Hydrate Film Research Articles

Carbon Dioxide Hydrate Formation in Porous Media Under Dynamic Conditions for CO2 Storage in Low-Temperature Water Zones

Injecting carbon dioxide (CO2) into subsea water zones, where the in situ temperatures are below the hydrate-forming temperature of CO2, has been recently proposed to lock CO2 inside the water zones in a solid hydrate form. It is a common concern that CO2 may form hydrates during the injection period, which would reduce well injectivity. CO2 injection into sandstone cores under simulated subsea temperatures ranging from 0 °C to 5 °C was investigated in this study. Experimental results show that flowing CO2 at Darcy velocity 0.033 cm/s begins to form hydrate in the sandstone core at dynamic pressures higher than the minimum required pressure under static conditions. At temperatures changing from 0 °C to 5 °C, the observed hydrate-forming pressure changes from 1.87 to 2.5 times the pressures required for CO2 hydrates under static conditions. The reason why the required minimum pressure for CO2 to form hydrates in dynamic conditions is higher than that in static conditions is attributed to the shear rate effect of flowing fluids that should slow down the growth of hydrate crystals and/or break down formed hydrate films in the dynamic conditions. Therefore, higher pressure energy, or fugacity, is required to promote the growth of hydrate crystals and hydrate films in dynamic conditions. More rigorous investigations in this area are needed in the future.

Insights into the carbonate/bicarbonate ion-induced failure mechanism of bentonite in drilling fluids

During deep oil and gas drilling, drilling fluids are often polluted with carbon dioxide (CO2). The intrusion of CO2 can affect bentonite performance, leading to deterioration or even failure of drilling fluids. To further investigate the influence of CO2 pollution on the bentonite and its failure mechanism, Na2CO3 simulation experiments were conducted. Performance evaluation showed that as the concentration of HCO3− and CO32− increased, the viscosity, filtration loss, and mud cake permeability of drilling fluids significantly increased. Meanwhile, the drilling fluid foaming was particularly evident. Mechanism studies indicated that the adsorption of HCO3− and CO32− on the bentonite diminished the electrostatic interactions and interlayer spacing between particles, leading to the particles aggregation and a decrease in Zeta potential, ultimately causing the hydration film on the bentonite to become thinner. Simultaneously, this also led to a decline in the dispersibility of bentonite. This study can offer a new research thread for the failure mechanism of bentonite under CO2 pollution and indicate the direction for the study of drilling fluid resistance to acidic gas pollution.

Carbon dioxide hydrate formation in porous media under dynamic conditions

AbstractInjecting carbon dioxide (CO2) into subsea water zones where the in situ temperatures are below the hydrate‐forming temperature of CO2 has been recently proposed to lock CO2 inside the water zones in solid hydrate form. It is a common concern that CO2 may form hydrates during the injection period that will reduce well injectivity. CO2 injection into sandstone cores under simulated subsea temperatures of 2°C and 3°C was investigated in this study. Experimental result shows that, at 2°C temperature, flowing CO2 at Darcy velocity 0.033 cm/s begins to form hydrate in the sandstone core at about 3.06 MPa (450 psi), which is much higher than the minimum required pressure of 1.5 MPa (220 psi) for CO2 to form hydrate in static condition. The pressure ratio is 450/220 = 2.05. At 3°C temperature, flowing CO2 at Darcy velocity 0.045 cm/s begins to form hydrate in sandstone core at about 3.67 MPa (540 psi), which is much higher than the minimum required pressure of 1.87 MPa (275 psi) for CO2 to form hydrate in static conditions. The pressure ratio is 540/275 = 1.96. The reason why the required minimum pressure for CO2 to form hydrates in dynamic conditions is about double the required hydrate‐forming pressure in static conditions is not fully understood. It is speculated that the shear rate effect of flowing fluids should slow down the growth of hydrate crystals or break down hydrate films, resulting in delayed formation of bulk CO2 hydrates. More investigations in this area are needed in the future.

Innovative discovery on the impact of hydration on the alternative flotation of smithsonite and calcite under benzohydroxamic acid system

Currently, it is still lacking of deep understanding of the alternative of benzohydroxamic acid (BHA) on smithsonite and calcite flotation. We hypothesize that the presence of hydration films plays a significant role. Therefore, this paper aims to uncover the impact of hydration on the alternative flotation of smithsonite and calcite with BHA, utilizing flotation experiments, DFT calculations, Zeta potential tests, FTIR measurements, and XPS analyses. The results of the flotation experiments confirmed the effective separation of smithsonite from calcite with BHA. DFT calculations innovatively discovered that Zn on the surface of smithsonite can interact with BHA− but the Ca on the surface of calcite was easier to interact with the H2O instead of BHA−, thus BHA was incapable of repelling the hydrated layer from the surface of calcite to interact with the calcium ions. Zeta potential tests, FTIR measurements, and XPS analyses further provided experimental support that BHA was selectively chemically adsorbed onto the surface of smithsonite via forming Zn-BHA complex, whereas no such interaction occurred with the surface of calcite by generating Ca-BHA complex, which validated the DFT calculation results. This study provides valuable insights into the role of hydration in the beneficiation of smithsonite and calcite.

Effect of Fe3+ doping on the electronic structure and surface hydration properties of quartz

In this study, the effects of Fe3+ doping on the crystal structure and surface properties of quartz were analyzed using density functional theory (DFT) calculations and molecular dynamics (MD) simulations. The crystal structure, surface model, and adsorption model of the water molecule layer for Fe3+-doped α-quartz were established. The DFT calculations reveal that Fe3+ doping affects the α-quartz lattice parameters and surface active sites. The adsorption energy near the sites occupied by Fe3+ is −66.20 kJ/mol, which is considerably lower than that of the undoped system (−42.35 kJ/mol). This makes it easier for water molecules to be adsorbed on the Fe3+-doped α-quartz (001) surface. The frontier orbital energy, electron density difference, charge density, and Mulliken bond population analyses indicate that the presence of Fe3+ improves the ability of the (001) surface of α-quartz to attract and bind water molecules. This improvement is mainly due to the formation of hydrogen bonds between the surface hydroxyl groups and water molecules on the surface of Fe3+-doped quartz and the equilibrium of the electrostatic interaction between the cation and water molecules. MD simulations show that a hydration layer with a thickness of approximately 8 Å is formed on the surface of Fe3+-doped α-quartz. Compared with the undoped system, the hydration film on the surface of the doped system is thicker, indicating that the incorporation of Fe3+ impurities in the lattice enhances the surface hydration characteristics of quartz. These results offer theoretical guidance for achieving efficient separation and thorough purification of quartz.

Reduction in the growth rate of a hydrate film at the interface of liquid CO2 and an aqueous solution of humic acids in comparison with that with pure water and sodium dodecyl sulfate solution

The rates of growth of a hydrate film on the contact surface of an aqueous phase and liquid carbon dioxide were studied. In 0.1% solutions of humic acids, the film growth rate was lower by a factor of approximately 4 than that in pure water and a 0.1% solution of sodium dodecyl sulfate. Possible reasons for the decrease in growth rates are briefly discussed.

Highly efficient phosphate adsorption using calcium silicate hydrate-embedded calcium crosslinked polyvinyl alcohol thin film

The removal of phosphate from water is necessary to avoid eutrophication. In this work, a novel composite film of calcium silicate hydrate (CSH) immobilized within calcium cross-linked polyvinyl alcohol (CSH–PVA) was developed for efficient phosphate removal from water using a simple and environmentally friendly preparation method. The characterization showed that flake crystal-like CSH nanoparticles were immobilized on a PVA film (86–106 μm). Amorphous calcium phosphate and hydroxyapatite were observed after phosphate adsorption. The adsorption efficiency and capability of phosphate were examined under various conditions using batch experiments. The phosphate removal data fitted well to the pseudo-second-order kinetic model (R2 = 0.9903–0.9999) and the Langmuir isotherm model (R2 = 0.9958), which estimated a maximum removal capacity (99.01 mg g−1). Phosphate adsorption was found to be endothermic with spontaneous adsorption via chemisorption with strong affinity (ΔG° = −3.96 to −8.62 kJ mol−1, ΔH° = 65.4 kJ mol−1, and ΔS° = 232.94 J mol−1 K−1). Additionally, significant amounts of fluoride and carbonate ions affected phosphate adsorption at levels exceeding 5-fold and 20-fold that of phosphate, respectively. An excellent removal efficiency was achieved in the range of 72.06%–97.87% using phosphate-containing real samples. Therefore, the proposed CSH–PVA film showed great potential for effective phosphate removal from water, with potential for further use as a fertilizer.

Enhancement of interaction between Shenhua coal and GON-based dispersant with “surface-to-surface” adsorption by regulating the oxidation degree of GON: Experiments and simulations

The present study focuses on the synthesis of several graphene oxide nanosheet (GON)-based dispersants with an adsorption mode of “surface-to-surface” for the preparation of Shenhua coal (SC) water slurry (SCWS), achieved by grafting allyl polyoxyethylene ether (APEG) onto GON edges with varying degrees of oxidation using emulsion polymerization and esterification techniques. The impacts of the oxidation degree of GON on its structural characteristics and the performance of GON-based dispersants in SCWS were comprehensively assessed through a range of experimental techniques, alongside molecular dynamics (MD) simulations. Results demonstrated that with the increase in oxidation degree, there was an elevation of oxygen-containing groups, in which the content of COH decreased while the content of COC increased. Among all dispersants, GA-2, which was synthesized using GON-2 as the raw material with a graphite-to-KMnO4 mass ratio of 1:2.5, exhibited superior viscosity-reducing and stabilizing abilities compared to other dispersants. All SCWSs demonstrated pseudoplastic fluid behavior and showed good agreement with the Herschel-Bulkley model. After the adsorption of dispersants in SC, both the Zeta potential and surface wettability of SC significantly improved, especially with GA-2. The interaction mechanism between the dispersant and SC was analyzed by establishing and employing three adsorption models (M-1, M-2, and M-3). The interfacial adsorption structure confirmed that the dispersant exhibited “surface-to-surface” mode on coal through hydrophobic interaction, hydrogen bonding, and π–π interaction. Energy studies revealed that M-2 with the highest Eads (−105.31 kcal/mol) demonstrated superior adsorption strength compared to M-1 and M-3. Investigations into water molecule mobility revealed that the interaction between the GON-based dispersant and SC resulted in a reduction of water molecule mobility, thereby promoting water molecule aggregation to facilitate the formation of hydration films and enhance SCWS stability. In summary, an optimal oxidation degree of GON was found to be crucial for enhancing the performance of GON-based dispersants; higher oxidation levels may hinder dispersant adsorption on coal surfaces by converting hydroxyl and carboxyl groups into epoxide groups, thus impairing the conjugated structure.

High efficiency filtration and optimization of pelletizing performance of fine hematite concentrate using sulfuric acid filter aid: Behavior and mechanism

Following the application of anionic reverse flotation to fine low-grade hematite ore, a significant challenge emerges with elevated slurry viscosity and heightened moisture content in the resulting filter cakes. To address the challenge of dewatering during the filtration process of fine hematite concentrate, the impact of sulfuric acid filter aid dosage and filtration temperature on the filtration performance of hematite concentrate was systematically investigated in this study. In addition, the effect of sulfuric acid filter aid on the preparation of hematite pellets was also studied. The results revealed a significant decrease from 1.10 × 1010 1/m2 to 5.7 × 109 1/m2 in the specific resistance of the hematite filter cake when the sulfuric acid dosage was 1.2 g/kg and the filtration temperature was 20 °C. The mechanism underlying the enhancement of filtration performance of fine hematite concentrate by sulfuric acid was summarized. Sulfuric acid compressed the double electric layer on the surface of hematite concentrate particles, reducing the surface zeta potential and causing the aggregation of fine particles into larger ones. This led to an increase in filter cake porosity and compression of the hydration film thickness on particle surfaces, facilitating easier removal of filtrate from the filter cake. The appropriate dosage of bentonite for pelletizing was not significantly affected by sulfuric acid filter aid. Sulfuric acid improved the porosity, drying rate, and burst temperature of hematite green pellets. While the compressive strength of preheated pellets from sulfuric acid-assisted filtration of hematite concentrate showed a slight decrease, the compressive strength of roasted pellets was significantly increased.

Influence of Ca2+ substitution on the surface hydration characteristics of kaolinite: Combination of simulations and experiments

To investigate the changes in kaolinite surface hydration characteristics after Ca2+ substitution, water molecule adsorption onto the surface of Ca2+-substituted kaolinite was studied using density functional theory. Changes in the hydration film on the surface of kaolinite (001) and the mineral surface hydrophilicity after Ca2+ substitution were studied using molecular dynamics methods. Several Ca2+-substituted kaolinite samples were hydrothermally synthesized, and their hydration characteristics were analyzed using contact-angle and microcantilever humidity-test methods. The energy of a water molecule adsorbed on a Ca2+-substituted kaolinite surface is > 5 % lower than on pure kaolinite, and microscopic interactions between water molecules and the kaolinite surface are enhanced. Further, water molecules are more likely to be adsorbed onto the (001) surface than the (001¯) surface of kaolinite. After Ca2+ substitution, the hydration film on the kaolinite (001) surface becomes denser and the hydrophilicity of the mineral surface is enhanced. Using X-ray diffraction, Fourier-transform infrared spectroscopy, and X-ray photoelectron spectroscopy to characterize the synthesized samples, we confirmed successful Ca2+ substitution within the kaolinite structure. Hydration-test results showed that the surface hydrophilicity of kaolinite is enhanced after Ca2+ substitution and increases with increasing Ca2+ substitution. The experimental results thus verified the simulations.

Leaching process assisted by cetyltrimethylammonium chloride for weathered crust elution-deposited rare earth ores: Leaching behavior, kinetic analysis and interfacial regulation

Magnesium salts are commonly employed as ammonium-free leaching agents in the extraction of weathered crust elution-deposited rare earth ores (WCE-REO). Nonetheless, these salts frequently face technical challenges, including relatively low leaching rates and inadequate permeability in the in-situ leaching process. In this study, cetyltrimethylammonium chloride (CTAC) was used as a novel leaching aid agent to improve the rare earth leaching process. The effects of CTAC and pH on the rare earth leaching behavior and permeability was investigated. The leaching kinetic model was established and the regulation mechanism by which CTAC interacts with clay mineral surfaces was revealed for rare earth leaching process enhanced by CTAC. The results indicate that the appropriate amount of CTAC can increase the permeation velocity by 1.16×10−4 cm·s−1. Moreover, the rare earth leaching rate increased from 83.75 % to 95.65 %, accompanied by a reduction in leaching equilibrium time under optimal conditions. However, a higher concentration of CTAC results in a lower permeation velocity due to the increasing viscosity and the hydrophilicity. The relatively low pH will affect permeability of composite leaching agent in the ore pillar, diminishing its beneficial impact on rare earth leaching. The kinetic equation, fitted by the shrinking core model, suggests that the leaching adheres to an internal diffusion control mechanism, underscoring mass transfer as the pivotal limiting factor in rare earth leaching. CTAC reduces surface tension and viscosity, facilitating the permeation of the leaching solution into the rare earth ore. Furthermore, CTAC can be adsorbed on the surface of rare earth mineral particles, increasing the contact angle of clay minerals, elevating the Zeta potential, and diminishing the thickness of the diffusion layer, thus promoting mass transfer during leaching. The results of atomic force microscopy (AFM) analysis shows that the appropriate amount of CTAC adsorbed on rare earth ores can decreases the thickness of the hydration film on the particles’ surface, further improving the mass transfer efficiency during the leaching process. The findings of this study offer new insights into the green and efficient extraction of rare earth resources from both theoretical and technical perspectives.

Investigation of methane gas bubble dynamics and hydrate film growth during hydrate formation using 4-D time-lapse synchrotron X-ray computed tomography

Investigation of methane gas bubble dynamics and hydrate film growth during hydrate formation using 4-D time-lapse synchrotron X-ray computed tomography

Influence of Hydration Film on the Frictional Behavior of Montmorillonite: Insights into Microscopic Mechanics of Layered Minerals

Influence of Hydration Film on the Frictional Behavior of Montmorillonite: Insights into Microscopic Mechanics of Layered Minerals

Enhanced hydrate formation at the liquid CO2-brine interface with shear flow for solid CO2 sequestration

The hydrate-based CO2 sequestration provides an alternative solution for reducing CO2 emissions. However, the hydrate film that forms preferentially at the CO2-water interface can severely restrict hydrate conversion rate. How to enhance CO2 hydrate formation remains a crucial question. Here, we constructed static and shear flow contact models of liquid CO2 and brine in a cubic cavity and investigated their hydrate growth behavior at different subcoolings from perspectives of morphology and kinetics. For static contact, nucleation usually occurs at the CO2-brine interface, and high subcooling increases the degree of hydrate film wrinkling and the CO2 hydrate formation amount. The shear flow can delay the explosive growth of hydrates and tends to nucleate in bottom water; meanwhile, the continuous flow causes the overall extrusion deformation of hydrate film until the injection hole is blocked. Compared to static contact, this forced CO2-H2O contact caused by film deformation enhanced the CO2 hydration amount by 2.68–3.62 times at the subcoolings of 6.94–3.25 K. Increasing the flow rate can further delay hydrate appearance and enhance hydrate growth. We also speculate on the hydration patterns of CO2 in sediment pores under static and flowing conditions, and think that maintaining long-term flow can be an effective means to improve CO2 hydrate storage and prevent blockage occurring in the pore throat. Our work provides new insights into the growth behavior of CO2 hydrate for future CO2 storage in submarine sediments.

Revealing the kinetic behaviors of hydrate formation on bubble surface with different pressure gradients in deep-sea methane seepage areas of the South China Sea

In the deep-sea methane seepage environment, hydrate formation on the methane bubbles is a crucial pathway for methane transformation, and plays an important role in determining whether seepage methane can enter the surface ocean. While how the pressure determines the hydrate formation process in different water depths remains unclear. In this study, we investigated the formation kinetic characteristics and microstructure evolution of methane hydrate on suspended gas bubbles within varied pressure conditions. The pressure range (4–14 MPa) was in the deep-sea methane seepage environment. The results indicated that pressure obviously affected the hydrate film formation characteristics. As pressure increased, the lateral growth rate of the hydrate film accelerated, the hydrate crystal particles became smaller, and the initial hydrate film surface became smoother. Raman spectroscopy results showed that pressure changes did not obviously alter the microporous evolution on the hydrate film surface, that the gas-phase/water-phase Raman peak area ratio exhibited similar trends. The dissolved methane concentration under different pressure conditions was not the primary factor affecting hydrate thickening, rather, it depended mainly on the driving force. This study is of great significance in revealing the characteristics of methane hydrate formation and methane transfer in the oceanic methane seepage environment.

The morphology of liquid CO2 hydrate films at different temperatures under saturation pressure

CO2 hydrate film formed on the surface of water droplets in liquid CO2 was studied via digital microscope system and in situ Raman spectrometer. Temperature significantly affects the initial morphology and lateral growth rate of hydrate film. In the temperature range of 273.15–279.15 K under corresponding saturation pressure of liquid CO2, the growth and development process is primarily separated into three stages, that is, rapid lateral growth, rapid thickening, and slow development. However, in the temperature range of 280.15–282.15 K, the growth and evolution of hydrated film is dominated by rapid lateral growth and slow development processes, while the rapid thickening disappears on our experimental scale, caused by the decrease in the driving force. Each of these two temperature ranges has unique characteristics and interesting discoveries during the hydrate film formation and development. For hydrate film formed at 283.15 K, the formation of hydrate is very difficult. It needs to nucleate inside the droplet with the assistance of the hydrate crystal seeds remaining in the water droplet after decomposition, so that the small hydrate crystals can grow in the water phase, and as the crystals get larger, they will eventually emerge on the droplet’s surface and produce a complete hydrate film. Combining the experimental phenomena during the growth and development of hydrate films at various temperatures, the further growth of the hydrate phase during the generation process mainly depends on the mass transfer process of water molecules through the hydrate film. This work provides valuable information on the mechanism of nucleation, growth and decomposition of liquid CO2 hydrate crystals, which is of great significance for applications in seafloor CO2 gas sequestration.

Investigation on methane hydrate formation behaviors in deep-sea methane seepage environments

Deep-sea cold seep is a natural phenomenon where methane leaks from the sea floor. Methane can be partially conversed through physical, chemical, and biological processes, but the excess methane that remains uncaptured escapes into the atmosphere and contributes to the greenhouse effect. Physical carbon sequestration via hydrate formation is a fast and high-energy density type of carbon sequestration; however, it has been largely overlooked. This study investigated hydrate formation in authigenic carbonate rocks through deep-sea geological surveys in cold seeps in the South China Sea. Investigations have shown that authigenic carbonate rocks can sequester carbon by blocking the methane plume from the seepage vents. This perspective provides a new physical carbon sequestration mode of carbonate rocks by observing the artificial collection of methane plumes in deep-sea seepage areas. The mode was simplified into two steps including the formation of a thin layer of planar hydrate film on carbonate rocks and a thick layer of hydrate through the stacking of bubbles under the thin film. Salinity, a key distinction between seawater and freshwater, was further investigated for its impact on the carbon sequestration mechanism. Results showed that saline ions in seawater had little impact on the thickening rate of the planar hydrate film but reduced the lateral growth rate of hydrates on the bubble by 60%. This reduction in the lateral growth rate greatly facilitated the three-dimensional growth, increased the hydrate thickness on the bubble, and improved the carbon sequestration efficiency. Hydrate formation on the exposed carbonate rock can effectively impede methane plume migration into upper water and atmosphere, mitigate the greenhouse effect, and present a promising strategy for carbon sequestration in deep-sea methane seepage areas.

Teneligliptin hydrobromide hydrate mouth dissolving strip: Formulation and evaluation

Oral route is considered as one of the most convenient route for administration of various pharmaceutical dosage form like tablet, capsule, syrup, suspension and emulsion. Fast Dissolving Drug Delivery systems have developed various fast disintegrating preparations like Oral disintegrating film, ODF. Oral disintegrating film is the solid oral drug delivery system, in which water soluble polymer involve to disintegrate film into mouth fastly. Oral disintegrating film is superior as compare to orally disintegrating tablet as the cost of production is low. The present research was undertaken to develop oral disintegrating film of tteneligliptin hydrobromide hydrate to have rapid onset of action. of tteneligliptin hydrobromide hydrate which is an anti-diabetic. The mechanism action of Teneligliptin is to increase incretin levels (GLP-1 and GIP), which inhibit glucagon release, which in turn increases insulin secretion, decreases gastric emptying, and decreases blood glucose levels.The concept of formulating fast disintegrating film Teneligliptin containing offers a suitable and practical approach in serving desired objective of faster disintegration and dissolution characteristics with increased bioavailability. ODF of Teneligliptin were prepared by solvent casting method and evaluated physicochemical parameters like thickness, weight variation, moisture content, folding endurance, drug content, etc. All the formulations of Teneligliptin ODF displayed optimum folding endurance, which indicates the formulation prepared can withstand handling and transportation. From the results obtained, it was concluded that the formulation of oral disintegrating film has better physical chemical properties with good disintegration property.

The effect of various crystalline forms of HFC 134a hydrate on the growth rate and desalination efficiency

Experimental studies on the synthesis of HFC 134a hydrate in the liquid HFC 134a – water system were performed. Despite today's lack of research on the use of HFC 134a hydrate for desalination of seawater and separation of harmful impurities by HFC 134a hydrate synthesis, this method has prospects for development: HFC 134a hydrate is synthesized at relatively high temperature and low pressure; it is poorly soluble in water, which simplifies gas hydrate separation from water–salt solution; it has high volumetric storage density and relatively high thermal conductivity. In spite of its low solubility in water, HFC hydrate exhibits relatively high growth rates. The growth of various crystalline forms and the peculiarities of their occurrence in pure water, aqueous salt solution, as well as with the addition of surfactant are considered. The use of SDS increases the HFC hydrate growth rate. For the first time, it was shown that the intensive growth of HFC 134a hydrate in the form of needles throughout the entire volume of the liquid allows increasing the efficiency of desalination. It is important to consider the desalination process comprehensively, taking into account the crystal forms, crystal growth rate, crystal defects, as well as taking into account the degree of salt removal. Simultaneously with the bubble growth, a thin gas hydrate film is shown to grow on the bubble surface. A detailed consideration of the stages of such hydrate growth is provided to explain the high-speed synthesis of porous HFC hydrate due to boiling of liquid HFC and vaporization.

CO2/H2 Separation by Synergistic Enhanced Hydrate Method with SDS and R134a.

The synergistic effect of thermodynamic promoter tetrafluoroethane (R134a) and kinetic promoter sodium dodecyl sulfate (SDS) can significantly improve the phase equilibrium conditions required for CO2 hydrate formation and promote rapid generation of CO2 hydrate. Based on this, this study investigates the influence of SDS and R134a synergy on the separation of CO2/H2 mixed gas using the hydrate method. The research reveals that without SDS addition, R134a hydrate forms first at the gas-liquid interface before CO2 hydrate induction, hindering gas-liquid exchange. The addition of SDS can inhibit the formation of the hydrate film, enhance the initiator effect of R134a in the CO2 hydrate formation process, accelerate the nucleation of CO2 hydrate, and thus synergistically strengthen the separation of CO2/H2 mixed gases. Hydrate formation can be achieved at a concentration of 100 ppm of SDS solution, and the synergistic growth effect of R134a and CO2 hydrate becomes more significant with increasing SDS concentration. Optimal separation efficiency and maximum H2 concentration are achieved at 500 ppm of SDS, with 42.29 and 54.88% separation efficiency and H2 concentration, respectively. Decreasing the initial charge temperature has little impact on separation efficiency but significantly reduces the induction time, reducing it to 3 min at 12 °C. This study improved the separation efficiency of CO2 and H2 mixed gas, providing a better reference for hydrogen purification by the hydrate method.