summary: Two experimental simulations of underground coal gasification processes were conducted using large bulk samples of lignites, and the results showed that the physicochemical properties of the lignite used considerably affect the in situ gasification process. Lignites with lower moisture content and higher energy density demonstrated higher process efficiency compared to lignites with higher moisture content.
Article
Energy & Fuels
Magdalena Pankiewicz-Sperka, Krzysztof Kapusta, Wioleta Basa, Katarzyna Stolecka
Summary: The study focused on qualitative and quantitative characterization of UCG wastewater produced during four different experiments, showing significant relationships between wastewater composition and coal properties as well as gasification pressure, especially for organic pollutants like phenols, BTEX, and PAH's. The concentrations of these pollutants were found to vary depending on the type of coal and gasification pressure, with phenols having the highest concentrations. Additionally, the study found that concentrations of phenols, BTEX, and PAH's decrease with increasing pressure.
Review
Energy & Fuels
Jacek Borgulat, Katarzyna Ponikiewska, Lukasz Jalowiecki, Aleksandra Strugala-Wilczek, Grazyna Plaza
Summary: Underground coal gasification (UCG) is a clean coal technology, but it carries environmental risks. This review focuses on wetlands systems as a bioremediation method for treating UCG wastewater and provides examples and operating principles.
Article
Chemistry, Multidisciplinary
Xiaopeng Liu, Liangji Xu, Kun Zhang
Summary: Underground coal gasification (UCG) technology is a green, safe, and efficient method of coal development, playing a key role in the sustainable development of resources and energy. However, there is limited research on the strata movement and surface subsidence under high-temperature environments, hindering the further development of UCG technology. This study aims to address the key problems of UCG strata movement and surface subsidence prediction.
APPLIED SCIENCES-BASEL
(2023)
Article
Automation & Control Systems
Ranjeet Mandal, Tanmoy Maity
Summary: This paper focuses on the variations of process parameters in underground coal gasification (UCG) and explores suitable sensors selection and monitoring units design for control, monitoring, and precaution during the gasification process. Experimental work is conducted on a laboratory scale, and individual control and monitoring techniques of different operational process parameters are described, aiming for successful UCG operation and complexity reduction.
JOURNAL OF PROCESS CONTROL
(2023)
Article
Green & Sustainable Science & Technology
Ni An, Renato Zagorscak, Hywel Rhys Thomas, Wu Gao
Summary: This study improves understanding of potential environmental impact of underground coal gasification by investigating the transport of gaseous and dissolved chemicals in surrounding strata. Results show gas propagation is limited by geological characteristics, and selecting the right coal seam can minimize gas losses and avoid negative environmental impact during operation and decommissioning stages.
JOURNAL OF CLEANER PRODUCTION
(2021)
Article
Environmental Sciences
Sivachidambaram Sadasivam, Renato Zagorscak, Hywel Rhys Thomas, Krzysztof Kapusta, Krzysztof Stanczyk
Summary: This paper investigates the inorganic constituents generated during underground coal gasification (UCG) under different operating conditions. It was found that increasing the water content in the oxidants decreased cationic elements but increased anionic species concentrations. Temperature had a minor impact on the experiments, while high-pressure experiments at the optimal temperature showed significant reduction in cationic element generation. Both coal specimens produced high amounts of anionic species, with the hard bituminous coal from Poland showing higher reactivity. The inorganic composition in the solid residue was used to predict dissolved product concentrations when interacting with deep coal seam water during UCG cavity flooding. Additionally, changes in groundwater geochemistry were observed, indicating the need for further study on their transportation in the subsurface.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2022)
Article
Energy & Fuels
Aleksandra Strugala-Wilczek, Krzysztof Kapusta
Summary: In this study, a numerical model of inorganic pollutant migration in the area of an underground coal gasification (UCG) reactor was constructed. The study compared the effect of different sorption affinities on the deceleration and shape of the contaminant plume in geological formations. The results showed that sorption parameters, time, and distance play important roles in pollutant migration.
Article
Agricultural Engineering
Oraleou Sangue Djandja, Fan-Gong Kong, Lin-Xin Yin, Pei-Gao Duan, Donghai Xu, Krzysztof Kapusta
Summary: Two types of aqueous phases prepared from hydrothermal carbonization of sewage sludge were cocarbonized with cellulose at different temperatures. The N content of the hydrochars was promoted by the N-heterocyclic compounds in the aqueous phase, while the O content was reduced. Increasing the temperature improved the incorporation of N into the aromatic rings. The derived N-doped carbons exhibited different properties depending on the O/N ratio. NC230280 showed the best performance in terms of specific capacitance, internal resistance, and time constant. The type of precursor and the elemental composition influenced the capacitance performance.
BIOMASS & BIOENERGY
(2022)
Article
Chemistry, Analytical
Botian Hao, Wanpeng Yang, Yu Wang, Donghai Xu, Krzysztof Kapusta, Yang Guo
Summary: This study investigated the coupling effects of reaction temperature and residence time on nitrogen transformation during hydrothermal liquefaction of municipal sludge. The optimal conditions were determined and the distribution and transformation pathways of nitrogen were clarified.
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
(2022)
Article
Energy & Fuels
Aleksandra Strugala-Wilczek, Krzysztof Kapusta, Magdalena Pankiewicz-Sperka
Summary: One of the most significant environmental risks associated with underground coal gasification (UCG) is groundwater contamination. This study investigates the characteristics of UCG solid residues and their potential to release pollutants to the surrounding area. Laboratory tests were conducted on the residues produced during ex situ UCG of two types of lignites. The results show that the samples from different parts of the reactor differ significantly and may release contaminants. However, no dangerous trace elements were found in the aqueous extracts, suggesting that UCG of lignite is safe for the aquatic environment during the post-operational phase.
Article
Chemistry, Physical
Krzysztof Kapusta, Marian Wiatowski, Hywel R. Thomas, Renato Zagorscak, Sivachidambaram Sadasivam, Shakil Masum, Thomas Kempka, Christopher Otto, Wioleta Basa, Marcin Szyja, Krzysztof Stanczyk
Summary: This paper presents a series of surface experimental simulations of methane-oriented underground coal gasification using hydrogen as gasification medium. The experiments demonstrated that the physicochemical properties of coal considerably affect the hydrogasification process and the feasibility of methane-rich gas production was initially demonstrated. However, further techno-economic studies are necessary to assess the economic feasibility of methane production using this process.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Energy & Fuels
Jacek Nowak, Magdalena Kokowska-Pawlowska, Joanna Komorek, Marian Wiatowski, Krzysztof Kapusta, Zdzislaw Adamczyk
Summary: This study conducted coal gasification experiments under different pressures to analyze the changes in optical properties of the organic matter and determine the temperature influence on coal. The results showed that the reflectance and bireflectance of coal decreased with increasing distance from the reactor chamber inlet, and the temperature influence on coal decreased as well. Additionally, the actual temperatures during the experiment were higher than recorded temperatures, and the distance at which temperature had a significant impact depended on the pressure used.
Article
Energy & Fuels
Botian Hao, Donghai Xu, Yu Wang, Yuanyuan Wang, Krzysztof Kapusta, Yang Guo
Summary: This study evaluated the effects of non-noble metal catalysts supported on activated carbon on the hydrothermal liquefaction (HTL) process of municipal sludge with ethanol solvent. The results showed that Ni-Co/AC and Ni-Cu/AC catalysts increased the energy value of biocrudes and reduced the sulfur content. Ethanol solvent significantly improved biocrude yields and promoted the conversion of high boiling point compounds to low boiling point compounds.
Article
Agricultural Engineering
Elendu Collins Chimezie, Zhicong Wang, Yun Yu, Ude Callistus Nonso, Pei-Gao Duan, Krzysztof Kapusta
Summary: This work utilized a solvent extraction technique to obtain oil from avocado pear seeds and peels, and used methanol and H2SO4 to pre-treat the extracted oil. Biodiesel production was optimized through trans-esterification between the pre-treated oil and methanol catalyzed by NaOH, yielding a 91 wt% biodiesel at specific conditions. Engine tests showed that the engine used less than 20% biodiesel mixture to generate the same amount of work compared to fossil diesel, with the 20% biodiesel mixture exhibiting the best engine performance.
INDUSTRIAL CROPS AND PRODUCTS
(2023)
Article
Energy & Fuels
Marian Wiatowski
Summary: The yield and composition of the tar collected during a three-day gasification test of a large coal block with oxygen in atmospheric pressure conditions were investigated. Sand was used as an insulating material and the tar was sampled every 7 hours. The results showed that the composition and amount of the obtained process gas and tar were significantly affected by the reaction between the water in the wet sand and the gasified coal. The total yield of the tar from this underground coal gasification (UCG) process was 1.8%, which was three times lower than the efficiency of the classic coking process.
Article
Energy & Fuels
Marian Wiatowski, Krzysztof Kapusta, Aleksandra Strugala-Wilczek, Krzysztof Stanczyk, Alberto Castro-Muniz, Fabian Suarez-Garcia, Juan Ignacio Paredes
Summary: This paper presents surface experiments investigating the influence of gasification medium and coal rank on the underground coal gasification process. The experiments show that using oxygen as the gasifying agent results in higher gas quality and process efficiency compared to using oxygen-enriched air. The coal rank also affects the gas quality and energy efficiency of the process. The rate of water condensate production is also influenced by the gasifying agent.
Article
Environmental Sciences
Longfei Xie, Le Gou, Donghai Xu, Krzysztof Kapusta, Liyi Dai, Yuanyuan Wang
Summary: This study investigates the influence of model compounds on nitrogen transformation during the hydrothermal carbonization (HTC) of sewage sludge (SS). It is found that the organic components can reduce nitrogen content and increase the aromaticity of the hydrochar, with humus showing the best performance. Hemicellulose and cellulose have the strongest effects on nitrogen retention, while lignin and humus promote nitrogen transformation. Although protein decreases energy recovery and yield, it favors the carbonization process. This research provides references for estimating nitrogen content and quality of hydrochar, and for future research on hydrochar upgrading.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Energy & Fuels
Oraleou Sangue Djandja, Linxin Yin, Zhicong Wang, Pei-Gao Duan, Donghai Xu, Krzysztof Kapusta
Summary: This study investigated the influence of reaction solvent (water/ethanol) and nitrogen source (pyridine/pyrrole) on the synthesis of N-doped carbon material through a hydrothermal process. The presence of water promoted cellulose carbonization and nitrogen doping through a Maillard reaction with pyridine. Increasing temperature and the water/pyridine ratio enhanced cellulose carbonization and the Maillard reaction. The obtained N-doped carbon materials exhibited high specific surface area and specific capacitance, and good capacitance retention after cycles.
JOURNAL OF ENERGY STORAGE
(2023)
Article
Energy & Fuels
Nuno Batalha, Ruben Checa, Chantal Lorentz, Pavel Afanasiev, Krzysztof Stanczyk, Krzysztof Kapusta, Dorothee Laurenti, Christophe Geantet
Summary: This study explores the relationship between hydrothermal liquefaction (HTL) crude oil composition and hydrotreatment (HDT) conversion. It was found that the composition differences of different crude oils determine the potential for producing hydrocarbon fuels, with HTL crude oils rich in aromatic compounds being more favorable for producing naphthenes and aromatic hydrocarbons, while crude oils richer in aliphatic carbon tend to yield paraffins. Additionally, the nature and concentration of heteroatom components also need to be considered.
Article
Green & Sustainable Science & Technology
Mingyan Ma, Donghai Xu, Xuehan Gong, Yunfei Diao, Peng Feng, Krzysztof Kapusta
Summary: Biochar derived from municipal sewage sludge (MSS) pyrolysis can be used as a catalyst to achieve product recycling and enhance conversion rate. The kinetics of MSS product recirculation catalytic pyrolysis were investigated through non-isothermal thermogravimetric experiments. The results revealed that MSS noncatalytic/catalytic pyrolysis reaction involves five stages, with the main decomposition occurring between 180 and 680 degrees C and accounting for a significant mass loss.
Article
Thermodynamics
Yong Cheng, Fukai Song, Lei Fu, Saishuai Dai, Zhiming Yuan, Atilla Incecik
Summary: This paper investigates the accessibility of wave energy absorption by a dual-pontoon floating breakwater integrated with hybrid-type wave energy converters (WECs) and proposes a hydraulic-pneumatic complementary energy extraction method. The performance of the system is validated through experiments and comparative analysis.
Article
Thermodynamics
Jing Gao, Chao Wang, Zhanwu Wang, Jin Lin, Runkai Zhang, Xin Wu, Guangyin Xu, Zhenfeng Wang
Summary: This study aims to establish a new integrated method for biomass cogeneration project site selection, with a focus on the application of the model in Henan Province. By integrating Geographic Information System and Multiple Criterion Decision Making methods, the study conducts site selection in two stages, providing a theoretical reference for the construction of biomass cogeneration projects.
Article
Thermodynamics
Mert Temiz, Ibrahim Dincer
Summary: The current study presents a hybrid small modular nuclear reactor and solar-based system for sustainable communities, integrating floating and bifacial photovoltaic arrays with a small modular reactor. The system efficiently generates power, hydrogen, ammonia, freshwater, and heat for residential, agricultural, and aquaculture facilities. Thermodynamic analysis shows high energy and exergy efficiencies, as well as large-scale ammonia production meeting the needs of metropolitan areas. The hybridization of nuclear and solar technologies offers advantages of reliability, environmental friendliness, and cost efficiency compared to renewable-alone and fossil-based systems.
Editorial Material
Thermodynamics
Wojciech Stanek, Wojciech Adamczyk
Article
Thermodynamics
Desheng Xu, Yanfeng Li, Tianmei Du, Hua Zhong, Youbo Huang, Lei Li, Xiangling Duanmu
Summary: This study investigates the optimization of hybrid mechanical-natural ventilation for smoke control in complex metro stations. The results show that atrium fires are more significantly impacted by outdoor temperature variations compared to concourse/platform fires. The gathered high-temperature smoke inside the atrium can reach up to 900 K under a 5 MW train fire energy release. The findings provide crucial engineering insights into integrating weather data and adaptable ventilation protocols for smoke prevention/mitigation.
Article
Thermodynamics
Da Guo, Heping Xie, Mingzhong Gao, Jianan Li, Zhiqiang He, Ling Chen, Cong Li, Le Zhao, Dingming Wang, Yiwei Zhang, Xin Fang, Guikang Liu, Zhongya Zhou, Lin Dai
Summary: This study proposes a new in-situ pressure-preserved coring tool and elaborates its pressure-preserving mechanism. The experimental and field test results demonstrate that this tool has a high pressure-preservation capability and can maintain a stable pressure in deep wells. This study provides a theoretical framework and design standards for the development of similar technologies.
Article
Thermodynamics
Aolin Lai, Qunwei Wang
Summary: This study assesses the impact of China's de-capacity policy on renewable energy development efficiency (REDE) using the Global-MSBM model and the difference-in-differences method. The findings indicate that the policy significantly enhances REDE, promoting technological advancements and marketization. Moreover, regions with stricter environmental regulations experience a higher impact.
Article
Thermodynamics
Mostafa Ghasemi, Hegazy Rezk
Summary: This study utilizes fuzzy modeling and optimization to enhance the performance of microbial fuel cells (MFCs). By simulating and analyzing experimental data sets, the ideal parameter values for increasing power density, COD elimination, and coulombic efficiency were determined. The results demonstrate that the fuzzy model and optimization methods can significantly improve the performance of MFCs.
Article
Thermodynamics
Zhang Ruan, Lianzhong Huang, Kai Wang, Ranqi Ma, Zhongyi Wang, Rui Zhang, Haoyang Zhao, Cong Wang
Summary: This paper proposes a grey box model for fuel consumption prediction of wing-diesel hybrid vessels based on feature construction. By using both parallel and series grey box modeling methods and six machine learning algorithms, twelve combinations of prediction models are established. A feature construction method based on the aerodynamic performance of the wing and the energy relationship of the hybrid system is introduced. The best combination is obtained by considering the root mean square error, and it shows improved accuracy compared to the white box model. The proposed grey box model can accurately predict the daily fuel consumption of wing-diesel hybrid vessels, contributing to operational optimization and the greenization and decarbonization of the shipping industry.
Article
Thermodynamics
Huayi Chang, Nico Heerink, Junbiao Zhang, Ke He
Summary: This study examines the interaction between off-farm employment decisions between couples and household clean energy consumption in rural China, and finds that two-paycheck households are more likely to consume clean energy. The off-farm employment of women is a key factor driving household clean energy consumption to a higher level, with wage-employed wives having a stronger influence on these decisions than self-employed ones.
Article
Thermodynamics
Hanguan Wen, Xiufeng Liu, Ming Yang, Bo Lei, Xu Cheng, Zhe Chen
Summary: Demand-side management is crucial to smart energy systems. This paper proposes a data-driven approach to understand the relationship between energy consumption patterns and household characteristics for better DSM services. The proposed method uses a clustering algorithm to generate optimal customer groups for DSM and a deep learning model for training. The model can predict the possibility of DSM membership for a given household. The results demonstrate the usefulness of weekly energy consumption data and household socio-demographic information for distinguishing consumer groups and the potential for targeted DSM strategies.
Article
Thermodynamics
Xinglan Hou, Xiuping Zhong, Shuaishuai Nie, Yafei Wang, Guigang Tu, Yingrui Ma, Kunyan Liu, Chen Chen
Summary: This study explores the feasibility of utilizing a multi-level horizontal branch well heat recovery system in the Qiabuqia geothermal field. The research systematically investigates the effects of various engineering parameters on production temperature, establishes mathematical models to describe their relationships, and evaluates the economic viability of the system. The findings demonstrate the significant economic feasibility of the multi-level branch well system.
Article
Thermodynamics
Longxin Zhang, Songtao Wang, Site Hu
Summary: This investigation reveals the influence of tip leakage flow on the modern transonic rotor and finds that the increase of tip clearance size leads to a decline in rotor performance. However, an optimal tip clearance size can extend the rotor's stall margin.
Article
Thermodynamics
Kristian Gjoka, Behzad Rismanchi, Robert H. Crawford
Summary: This paper proposes a framework for assessing the performance of 5GDHC systems and demonstrates it through a case study in a university campus in Melbourne, Australia. The results show that 5GDHC systems are a cost-effective and environmentally viable solution in mild climates, and their successful implementation in Australia can create new market opportunities and potential adoption in other countries with similar climatic conditions.
Article
Thermodynamics
Jianwei Li, Guotai Wang, Panpan Yang, Yongshuang Wen, Leian Zhang, Rujun Song, Chengwei Hou
Summary: This study proposes an orientation-adaptive electromagnetic energy harvester by introducing a rotatable bluff body, which allows for self-regulation to cater for changing wind flow direction. Experimental results show that the output power of the energy harvester can be greatly enhanced with increased rotatory inertia of the rotating bluff body, providing a promising solution for harnessing wind-induced vibration energy.
