Article
Energy & Fuels
Qian Ouyang, Jyoti Shanker Pandey, Nicolas von Solms
Summary: Early studies have shown that multistep depressurization of CH4/CO2 mixed hydrates can simultaneously produce additional CH4 and store CO2 in hydrate-bearing sediments. This experimental work identified three critical parameters (CH4/CO2 ratio, residual water saturation, and shut-in period) and investigated their effects on production parameters. The results showed that low residual water saturation and a higher CH4/CO2 ratio in CH4/CO2 mixed hydrates resulted in optimal production parameters. Additionally, the shut-in period between pressure releases had a direct effect on production and storage performances. The importance of these critical parameters in designing an effective production and storage scheme after CO2 injection into CH4 hydrates was demonstrated.
Article
Energy & Fuels
Changrui Shi, Shuai Wang, Huiquan Liu, Lunxiang Zhang, Mingjun Yang, Yongchen Song, Jiafei Zhao, Zheng Ling
Summary: This study presents a simple and scalable strategy to produce aerogels as efficient promoters for methane hydrate formation. The as-made aerogels significantly improve the formation kinetics of methane hydrate and show high storage capacity and cycling stability. The study also investigates the molecular mechanisms behind the enhanced formation of methane hydrate through the interaction between oxygen-containing surface functional groups and water molecules.
Article
Energy & Fuels
Guobiao Zhang, Youhong Sun, Bing Li, Yifeng Shen, Yun Qi
Summary: Research has found that in the dissociation of mixed hydrates, CH4 and C2H6 are preferentially released over C3H8. Gas sweep method can continue the decomposition of mixed hydrates and recover more C3H8 at the beginning. The formation and decomposition of the C3H8-rich hydrate shell may control the decomposition rate of mixed hydrates.
Article
Chemistry, Physical
Asheesh Kumar, Hari Prakash Veluswamy, Sanat Kumar, Rajnish Kumar, Praveen Linga
Summary: Clathrate hydrate-based sustainable technologies, such as solidified natural gas (SNG) technology, show great potential for storing natural gas. Experiments on mixed hydrates in a seawater environment reveal the promotional effect of seawater on hydrate formation and suggest the economic feasibility of using natural seawater to enhance SNG technology.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Engineering, Marine
Yaobin Li, Xin Xin, Tianfu Xu, Yingqi Zang, Zimeng Yu, Huixing Zhu, Yilong Yuan
Summary: Most hydrate-bearing sediments worldwide have both pore-filling and fracture-filling hydrates. The focus of current hydrate production research is on pore-filling hydrate production, and there is a lack of systematic research on the decomposition of fracture-filling hydrates and their effects on temperature and pressure evolution in hydrate-bearing sediments. This study investigated the effects of fracture-filling hydrates with different dipping angles on the hydrate production process, highlighting the importance of considering mixed pore- and fracture-filling hydrates in hydrate-bearing sediments. The results showed that fracture-filling hydrates formed in shallow sediments and gradually approached the area of pore-filling hydrates, contributing to depressurization production of hydrate-bearing sediments.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
Jai Krishna Sahith Sayani, Niall J. English, Muhammad Saad Khan, Bhajan Lal, Venkateswara Rao Kamireddi
Summary: This study investigates the impact of hydrogen sulfide gas on the phase behavior of methane and carbon dioxide hydrate formation. Simulation using PVTSim software, experimental approach, and literature comparison were utilized to determine the thermodynamic equilibrium conditions. The results indicate that the increase in H2S composition in the gas mixture leads to decreased stability of methane and carbon dioxide hydrates.
Article
Thermodynamics
Yongchen Song, Mengru Tian, Jia-nan Zheng, Mingjun Yang
Summary: This study investigates the thermodynamics characteristics during hydrate dissociation and finds that the dissociation rate is significantly influenced by the depressurization rate and gas space. During the constant pressure stage, ice formation can nearly quintuple the instantaneous rate of hydrate dissociation. These findings are of great importance for pressure control and efficiency optimization in the later period of methane hydrate exploitation.
Article
Thermodynamics
Rahul Sarkhel, Chandan Sahu, Rajnish Kumar, Jitendra S. Sangwai
Summary: This study investigates the inhibitory effects of alkalis on methane hydrate formation and finds that sodium hydroxide performs better as an inhibitor. A simple model based on the vdW-P thermodynamic model accurately predicts the phase equilibrium of methane hydrate in the presence of alkali solutions. This research is important for designing efficient and cost-effective thermodynamic inhibitors for methane hydrate in the oil and gas industry.
JOURNAL OF CHEMICAL THERMODYNAMICS
(2023)
Article
Geosciences, Multidisciplinary
Jiangong Wei, Tingting Wu, Linqi Zhu, Yunxin Fang, Jinqiang Liang, Hailong Lu, Wenjiu Cai, Zhiyuan Xie, Peixin Lai, Jun Cao, Tianbang Yang
Summary: The analysis of gas hydrate samples from the Qiongdongnan basin of the South China Sea revealed that methane is the main component of the hydrate-bound gas, along with other hydrocarbon gases, suggesting a mixture of microbial and thermogenic gases. Raman spectroscopy showed a co-existence of structure I and structure II gas hydrates in the samples, indicating that natural gas hydrate resources might be underestimated.
MARINE AND PETROLEUM GEOLOGY
(2021)
Article
Engineering, Environmental
Shengli Li, Shijing Zhang, Kai Su, Qiang Liu, Haonan Wu, Zhiyong Chang
Summary: This study investigates the formation and decomposition processes of binary and ternary gas hydrates. The results show that in the formation stage, CH4 is adsorbed in the hydrate cages constructed by C2H6 and C3H8. During the decompositions, CH4 and C2H6 molecules are preferentially released from the hydrate structures, while C3H8 molecules can stay in the hydrate phase.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Energy & Fuels
Shamil E. Gainullin, Abdolreza Farhadian, Polina Y. Kazakova, Matvei E. Semenov, Yulia F. Chirkova, Atousa Heydari, Roman S. Pavelyev, Mikhail A. Varfolomeev
Summary: Novel amino acid derivatives (ACDs) were developed as efficient promoters for methane hydrate formation and recovery, exhibiting superior kinetics compared to anionic surfactants without foaming. ACD5 achieved the highest promotion effect in distilled water, increasing the water-to-hydrate conversion from 39.6% to 94.3%, exceeding sodium dodecyl sulfate (SDS). ACDs also showed higher promotion activity than SDS in salt water, making seawater a cost-effective alternative for methane hydrate production.
Article
Thermodynamics
Chen Chen, Haoyu Yuan, Rongshan Bi, Na Wang, Yujiao Li, Yan He, Fei Wang
Summary: This study aims to propose a novel natural gas peak-shaving process using gas hydrates as the medium to address the supply-demand imbalance in natural gas. Through process simulation and economic analysis, the study shows that the proposed peak-shaving process can improve economic efficiency compared to traditional operational models.
Article
Green & Sustainable Science & Technology
Chuanliang Yan, Leifeng Dong, Xu Ren, Yuanfang Cheng
Summary: Replacing methane in natural gas hydrates with carbon dioxide can sequester CO2 in the seabed while developing natural gas, making it an environmentally friendly energy production and carbon sequestration mode. A dynamic evolution model and a multi-field coupling model were established to study the mechanical and physical parameters evolution during CH4-CO2 replacement in a NGH reservoir. The results show that the saturation positively affects the mechanical parameters of NGH and CO2 hydrate bearing sediment samples, while the generation of CO2 hydrates decreases the permeability of the reservoir.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Engineering, Environmental
Alberto Maria Gambelli
Summary: Replacement processes have the potential to recover methane from natural gas hydrate reservoirs, but their industrial application is limited. This study discusses the influencing factors of replacement, including heat and mass transfer limitations, expansion of the thermodynamic region, maximum efficiency achievable, and the role of gas phase composition. Experimental investigation shows that methane recovery and carbon dioxide storage are influenced by the composition of the replacing gas phase.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Engineering, Chemical
Harshal J. Dongre, Amiya K. Jana
Summary: This work aims to formulate the noncovalent interactions of mixed guest hydrate lattices and fills the research gap in hydrate phase equilibrium modeling. By using computational methods, the contributions of hydrogen bonding, dispersion, van der Waals interaction, and steric effects to lattice stability are revealed. The spherical harmonics shape descriptor is used to describe the natural regularity in nonstoichiometric hydrates.
