《佳文速递》2025年第13期

Hydrate formation and agglomeration in pickering emulsions stabilized by hydrophilic and hydrophobic nano-CaCO3 particles

亲水性和疏水性纳米CaCO3颗粒稳定的皮克林乳液中的水合物形成与聚集

发表时间：2025年8月21日

发表期刊：《Petroleum Science》

Dong-Dong Guo1,2, Wen-Jia Ou2, Yun-Hong Zhang1, Heng-Yin Zhu1, Shahab Ud Din3, Ren Wang4, Fu-Long Ning2

1 The Innovation Base of Fine Mine Prospecting and Intelligent Monitoring Technology, School of Earth and Environment, Anhui University of Science and Technology, Huainan 232001, Anhui, China 

2 Engineering Research Center of Rock-Soil Drilling & Excavation and Protection, Ministry of Education, China University of Geosciences, Wuhan 430074, Hubei, China 

3 Department of Oil-Gas Field Development, College of Petroleum Engineering, China University of Petroleum (Beijing), Beijing, 102249, China 

4 CNPC Engineering Technology Research and Development Company Limited, Beijing, 102206, China

Abstract: The stability of oil-dominated emulsions, including oil-based drilling fluids and crude oils, is crucial for mitigating gas hydrate risks in the petroleum and natural gas industries. Nanoparticles can stabilize oil-water systems (Pickering emulsions) by residing at the oil-water interface. However, their effects on the kinetics of hydrate formation in these systems remain unclear. To address this, we experimentally investigated how hydrophilic and hydrophobic nano-CaCO3 influence CH4 hydrate formation within dynamic oil-water systems. A series of hydrate formation experiments were conducted with varying water cuts and different concentrations of nano-CaCO3 at a particle size of 20nm, under 3°C and 6MPa. The induction time, hydrate formation volume, and hydrate growth rate were measured and calculated. The results indicate that hydrophilic nano-CaCO3 generally inhibits hydrate formation, particularly at high water cuts, while hydrophobic nano-CaCO3 can significantly inhibit or even prevent hydrate formation at low water cuts. Water cut strongly influences the kinetics of hydrate formation, and nanoparticle concentration also impacts the results, likely due to changes in oil-water interface stability caused by nanoparticle distribution. This study will offer valuable insights for designing deepwater oil-based drilling fluids using nanoparticles and ensuring safe multiphase flow in deepwater oil and gas operations.

Keywords: Gas hydrate; Pickering emulsion; Nano-CaCO3 particles; Hydrophilicity and hydrophobicity; Inhibition effect

Fig. 10. Schematic of the comprehensive study on the influence and mechanisms of nanoparticles on hydrate formation in OW systems.(a) Key influencing factors; (b) the distribution of oil, water, and nanoparticles in the system; (c) emulsion type (W/O or O/W), OW interface stability, and overall system stability; (d) kinetics inhibition and anti-agglomeration performance. 

阅读原文：https://doi.org/10.1016/j.petsci.2025.08.022

Assessing IoliLyte® ionic liquids potential as gas hydrate inhibitors: thermodynamics, kinetics and toxicity evaluation

评估IoliLyte®离子液体作为气体水合物抑制剂的潜力：热力学、动力学及毒性评估

发表时间：2025年8月18日

发表期刊：《Journal of Molecular Liquids》

Mohammad Tariq1,2, David Rodrigues1, Aliya Fathima Anwar3, Tausif Altamash4, K. Kala5, Ana Rodriguez2, Francisco Javier Deive2, José M.S.S. Esperança1

1 LAQV-REQUIMTE, Department of Chemistry, NOVA School of Science & Technology, NOVA FCT, 2829-516, Caparica, Portugal 

2 University of Vigo, Department of Chemical Engineering, 36310, Vigo, Spain 

3 African Genome Centre, Mohammed VI Polytechnic University, Lot 660-Hay Moulay Rachid, Ben Guerir 43150, Morocco 

4 Materials Science and Nano-Engineering (MSN) Department, Mohammed VI Polytechnic University, Lot 660-Hay Moulay Rachid, Ben Guerir 43150, Morocco 

5 Department of Bioinformatics, Saveetha School of Engineering, Saveetha School of 

Medical and Technical Sciences, Saveetha University, Chennai, Tamilnadu 602105, India

Abstract: The inhibition of gas hydrates is a critical challenge for the petrochemical industry, particularly for flow assurance in deep-sea pipelines. This study investigates the potential of three commercial ionic liquids (ILs) from the IoliLyte® family—T2EG, C1EG, and 221PG— as hydrate inhibitors. The phase behaviour of CO₂ hydrates in the presence of different IL concentrations (10 wt%–40 wt%) was analyzed using an isochoric pressure search method within temperature and pressure ranges of 3 °C–9 °C and 16 bar–37 bar, respectively. While T2EG and C1EG exhibited no effect on the hydrate equilibrium, 221PG acted as a thermodynamic hydrate inhibitor (THI), shifting the equilibrium curve in a concentration-dependent manner. Additionally, the kinetic inhibition efficiency was evaluated (0.1 wt%–1 wt%) using a constant cooling ramp method at 30 bar, revealing a decrease in the onset nucleation temperatures and reduction in pressure drops, indicating delayed nucleation and inhibited hydrate growth. The ILs were further tested for their influence on tetrahydrofuran (THF) hydrate dissociation at atmospheric pressure using differential scanning calorimetry (DSC), which qualitatively indicates thermodynamic inhibition of sII hydrates. The physicochemical properties, including density, viscosity, speed of sound, and refractive index, were measured at different temperatures, and the thermal characterization was performed via DSC. Finally, the microbial and the acute toxicity were assessed through minimum inhibitory concentration (MIC), minimal bactericidal concentration (MBC) and zebra fish embryo tests (ZFET) to evaluate their suitability for deep-sea applications. Among the tested ILs, 221PG emerged as the most promising, displaying both thermodynamic and kinetic inhibition capabilities for CO2 hydrates, while also being the most environmentally benign option.

Keywords: CO2 hydrates; Ionic liquids; Phase behaviour; Nucleation; Microbial toxicity

Fig.8.Representative images of morphology observed during the ionic liquid exposure. Control (absence of ionic liquid) and 221PG exposed at 10 mg/mL, C1EG and T2EG exposed at concentration at 400 μg/mL. Hatching of embryos was observed in the 221PG treatments. No embryos hatching was observed in treatments C1EG and T2EG. Red arrows indicate malformations.

阅读原文：https://doi.org/10.1016/j.molliq.2025.128335

Does dimethyl sulfoxide inhibit or promote methane hydrate nucleation and growth?

二甲基亚砜是否抑制或促进甲烷水合物成核和生长？

发表时间：2025年8月24日

发表期刊：《Journal of Molecular Liquids》

Anton P. Semenov1, Timur B. Tulegenov1, Andrey S. Stoporev1,2, Andrei A. Novikov1, Pavel A. Gushchin1, Vladimir A. Vinokurov1

1 Gubkin University, Department of Physical and Colloid Chemistry, 65, Leninsky prospekt, Building 1, 119991, Moscow, Russian Federation 

2 Moscow Institute of Physics and Technology, National Research University, Institutskiy per. 9, Dolgoprudny 141700, Russian Federation

Abstract: As a thermodynamic hydrate inhibitor, dimethyl sulfoxide (DMSO) shifts the gas hydrate equilibrium curve to lower temperatures [https://doi.org/10.1016/j.cej.2021.130227]. However, it's equally important to consider how quickly and how much gas hydrates will form if the system enters the hydrate stability zone. This study systematically addressed the effects of DMSO on the kinetics of methane hydrate nucleation and growth in the rocking cells. Depending on its concentration, DMSO was revealed to promote or inhibit the nucleation and growth of methane hydrate. Hydrate onset temperature To and subcooling ∆To were measured for 0–40mass% aqueous DMSO solutions. The dependence To(ωDMSO) reaches a maximum of 281.52 ± 0.58K at 1 mass%. Hydrate nucleation events are less stochastic for 1–20mass% compared to H2O and more scattered for higher concentrations. ΔTo for 1–20mass% DMSO is smaller than for water with a minimum of 1.83 ± 0.40 K at 5mass%. At 40mass%, ∆To exceeds that observed for H2O. Consequently, ~30 mass% is a threshold below which DMSO accelerates hydrate nucleation, while at higher levels, it acts as an inhibitor. For a 5 mass% (ΔTo = 1.5 K), hydrate nucleation rate J increases by a factor of 6 compared to H2O. In contrast, at 40 mass% (ΔTo = 2 K), J decreased by the same factor. The analysis indicates an increase in the number of nucleation centers and a decrease in the nucleation work for 1–20mass%, and the opposite effect for 40mass%. DMSO enhances methane hydrate growth over a range of 1–40mass%, with the best effect at 20 %. However, in concentrated solutions (>20mass%), the promoting effect of DMSO on hydrate growth diminishes. Extrapolating the results, we conclude that the hydrate growth is inhibited by DMSO concentrations >40mass%.

Keywords: Gas hydrates; Methane; Dimethyl sulfoxide; Subcooling; Nucleation rate; Hydrate growth

Fig.10. Marginal box charts of initial methane hydrate growth rh, initial, as a function of onset subcooling ∆To; color boxes show ±standard deviation of values, mean and median values are shown as hexagons and solid lines inside color boxes, whiskers cover the range from minimum to maximum; legend shows concentrations of aqueous DMSO solutions in mass%.

阅读原文：https://doi.org/10.1016/j.molliq.2025.128393.

Improving CO2 storage and methane production from gas hydrate reservoir using different techniques and nanoparticles

利用不同技术和纳米颗粒改善气水合物储层中的二氧化碳储存和甲烷生产

发表时间：2025年8月7日

发表期刊：《Journal of Molecular Liquids》

Mohammad Shahbazian, Hamidreza Shahverdi, Mohsen Mohammadi, Mahsa Jafari Khamirani

Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran

Abstract: Recently, natural gas hydrate reservoirs have been considered as a vast potential energy source. One of the proposed production methods is the replacement of methane with carbon dioxide, which offers advantages such as methane recovery and greenhouse gas sequestration. However, this method suffers from low efficiency. In this study, the enhancement of methane production from gas hydrate reservoirs, as well as the increased storage of carbon dioxide within them, was investigated using a realistic approach. To this end, after characterization of nanoparticles via FESEM, FTIR, XRD, and DLS analysis, methane hydrate was first formed at an initial pressure of 65bar and a temperature of 1°C to simulate a gas hydrate reservoir. Subsequently, a suspension of ZnO or clay-nanoparticles was injected into the hydrate reservoir to enhance heat and mass transfer. Following this, methane production was initiated using either depressurization or thermal stimulation methods. Finally, carbon dioxide gas was injected to carry out the replacement process. The methane production from gas hydrate through a combination of gas replacement and depressurization methods was improved from 5.66% for pure water to 9.75, 13.62 and 14.97% and the carbon dioxide storage increased from 38.41% for pure water to 60.17, 60.51 and 66.79% in the presence at 500, 1000, and 1500 ppm of aqueous ZnO suspensions, respectively. A 66.21% enhancement in methane production was observed when using nanofluid (ZnO) in the gas replacement/thermal stimulation combined method compared to pure water. Also, nano-clay improved both methane production to 8.12, 11.76, and 13.20%, and carbon dioxide storage to 42.07, 56.53, and 57.10% compared to pure water with particle loadings of 300, 500, and 800 ppm, respectively. Finally, among the various experiments performed, combining three production methods including CO2-CH4 replacement, depressurization and thermal stimulation, in the presence of ZnO particles, showed the highest amount of methane production (51.79% of the initial methane in the hydrate phase).

Keywords: Gas hydrates; Methane production; CO2 storage; ZnO; Nanoclay

Fig. 4. FESEM (a) and EDS (b) of zinc oxide nanoparticles.

阅读原文：https://doi.org/10.1016/j.molliq.2025.128300

Comparative analysis of CH4 and CO2 hydrate formation kinetics in heterogeneous marine sediments

异质性海洋沉积物中甲烷（CH4）与二氧化碳（CO2）水合物形成动力学的比较分析

发表时间：2025年8月12日

发表期刊：《Chemical Engineering Science》

Jiaxian Wang1,2, Changling Liu2,3, Yunkai Ji2,3, Fulong Ning1,3, Chuanqi Sun2,4, Qingguo Meng2,3, Yapeng Zhao2,3, Qingtao Bu2,3

1 Faculty of Engineering, China University of Geosciences, Wuhan 430074, China 

2 Key Laboratory of Gas Hydrate, Ministry of Natural Resources, Qingdao Institute of Marine Geology, Qingdao 266237, China 

3 Laboratory for Marine Mineral Resources, Qingdao Marine Science and Technology Center, Qingdao 266237, China 

4 College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058, China

Abstract: Understanding water-to-hydrate conversion behavior in marine sediments is critical for evaluating natural gas hydrate resources and optimizing CO2 sequestration strategies. This study enabled real-time in situ monitoring of CH4and CO2 hydrate formation in sandy sediments using a self-developed low-field nuclear magnetic resonance system, enriching knowledge in sediment-hosted hydrate kinetics. Effects of guest molecule type, initial water saturation (28.96–79.24%), and sediment particle size (20–600μm) on water-to-hydrate conversion behavior were quantitatively analyzed. Results show that CO2 hydrates occupy both macro- (>100μm) and micropores (<10μm) due to the high aqueous solubility of CO2 under experimental conditions (4.0MPa, 274.65K). In contrast, CH4 hydrates predominantly form in macropores, constrained by lower gas concentration. CO2 achieves 1.75–78.25h faster conversion rates (t90) and 1.56–4.47 % higher final conversion percentages than CH4, driven by greater supercooling (7.5°C vs. 6.0°C), higher aqueous solubility, and enhanced mass transfer through partial liquefaction. Particle size ≤150μm accelerates conversion rates by 2.57–27.88 times through increased specific surface area (~36 times higher in 20–40μm vs. 400–600μm sediments) and capillary-driven water migration. High initial water saturation (79.24% and 77.69%) triggers abrupt percentage losses (CH4: ~95 % to 65.75%, CO2: ~98% to 91.97%) due to hydrate film termination and pore blockage effects. MRI data demonstrate asymmetric water redistribution during gas injection alters local conversion rates, explaining anomalous kinetics in mid-saturation CH4 systems. This work provides reliable data support and mechanism insights for gas hydrate resource assessment, CO2-CH4 exchange technology optimization, and subsea CO2 storage in heterogeneous marine reservoirs.

Keywords: Hydrate; Guest molecules; Sandy sediments; Water-to-hydrate conversion rate; Water conversion percentage; Low-field NMR

Fig. 13. Schematic of water distribution evolution in sandy sediment samples before and after CH4 injection. (a) is Case5 before CH4 injection (Sw0 = 49.40 %); (b) is 

Case5 after CH4 injection (Sw0 = 49.40 %); (c) is Case11 before CH4 injection (Sw0 = 67.32 %); (d) is Case11 after CH4 injection (Sw0 = 67.32 %). The red arrow 

indicates the direction of CH4 gas injection.

阅读原文：https://doi.org/10.1016/j.ces.2025.122419