Article
Energy & Fuels
Namrata Gaikwad, Jitendra Sangwai, Praveen Linga, Rajnish Kumar
Summary: In this study, methane separation from CMM gas mixture was achieved by forming sII and sH hydrates with the use of different thermodynamic promoters at moderate temperature and pressure conditions. The formation of sII hydrate showed better methane recovery, while the formation of sH hydrate demonstrated a better separation factor. The use of water-soluble hydrate promoter sodium dodecyl sulfate (SDS) enhanced the rate of hydrate formation for better separation efficiency.
Article
Thermodynamics
Qiang Zhang, Junjie Zheng, Baoyong Zhang, Praveen Linga
Summary: Coalbed methane recovery is crucial for coal mine safety, reducing greenhouse gas emissions, and economic benefits. Gas hydrate technology can effectively separate CH4 from N2-rich coal mine gas. The synergistic effect of sII hydrate promoters and amino acids was examined for enhancing hydrate formation kinetics, separation performance, and CH4 recovery. Amino acids showed significant promotion effects, particularly for the propane system, and improved kinetics by over 10 times. CP-amino acid systems demonstrated excellent separation performance, increasing CH4 content from 30% to 70%. THF-amino acid systems achieved the highest CH4 recovery of up to 50.27%. The impact of amino acids varied depending on the system, and two possible mechanisms, including interfacial tension alteration and amino acid hydrophobicity, were discussed. These insights provide a basis for optimizing the hydrate process for coalbed methane recovery and other applications.
Article
Energy & Fuels
Pengfei Wang, Ying Teng
Summary: The heterogeneous distribution of hydrate in the experiment leads to local low temperature, which has a significant impact on the hydrate dissociation process. The methane production in the experiment is lower than the simulation, and the high water saturation in the Class 2 sample affects gas flow.
Article
Energy & Fuels
Huiru Sun, Bingbing Chen, Ziming Yang, Yongchen Song, Mingjun Yang
Summary: This study focused on the effects of hydrate saturation change and multiphase flow on NGHs production behaviors at different exploitation stages. The results showed that initial hydrate saturation and water-gas flowrate were negatively correlated with the onset time of blockage and amount of hydrate reformation.
Article
Chemistry, Multidisciplinary
Chuanhai Liu, Qiang Wu, Baoyong Zhang, Qiang Zhang, Qiong Wu, Yu Kang
Summary: The microfeatures of coal mine methane (CMM) hydrates were studied using Raman spectroscopy with three different gas samples. The results showed a competition between C2H6 and CH4 in terms of cavity occupancies and molecular compositions in the hydrates.
Article
Energy & Fuels
Liang Mu, Xianlong Li, Qiqi Tan, Qingyun Zhang, Qingyan Cui
Summary: CH4 separation from simulated CBG was successfully achieved using an absorption-hydration method. The hybrid separation efficiency was significantly improved compared to single absorption or hydration methods. The use of emulsions with different water droplet sizes enabled a multi-stage separation process, leading to the enrichment of CH4. This study contributes to the optimization of the CH4 separation process from CBG.
Article
Energy & Fuels
Yingmei Wang, Aili Niu, Wenze Jiao, Ji Chen, Peng Zhang, Jinping Li
Summary: Carbon dioxide hydrate formation rate is improved by using different accelerator systems. The combination of nanographite-TBAB and SDS-TBAB shows better performance in reducing the nucleation time. TBAB shows the best nucleation amount, formation rate, and conversion rate among the single acceleration systems.
Article
Energy & Fuels
Nikodem Szlazak, Marek Korzec, Kazimierz Piergies
Summary: In the determination of methane content in coal seams, researchers have doubts about the coal sampling procedures and the time taken from sampling to sealing the sample. Therefore, a study was conducted to evaluate the degassing of samples taken in the form of drill cuttings according to the standard procedure and cores from a coal mine roadway. The results indicate that determinations made for the cores are consistent with those made for drill cutting samples, taking into account the gas loss.
Article
Chemistry, Multidisciplinary
Qiang Zhang, Chenwei Li, Xue Guangxin, Baoyong Zhang, Chuanhai Liu
Summary: This study investigated the formation and dissociation kinetics of gas hydrate in coal under different geological conditions in China. Results showed that impedance changes can qualitatively describe the kinetic characteristics of hydrate formation and dissociation, highlighting the potential of this technology in preventing gas outbursts in coal mines.
Review
Biochemistry & Molecular Biology
Yu Wei, Nobuo Maeda
Summary: Applications of clathrate hydrate require fast formation kinetics, which has been limited by mass transfer and heat transfer. Surfactants and mechanical stirring have been used to accelerate hydrate formation but have drawbacks. Dry water, a water-in-air dispersion stabilized by hydrophobic nanosilica, is an effective promoter for hydrate formation. It shifts the hydrate phase boundary, increases formation rate and improves gas storage capacity. Reusability and knowledge gaps in dry water research are highlighted.
Article
Multidisciplinary Sciences
Shubhangi Srivastava, Ann Mary Kollemparembil, Viktoria Zettel, Timo Classen, Bernhard Gatternig, Antonio Delgado, Bernd Hitzmann
Summary: The dissociation of CO2 gas hydrates with amino acid and surfactant promoters was studied, and it was found that leucine and lecithin are effective promoters for enhancing CO2 uptake and stability in gas hydrate formation.
SCIENTIFIC REPORTS
(2022)
Article
Energy & Fuels
Jie Wang, Ziyi Yao, Runpu Gong, Panyang Guo, Houshun Jiang, Yang Wang
Summary: This paper develops a high-efficiency hydrate inhibition drilling fluid system based on the evaluation and analysis of the synergistic effect between commonly used kinetic inhibitors and thermodynamic inhibitors. The results provide a reference for solving the stability and safety problems in the process of hydrate drilling.
Article
Thermodynamics
Jidong Zhang, Zhenyuan Yin, Qingping Li, Shuaijun Li, Yi Wang, Xiao-Sen Li
Summary: Methane hydrates are considered as a future energy source with abundant resources and high energy density. The fluid production and thermal response of two types of hydrate-bearing sediments (excess-gas and excess-water) under controlled depressurization are still unclear. This study examines the hydrate dissociation kinetics and fluid production behavior in these sediments to shed light on optimizing production strategies for future field production trials.
Article
Environmental Sciences
Chengmin Wei, Chengwu Li, Qiusheng Ye, Zhenfei Li, Min Hao, Shanyang Wei
Summary: In this research, a mathematical model for predicting gas emission from coalbed methane excavation workface was constructed, and a new model with higher accuracy and conciseness was proposed and validated. The study also analyzed the sensitivity of gas emission parameters and the participation ratio of gas emission sources.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Environmental Sciences
Chengmin Wei, Chengwu Li, Qiusheng Ye, Zhenfei Li, Min Hao, Shanyang Wei
Summary: This research constructed a mathematical model to accurately predict the emission of coalbed methane and validated the model in the field. The study found that the new model had higher accuracy than the traditional model, leading to improved efficiency in controlling and utilizing coal mine gas disasters.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Chemistry, Multidisciplinary
Qiang Zhang, Chenwei Li, Xue Guangxin, Baoyong Zhang, Chuanhai Liu
Summary: This study investigated the formation and dissociation kinetics of gas hydrate in coal under different geological conditions in China. Results showed that impedance changes can qualitatively describe the kinetic characteristics of hydrate formation and dissociation, highlighting the potential of this technology in preventing gas outbursts in coal mines.
Article
Chemistry, Multidisciplinary
Baoyong Zhang, Wei Cheng, Qiang Zhang, Yuanji Li, Pingchang Sun, Douaa Fathy
Summary: This study estimates the element enrichment and influencing factors of Paleogene coal seams in the Fushun Basin through statistical and geochemical analyses. The coals in the basin show enrichment of certain elements, depletion of others, and have specific mineral carriers. The preliminary results provide a foundation for further research.
ACS EARTH AND SPACE CHEMISTRY
(2022)