Hydrate Growth Research Articles

Co-grinding treatment for developing integrated-properties SCMs from basic oxygen furnace slag and furnace bottom ash: A step toward synthesis advanced SCMs

The recycling of the basic oxygen furnace slag (BOF) and the furnace bottom ash (FBA) as supplementary cementitious materials (SCMs) will contribute to achieving the sustainability requirements of the infrastructure sector. The BOF possesses inherent hydraulic properties due to its high content of glass network-modifying phases (e.g., CaO, MgO, Na2O, and K2O). However, its poor grindability, variability in quality, and purity are factors that may limit its reuse as a SCM. This paper aims to explore the impact of co-grinding BOF with FBA on the chemical, physical, and microscopic properties of the new combinations and their effect on the performance of their designed mortar. Combinations consisting of three ratios of BOF to FBA (3:1, 3:2, and 1:1) were synthesized, and the results of the co-grinding were compared with those equivalents in separate grinding. The findings indicate that co-grinding improved the fineness and synergies of the BOF-FBA particles without significantly altering the crystalline phases or developing new ones compared to the original materials. Combined grinding had a positive effect on the flowability of mortar mixtures and the development of compressive strength at all curing ages. Microstructural analyses revealed denser and more compact microstructures in mortar designed from the co-ground BOF-FBA combinations, along with lower Ca/Si and Si/Al ratios, indicating the positive influence of co-grinding on the growth of hydrates.

Molecular Insights into the Dual Promotion-Inhibition Effects of NaCl at Various Concentrations on the CO2 Hydrate Growth: A Molecular Simulation Study.

Hydrate-based CO2 storage in the ocean is considered a potential method for mitigating the greenhouse effect. Numerous studies demonstrated that NaCl exhibited the dual effects of promotion and inhibition in the nucleation and growth processes of CO2 hydrate, whose mechanisms remain unclear. In this study, the effects of NaCl at various concentrations on the CO2 hydrate growth and crystal are investigated. The independent gradient model based on Hirshfeld partition, electrostatic potential, and binding energy is conducted to study the interaction between ions and water molecules. The motion trajectories of ions are observed at the molecular level to reflect the impact of ion motion on hydrate growth. The results show that the influence of NaCl on hydrate growth depends on a delicate balance of dual promotion-inhibition effects. NaCl can combine more water molecules and provide a transport channel of CO2 to promote hydrate growth at low concentrations. Meanwhile, the promoting effects shift toward inhibition with increasing NaCl concentrations. In a word, this paper proposes a novel mechanism for the dual promotion-inhibition effects of NaCl on hydrate growth, which is significant for further research on hydrate-based CO2 storage in the ocean.

Growth dynamics and morphology of D2O + HFC-134a clathrate hydrate crystal toward tritiated water separation

This work represents the crystal growth and morphology of Deuterium water (D2O) and HFC-134a clathrate hydrate toward enhancing the hydrate-based tritiated water separation method. The utilization of the method involves the use of D2O + HFC-134a hydrate as a substrate to capture tritiated water. It is imperative to have a comprehensive understanding of the morphology of each crystal and the precise temperature and pressure conditions required for their production, given that the substrate consists of individual crystals. Experiments were conducted within Δ T sub range from 1.0 K to 7.8 K. The pressure was set at 0.305 to 0.398 MPa to avoid the liquefaction of HFC-134a. The results revealed that at Δ T sub less than 5.2 K, the hydrate crystals were plates and polyhedrons with a size of 1.0–3.0 mm. When Δ T sub exceeded 5.2 K, the crystals of columnar or dendritic morphologies were observed. They formed elongated shapes of 3.0 mm in length and 0.1 mm in width. Columnar or dendritic crystals are suitable for increasing surface area. In contrast plate and polyhedral crystals decrease the surface area of the substrate and reduce flow resistance. Selecting the favorable crystalline form to intensify the equipment and processes is essential.

Modeling oceanic sedimentary methane hydrate growth through molecular dynamics simulation.

The crystallization process of methane hydrates in a confined geometry resembling seabed porous silica sedimentary conditions has been studied using molecular dynamics simulations. With this objective in mind, a fully atomistic quartz silica slit pore has been designed, and the temperature stability of a methane hydrate crystalline seed in the presence of water and guest molecule methane has been analyzed. NaCl ion pairs have been added in different concentrations, simulating salinity conditions up to values higher than average oceanic conditions. The structure obtained when the hydrate crystallizes inside the pore is discussed, paying special attention to the presence of ionic doping inside the hydrate and the subsequent induced structural distortion. The shift in the hydrate stability conditions due to the increasing water salinity is discussed and compared with the case of unconfined hydrate, concluding that the influence of the confinement geometry and pore hydrophilicity produces a larger deviation in the confined hydrate phase equilibria.

Branched sulfonated promoter: Achieving high methane uptake and foam-free gas recovery for solidified gas storage

Gas hydrates offer a promising solution for clean and low-carbon energy storage and the transportation of natural gas. However, their slow formation kinetics and dissociation-induced foaming hinder their practical application. This study investigates a novel branched sulfonated promoter (BSP) to address these challenges. The effectiveness of BSP in promoting methane hydrate formation was evaluated by measuring the conversion degree, methane consumption, storage capacity, hydrate growth rate, and reaction rate constant. Molecular dynamics (MD) simulations provided insights into BSP's interaction with methane and water molecules, its self-aggregation, adsorption, and its role in hydrate cage formation. BSP demonstrated comparable performance to SDS in accelerating methane hydrate formation. At a concentration of 500 ppm, BSP achieved a water-to-hydrate conversion rate of 89.54 %, methane consumption of 432.16 mmol, and a storage capacity of 165.1 v/v after 450 min. BSP effectively suppressed foam formation during methane hydrate dissociation, and all the hydrates melted within 15 min. Moreover, BSP promotes the formation of dense and solid hydrates, unlike SDS, which favors hydrate growth on reactor walls. MD simulations revealed that BSP molecules do not form micelles but interact with water molecules through their hydrophilic chains, facilitating methane accumulation around their hydrophobic tails. This behavior promotes methane aggregation and hydrate formation. BSP surpasses SDS in terms of foam-free dissociation, making it a promising candidate for practical hydrate-based energy storage and transportation technologies. The combined experimental and computational approach provides valuable insights into the mechanisms underlying BSP's promotional effect, challenging the long-held belief that long alkyl chains are essential for hydrate promotion. This paves the way for further development of effective and environmentally friendly hydrate promoters.

Crystal Growth of Clathrate Hydrate Formed with Carbon Dioxide and Deuterium Oxide: Implications for Hydrate-based Tritium Separation

Crystal Growth of Clathrate Hydrate Formed with Carbon Dioxide and Deuterium Oxide: Implications for Hydrate-based Tritium Separation

Ultra-rapid formation of mixed H2/DIOX/THF hydrate under low driving force: Important insight for hydrate-based hydrogen storage

Hydrate was considered to be the next generation hydrogen storage material, and hydrate-based hydrogen storage (HBHS) would play an important role in future hydrogen economy, but sluggish hydrate formation kinetics presents huge technological challenge for its application. Herein, a nano promoter of -SO3−@PSNS was prepared by soap-free emulsion polymerization, and a dual kinetic promoter system (L-methionine/-SO3−@PSNS) was applied to enhance the formation kinetics of mixed H2/DIOX hydrate. At a moderate condition (12 MPa and 274.15 K), hydration efficiency under a driving force of 2.1 MPa is significantly enhanced by the synergy of the dual kinetic promoters, hydrate induction time reduces from 443.2 ± 209.73 min to 24.7 ± 17.16 min, while hydrate growth rate increases by 43.75%, and hydrogen storage capacity is up to 0.473 ± 0.041 wt% that increases by 62.8%. At a more moderate condition (10 MPa and 274.15 K) with an extremely low driving force of 0.1 MPa, enhanced hydrate formation was obtained in a composite promotion system of the dual kinetic promoters and dual thermodynamic promoters (THF/DIOX), which also performs exceptionally in term of recycling. The presence of a small amount (0.35 mol%) of THF reduces the induction time by 93.5%, and hydrate growth rate increases by 130.18%, while satisfactory hydrogen storage capacity (0.346 ± 0.017 g/g) is still remained in mixed H2/DIOX/THF hydrate, the structure of which was confirmed by Raman spectrum. This work presents an effect approach on enhancing the formation kinetics of H2-contained hydrate under low driving force, and this finding provides important insight for HBHS.

Effective prevention of structure II gas hydrate formation using the newly synthesized kinetic inhibitors

Gas hydrate deposition is a complex issue with significant implications for the oil and gas industry. The formation of solid gas hydrates in the hydrocarbon transportation pipelines leads to production disruptions and potentially even complete blockages, resulting in huge financial losses and operational difficulties. For over two decades, kinetic gas hydrate inhibitors have played a crucial role in preventing the formation of gas hydrates within the flow lines of oil and gas production. They directly influence the kinetics of hydrate formation, hindering nucleation and slowing down crystal growth. In this study, five new waterborne polyurethanes (WPUs) with varying degrees of hydrophobicity as inhibitors for cubic structure II gas hydrates were synthesized and tested using rocking cells and differential scanning calorimetry. The synthesis of WPUs involved the reaction between dialkylamines (diethyl, dipropyl, dibutyl, dibenzyl, and dioctyl) and glycidol under mild conditions. All WPUs effectively prevented gas hydrate formation, and a correlation between their efficiency and the alkyl chain length was observed. The inhibitory efficacy of WPUs increased with the extension of the alkyl chain from ethyl to butyl. WPU-DBuA, featuring butyl groups, exhibited the highest inhibition activity. It provided a subcooling temperature of 12.9 and 15.6 °C at 0.25 and 0.5 wt%, respectively, surpassing commercial samples, such as Luvicap EG and Luvicap 55 W. Additionally, the solutions containing 1 and 2 wt% of WPU-DBu exhibited maximum subcooling temperatures of 16.2 °C and 16.7 °C, respectively, which correspond to a 79.7 % and 85.4 % reduction in gas uptake during hydrate growth compared to pure water. However, the inhibitory power of WPUs diminished with larger alkyl (dioctyl) or aromatic groups (dibenzyl), indicating that dibutyl represents the optimal alkyl length for achieving maximum performance. Moreover, WPUs demonstrated a reduction in hydrate conversion under static conditions, signifying their efficiency when the flow is stopped. WPUs lowered the onset temperature of hydrate formation from 3 °C in pure water to temperatures below −12 °C. Thus, WPUs demonstrated a remarkable ability to prevent the formation of structure II gas hydrates, even under high subcooling conditions. Additionally, WPU-DBuA exhibits a considerable degree of biodegradability, as evidenced by its biodegradation level of 44 %, suggesting that it has the potential to break down more easily in the environment compared to Luvicap 55 W. This research contributes to a deeper understanding of the structure–property relationships of KHIs. This can facilitate the development of more effective and eco-friendly inhibitors, which helps address environmental concerns associated with using KHIs in the oil and gas industry.

Kinetic study of hydrate formation in CO2 + fruit Juice systems with application of Juice concentration

The utilization of gas hydrates technology for concentrating liquid foods has garnered significant interest in recent years. In this experimental study, we aimed to investigate the influence of various fruit juices, including cherry, pineapple, pomegranate, mango, grape, tomato, grapefruit, peach, lemon, orange, apple, and apricot juices, on the kinetic parameters of carbon dioxide hydrate formation. These investigations provide valuable insights into the industrialization potential of hydrate-based juice concentration processes. The kinetic experiments were conducted in a 460 cm3 reactor under an initial pressure of 3 MPa and a temperature of 275.65 K. Our findings reveal that the addition of fruit juices prolongs the induction time by up to 377 min compared to pure water, while reducing the CO2 uptake by 25.3%. Moreover, our results demonstrate variations in storage capacity (SC) among different fruit juices, with apple juice exhibiting the highest SC (31.74 v/v) and pineapple displaying the lowest (21.92 v/v). Furthermore, the apparent rate constant (kapp) values obtained during carbon dioxide hydrate growth indicate a slight increase in kapp for apple juice, while other juices exhibit a decrease in kapp, suggesting varying effects on hydrate growth kinetics. Our analysis suggests that concentration via CO2 hydrate may be particularly suitable for apple juice due to its promotional effect, whereas pineapple, apricot, and mango juices exhibit high inhibition influences on kinetic parameters, making them less recommended for concentration via CO2 hydrate formation.

Influence of SDS on the Growth of Natural Gas Hydrates in a Sand Bed Depending on Saturation and Mineralization of Pore Moisture

Introduction:: Evaluate the effect of SDS on induction time and conversion of water to hydrate in a porous medium model depending on the saturation and salinity of pore moisture. Methods:: The work presents data on the formation of natural gas hydrates in sand bed fraction of 200-500 μm. The silica sand was saturated with water, solutions of SDS or NaCl, or a mixture of these. The saturation was 50% or 100%. The experiments were carried out under isochoric conditions at a temperature of 275 K and an initial pressure of 8 MPa. Results:: It was shown that the main hydrate formation occurred in the first 60 minutes. The addition of SDS 0.05-0.2 wt.% in the sand bed does not exhibit a promoting effect, as was previously shown for pure water. The addition of NaCl 3 wt.% reduces the conversion of water to hydrate by 1.6 and 2 times for 50% and 100% saturation of the sand bed. Conclusion:: The optimal concentration of the SDS additive to the salt solution has been found to reduce the inhibitory effect of the salt. The data obtained can be used to develop technologies for storing and transporting natural gas using sand and seawater.

Probing the nucleation and growth mechanism of hydrates in emulsion system under the influence of asphaltenes: A molecular dynamics simulation study

Asphaltenes are important components in crude oil, and hydrates are key elements impairing deep-sea flow assurance. So far, the study on the interaction mechanism between the two in water-in-oil emulsion systems is still limited. In this article, the effects of the molecule number of asphaltenes on the nucleation and growth of hydrates was investigated through 2500 ns molecular dynamics simulation. Moreover, hydrate growth experiments were conducted synchronously to verify the relationship between the effect of an increase in asphaltene concentration on hydrate growth at the macro level and the effect of an increase in asphaltene molecule number on hydrate growth at the micro level. The simulation results indicate that the addition of 5 and 10 asphaltene molecules can inhibit the nucleation of hydrates while 15 asphaltene molecules will shorten the induction period. Besides, hydrate growth is promoted in the presence of 5 asphaltene molecules but inhibited with further increase of asphaltene molecules. Experimentally, all concentrations of asphaltenes show inhibitory effects on the growth of hydrates. Based on the comprehensive analysis of structural parameters, potential energy and molecular transport properties, and by combining the measurement results of dynamic interfacial tension and interfacial dilational modulus, it is concluded that affecting the mass transfer process is the major way of asphaltenes affecting the growth of hydrates.

Kinetic analysis of CO2 hydrate formation in the aqueous solutions of transition metal chlorides

AbstractCO2 hydrate technology can be applied to seawater desalination. However, the kinetics of CO2 hydrate formation were inhibited in the aqueous solution with inorganic salts, and the kinetic mechanism of CO2 hydrate formation for inorganic salts with different metal cations and anions was still unclear. In this work, CO2 hydrate nucleation and growth were studied in aqueous solutions of metal chlorides. Instead of Na+ and K+ ions, CO2 hydrate nucleation was promoted in the presence of Ni2+, Mn2+, Zn2+ and Fe3+ ions due to the co‐ordination bonds between transition metal ions and water molecules to enhance the formation of the critical crystal nuclei. The induction time was increased by 61.1% in aqueous solution with 0.32 mol/L NaCl, while it was shortened by 55.6% in FeCl3 aqueous solution at the same concentration of Cl− anions. In the process of CO2 hydrate growth, Cl− ions played a more important role than the metal ions in affecting the stability of CO2 hydrate cages. The gas storage capacity was reduced by 10.3% in the presence of NaCl, and was lower than that of other metal chlorides. Cl− anions were absorbed on the hydrate surface and involved in hydrate cages to inhibit the hydrate growth due to the hydrogen bonds between the Cl− ions and water molecules of the hydrate cages. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.

Insights into the effects of 1,3-dioxolane on the growth of sI CO2 hydrate: A molecular dynamics simulation study

This study investigates the effect of 1,3-dioxolane (DIOX) with low concentrations on the growth of CO2 hydrate. The hydrate growth dynamics were investigated with molecular dynamics simulation performed on pure and additive-containing hydrate systems at a range of temperature conditions. The simulation results were analyzed using various techniques including potential energy analysis, mean square displacement (MSD), and independent gradient model based on Hirshfeld partition (IGMH) analysis. The results showed that the presence of DIOX with low concentrations significantly improved the growth rate and stability of CO2 hydrate in the moderate temperature range. The corresponding system configuration revealed that the generated hydrogen bonds among water molecules, DIOX, and CO2 formed the ternary structure of DIOX-Water-CO2 (D-W-C). This unique structure delicately dominated the rate of CO2 diffusion to mitigate their negative effects on the ordered arrangement of the water molecules, thereby augmenting the growth of CO2 hydrate. This study provides novel insights into the molecular mechanisms of CO2 hydrate growth in the presence of 1,3-dioxolane, which can inspire the development of hydrate-based CO2 sequestration technologies.

Leaf drought adaptive response in winter oilseed rape is altered at the onset of senescence: a study combining NMR relaxometry, multi-omics and microscopy.

Climate change is bringing more frequent and intense droughts, reducing overall water availability and adversely affecting crops. There is a need to improve our understanding of the tissular and cellular adaptation mechanisms that are critical for plant water conservation strategies. Here, we have used NMR relaxometry in combination with microscopy and multi-omic analysis to study the effects of progressive soil drought on winter oilseed rape (WOSR, Brassica napus L., cv. Aviso) leaves. This study reveals the structural and metabolic adjustments these leaves operate to maintain cell homeostasis. Our results are original in showing that the adaptive responses are altered in leaves at the onset of senescence, associated with changes in metabolic plasticity and mesophyll structures. Thus, long-term responses in young leaves involving osmotic adjustment were combined with the maintenance of tissue hydration and cell growth, contributing to high survival and recovery capacity. For the first time, short-term responses observed in early senescent-old leaves were associated with early drought-induced dehydration of the spongy layer. However, this dehydration was not followed by osmotic adjustment and did not allow maintenance of leaf tissue turgor. These findings open further studies on the genetic variability of drought responses related to identified short- and long-term structural and metabolic plasticity traits in Brassica species.

Molecular Insights into the Influence of Major Marine Ions on Carbon Dioxide Hydrate Growth

Molecular Insights into the Influence of Major Marine Ions on Carbon Dioxide Hydrate Growth

Adsorption enhances CH4 transport-driven hydrate formation in size-varied ZIF-8: Micro-mechanism for CH4 storage by adsorption-hydration hybrid technology

The adsorption-hydration hybrid technology holds significant potential for future CH4 storage applications. However, the transport of CH4/H2O and the mechanisms governing hydrate formation within metal-organic framework (MOF) systems remain unclear. In this study, the mechanism of CH4 adsorption, transport, and hydrate formation within ZIF-8 pores of different sizes was delineated utilizing the magnetic resonance imaging (MRI) technique. Primarily, CH4 undergoes physisorption within the inner cavity of ZIF-8, facilitating diffusion through the pores, which preferentially accumulate in larger pore spaces. Due to favorable interactions between CH4 and pre-absorbed water on the ZIF-8 surface, ZIF-8–01 and ZIF-8–02 preferentially facilitate substantial hydrate formation within larger pore spaces. The continuous hydrate growth depletes CH4 in the pore space, enabling two-way migration of adsorbed CH4 to support ongoing hydrate formation. This limited availability of adsorption sites within ZIF-8 induces the diffusion of surrounding CH4 into smaller pore spaces, facilitating the conversion of bound water. The size of the particles considerably influences the transport of physically adsorbed CH4 and impacts hydrate formation. Similar patterns are observed in the adsorption mass transfer coefficients of ZIF-8–01 and ZIF-8–02, which range from 0.0038 to 0.0044 and 0.0031 to 0.0124, respectively. The presence of more adsorption vacancies in the early stage leads to rapid diffusion adsorption of CH4 owing to strong adsorption effects. As adsorption within ZIF-8 pore cavities approaches saturation, increased water transport elevates internal gas-liquid two-phase resistance, slowing the kinetics of late-stage CH4 adsorption. At 6 MPa, CH4 with a larger particle size preferentially overcomes the gas-liquid energy barrier, expediting transport and promoting hydrate formation. Furthermore, the optimal particle sizes of ZIF-8 substantially influence physisorption and significantly improve the kinetics of hydrate formation.

Enhanced CO2 hydrate formation using hydrogen-rich stones, L-Methionine and SDS: Insights from kinetic and morphological studies

One promising proposal for CO2 capture and storage is based on hydrate technology, which grapples with challenges related to stringent formation conditions and slow formation rates. In this study, the induction time, gas uptake and the rate of CO2 hydrate formation were measured with varying concentrations (ranging from 0.05 wt% to 0.2 wt%) of L-Methionine (L-Met) and sodium dodecyl sulfate (SDS). Remarkably, the novel additive hydrogen-rich stone significantly reduced the induction time by 89.74 % and 85.16 %, even under static conditions. The morphology analysis reveals that L-Met foster the creeping growth of hydrates, resulting in an approximate 41.89 % increase in the initial 1 h gas uptake. The efficient heat diffusion further enables the rapid formation of hydrates, resulting in a high gas uptake in a short period. L-Met outperforms SDS in terms of induction time and gas uptake, with the optimal choice for CO2 hydrate formation being 0.1 wt% L-Met. This study briefly describes the mechanisms of three different kinetic promoters for hydrate formation, which provides new ideas for subsequent studies on CO2 capture and storage via hydrate technology.

Molecular study on the growth mechanism of CO2-H2 binary hydrate promoted by electric field

The storage and transportation of hydrogen (H2) are widely recognized as the main challenge of hydrogen utilization technology. The hydrate-based method is one of the safe and environmentally friendly hydrogen storage methods. However, the harsh generation conditions and slow growth rate of H2 hydrate hinder its industrial application. Therefore, exploring methods to reduce the reaction conditions of H2 hydrate and improve growth efficiency is worth further research. This study investigated the effect of different intensities of electrostatic fields (0–0.9 V/nm) on the growth of CO2-H2 binary hydrates through molecular dynamics (MD) simulation. Representative parameters such as growth configuration, number of cages, dipole moment, four body angular order parameters, mean square displacement, occupancy rate, etc. were analyzed. The T, P conditions used for the simulation were 255 K, 80 MPa, and 400 ns in duration. The results suggest that a certain range of electric field strength can increase the growth rate of CO2-H2 binary hydrates and reduce the conditions required for hydrogen hydrate formation. The growth-promoting effect of the electric field is primarily manifested in the increased growth rate of binary hydrates. Detailed analysis reveals that electric field of a certain strength can to some extent promote the multiple occupancy of H2 within cage structures, thereby enhancing the hydrate's ability to capture H2. These molecular insights are beneficial for the application of electrostatic field in hydrate-based technologies to improving the storage efficiency of H2 hydrate and the reuse of CO2.

Eco-friendly hydrogels serving as water carriers for improving methane hydrate formation and dissociation processes

Natural gas hydrate (NGH) technology has broad application prospects in natural gas storage & transportation. In this work, we used eco-friendly hydrogel-based carriers to retain water, which were biodegradable polyvinyl alcohol-co-acrylic acid (PVA-co-PAA) hydrogels, and to react with methane gas and form hydrates. Results indicated that hydrates could be formed in the presences of swollen hydrogel particles without stirring or promoter adding, which might be owed to the enlarged gas–liquid interface and bulk of hydrophilic groups. When mass ratio of PVA to AA (MR) was 1:4, hydrogels performed best in improving hydrate formation kinetics: the induction time was 20.3 ± 20 min, the hydrate growth rate was 0.0217 ± 0.0088 mmol mL−1 min−1, and the methane uptake was 75.84 ± 4.70 mmol mol−1 water. Morphological observations revealed the water retaining behaviors of hydrogels during hydrate formation-dissociation process: a part of absorbed water transferred out of hydrogels to participate in hydrate formation, and afterwards hydrogels could re-absorbed the water released by hydrate dissociation. Moreover, hydrogels kept excellent recycling performance in seven repeated hydrate formation-dissociation cycles. Collectively, PVA-co-PAA hydrogels used as water carriers could improve mass transfer and reaction efficiency during methane hydrate formation-dissociation process, and meanwhile exhibited good recyclability due to strong water absorbing and retaining capabilities, implying that PVA-co-PAA hydrogels might potentially have broad applications in NGH technology.

Molecular dynamics simulation study of the cosine oscillation electric field's effect on methane hydrate growth

Cosine oscillation electric field could be a promising option to fasten methane hydrate formation in pure water. Molecular dynamics simulation was employed to examine the performance of cosine oscillation electric field in the intensity range of (0.5–2.0) V•nm−1 and frequency range of (0.2–1.0) THz. The hydrate growth time and the hydrate growth rate were firstly defined and obtained by calculating the four-body structure order parameter for different systems at different x positions. The results showed that the added electric field with appropriate parameters could promote methane hydrate formation significantly, represented by shorter hydrate growth time and higher hydrate growth rate. In all studied systems, system with 1.5 V•nm−1 intensity and 0.4 THz field intensity was recommended for fast hydrate growth rate, which could be three times higher than that of system without electric field. It was noteworthy that there was an electric field frequency boundary, lower than which the effect of cosine oscillation electric field on methane hydrate formation could be totally different. The electric field frequency boundary for systems with different electric field intensities was identified and fitted with two exponential growth functions.