Rapid formation of methane hydrate in environment-friendly leucine-based complex systems

Qin, Yue; Shang, Liyan; Lv, Zhenbo; Liu, Zhiming; He, Jianyu; Li, Xu

doi:10.1016/j.energy.2022.124214

Cited by 29 publications

(22 citation statements)

References 65 publications

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“…A large number of hydrate clusters exist in the liquid phase; thus, the macroscopic phenomenon of the solution becoming turbid was observed. A similar phenomenon was also observed in the study of Qin et al 32 At the same time, a large number of hydrate clusters in the 0.1 wt % NaCl system help large-scale hydrate growth in the liquid phase, so a high-speed hydrate reaction occurs in the growth stage. A high concentration (5 wt %) of EG molecules formed hydrogen bonds with water molecules through hydroxyl groups, which prevented water molecules from forming hydrate crystal structures.…”

Section: Kinetic Comparison Of Nacl and Eg In Sds Systemsupporting

confidence: 83%

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Effects of Low Concentrations of NaCl and EG on Hydrate Formation Kinetics and Morphology in the Presence of SDS

Bai

Shang³

et al. 2022

Energy Fuels

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The research on gas hydrates can be divided into two subfields: risk prevention and control of pipeline blockage by hydrates and industrial applications of solidified natural gas (SNG) in gas storage and transportation, seawater desalination, and gas recovery. The two opposing properties of hydrates have stimulated research into promoting and inhibiting methods. A considerable number of studies have reported that the same type of additive can play a promoting or inhibiting effect at different concentrations. This study evaluated the kinetic effects of low concentrations of ethylene glycol (EG) and sodium chloride (NaCl) on methane hydrate production in sodium dodecyl sulfate (SDS) solution. The results showed that both NaCl and EG had kinetic inhibitory effects on the hydrate reaction in SDS solution, and the inhibitory effects gradually increased with the increase of the concentration. Among them, the inhibitory effect of NaCl was stronger than that of EG at the same content. 5 wt % NaCl can reduce the reaction rate of hydrate in SDS solution by 81%, but 0.1 wt % NaCl helped SDS to act on hydrate growth, and the rate of hydrate growth stage was increased by 100%. When 0.1 wt % NaCl or 5 wt % EG existed in the SDS solution, the hydrate mainly grew in the bulk solution and on the inner wall surface of the container, forming a peak-like structure below the interface, and 5 wt % EG also formed a ridge-like structure above the interface. Exploring the macroscopic formation characteristics of hydrate is helpful to industrial process optimization and predicting the additive concentration in the pipeline. This work emphasizes that the selection of substances can be broadened and the rational use of resources can be achieved as much as possible when selecting promoters that are conducive to hydrate formation kinetics or inhibitors that control hydrate growth.

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Section: Kinetic Comparison Of Nacl and Eg In Sds Systemsupporting

confidence: 83%

“…But at lower pressures, the hydrate appears cottony. Qin et al 32 combined NaCl and leucine to promote the formation of hydrates. During the experiment, they found that a large number of dendritic hydrates and hill-like hydrates that appeared in the early stage of the reaction were formed.…”

Section: Introductionmentioning

confidence: 99%

Effects of Low Concentrations of NaCl and EG on Hydrate Formation Kinetics and Morphology in the Presence of SDS

Bai

Shang³

et al. 2022

Energy Fuels

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“…The storage and transportation of NG in the form of gas hydrates have received much attention as promising alternatives in recent years. − Gas hydrates are ice-like materials that form in the presence of water and gas molecules, such as methane, carbon dioxide, ethane, and propane at suitable temperature and pressure conditions. − These compounds can be used as an efficient medium for gas storage as they can accumulate approximately 170 m 3 of gas inside their cavities. − Additionally, they have a high potential for gas separation, CO 2 capture, and desalination applications. − This is an environmentally friendly and safe method because gas hydrates are not explosive as they are mainly composed of gas and water molecules. , Moreover, mild temperature and pressure conditions are required to form gas hydrates, and the gas can be easily extracted from the gas hydrate by reducing pressure or heating. , Furthermore, hydrate formation and dissociation cycles allow gases to be separated. , …”

Section: Introductionmentioning

confidence: 99%

Sulfonated Castor Oil as an Efficient Biosurfactant for Improving Methane Storage in Clathrate Hydrates

Farhadian

Stoporev

Varfolomeev

et al. 2022

ACS Sustainable Chem. Eng.

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High toxicity and huge foaming are two severe challenges for gas storage strategies based on promoting the gas hydrate formation using surfactants. The present study used castor oil as an eco-friendly resource to develop novel biosurfactants for methane storage. Transmission and scanning electron microscopy, dynamic light scattering, and interfacial tension measurements revealed the surfactant properties of sulfonated castor oil (SCO). In addition, a high-pressure autoclave and a microdifferential scanning calorimeter test unveiled SCO as an effective kinetic hydrate promoter. The results showed that SCO significantly enhanced the rate of methane hydrate formation. A maximum of 76% water-tohydrate conversion was observed in 0.1 wt % SCO solution under stirring conditions. Pure water, 0.1 wt % SCO, and 0.1 wt % sodium dodecyl sulfate (SDS) solutions allowed 50% conversion to be achieved for 329, 39, and 27 min, respectively. This made the castor oil-based reagent as effective as the well-known kinetic hydrate promoter SDS. Furthermore, the SCO solution's foam ratio and stability were 8.25 and 2.75 times lower than those of SDS. Additionally, SCO showed a more favorable safety profile for humans and the environment as it is toxic to animals in higher concentrations than SDS according to in vivo studies. In addition, a combination of high-pressure DSC, low-temperature powder Xray diffractometry, and visual analysis of hydrate samples depending on the temperature mode, promoter type, and its concentration revealed that SCO and SDS enhanced hydrate growth by different mechanisms. The loose hydrate mass was squeezed out toward the gas phase in both cases. However, in the case of SDS, the hydrate traditionally climbed the cell walls while SCO seemed to change the wall wettability, which led to the transfer of water into the reaction zone along with the forming hydrate crystals and the domed shape of the hydrate. These findings provide reliable evidence to synthesize efficient and environmentally friendly reagents based on castor oil to improve methane storage in the clathrate hydrate.

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“…Surfactant molecules are composed of hydrophilic and hydrophobic groups. In the solution, the surfactant molecules tend to aggregate around the gas–liquid interface and reduce the surface tension, thus facilitating the dissolution of the gas into the liquid phase. , Therefore, the surfactants can be used as a kinetic promoter to accelerate the hydrate generation in hydrate-based storage and transportation technologies, of which sodium dodecyl sulfate (SDS) is representative of these hydrate promoters. , However, some stationary experiments have also indicated that the presence of the surfactants can also prevent the aggregation of hydrates and change the morphology of the hydrate formation. , Meshram et al considered that the modification of hydrate morphology by surfactants such as SDS is critical to ensure the flow in the pipeline, because in the system without surfactants, hydrates form a stable structure, which is not conducive to the flow assurance. In addition, the experiments of Oignet et al showed that SDS can also effectively reduce the viscosity and enhance the flowability of hydrate slurry.…”

Section: Introductionmentioning

confidence: 99%

“…23,24 Therefore, the surfactants can be used as a kinetic promoter to accelerate the hydrate generation in hydratebased storage and transportation technologies, of which sodium dodecyl sulfate (SDS) is representative of these hydrate promoters. 25,26 However, some stationary experiments have also indicated that the presence of the surfactants can also prevent the aggregation of hydrates and change the morphology of the hydrate formation. 27, 28 Meshram et al 29 considered that the modification of hydrate morphology by surfactants such as SDS is critical to ensure the flow in the pipeline, because in the system without surfactants, hydrates form a stable structure, which is not conducive to the flow assurance.…”

Section: Introductionmentioning

confidence: 99%

Effect of SDS on the Formation and Blockage Characteristics of the CH₄ Hydrate in a Flow Loop

Zang

Huang

et al. 2022

Ind. Eng. Chem. Res.

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Hydrate is easily formed in deep-sea pipelines and brings serious flow assurance problems, so it is necessary to look for appropriate hydrate control strategies. In this work, the effects of the anionic surfactant sodium dodecyl sulfate (SDS) on hydrate growth and flow characteristics in the methane−water system were investigated under horizontal and tilted conditions using a highpressure flow loop, and the growth and plugging rules of hydrates in the SDS solution and the effects of different flow rates and tilt angles on hydrate induction time and plugging time were obtained. The experimental results show that hydrates can be easily deposited on the tube wall in the freshwater system. After the addition of SDS, the hydrate can hardly deposit on the wall, allowing the hydrate slurry to flow stably for a long time and a higher volume fraction. The volume fraction of hydrates in the freshwater system is plugged at less than 15%, while in the SDS solution, hydrate slurry can flow steadily for a longer time at more than 30% volume fraction. Although increasing the flow rate reduces the hydrate induction time, the plugging time is significantly prolonged. With the increase in the inclination angle of the loop, hydrate particles with larger particle sizes are more likely to appear, and the time until blockage is decreased. The flow rate in the loop decreases with increasing hydrate particle size. The sensitivity analysis of different influence factors was carried out by the linear regression coefficient method, and the initial flow rate has the most influence on the hydrate induction time, followed by the initial pressure, and the inclination angle has the least influence. This work provides insights into the flow characteristics of the hydrate in the SDS solution, which facilitates the flow assurance studies of hydrates in the gas−water system.

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Rapid formation of methane hydrate in environment-friendly leucine-based complex systems

Cited by 29 publications

References 65 publications

Effects of Low Concentrations of NaCl and EG on Hydrate Formation Kinetics and Morphology in the Presence of SDS

Effects of Low Concentrations of NaCl and EG on Hydrate Formation Kinetics and Morphology in the Presence of SDS

Sulfonated Castor Oil as an Efficient Biosurfactant for Improving Methane Storage in Clathrate Hydrates

Effect of SDS on the Formation and Blockage Characteristics of the CH₄ Hydrate in a Flow Loop

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Rapid formation of methane hydrate in environment-friendly leucine-based complex systems

Cited by 29 publications

References 65 publications

Effects of Low Concentrations of NaCl and EG on Hydrate Formation Kinetics and Morphology in the Presence of SDS

Effects of Low Concentrations of NaCl and EG on Hydrate Formation Kinetics and Morphology in the Presence of SDS

Sulfonated Castor Oil as an Efficient Biosurfactant for Improving Methane Storage in Clathrate Hydrates

Effect of SDS on the Formation and Blockage Characteristics of the CH4 Hydrate in a Flow Loop

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Effect of SDS on the Formation and Blockage Characteristics of the CH₄ Hydrate in a Flow Loop