《佳文速递》2025年第12期

Analysis of heat and mass transfer in the thermal storage of salt hydrate embedded in metal foam with leaf-shaped channel

盐水合物嵌入金属泡沫中的叶片状通道热储存中热质传递分析

发表时间：2025年8月5日

发表期刊：《Chemical Engineering Journal》

Zidong Miao, Wei Chen

School of Merchant Marine, Shanghai Maritime University, Shanghai 201306, PR China

Abstract: To obtain higher utilization of salt bed and more heat of hot airflow to be stored for thermal storage during charging, the novel thermochemical thermal storage of strontium bromide hexahydrate (SrBr2∙6H2O) embedded in porous metal foam with leaf-shaped channel is proposed, in which the heat and mass transfer can be enhanced in salt bed as porous layer due to metal foam with high thermal conduction, as well as facilitating convection between the hot airflow and salt bed with leaf-shaped channel. The Clausius-Clapeyron formula and Navier-Stokes equations together with Darcy relation describing the reactive kinetics and heat transfer are employed to analyze the effect of channel distribution in salt bed and porosity of metal foam on dehydration of SrBr2∙6H2O salt for thermal storage under different operating conductions. At 90% conversation in salt bed, the 8.17% shorter charging time is taken in salt bed with leaf-shaped channel than that with tree-shaped channel, while the 1.9% increase in chemical heat absorption efficiency happens in salt bed of leaf-shaped channel with aluminum foam than that without. The lower inlet velocity of hot airflow with higher inlet temperature will benefit for more heat to be stored in salt beds. The simulations agree with the published experimental data. All results can be taken into account for the utilization of salt hydrate for thermochemical thermal storage.

Keywords: Thermochemical heat storage; Dehydration; SrBr2∙6H2O; Metal foam; Leaf-shaped channel

Fig. 1. Schematic view of SrBr2∙6H2O salt beds embedded in metal foam (or not) respectively with leaf-shaped channel and tree-shaped channel for thermal storage.

阅读原文：https://doi.org/10.1016/j.cej.2025.166783.

CO2 leakage-induced hydrate evolution and sequestration dynamics under 

time-variant capillary pressure in subsea

二氧化碳泄漏诱导的水合物演变与封存动力学在海底时间变异毛细管压力下的研究

发表时间：2025年8月5日

发表期刊：《Chemical Engineering Journal》

Guodong Cui1,2,3, Leichao Zhao1,2, Zhenyu Liu1, Xi Chen1, Fulong Ning1,2,3

1 National Center for International Research on Deep Earth Drilling and Resource Development, Faculty of Engineering, China University of Geosciences, Wuhan 430074, China 

2 School of Future Technology, China University of Geosciences, Wuhan 430074, China 

3 State Key Laboratory of Deep Geothermal Resources, School of Sustainable Energy, China University of Geosciences, Wuhan 430074, China

Abstract: Subsea CO2 storage is an essential underground CO2 storage method and can reduce CO2 emissions greatly. However, the potential CO2 leakage threatens to sequestration effectiveness and marine ecosystems, restricting the large-scale application of subsea CO2 storage. Encouragingly, leaked CO2 can form solid hydrates and hence impede subsequent CO2 leakage. However previous studies ignored the change of capillary pressure caused by CO2 hydrate formation, and underestimated the sealing capacity of CO2 hydrate, which seriously affects the risk assessment and application of subsea CO2 storage projects. To fill this research gap, the present study pioneers the procedural treatment and numerical simulation of time-variant capillary pressure. By developing a coupled model integrating temporally variable capillary pressure with hydrate formation dynamics following CO2 leakage, we reveal how changes in capillary pressure over time influence CO2 distribution patterns within reservoirs and the spatial-temporal evolution of hydrate formation. The findings demonstrate that under time-variant conditions, CO2 preferentially migrates laterally rather than vertically, primarily due to the formation of overlying CO2 hydrate. The interplay between hydrate formation and CO2migration promotes their co-evolution, enhancing the formation and stability of the hydrate barrier. Specifically, after 50 years, the horizontal migration distance increased by 34.09%, while the vertical migration distance decreased by 11.76%. Ignoring time-variant effects would underestimate hydrates' role in constraining CO₂ leakage, leading to inaccuracies in long-term safety assessments. This research supports the selection of sequestration sites and mitigates leakage risks, thereby enhancing the feasibility of subsea CO2 storage.

Keywords: Time-variant capillary pressure; CO2 sequestration; CO2 leakage; CO2 hydrates

Fig. 5. Schematic diagram of the model and partial parameters.

阅读原文：https://doi.org/10.1016/j.cej.2025.166711.

Promoting hydrogen storage under mild conditions by binary clathrate 

hydrates in porous activated carbon

通过多孔活性炭中的二元包合物水合物在温和条件下促进氢气储存

发表时间：2025年8月8日

发表期刊：《Chemical Engineering Journal》

Erling Velten Rothmund, Jianying He, Zhiliang Zhang, Senbo Xiao

Department of Structural Engineering, Norwegian University of Science and Technology (NTNU), Trondheim, 7491, Norway

Abstract: Hydrogen (H2) clathrate is an ideal solid-state medium for hydrogen storage, yet practical applications are hindered by high formation pressures or insufficient storage capacities with conventional promoters. To address these challenges, binary methane-hydrogen clathrates have emerged as a promising high-energy-density fuel capable of bridging existing natural gas infrastructure with future hydrogen-based energy systems. Using molecular dynamics simulations, this study investigates a two-tiered promotion strategy for effective hydrogen storage under milder conditions (e.g., 260K and 100bar), combining methane (CH4) as a thermodynamic promoter and nanoporous activated carbon as a host material to leverage advantageous confinement effects. By analyzing formation and dissociation of clathrates under systematic variation of temperature and pressure, favorable conditions for H2 enclathration in different cage configurations were identified, including H2-occupancy in 512 cages and CH4-presence in both 512 and 62512 cages at 270K. Clathrate dissociation temperatures varied by up to~30K depending on local pore size and cage configuration. The results yield a predictive phase diagram for the formation of binary CH4–H2 clathrates in porous media. Furthermore, critical pore sizes of 2.5nm for stability and 4.7nm for formation of the binary clathrates was established, informing future material synthesis and highlighting the metastability of gas clathrates. These insights into the relationship between clathrate structure, pore size, and gas storage mechanisms provide a molecular-level foundation for H2 storage in porous materials, and support that a dual-storage mechanism combining micropore physisorption and meso-/macro-pore enclathration can be utilized to enhance storage efficiency.

Keywords: Hydrogen storage; Gas clathrate; Methane; Dual-storage mechanism; Activated carbon; Critical pore size; Molecular dynamics

Fig. 1. Hydrogen storage in porous activated carbon via enclathration with methane as a clathrate promoter. The left panel illustrates the macroscopic components leading to 

formation of binary hydrogen–methane clathrate in the activated carbon pores, depicted at the nanoscale in the middle panel. The two most commonly observed gas clathrate hydrate crystal structures are detailed in the right panel: structure-I and structure-II. Water molecules are drawn as red angles and connected by white hydrogen bonds. Small 512, medium 62512, and large 64512 cages are colored green, purple, and blue respectively. For ease of visualization, more than one unit cell of structure-I and less than one unit cell of structure-II are shown.

阅读原文：https://doi.org/10.1016/j.cej.2025.166696.

Assessing the prospect of long-term exploitation of Class 1 hydrate deposit with horizontal well in the South China Sea from energy, environmental, and economic perspectives

从能源、环境和经济角度评估在南海利用水平井开采一级水合物储层的长期开发前景

发表时间：2025年8月9日

发表期刊：《Applied Energy》

Weiyu Yuan1,2,3, Jing-Chun Feng1,2,3, Bo Li4, Tingting Zhang4, Yan Xie1,2,3, Bin Wang1,2,3, Si Zhang2,5, Zhifeng Yang1,2,3,

1 Guangdong Basic Research Center of Excellence for Ecological Security and Green Development, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China 

2 Research Centre of Ecology & Environment for Coastal Area and Deep Sea, Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China 

3 Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for Watersheds, Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou 510006, China 

4 School of Resources and Safety Engineering, Chongqing University, Chongqing 400044, PR China 

5 South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, PR China

Abstract: Economical gas recovery from hydrate reservoirs with underlying gas, namely Class 1 hydrate deposits, still remains a challenge. Although the mining potential of the Class 1 hydrate deposits have been investigated by some researchers, the knowledge of the production responses under different exploitation schemes in horizontal-well systems is insufficient. Additionally, few studies have systematically evaluated the long-term mining potential of the Class 1 hydrate deposits from economic perspective. On this basis, in this study, we investigated the characteristics of the gas–water production stage and numerically analyzed the risk of methane leakage from a typical Class 1 hydrate deposit in the South China Sea (SCS). Then, the economic benefits and the energy utilization efficiency were evaluated. The results revealed that the depressurization method with dual wells exhibited the best performance, with cumulative produced gas values 1.1–1.5 times higher than those in the other simulated cases at the end of production. In all of the studied cases, extremely low energy utilization was achieved in the initial stage of production, and it is concluded that considerable economic benefits can be generated in the production stage dominated by free gas. Only a small amount of dissolved methane effused during the entire production process. Additionally, the permeability of hydrate-bearing layer and the initial gas saturation were the key factors influencing the gas production. However, the average production level of the Class 1 hydrate deposits in the SCS was still an order of magnitude away from that required for commercial exploitation.

Keywords: Hydrate exploitation; Underlying gas; Horizontal well; Numerical simulation; Mining potential evaluation

Fig. 2. (a) Schematic diagram of the conceptual model of gas production from Site SC_W02 (not to scale); and (b) domain discretization patterns of the lateral dual horizontal wells system. Noting that the entire mesh took the left wellbore as the coordinate origin, regardless of whether the wells were located in the middle of the HBL or near the hydrate-gas interface.

阅读原文：https://doi.org/10.1016/j.apenergy.2025.126552.

Enhancing hydrate-based CO2 storage security in muddy reservoirs: Quantitative analysis of permeability and breakthrough pressure

提升含泥储层中基于水合物的二氧化碳储存安全性：渗透率与突破压力的定量分析

发表时间：2025年8月7日

发表期刊：《Energy》

Jingru Zhang, Guangjun Gong, Yi Zhang, Lanlan Jiang, Cong Chen, Yongchen Song

Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian 116024, China

Abstract: CO2 breakthrough pressure is a critical parameter for evaluating the storage security of muddy hydrate-bearing reservoirs. It is determined by the synergistic effects of fluid saturation and stress conditions on permeability. However, the quantitative coupling mechanisms between permeability and breakthrough pressure in muddy hydrate-bearing cores remain poorly understood. Therefore, this study remolded 18 muddy cores under different water saturation, hydrate saturation, and effective stress conditions. Permeability and breakthrough pressure were measured continuously using the pulse method and the gradient pressurization method, respectively. The maximum increase in the stress sensitivity coefficient of muddy cores is approximately 69.12%, and the maximum increase in the stress damage coefficient is approximately 23.08%. Increasing water saturation and effective stress can reduce core permeability, thereby significantly elevating the breakthrough pressure. In contrast, increasing hydrate saturation enhances the permeability stress sensitivity coefficient by up to 75.20%, while restricting the increase in the permeability stress damage coefficient to a maximum of 6.26%. Pearson correlation analysis reveals that among all parameters, effective stress exhibits the strongest influence on permeability. Comparative analysis demonstrates that the hydrate saturation's permeability effect is 1.16 times more pronounced than water saturation's impact. Furthermore, to our knowledge, this study presents the quantitative correlation between permeability and breakthrough pressure in CO2 hydrate-bearing muddy cores firstly. Their synergistic variation follows a power-exponential empirical relationship. These findings provide both theoretical foundations and practical guidance for safe and efficient CO2 storage in muddy reservoirs via the hydrate method.

Keywords: Muddy core; Breakthrough pressure; Permeability; CO2 hydrate storage; Equivalent water saturation

Fig. 4. Coupled water saturation-stress-permeability relationships for different conditions in cores without hydrates (a); stress sensitivity coefffcient (b); stress damage coefffcient (c); Pearson correlation coefffcients for inffuencing factors (d).

阅读原文：https://doi.org/10.1016/j.energy.2025.137958.