Review
Energy & Fuels
Wancheng Zhu, Shuyuan Liu, Xiufeng Zhang, Chenhui Wei
Summary: This paper provides a comprehensive review of the mechanisms and properties of gas adsorption in coal, the geomechanical behavior of coal, and the mechanisms of gas transport in coal. It also discusses several waterless fracturing techniques for improving coalbed permeability and identifies current knowledge and research gaps.
GEOMECHANICS AND GEOPHYSICS FOR GEO-ENERGY AND GEO-RESOURCES
(2022)
Article
Environmental Sciences
Xiaoming Ni, Xuebin Tan, Sen Yang, Bin Xu, Xiaokang Fu
Summary: The evaluation of CBM production potential considering different coal structures can better reflect the objective facts, especially in areas with strong heterogeneity in coal structure. The proposed method provides a novel approach to accurately evaluate CBM production potential in regions with highly heterogeneous coal structures.
ENVIRONMENTAL EARTH SCIENCES
(2021)
Article
Thermodynamics
Zhengdong Liu, Xiaoson Lin, Wancheng Zhu, Ze Hu, Congmeng Hao, Weiwei Su, Gang Bai
Summary: Permeability rebound and recovery during the permeability evolution process is an important behavior affected by temperature and reservoir pressure changes. A binary gas permeability evolution model was used to study the dynamic evolution of various parameters during CO2 injection into CH4-containing coal at different temperatures. The study found that permeability shows a complex evolution over time, with the time required for rebound and recovery increasing with temperature. Monitoring gas migration patterns revealed that CO2 flow rate and cumulative storage volume decrease with increased rebound and recovery time. The study proposed using the stage-pressure injection method to increase CO2 injection effect.
Article
Geosciences, Multidisciplinary
Yubing Liu, Maxim Lebedev, Yihuai Zhang, Enyuan Wang, Wenpu Li, Jiabin Liang, Runhua Feng, Rupeng Ma
Summary: Cleat and permeability in coal play a crucial role in enhanced coalbed methane production and CO2 geo-sequestration. This study used a novel in situ micro-CT core flooding apparatus to observe the closure of micro-cleats in small anthracite coal at different CO2 injection pressures. The results showed that the mean aperture size of the micro-cleat increased and then decreased with increasing injection pressures, with a higher rebound in mean aperture size parallel to cleat directions. The permeability decreased drastically initially and then slowly with an increase in saturation time.
NATURAL RESOURCES RESEARCH
(2022)
Article
Thermodynamics
Gang Bai, Jun Su, Xueming Li, Chunsheng Guo, Mingxu Han, Xihua Zhou, Chaojun Fan
Summary: The study proposes an SBS-CO2 method that gradually increases the CO2 injection pressure, which can improve the total recovery rate of methane and reduce the risk of CO2 consumption and outburst compared to the traditional constant CO2 injection pressure method.
Article
Energy & Fuels
Mohammadreza Zare Reisabadi, Mohammad Sayyafzadeh, Manouchehr Haghighi
Summary: This study investigates the effects of matrix swelling and well trajectory on permeability in coal seam gas reservoirs during CO2 injection. The results show that vertical injection wells experience a significant decline in permeability due to swelling, while horizontal wells do not.
Article
Energy & Fuels
Yi Chen, Lei Zhou, Yu Peng, Xiangyan Ren
Summary: This study investigates the potential of directional wells with multiple hydraulic slots as a stimulation technology for deep coalbed methane extraction. The research finds that hydraulic slotting increases permeability and gas desorption, and directional wells with multiple slots optimize performance and enhance CBM recovery.
GEOMECHANICS AND GEOPHYSICS FOR GEO-ENERGY AND GEO-RESOURCES
(2023)
Article
Mechanics
Zheng Shang, Haifeng Wang, Bing Li, Yuanping Cheng, Xinghua Zhang, Fei Zhao, Xiao Zhang, Congmeng Hao, Zhenyang Wang
Summary: The research findings indicate that in liquid carbon dioxide phase-transition blasting, the release pressure plays a decisive role in the generation of fractures in terms of quantity and direction. Increase in confining pressure stress decreases expansion of boreholes and fracture zones, but does not affect the number and direction of blast cracks.
ENGINEERING FRACTURE MECHANICS
(2021)
Article
Energy & Fuels
Lei Zhang, Jinghua Li, Junhua Xue, Cun Zhang, Xinqiu Fang
Summary: This study examined the changing characteristics of gas flow capacity in ECBM, finding that the differences between CO2 and N2 tests affect the outflow rate, volumetric strain, and duration of each stage in permeability. The observation of different characteristics in the two tests provides new insight into the behavior of gas flow in coal reservoirs.
Article
Energy & Fuels
Xiangliang Zhang, Baiquan Lin, Jian Shen
Summary: The study found that plasma based on the principle of electrical breakdown can enhance the permeability of loaded coal, with the formation of interconnected fracture networks significantly increasing coal permeability. The changes in flow state from Darcy flow to non-Darcy flow after breakdown also facilitate fluid migration in coal.
Article
Chemistry, Multidisciplinary
Qianqian Ma, Hong Li, Kun Ji, Fengjun Huang
Summary: CO2 injection technology into coal seams enhances CH4 recovery and reduces greenhouse gas emissions. The Thermal-Hydraulic-Mechanical coupling mechanism of CO2 injection into coal seams is investigated, considering competitive adsorption, diffusion, and seepage flowing of CO2 and CH4. Numerical simulations based on the Canadian CO2-ECBM project reveal that CO2 injection significantly improves methane production. Injection pressure and temperature have an impact on CH4 production and CO2 storage, with increasing pressure increasing production but weakening injection capacity, and increasing temperature slightly decreasing production and storage.
APPLIED SCIENCES-BASEL
(2023)
Article
Microbiology
Mansi Chawla, Meeta Lavania, Nishi Sahu, Sudhanshu Shekhar, Nimmi Singh, Anand More, Magesh Iyer, Sanjay Kumar, Komal Singh, Banwari Lal
Summary: It is acknowledged that conventional mining techniques have resulted in depleting coal reserves globally. A sustainable approach to improve coalbed methane (CBM) recovery involves enhancing biogenic methane production through microbial stimulation. In this study, a culture-independent approach was used to investigate the microbial community in an Indian reservoir, and it was found that bacteria were more abundant than archaea. The dominant phyla were Proteobacteria, Firmicutes, and Bacteroidetes, which play crucial roles in methanogenesis.
FRONTIERS IN MICROBIOLOGY
(2023)
Article
Energy & Fuels
Jiang Liu, Yili Kang, Mingjun Chen, Lijun You, Tingshan Zhang, Xinping Gao, Zhangxing Chen
Summary: Enhancing coal permeability through formation heat treatment is an effective method for coalbed methane exploitation. The process involves removing residual water and inducing cracks in the coal structure, significantly increasing permeability. Additionally, the stimulation mechanisms consist of alleviating aqueous phase trapping, weakening coal mechanical properties, and inducing coal fracture to produce more gas flow channels.
Article
Environmental Sciences
Xiao Feng, Panpan Zhang, Zizhong Zhang, Hongguang Guo, Zhigang Li, Zaixing Huang, Michael Urynowicz, Muhammad Ishtiaq Ali
Summary: Biomethane generation by coal degradation can increase coalbed methane (CBM) reserves and affect the pore structure of coal. The biodegradation of bituminous coal and lignite to produce methane was performed to analyze the effect on coal pore development. The results showed that biodegradation decreased the specific surface area and pore volume of micropores and increased the fractal dimension. Various organics were generated, with a portion released into the culture solution and the majority remaining in residual coal. The effect of biodegradation on pore development depended on the combined action of methane production and organics retention in coal.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Engineering, Environmental
Gaoming Wei, Hu Wen, Jun Deng, Zhenbao Li, Shixing Fan, Changkui Lei, Mingyang Liu, Lifeng Ren
Summary: The study utilizes hydraulic slotting and liquid CO2 injection to enhance coalbed permeability and methane recovery efficiency. The results show a significant increase in coal porosity and permeability, leading to more than 90% CBM recovery efficiency. The in-situ test indicates effective radii for HS and LCO2 injection were 2.5 m and 10 m, respectively, with a 2.2-fold increase in CBM recovery efficiency.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2021)
Article
Engineering, Chemical
Jian Chen, Jiahe Shen, Jie Guo, Geoff Wang
Summary: Vibrating separation is an important method for liquid-solid separation. This study investigated the effect of vibration parameters in separation based on numerical simulation of large-scale liquid bridge breakage. The results showed that separation efficiency increased significantly with the peak acceleration, but growth slowed down after exceeding 1 m/s^2.
Article
Energy & Fuels
Yunsong Yu, Chen Zhang, Chenyang Zhou, Jingfeng Zhang, Zaoxiao Zhang, Geoff G. X. Wang
Summary: The single atom fluid, developed as a new solvent, shows promising performance in capturing CO2, as validated by experiments against the theoretical model. The effects of temperature, pressure, and weight fraction on CO2 capture efficiency are carefully studied and concluded to improve with the use of the advanced solvent.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2022)
Article
Energy & Fuels
Xiaodong Zhang, Shuo Zhang, Zhigang Du, Geoff G. X. Wang, Shuai Heng, Xiao Liu, Junfeng Lin
Summary: This study conducted experiments using high volatile bituminous coal to investigate the adsorption-induced deformation mechanism of confined coals with CO2 and N2, and developed a thermodynamic model based on the swelling characteristics. The results showed that the coal matrix exhibited different stages of swelling/shrinkage during the adsorption/desorption process. Furthermore, factors such as adsorbate type, chemical potential, and stress conditions were identified as key factors affecting coal swelling.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2021)
Article
Engineering, Chemical
Jian Chen, Zhenjiang You, Ognjen Orozovic, Geoff Wang
Summary: This paper developed a model based on the Richards equation to quantitatively analyze the effect of oscillation on water distribution in unsaturated coal and iron ores. The findings suggest that the dynamic potential plays a role in the water distribution and can be applied to optimize the processing of coal and iron ores.
Article
Metallurgy & Metallurgical Engineering
Jian Chen, Dongling Wu, Yichao Hu, Yansong Shen, Geoff Wang
Summary: The wear of tuyere in blast furnaces is a common problem in iron-making production. This study developed a computational fluid dynamics model to simulate the abrasion rate on the tuyere surface considering various factors. The results showed that high temperature and severe abrasion mainly occurred on the top surface of the tuyere, and the abrasive rate was influenced by the high-temperature area.
STEEL RESEARCH INTERNATIONAL
(2022)
Article
Chemistry, Physical
Chen Zhang, Jingfeng Zhang, Yunsong Yu, Zaoxiao Zhang, Geoff G. X. Wang
Summary: The study analyzed the influence of B, Al, and Ga on the CO2 adsorption performance of lithium silicate using density functional theory model, revealing that doping Si atoms can enhance CO2 adsorption while doping Li atoms has the opposite effect.
COMPUTATIONAL AND THEORETICAL CHEMISTRY
(2021)
Article
Chemistry, Physical
Yichao Hu, Yinxuan Qiu, Jian Chen, Liangyuan Hao, Thomas Edward Rufford, Victor Rudolph, Geoff Wang
Summary: Introducing CO2 electrochemical conversion technology to the iron-making blast furnace reduces CO2 emissions and produces H-2 as a byproduct. By considering different injection positions and operating conditions, the efficiency of H-2 utilization can be increased and coke rate can be decreased. However, increasing the hydrogen injection amount results in higher energy consumption.
Article
Materials Science, Multidisciplinary
Zhe Rong, Hongbo Liu, Peng Zhang, Feng Wang, Geoff Wang, Baojun Zhao, Fengqiu Tang, Xiaodong Ma
Summary: This study investigates the formation mechanisms and evolution of complex inclusions in Ti-Ca deoxidized offshore structural steel. The number density of total inclusions generally decreases during the refining process, except for Ti and Ca addition. The major inclusions identified were CaO-Al2O3-SiO2-(MgO)-TiOx and CaO-Al2O3-SiO2. These inclusions originate from the combination of CaO-SiO2-(MgO) in refining slag or refractory and deoxidization product Al2O3 and TiO2. With the refining process and Ca addition, the composition of these inclusions changes, resulting in the promotion of intragranular acicular ferrite.
Article
Nanoscience & Nanotechnology
Sahil Garg, Mengran Li, Tanveer Hussain, Mohamed Nazmi Idros, Yuming Wu, Xiu Song Zhao, Geoff G. X. Wang, Thomas E. Rufford
Summary: We have developed a new strategy to improve the reactivity and durability of a membrane electrode assembly (MEA)-type electrolyzer for CO2 electrolysis to CO. By modifying the silver catalyst layer with urea, we have successfully promoted electrochemical CO2 reduction (CO2R), relieved limitations of alkali cation transport, and mitigated salt precipitation in the gas diffusion electrode. The urea-modified Ag catalyst exhibited significantly better CO selectivity and energy efficiency than the untreated Ag catalyst, and maintained stable performance over 200 hours. Our work provides an alternative approach to fabricating catalyst interfaces in MEAs, with important implications for CO2 electrolysis and fuel cells.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Physical
Yuming Wu, Liam Charlesworth, Irving Maglaya, Mohamed Nazmi Idros, Mengran Li, Thomas Burdyny, Geoff Wang, Thomas E. Rufford
Summary: PTFE-embedded GDL can mitigate electrode flooding, increase electrochemical active area, and improve the stable operation time and Faradaic efficiency of CO2 electrolysis to CO.
ACS ENERGY LETTERS
(2022)
Article
Thermodynamics
Luke Henderson, Pradeep Shukla, Victor Rudolph, Suresh K. Bhatia
Summary: A 2-D population balance model with internal variables of carbon mass and surface sites was developed to study soot formation during hydrocarbon decomposition reactions. The model accurately predicts the size and composition distribution of soot particles under various conditions, which was confirmed by experimental data.
COMBUSTION AND FLAME
(2022)
Article
Energy & Fuels
Difei Zhao, Yinghai Guo, Geoff Wang, Xin Guan, Xueqing Zhou, Jing Liu
Summary: The influence of high-rank coal's pore characteristics on the physical properties, gas-bearing properties, and exploitation of coal reservoirs is becoming more prominent. This research analyzed the structure and fractal characteristics of reservoir pores in high-rank coal samples and established a natural classification system to describe the relationship between pore types and gas occurrence and transport mechanisms.
Article
Engineering, Chemical
Chen Zhang, Xinhua Xie, Yuan Li, Teng Zhang, Pengfei Ma, Yunsong Yu, Geoff Wang, Yongzhi Zhao
Summary: This work proposes solutions to resolve catalyst deactivation caused by fly ash in SCR denitration systems using a deflector at the economizer outlet and an ash blocking device at the ash hopper outlet. New integrated models are developed to analyze the gas and solid flow field in a SCR reactor, and have been validated by particle image velocimetry experiment. The study finds that the use of curved deflectors effectively improves the distribution of fly ash and shows the best rectification effect.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2022)
Article
Engineering, Environmental
Thomas Buckley, Kavitha Karanam, Han Han, Hoang Nhat Phong Vo, Pradeep Shukla, Mahshid Firouzi, Victor Rudolph
Article
Chemistry, Physical
Chen Zhang, Chenyang Zhou, Yuan Li, Yunsong Yu, Jingfeng Zhang, Zaoxiao Zhang, Geoff Wang
Summary: New solvents are being explored as effective methods for enhancing reaction rates and reducing reaction energy barriers. The traditional approach for developing new solvents has reached a dead end, leading to the design of a breakthrough technique involving single atom solutions. Experiments have demonstrated the presence of single atoms in the solutions and their charge-producing effects, while a density functional theory model has been used to analyze microscale characteristics. This method has been applied to carbon dioxide capture, resulting in intensified CO2 desorption rates in the single atom solution system by controlling the reaction energy barrier. The results indicate that single atom solutions can generate a maximum voltage of 2.12 V and effectively utilize substantial waste heat below 373 K, contributing to near zero energy consumption.
JOURNAL OF CHEMICAL PHYSICS
(2023)