Article
Chemistry, Multidisciplinary
Xiaofang Lv, Yang Liu, Shidong Zhou, Bohui Shi, Kele Yan
Summary: The study investigates the decomposition mechanism of hydrate slurry and proposes that desorption of gas from the surface of decomposed particles may be the main cause of particle coalescence. A comprehensive kinetic model considering influencing factors such as intrinsic kinetics, heat, and mass transfer is proposed, using fugacity difference as the driving force for hydrate decomposition. The model integrates heat and mass transfer effects and can describe trends in gas release and dissociation rate in experimental flow systems.
Article
Energy & Fuels
Yue Ma, Qiang Gao, Jian Guan, Chi Zhang, Jianzhong Zhao
Summary: In this study, experiments were conducted to dissociate mixed CO2 + CH4 hydrates by depressurization and thermal stimulation. The kinetics, fluid production behavior, heat transfer characteristics, and separation factors were examined during the hydrate formation and dissociation processes. The results showed consistent gas consumption and phase saturation, with a stochastic induction time ranging from 38 to 58 minutes. The hydrate exhibited a strong selectivity to CH4 during the gas mixture hydrate formation process, and the gas production increased with decreasing depressurization pressure.
Article
Engineering, Environmental
Pengfei Wang, Kehan Li, Jianyu Yang, Jinlong Zhu, Yusheng Zhao, Ying Teng
Summary: This study investigates the dissociation properties of hydrogen-propane hydrates through experiments and simulations, revealing the characteristics of the dissociation process and the impact of different dissociation driving mechanisms on hydrogen release. The results indicate that the release rate of hydrogen from hydrates is higher than that of propane, and propose the concept of recycling hydrate clathrate structure to accelerate hydrogen storage rate.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Energy & Fuels
Bin Fang, Othonas A. Moultos, Tao Lu, Jiaxin Sun, Zhichao Liu, Fulong Ning, Thijs J. H. Vlugt
Summary: Hydrate dissociation is often accompanied by the formation of nanobubbles. Knowledge of the effects of nanobubbles on hydrate dissociation is essential for understanding the dynamic behavior of the hydrate phase change and improving the gas production efficiency.
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
Engineering, Marine
Song Zeng, Liangjie Mao, Qingyou Liu, Guorong Wang, Juan Li
Summary: A dynamic analysis model for natural gas hydrate production riser was established, which considered the internal phase transition of hydrate multiphase flow and external marine environmental loads. The correctness of the model was verified by experiment and field testing data, showing that NGH decomposition in the middle of the riser causes a sudden pressure drop, increasing axial tension and Von Mises stress.
Article
Energy & Fuels
Xuke Ruan, Chun-Gang Xu, Ke-Feng Yan, Xiao-Sen Li
Summary: The study experimentally and numerically investigated the effects of permeability and hydrate dissociation surface area on the kinetics of hydrate decomposition in porous media, finding that these factors are crucial for gas production from hydrates and the controlling factor for dissociation kinetics can switch from permeability to hydrate dissociation surface area depending on hydrate saturation and accumulation habits in porous media.
FRONTIERS IN ENERGY RESEARCH
(2021)
Article
Energy & Fuels
Yi Lu, Yu Feng, Dawei Guan, Xin Lv, Qingping Li, Lunxiang Zhang, Jiafei Zhao, Lei Yang, Yongchen Song
Summary: This study investigated the formation condition of nanobubbles and its effect on the dissociation of methane hydrate through molecular dynamics simulations. Two different initial configurations were used to examine the influence of liquid water proportion on the dissociation path and nanobubble formation. The results revealed four main dissociation stages under low liquid water proportion, with nanobubbles forming when the methane supersaturation condition was met. The formation of nanobubbles broke the mass transfer limitation, leading to an increased hydrate dissociation rate. Small nanobubbles formed at the end of the dissociation process contributed to the collapse of the final hydrate slice by shortening the diffusion distance of methane molecules to the gas phase. One surviving nanobubble was observed at the end of the simulation for systems with methane mole percent in water of 0.4 and 0.9, respectively.
Article
Thermodynamics
Qi Zhao, Zhao-Yang Chen, Xiao-Sen Li, Zhi-Ming Xia
Summary: This study investigates the influence of an electrostatic field on the formation of CO2 hydrate in fresh water, memory water, and saltwater systems. Experimental results show that the presence of an electrostatic field can promote the nucleation and growth of CO2 hydrate. However, the electrostatic field weakens the memory effect in the memory water system and increases the completion time of hydrate formation in the salt water system.
Article
Energy & Fuels
Yu Wei, Maeda Nobuo
Summary: This study investigates the nucleation kinetics of CO2 hydrate and compares it to the nucleation kinetics of methane/propane mixed gas hydrate. The results show that stainless-steel walls promote the nucleation of CO2 hydrate and CO2 hydrate has higher nucleation rates than methane/propane mixed gas hydrate.
Article
Nanoscience & Nanotechnology
Yang Zhao, Mingzhao Yang, Man Li, Hongsheng Dong, Yang Ge, Qingping Li, Lunxiang Zhang, Yu Liu, Lei Yang, Yongchen Song, Jiafei Zhao
Summary: Efficient gas enrichment methods are crucial for the storage, transportation, and sequestration of clean energy and carbon dioxide. A novel recyclable hydrate promoter has been developed, which effectively reduces the induction time of methane hydrate formation, increases gas storage capacity, and inhibits foam during hydrate decomposition. Additionally, this promoter enhances CO2 storage capacity and shows potential for sequestering CO2 in the form of gas hydrate under the seafloor.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Energy & Fuels
Xin Lei, Yanbin Yao, Wanjing Luo, Zhiang Wen
Summary: A new Cubic model was proposed to calculate the permeability increase induced by hydrate dissociation, and experimental results showed that a hybrid growth pattern of pore wall coating and pore center occupying hydrates better explained the data. This model can be applied to predict permeability changes during gas production and provide insights into microscopic hydrate growth mechanisms.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Chemistry, Physical
Srivathsan P. Sundar, Saddam Al-Hammadi, Zhonghua Ren, Gabriel da Silva
Summary: Quantum chemistry and statistical reaction rate theory calculations were used to investigate the products and kinetics of indenyl radical decomposition, identifying three competitive product sets. The main products of indenyl decomposition were found to be o-benzyne (o-C6H4) + propargyl (C3H3), with some additional byproducts not considered in previous theoretical kinetics investigations.
JOURNAL OF PHYSICAL CHEMISTRY A
(2021)
Article
Environmental Sciences
Xin-Yang Zeng, Guozhong Wu, Si Zhang, Liwei Sun, Changyu Sun, Guangjin Chen, Jinrong Zhong, Pian Li, Zhifeng Yang, Jing-Chun Feng
Summary: This study investigated the thickening growth kinetics of hydrated bubble using in-situ Raman spectroscopy and found that the thickening of the hydrated bubble was a multi-stages growth process, with texture structures and the type and size of gas pore being critical for the kinetics growth rate of hydrated bubble in thickening. Additionally, the theory of heterogeneous growth of hydrated bubble was proposed to accelerate the efficiency of carbon sequestration at the interface of multiple bubbles.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
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.
