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
Environmental Sciences
Viktor Alexandrovich Kuznetsov, Daria Mikhailovna Bozheeva, Andrey Viktorovich Minakov
Summary: Combustion or gasification of coal in a nitrogen-free environment is a promising technology for reducing the carbon footprint. This study numerically investigates the oxy-gasification processes of pulverized coal in a CO2-H2O-O-2 environment and examines the influence of various factors on the physicochemical processes and syngas composition. The results show that increasing oxygen concentration in the blast can stabilize ignition and combustion of coal, while decreasing the excess oxygen ratio leads to increased combustible losses in the gasifier.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
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
Green & Sustainable Science & Technology
Ye Feng, Bo Yang, Yunbing Hou, Tian-Hong Duan, Lai Yang, Yixuan Wang
Summary: This study assessed the environmental impacts of UGCC with and without CCS through life cycle assessment, revealing that UGCC power plants have lower mid-point impact values but higher global warming potential compared to IGCC power plants. Additionally, UGCC power plants show superior end-point environmental benefits, but the implementation of CCS may result in an increase in damage to ecosystem quality and resources.
JOURNAL OF CLEANER PRODUCTION
(2021)
Article
Thermodynamics
Pradeep Sahu, Prabu Vairakannu
Summary: Electronic wastes, especially printed circuit boards (PCBs), are thermally treated under N2 and CO2 conditions by pyrolysis and gasification processes. PCB pyrolysis at 500 degrees C yields 7.46% of tar with a calorific value of 31.28 MJ/kg. CO2 gasification of PCB mixture at 1000 degrees C achieves a conversion rate of 97.6%, resulting in high cold gas and exergy efficiencies. Co-gasification with high ash Indian coal increases the overall efficiency, and the residue can be used as a catalyst or additives in concrete material.
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
Thermodynamics
Xiangyu Li, Zhiqing Wang, Ru Feng, Jiejie Huang, Yitian Fang
Summary: The technology of extracting alumina from coal ash provides a way to reuse coal-based solid waste, but the challenge lies in the harmless treatment of alumina-extracted residue. By functionalizing the residue, it can serve as a potential sorbent for CO2, showing enhanced adsorption performance.
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
Environmental Sciences
Yan Cao, Yu Bai, Jiang Du
Summary: Biomass was studied as a potential renewable energy source, and a model was developed to predict gasification characteristics and performances. The study found that gasification temperature significantly influenced gas composition and product yields, while equivalence ratio and steam/biomass ratio affected gasification characteristics.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Chemistry, Physical
Praphulla Rao, Sreenivas Jayanti
Summary: This paper investigates the sensitivity of vanadium redox flow battery (VRFB) to cell operating temperature, particularly at low temperatures. The results show significant loss of discharge capacity and cell efficiency at low temperatures, which can be attributed to increased ohmic and charge transfer resistance. By optimizing electrode parameters and using electrocatalysts, potential improvements can be made in the low temperature performance of VRFB cells.
JOURNAL OF POWER SOURCES
(2021)
Article
Energy & Fuels
Ravendra Gundlapalli, Sreenivas Jayanti
Summary: Vanadium redox flow batteries have great potential for large-scale storage and balancing of energy from renewable sources, but practical aspects like design and failure diagnosis need to be addressed. This paper discusses operational failures during the design and development of kilowatt-scale flow batteries, providing recommendations and guidelines to avoid such failures.
JOURNAL OF ENERGY STORAGE
(2021)
Article
Chemistry, Physical
Ravendra Gundlapalli, Sreenivas Jayanti
Summary: A new flip-flop directional split serpentine flow field is proposed to reduce pressure drop and improve electrochemical performance in industrial flow battery stacks. Experimental studies and computational fluid dynamics simulations confirm the effectiveness of the new flow field, showing improvements in discharge energy and efficiency compared to traditional serpentine flow fields. Scalability of the new flow field to large cell sizes has also been demonstrated.
JOURNAL OF POWER SOURCES
(2021)
Article
Green & Sustainable Science & Technology
Ankit Kumar, Sreenivas Jayanti
Summary: Efficient utilization of land resources and coordination between electricity generation and consumption at different levels can lead to sustainable energy solutions and move towards carbon neutrality.
CLEAN TECHNOLOGIES AND ENVIRONMENTAL POLICY
(2021)
Article
Engineering, Chemical
Md. Malik Nawaz Khan, Sreenivas Jayanti
Summary: This article introduces a sophisticated reformer design using Hilbert's space-filling curves, which solves the problem of high thermal resistance in conventional packed bed methanol steam reformers, and achieves high methanol conversion and low carbon monoxide production.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2022)
Article
Green & Sustainable Science & Technology
Ankit Kumar, Sreenivas Jayanti
Summary: This paper proposes a model that integrates geographically distributed and diverse power sources, geographically spread-out power consumption centers, and distributed and diverse electrical energy storage systems. The model calculates the minute-by-minute power demand and generation in each district over a given day, extracts matching power to minimize transmission and storage losses, and stores or draws excess power in various storage options. It shows that about 240 GWh of new electrical storage is needed for round-the-clock power supply from non-GHG power sources in the South Indian Power Grid.
CLEAN TECHNOLOGIES AND ENVIRONMENTAL POLICY
(2022)
Article
Energy & Fuels
Praphulla Rao, Ravendra Gundlapalli, Sreenivas Jayanti
Summary: Recent literature has shown that the performance of vanadium redox flow batteries deteriorates at low temperature due to increased resistance for reaction kinetics and species transport. This study investigates the impact of low temperature operation on hydrodynamic parameters, such as electrolyte viscosity and electrode permeability, which can affect parasitic losses associated with electrolyte circulation. The results indicate that both viscosity and permeability increase as the operating temperature decreases, leading to substantial losses in parasitic power consumption. Careful balancing of discharge energy density, round-trip energy efficiency, and cell pressure drop is necessary for optimal performance at low temperatures.
JOURNAL OF ENERGY STORAGE
(2022)
Article
Engineering, Chemical
T. V. Binu, Sreenivas Jayanti
Summary: The influence of internal circulation on the heat and mass transfer within dispersed fluid drops in translation was numerically studied using ANSYS FLUENT. Three phases were identified for heat/mass transfer: the initial and final diffusion-dominated phases and a middle convection-dominated phase. Non-isothermal mass transfer simulations, with temperature-dependent diffusion coefficients, showed that mass transfer is slower compared to heat transfer. The final diffusion-dominated mass transfer occurs at the final temperature attained by the drop. Mass transfer is faster for drop heating than for drop cooling, as significant solute transfer occurs at the final higher temperature, with the final diffusion phase controlling the rate.
CHEMICAL ENGINEERING & TECHNOLOGY
(2023)
Article
Physics, Fluids & Plasmas
Sampath Bharadwaj Kota, Seik Mansoor Ali, Sreenivas Jayanti
Summary: Computational fluid dynamics simulations were used to study the buoyancy-induced circulation caused by steam condensation in a suppression pool. The influence of important design parameters on thermal stratification characteristics was investigated. Results showed that the surface temperature was significantly higher than the bulk pool temperature, leading to over-pressurization. Multiple injection points increased the surface temperatures due to a shortened circulation path, and a deeper and narrower pool resulted in higher temperatures compared to a wider and shallower pool.
Article
Chemistry, Physical
M. Maruthi Prasanna, Sreenivas Jayanti
Summary: This study explores the use of thin graphite sheets in large-scale redox flow batteries to reduce pressure drop and weight. Experimental results show that sufficient convection velocities of electrolyte in the carbon felt are needed to achieve high energy efficiency and energy density.
JOURNAL OF POWER SOURCES
(2023)
Article
Energy & Fuels
Sanjay Kumar, Sreenivas Jayanti, Arvind Singh
Summary: In this study, the electrochemical performance and hydrodynamic effects of various flow fields in a vanadium redox flow battery were compared. The results showed that the serpentine flow field achieved higher coulombic, voltage, and energy efficiencies, and stable energy efficiency was maintained. Computational fluid dynamics simulations provided insights into the reasons behind the superior performance of the serpentine flow field compared to other flow fields.
Article
Electrochemistry
Pavan Kumar Vudisi, Sreenivas Jayanti, Raghuram Chetty
Summary: A method for estimating the stack rating of vanadium redox flow batteries (VRFBs) through constant power characterization was developed. The results showed that fractional energy storage capacity utilization and round-trip energy efficiency varied linearly with the power at which the energy was charged or discharged. A zero-dimensional electrochemical model was proposed based on the area-specific resistance to account for the energy stored/extracted during constant power discharge in the state of charge (SoC) window of 20% to 80%. The proposed method enables stack rating based on a single polarization test and can be extended to flow battery systems in general.
Article
Multidisciplinary Sciences
Abdul Gani Abdul Jameel, Chandrakant Dahiphale, Awad B. S. Alquaity, Umer Zahid, Sreenivas Jayanti
Summary: Burner tilt has a significant effect on the flow and heat transfer inside a boiler, reducing nitrous oxide emissions and residence time of coal particles in high temperature zones while lowering the exit gas temperature. The thermal NOx mechanism and NOx reburning play key roles in reducing NOx emissions in utility boilers.
ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING
(2022)
Article
Electrochemistry
Purnima Parmeshwarappa, Ravendra Gundlapalli, Sreenivas Jayanti
Summary: The study examines the integration of a vanadium redox flow battery (VRFB) in the pairing of solar photovoltaic generation with residential electricity consumption systems. It highlights the importance of considering the power and energy storage capacities of the battery components, as well as sizing the capacity of the PV source appropriately for optimal performance.
Article
Electrochemistry
Ravendra Gundlapalli, Sreenivas Jayanti
Summary: A low-pressure drop stack design for vanadium redox flow batteries was explored, showing that stacks of different cell sizes have different optimal flow rate conditions. Stacks with larger cell sizes can be operated at lower stoichiometric factors and fixed flow rates for power variations without significant changes in performance.
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.
