Kinetics Of Hydrate Formation Research Articles

Comparative Analysis of the Mechanisms and Kinetics of CO2 Hydrate Formation with Sodium Dodecyl Sulfate and L-Leucine Additions under Static Conditions

Comparative Analysis of the Mechanisms and Kinetics of CO2 Hydrate Formation with Sodium Dodecyl Sulfate and L-Leucine Additions under Static Conditions

Promoting CH4 Hydrate Formation Kinetics by Utilizing Synergistic Promotion Effects of Graphite Particles with Sodium Dodecyl Sulfate

Promoting CH₄ Hydrate Formation Kinetics by Utilizing Synergistic Promotion Effects of Graphite Particles with Sodium Dodecyl Sulfate

The effect of PVP and PVA on hydrate formation kinetics of ethane and propane mixture in the presence of kaolin nanoparticles

AbstractThe blockage of gas transmission pipelines due to gas hydrates poses a significant challenge for the gas industry. Low‐dosage hydrate inhibitors (LDHI) are utilized to influence the kinetics of hydrate formation, including nucleation, growth, and/or agglomeration. In the current study, a series of batch, isochoric, and isothermal tests were carried out to investigate the impacts of two LDHIs, poly N‐vinylpyrrolidone (PVP) and polyvinyl alcohols (PVA). This study examined the influence of these inhibitors on nucleation and growth of ethane+propane mixture in the presence of kaolin nanoparticles. In laboratory studies and using pure constituents, the rate of hydrate formation is low to investigate the inhibitors effect. To enhance the rate of hydrate formation, kaolin nanoparticles were utilized as they serve as a suitable representative for solid minerals commonly found in pipelines. The gas phase's compositional change were measured using a gas chromatograph. The results revealed that the growth stage of mixed‐gas exhibited two distinct steps, attributed to the formation of two different structures known as structure II and structure I. During the first step, structure II was formed, and the cavities were occupied by both gas components. In the second stage, structure I was formed by ethane. The effect of temperature on the induction time (nucleation rate) and the growth rate during the second stage was lower than that at the first stage. The increase in PVA concentration resulted in an increase in the induction time and a decrease in the rate of growth during the first stage. The performance of PVA was found to be affected by temperature. Lower temperatures resulted in the formation of less foam, providing improved performance for PVA at −0.5°C. PVP had a stronger impact on induction time and both growth steps compared to PVA, indicating stronger inhibitory impact of PVP on nucleation of hydrates initiated by propane and the growth of both propane and ethane hydrates.

Dual nature of methanol as a thermodynamic inhibitor and kinetic promoter of methane hydrate formation in a wide concentration range

Methanol (MeOH) is a common thermodynamic inhibitor of gas hydrates. However, its impact on the kinetics of methane hydrate formation has not been systematically investigated. We have thoroughly examined the effect of MeOH in a wide concentration range on the nucleation and growth kinetics of methane hydrate. The onset temperature To and subcooling ΔTo of methane hydrate were determined under ramp cooling of 1 K/h. The mean To is not affected by methanol in the 0–2.5mass% range but decreases within 2.5–50mass%. At the same time, it was revealed that ΔTo for 1–40mass%MeOH is significantly smaller than that of water, making methanol a hydrate nucleation promoter within the concentration range. The relationship between ΔTo and the methanol concentration shows a minimum of 0.53 ± 0.36 K (at 20mass%). Adding 1–30mass% of methanol reduces the stochasticity of the methane hydrate nucleation events. The hydrate nucleation rate increases by an order of magnitude at 1.5 K subcooling when 5 % of MeOH is added to water. Besides, methanol enhances the methane hydrate growth at 1–40mass%, with the maximum rate occurring at 10mass% MeOH. Despite the excellent promoting properties of methanol, extrapolation suggests that MeOH may inhibit both nucleation and growth of methane hydrate in more concentrated solutions (≥50mass%).Methanol has a dual nature as a thermodynamic inhibitor and a kinetic promoter of methane hydrate formation. The kinetic promotion function of methanol is observed within a specific range (1–40mass%), but in more concentrated systems, it seems to be reversed.

Experimental study on the cold-seep methane hydrate formation kinetics

Cold-seep methane hydrates are widespread in the natural environment. A comprehensive understanding of the cold-seep methane hydrate formation kinetics is crucial for the knowledge of formation mechanisms and the development and utilization of natural gas hydrate. This study monitored the kinetics of methane hydrate formation in cold-seep fluids using continuous time-series Raman spectroscopy. A novel spectroscopic method was proposed to accurately determine the nucleation time of gas hydrates with a ten-second accuracy. Experimental results showed a smooth transition from dissolved methane to hydrated methane. Rapid hydrate nucleation and growth initiation were observed at the gas–liquid interface, forming hydrate films wrapping gas bubbles and suspending hydrate microcrystals in cold-seep fluids. Furthermore, a model for cold-seep methane hydrate formation kinetics was proposed, which indicated three distinct stages including an induction period, a metastable nucleation period, and a stable growth period.

Kinetics studies of CO2 hydrate formation in the presence of l-methionine coupled with multi-walled carbon nanotubes

In recent years, gas hydrate technology has been considered to be a promising method for CO2 capture and transport. Nevertheless, the development of the gas hydrate technology is hindered by the slow hydrate formation. In this work, the effects of concentration, initial pressure and gas-liquid ratio on the CO2 hydrate formation kinetics in the compound system of environmentally friendly additive l-methionine (L-met) coupled with low-dose multi-walled carbon nanotubes (MWCNTs) were investigated for the first time. The results showed that L-met coupled with MWCNTs could effectively promote the CO2 hydrate formation, and the promotion effect was related to the MWCNTs concentration. At 4.0 MPa, compared to the 0.1250 wt% L-met single system, the compound system with the MWCNTs concentration of 0.0270 wt%∼0.0720 wt% increased the CO2 gas consumption (Gsum) by an average of 6.37 %, and the induction time (tin) of CO2 hydrate formation were shortened by an average of 36.03 %. The optimal concentration of MWCNTs was 0.0450 wt%. Meanwhile, the increase of the pressure and gas-liquid ratio could effectively accelerate the kinetics of CO2 hydrate formation. The promotion effect of the pressure increasing was better than that of the gas-liquid ratio increasing. The pressure increasing could result in the maximum increase of 39.75 %, 122.83 %, and 69.85 % in Gsum, initial gas consumption rate (N10), and the gas to hydrate conversion (GTH), respectively; and the highest reduction of tin was 83.72 %. Furthermore, the hydrate morphological observations revealed that CO2 hydrate initially nucleated in the inner of L-met solution, and the hydrate particles in the compound system of L-met coupled with the MWCNTs were porous snowflakes. The wall climbing effect induced by capillary forces was further explained, and the presence of L-met enhanced the mass transfer capacity of CO2 hydrates. The practical use of fast hydrate formation technology for CO2 capture and sequestration has been facilitated by this work.

Introducing sodium lignosulfonate as an effective promoter for CO2 sequestration as hydrates targeting gaseous and liquid CO2

Hydrate-based CO2 sequestration (HBCS) emerges as a promising solution to sequestrate CO2 as solid hydrates for the benefit of reducing CO2 concentration in the atmosphere. The natural conditions of high-pressure and low-temperature in marine seabed provide an ideal reservoir for CO2 hydrate, enabling long-term sequestration. A significant challenge in the application of HBCS is the identification of an environmental-friendly promoter to enhance or tune CO2 hydrate kinetics, which is intrinsically sluggish. In addition, the promoter identified should be effective in all CO2 sequestration conditions, covering CO2 injection as gas or liquid. In this study, we introduced sodium lignosulfonate (SL), a by-product from the papermaking industry, as an eco-friendly kinetic promoter for CO2 hydrate formation. The impact of SL (0–3.0 wt.%) on the kinetics of CO2 hydrate formation from gaseous and liquid CO2 was systematically investigated. CO2 hydrate morphology images were acquired for both gaseous and liquid CO2 in the presence of SL for the explanation of the observed promotion effect. The promotion effect of SL on CO2 hydrate formation is optimal at 1.0 wt.% with induction time reduced to 5.3 min and 21.1 min for gaseous and liquid CO2, respectively. Moreover, CO2 storage capacity increases by around two times at 1.0 wt.% SL, reaching 85.1 v/v and 57.1 v/v for gaseous and liquid CO2, respectively. The applicability of SL as an effective kinetic promoter for both gaseous and liquid CO2 was first demonstrated. A mechanism explaining how SL promotes CO2 hydrate formation was formulated with additional nucleation sites by SL micelles and the extended contact surface offered by generated gas bubbles or liquid droplets with SL. The study demonstrates that SL as an effective promoter for CO2 hydrate kinetics is possible for adoption in large-scale HBCS projects both nearshore and offshore.

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.

Direct measurement of hydrate equilibrium temperature in CO2 and CO2 rich fluids with low water content

A high-pressure experimental setup was used to obtain experimental data on the hydrate equilibrium (melting) temperature (HET) of hydrates formed from low water content CO2 and CO2 rich mixtures. A novel method was used to measure hydrate formation temperature in addition to melting temperature directly at realistic temperature/pressure conditions encountered in transport by pipelines or ship. The method can be used to evaluate the likelihood of hydrate formation in pipelines/ships transporting pure CO2 and CO2 coming from capture processes as well as from high CO2 content produced gas. The data generated from the measurement can also be used to investigate the kinetics of hydrate formation and dissociation in low water content fluids at pipeline/ship conditions. This paper details the experimental equipment, methods, test fluids and results. Experimental results are compared against predictions of the simplified cubic plus association equation of state (sCPA-EoS) coupled with the van der Waals and Platteeuw solid solution theory.

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.

Synergistic effect of alkanes with tween 80 on the kinetics of CO2 hydrate formation

The environmental problems brought about by the drastic increase in CO2 concentration are a great challenge that must be faced by mankind for sustainable development. Fortunately, research on CO2 hydrates has provided new views to effectively address these challenges. However, the slow kinetics of CO2 hydrate formation, unclear enhancement mechanisms, and high process costs have limited the practical application of hydrate-based carbon capture (HBCC) technology. In this work, we investigated the potential value of long-chain alkanes (n-decane) and Tween80 promoter (kinetics) in HBCC. We examined the key factors determining the promoter effect of long-chain alkanes and the synergistic effect of Tween80 with long-chain alkanes for the first time. The results showed that long-chain alkanes can play a facilitating or inhibiting role for the hydrate formation, depending on the state of the long-chain alkanes. The mechanism of long-chain alkanes to improve the kinetics of hydrate formation was mainly due to the hydrophobic effect and gas mass transfer. The addition of Tween 80 enhanced the stability of the system and promoted the gas mass transfer of long-chain alkanes, which could realize the kinetic enhancement under low-speed stirring conditions. This work helps to elucidate the mechanism of hydrocarbon compounds' influence on the kinetics of hydrate formation and provides a basis for their potential value for HBCC. It also provides some theoretical guidance for the use of inhibitors in the presence of hydrocarbon compounds.

WITHDRAWN: Corrigendum to “Investigation on the kinetics of carbon dioxide hydrate formation using flow loop testing” [J. Nat. Gas Sci. Eng. 49C, December 2023, 2357

WITHDRAWN: Corrigendum to “Investigation on the kinetics of carbon dioxide hydrate formation using flow loop testing” [J. Nat. Gas Sci. Eng. 49C, December 2023, 2357

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 methane hydrate formation using a newly synthesized biosurfactant: Application to solidified gas storage

Surfactants are considered the most influential promoters for accelerating the formation of gas hydrates in gas storage applications. However, their promotion mechanism remains unclear, and the formation of foam during the hydrate dissociation step severely limits hydrate-based gas storage technology. Oleic acid was used as a renewable biomass source in this study to develop a novel biosurfactant capable of enhancing methane hydrate formation. Oleic acid-based promoter (OAP) significantly improved kinetics of methane hydrate formation, and enhanced growth of hydrate crystals. A maximum conversion of 81 % and storage capacity of ∼151 v/v were achieved in a solution containing 1000 ppm OAP at 9 MPa. Additionally, OAP showed good promotion activity at a lower driving force (7 MPa), resulting in conversion and storage capacity 4.2 times greater than pure water. Moreover, molecular dynamics simulations revealed that the primary mechanism action of OAP is to increase the solubility of methane in an aqueous solution by forming promoter micelles. A gas release simulation for sodium dodecyl sulfate (SDS) solution generated significant foam, whereas no foam formed when OAP was present. The obtained findings are useful for developing efficient biosurfactants based on vegetable oils and can shed light on the promotion mechanism of promoters.

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.

Amino acid-assisted effect on hydrate-based CO2 storage in porous media with brine.

CO2 storage as hydrates in porous media is a promising method for storing carbon dioxide (CO2). However, the sluggish formation kinetics of hydrates urge the need to focus on the use of additives (promoters) to accelerate hydrate kinetics. This study investigates the effect of amino acid solutions in brine on CO2 hydrate formation and dissociation kinetics in quartz sand particles QS-2 (0.6-0.8 mm) with 38% porosity. The amino acids l-methionine (l-meth), l-isoleucine (l-iso), and l-threonine (l-threo) were studied at 0.2 wt% using an autoclave hydrate reactor at 4 MPa and 274.15 K in the presence and absence of salt (3.3 wt% NaCl) in 100% water saturation. The hydrate dissociation kinetics was studied at a temperature of 277.15 K. These conditions represent the normal seabed temperature range in Malaysia and hence were used for testing CO2 hydrate formation and dissociation kinetics in quartz sand in this study. Further, CO2 hydrate formation and dissociation experiments were conducted with sodium dodecyl sulphate (SDS) and brine systems as standards for comparison. The findings reveal the best kinetics for l-meth exhibiting the highest CO2 hydrate storage capacity. l-meth recorded a gas-to-hydrate conversion ratio of about 93% at 0.2 wt% in quartz sand with brine. Moreover, l-meth exhibited the lowest hydrate dissociation rate compared to l-iso and l-threo systems, thereby enhancing CO2 hydrate stability in quartz sand. Comparatively, l-meth enhanced the storage capacity by 36% and reduced the induction time by more than 50% compared to conventional promoter SDS in quartz sand with brine, suggesting it to be favorable for CO2 storage applications. CO2 hydrate nucleation time was predicted in quartz sand with and without the best-studied amino acid l-meth system with high prediction accuracy and an absolute average deviation of 2.4 hours. The findings of this study substantiate the influence of amino acids in promoting the storage capacity of CO2 in sediments as hydrates.

Kinetic promotion of gas hydrate formations using dispersions

CO2 hydrate has promising applications like carbon capture and storage (CCS). However, the slow formation kinetics hinders these large-scale applications. Dry water, a water-in-gas dispersion stabilized by a Pickering agent (usually partially hydrophobized silica nanoparticles) has been used to enhance CO2 hydrate formation kinetics by massively increasing the water – gas interfacial area for a given volume of water. We investigated CO2 hydrate nucleation and crystal growth kinetics in dry water in the presence of sodium dodecyl sulfate (SDS) and seven water-insoluble nucleation promoters. Doping a small amount of nucleation promoters did not ruin the stability of dry water or weaken the promoting effect of dry water on CO2 hydrate nucleation kinetics. Dispersing water in CO2 as dry water promoted hydrate nucleation kinetics and doping of the additives promoted hydrate crystal growth kinetics. This synergistic effect could be utilized to store more CO2 in a hydrate form at a faster rate.

Promotion Effects of Hydrophobic Amino Acids on CO2 Hydrate Formation Kinetics under Isochoric/Isobaric and Stirred/Nonstirred Conditions

Promotion Effects of Hydrophobic Amino Acids on CO₂ Hydrate Formation Kinetics under Isochoric/Isobaric and Stirred/Nonstirred Conditions

Kinetics of methane hydrate formation from stirred aqueous NaCl solutions

We experimentally studied the kinetics of methane hydrate formation from stirred aqueous NaCl solutions. The studies were carried out with pure water and aqueous solutions in which the mass fractions of NaCl were 0.2%, 0.5%, 1.5%, 3.0%, 5.0%, and 7.0%. In all our kinetic experiments, there was the same initial mass of liquid water, a similar temperature, and a similar driving force for gas hydrate formation in terms of pressure. Under these conditions, the values of the rate of change in the mass of liquid water during the initial stage of methane hydrate formation from stirred aqueous NaCl solutions were determined. It has been found that if the mass fraction of NaCl in an aqueous solution is less than 1.0%, then methane hydrate is formed more rapidly from this solution compared to pure water, and if the mass fraction of NaCl in an aqueous solution is greater than 1.0%, then methane hydrate is formed more slowly from this solution compared to pure water. It has also been found that the presence of NaCl in an aqueous solution has little effect on the kinetics of methane hydrate formation from this solution. Additionally, we experimentally determined the phase equilibrium points for methane hydrate in the pure water–methane and 3.0 wt% NaCl solution–methane systems.