Pure Water System Research Articles

A highly water-soluble rhodol-based fluorescent probe for the organic-solvent independent sensing of biological hypochlorous acid

As a vital reactive oxygen species (ROS), endogenous hypochlorous acid (HOCl) deeply engaged in masses of pathophysiological processes owing to its high reactivity, thus the detection of HOCl is awfully valuable for elucidating HOCl-related pathophysiology mechanism. Despite the extensive development of outstanding HOCl fluorescent probes so far, very few of them could be applied for monitoring HOCl in the pure water system. Herein, we present a novel rhodol-based fluorescent probe 6 for the unambiguous detection of HOCl in pure water, which was effectively designed and synthesized by using the spirocyclic hydrazide group as the HOCl sensitive site and introducing two hydroxyethyl groups for obtaining high hydrophilicity into the rhodol skeleton, a unique rhodamine structure. Compared to the control compound 5 without hydrophilic groups only capable to be used in the aqueous system containing organic solvent, 6 achieves the detection of HOCl not only in the above regular system but also in pure water, indicating that the introduction of hydrophilic hydroxyethyl group is an effective and reasonable approach to achieve the broader-spectrum detection of HOCl. More importantly, different with 5, highly water-soluble 6 regardless of dissolving in the regular system or pure water system can achieve the visual monitoring of HOCl with prominent sensitivity and high spatiotemporal resolution in living HepG2 cells and zebrafish, confirming the robust imaging ability of our probe 6 to HOCl in complex biosystem.

Recent Development and Applications of the ABEEM/MM Polarizable Force Field

In this paper, we review both development and applications of the atom-bond electronegativity equalization method fused into molecular mechanics, i.e., ABEEM/MM polarizable force field (FF). We will focus on the applications of the ABEEM/MM in pure water systems, chemical and biomolecular ion-containing systems, small molecules and biomolecules, etc. The results show that the performance of ABEEM/MM is generally better than that of the commonly used nonpolarizable force fields.

Spherical shell CdS@NiO Z-scheme composites for solar-driven overall water splitting and carbon dioxide reduction

Industrial applications of water splitting to produce hydrogen and carbon dioxide reduction to produce high value added products remain significant challenges, owing to the low density of electrons and holes produced by photoexcitation, rapid recombination of photogenerated carriers and sluggish redox reactions. Direct Z scheme photocatalysts have attracted much attention due to their excellent space–photogenerated electron−hole pairs and stronger redox ability. Herein, the core−shell direct Z scheme construct was established by a structure of NiO/Ni coated CdS spherical, finally achieved photocatalytic pure water splitting, simultaneously produced with stoichiometric ratio 2:1 (include 42.5 μmol g−1 h−1 H2 and 20.1 μmol g−1 h−1 O2), AQY (apparent quantum yield) was 1.6% (in pure water system, λ = 420 nm) and STH (Solar to Hydrogen Conversion Efficiency) was 2.1×10−4%. The yield of CO from photocatalytic reduction of carbon dioxide was 36.7 μmol g−1 h−1. Insight into the reaction mechanism provides an initial attempt to reveal the direct Z scheme of NiO@CdS and the Schottky junction of NiO/Ni together to promote the photocatalytic performance. This work can provide a strategy scheme for constructing a bifunctional sphere−shell direct Z scheme catalyst and applying it to photocatalytic overall water splitting and carbon dioxide reduction.

A two-step bioluminescence assay for optimizing antibacterial coating of hollow-fiber membranes with polydopamine in an integrative approach

Pure-water filtration membranes are often fouled by bacterial biofilms. Antibacterial coatings for preventing biofilm formation on such membranes should not rely on leaching of inhibiting compounds but should only be effective on surface contact. Certified assays for antibacterial coatings do not sufficiently exclude leaching effects and involve nutrient-rich cultivation media that do not correspond to conditions in pure-water systems. In this study, a two-step bioluminescence assay was developed for optimizing an antibacterial coating of PES/PVP ultrafiltration hollow-fiber membranes with a polydopamine as a sustainable, bio-inspired material for preventing bacterial biofilm formation. In the first step, leaching of the antimicrobial coating was analyzed by a bioluminescence assay with supernatants generated by washing coated membranes. In the second step, bioluminescence of bacterial biofilms on coated and uncoated membranes was measured using a nutrient-poor medium resembling site-specific conditions. Based on this bioluminescence assay, an optimized protocol for the coating process could be established by acidic polymerization of dopamine using 2 g/L sodium periodate and 4 g/L dopamine at 40 °C for 20 min reaction time. With coatings produced in this way, bioluminescence was reduced on coated membranes only while the corresponding supernatants exhibited no inhibitory effects.

Molecular dynamics simulations of the effects of metal nanoparticles on methane hydrate formation

Understanding the properties of methane hydrate formation is important for the storage and transport of methane in the form of gas hydrates. In this study, nanosecond simulations were performed to investigate the formation of methane hydrates in the presence of Fe, Cu, Ag and their corresponding oxide nanoparticles. The effects of different nanoparticle and nanoparticle concentration on the rate and amount of CH4 hydrate formation were explored. The simulation results show that metal nanoparticles have a mixed effect on the kinetic improvement of methane hydrate generation process, which varies with the type and concentration of metal nanoparticles. Compared to the pure water system, the formation of methane hydrate was promoted to different degrees in the metal nanoparticle system, in the order of nano-Ag > nano-Cu > nano-Fe, which is mainly attributed to the excellent thermal conductivity of the metal itself. For the single metal oxide nanoparticle system, the promotion effect of nano-Ag2O was not obvious, while the promotion effect of nano-CuO was the best, and the promotion degree is in the order of nano-CuO > nano-FeO > nano-Ag2O. For the multiple metal oxide nanoparticle systems, the two nano-FeO system showed faster growth rate and more hydrate cages formed, which was better than the single nano-FeO and nano-Fe systems. The nano-CuO system showed the same results. However, the promotion effect of nano-Ag2O was slightly smaller than that of nano-Ag at the particle size and concentration studied in this work.

Storage capacities of CO2 hydrates in packed silica bed in multiple formation processes

Hydrate-based gas storage is known to be an economical and eco-friendly method. In this work, the growth of CO2 hydrate was repeated 5 times in the silica gels with certain water saturation at an initial pressure of 3.7 MPa, 278.15 K. The influence of sodium dodecyl sulfate (SDS) and water saturation ranging from 30 to 60% on CO2 storage efficiency was measured. Results showed that silica gels with 30% water saturation got the highest CO2 storage capacity with the water conversion of 91% within 24 h and did not have evident decay in repeated tests. The volume ratio of adsorbed CO2 to silica gels was found to decrease from 46 to 19 as the initial water saturation increased from 30 to 60%. In repeated runs, the volume ratio descended evidently in the initial 3 runs. Water film covered on the silica gel particles was assumed to be the major obstacle for hydrate growth. SDS was found to enhance the volume ratio in the silica gel with high water saturations and reduce the decay of volume ratio in repeated test. However, the unexpected long hydrate nucleation period ranging from 5 to 8 h would occur after 3 repeated test. SEM images revealed that the hydrate crystals attached with each other like pomegranate seeds in pure water system, while they changed into flakes which adhere on the silica gel particles. Neither of these morphologies provide a path for CO2 diffusion. Therefore, avoiding the formation water film on silica gel particles and increasing the porosity of the porous particles are the key to improve gas storage efficiency.

Study on the preparation of coal wastewater slurry from salt/alkali wastewater

Combining experimental research and simulation calculation, the effect of high-concentration salt/alkali wastewater on the preparation of coal wastewater slurry (CWWS) was studied. The research on the slurry-ability of CWWS shows that Na+ in NaCl will be electrically neutralized with the negative charge on the coal, the electrostatic repulsion of particles will decrease, and the viscosity will increase. In the presence of HCO3c, negative charge increases on coal particles, the apparent viscosity decreases by 42 mPa·s compared with the absence of HCO3−. In the CO32− systems, the pH is 8.25. Higher pH indicates that there are more OH−. Because CO32− is easy to combine with water to form a stable structure, and the strong polar effect of OH− is also easy to bind water molecules, forming a stable water molecule layer configuration on the coal, which hinders the adsorption of sodium lignosulfonate (SL), resulting in a decrease in steric hindrance effect, which is not conducive to the dispersion of particles. The molecular dynamics (MD) simulation results confirmed the existence of the neutralization of Na+ and the negative charge on coal in the NaCl system. The adsorption energies (Eadsorption) of each system were negative, indicating that the dispersant was easily adsorbed on the coal. However, in the CO32− system, the absolute value of Eadsorption was lower than that the pure water system, indicating that the presence of CO32− is not conducive to the adsorption of SL. The self-diffusion coefficient(D) of Na2CO3 system is lower than that of coal/water/SL system, NaCl system, and NaHCO3 system. It shows that the presence of CO32− can significantly reduce the migration rate of water molecules and is easy to bind water molecules. The presence of HCO3− is also easy to bind water molecules, but it is weaker than CO32−. The migration and diffusion rate of water molecules in the saline-alkali mixed system decrease. This may be mainly affected by CO32−, which easily binds water molecules on the coal surface and hinders the adsorption of SL.

Investigating the effects of MWCNT-HB on gas storage performance of CO2 hydrate

The technology of capturing CO2 using hydrate has attracted wide attention. In this study, the effects of two carbon nanomaterials, original multiwalled carbon nanotube (MWCNT) and modified herringbone carbon nanotube (MWCNT-HB), on the gas storage performance of CO2 hydrate were investigated under static conditions. Compared with the MWCNT system, the MWCNT-HB system showed a stronger ability to improve gas storage performance. Secondary formation of hydrate in the MWCNT-HB system was observed, and the final gas storage capacity could be increased by 119.2% compared to the pure water system. Due to the long stationary period between the two hydrate formation processes, MWCNT-HB was used in combination with tetrahydrofuran (THF) and sodium dodecyl sulfate (SDS) respectively. It was found that the MWCNT-HB/THF system inhibited the hydrate formation owing to a film formed on the suspension surface. In the MWCNT-HB/0.2% SDS system, the coupling effect of the two materials further enhanced the heat and mass transfer. The gas storage rate could reach 1.25 m3·m−3·min−1, the gas storage capacity also increased to about 85 m3·m−3, and the induction time was only 5.1 min. The compound system not only enhanced the gas storage performance of CO2 hydrate but also effectively improved the phase equilibrium conditions. To further investigate the promotion mechanism, the thermal conductivity of the experimental materials, the surface tension of the solution, and the exothermic process of hydrate formation were measured and analyzed.

The kinetic effects of hydrate anti-agglomerants/surfactants

The addition of anti-agglomerants (AAs) is a promising solution for decreasing the risk of gas hydrate plugging in deepwater hydrocarbon flowlines or during drilling operations. AAs (usually surfactants) can adsorb on small hydrate particles and make them dispersing, thus leading to the prevention of agglomeration. However, it is not fully clear whether AAs promote or inhibit hydrate nucleation and growth during this process. Here, a series of AAs/surfactants (dodecyl benzene sulfonic acid, 1-naphthylacetic acid, tetramethyl ammonium bromide, Span80, rhamnolipid, and cocamidopropyl dimethylamine) with different types and concentrations were studied so as to clarify the effects of AAs/surfactants on formation kinetics of CH4 hydrate using a dynamic experimental system. In the experiments, 20%, 60%, 95%, 100% water-cut systems with or without 0.5 wt% and 1.0 wt% concentrations of AAs/surfactants were pressurized with CH4 at 3.0 °C and 6.0 MPa. The induction time, the amount of hydrate formation, and the average rate of hydrate growth in these systems were measured. The results show that AAs/surfactants can promote hydrate formation in pure water (100%) and high water cut (95%) systems. Only in these high water cut systems will the pressure decrease in a multi-step manner. The occurrence of this interesting phenomenon is related to the water cut and the type of AAs, which may be due to the rapid hydrate formation and large expansion of the hydrate volume. While in relatively low water cut (20% and 60%) systems, AAs/surfactants slow down or even completely prevent the hydrate nucleation and growth under our experimental conditions, which may mainly result from the mass transfer barrier of AAs/surfactants. This study will be conducive to revealing the kinetic inhibition mechanism of AAs on hydrate agglomeration, and can be of importance to the safe implementation of multiphase flow transportation and deepwater oil and gas exploration.

Enhanced hydrate formation under mild conditions using a novel spiral‐agitated reactor

AbstractHydrate‐based solidified natural gas (SNG) technology provides a promising approach to store and transport natural gas, but demanding formation conditions and low methane storage capacity limit its application. Here, we presented a novel spiral‐agitated reactor, and hydrate formation in pure water and amino acid systems was evaluated. It is worth to highlight that spiral agitation significantly enhances initial hydrate grow kinetics, and satisfied methane uptake of 134.9 V/V was obtained under a mild condition (4.3 MPa, 275.15 K, and 30 rpm). Impressively, when amino acids were introduced, late hydrate growth was greatly improved because of secondary uptake, and a large methane uptake (145.97 V/V) was obtained under a milder condition (3.8 MPa, 275.15 K, and 60 rpm), which increases by 82.97% comparing to that in pure water systems. These findings provide a new insight (synergistic effect of spiral agitation and amino acids) on enhanced hydrate production under extremely mild conditions.

Influence of the Co-Condensation of Water and n-Heptane on Top of the Line Corrosion

Top of the line corrosion (TLC) is a serious concern in wet gas transportation pipelines operating in a stratified flow regime. Extensive research on TLC has been conducted in hydrocarbon-free environments while, in production environments, condensable hydrocarbons are always present. When water and hydrocarbons co-condense, the condensate comprises two immiscible liquids which have different wettability and corrosivity. In this study, the co-condensation process was investigated using a borescope for visual observation and a set of conductivity probes for quantification of water-wetted area. The corrosion behavior of carbon steel under water-only condensation and water/hydrocarbon co-condensation scenarios was evaluated with weight loss measurements and surface analytical techniques (scanning electron microscopy, energy dispersive spectroscopy, and 3D profilometry). The results showed that water and hydrocarbon condensation processes interacted with each other. Even though the rate of hydrocarbon condensation was much greater than that of water, the hydrophilicity of the steel surface always ensured that it would be mainly wetted by water. However, the presence of n-heptane interfered with the water droplet coalescence and segregated water into smaller droplets which affected the water chemistry. This resulted in a potentially higher pH and iron ion concentration in the water droplet as compared to a water-only scenario. The corrosion rate consequently decreased and was found to be less dependent on the water condensation rate in the co-condensation scenario, as compared to a pure water system.

Kinetics for glucose conversion to levulinic acid over solid acid catalyst in γ-valerolactone solution

A CH3-SBA-15-SO3H catalyst was synthesized for the conversion of glucose to levulinic acid. The performance of the catalyst was demonstrated by comparative experiments using γ-valerolactone solution system versus pure water system. Significantly, the conversion efficiency was almost five times higher for γ-valerolactone solution than that of the pure water. The side reactions of the γ-valerolactone solution system were probably less than that of water system. In order to provide a better understanding of the catalytic reaction and guide the engineering design, the kinetics of levulinic acid production from glucose over CH3-SBA-15-SO3H catalyst in γ-valerolactone solution were investigated. The kinetic model was established based on four differential equations, and the model results were fitted well to the experimental results. Notably, the activation energies of the production of 5-HMF and levulinic acid were 76.55 kJ/mol and 62.66 kJ/mol, respectively, which were obviously smaller than those previously reported, this may be attributed to the synergistic effect of the solid acid and the high concentration of γ-valerolactone solution.

Formation kinetics and microscopic characteristics of synthesized ternary gas mixture hydrates in TBAB aqueous solutions

Tetrabutylammonium bromide (TBAB) is a typical thermodynamic additive that can enhance the hydrate equilibrium temperature. Additionally, semi-clathrate hydrates formed from TBAB solutions exhibit reasonable CO2 adsorption performance. In this study, TBAB hydrates were synthesized to determine their carbon capture capacity from a ternary gas mixture of CH4/CO2/N2 (0.5/0.4/0.1). We measured the effect of temperature, pressure, and TBAB mass fractions (0.05–0.2) on the formation of gas hydrates, which were analyzed using Raman spectroscopy, powder X-ray diffraction (PXRD), and cryo-scanning electron microscopy (Cryo-SEM). With a 0.05 TBAB aqueous solution, the maximum recovery factor of CH4 was 1.646 at 290.1 K and 7.0 MPa, whereas the maximum CO2 split ratio was 0.454 at a pressure of 7.0 MPa and temperature of 280.1 K. Furthermore, the cryo-SEM images revealed that the addition of TBAB significantly increased the specific surface area of the hydrate crystals compared with the pure water system. PXRD and Raman spectroscopy showed that the hydrate structure transformed from a SI to a semi-clathrate hydrate. The hydrate samples formed from the 0.05 TBAB solution were found to be type A and B, leading to greater gas consumption. These results are expected to provide support for hydrate gas separation technology.

Insights into carbon dioxide hydrate formation, fluid type, and agglomeration in the system with or without tween-80

In this work, the flow of carbon dioxide (CO2) hydrate slurry is systematically investigated by analyzing its rheological behavior, apparent viscosity, and crystal shape. The results show that blocking is easy to occur in the pure water system, while no blockage is observed from the system containing Tween-80. Besides, we confirm that the hydrate slurry formed in the pure water system is a dilatant fluid with shear-thickening behavior. However, that obtained from the system containing Tween-80 are pseudoplastic fluids with shear-thinning behavior. The time development of hydrate slurry flow in the system with or without Tween-80 showed that the shear-thinning behavior is a key factor in preventing the hydrate slurry from blockage. In addition, in the presence of Tween-80, hydrates will form on the surface of the bubble. These hydrates are easily dispersed on top of the liquid phase and will not adhere to the top wall of the pipeline. However, in pure water, a dense adhesive layer is observed on the top of the pipeline, which will reduce the flow area in the pipeline, increasing the flow resistance. Overall, the main role of Tween-80 in preventing hydrates from aggregation includes two aspects, (1) changing the type of fluid from dilatant to pseudoplastic; (2) providing bubbles for hydrate formation. The addition of defoamer(BK601) will reduce the Tween-80′s effects in preventing hydrates by reducing shear-thinning behavior and the amount of bubbles.

Unusual CO2 hydrate formation in porous media: Implications on geo-CO2 storage laboratory testing methods

CO2 sequestration in geological sediments as hydrates is a promising technique currently being explored by research to permanently store CO2. To achieve this, studies on site selection and best experimental practices are useful to provide recommendations for understanding and implementing the process. In this study, the kinetics of CO2 hydrate formation was evaluated in quartz sand at 4 MPa and 274.15 K to gain insight on selecting a suitable location that provides high CO2 hydrate storage capacity. The study was conducted using a stainless-steel autoclave cell and a constant cooling method in pure water and brine system (3.3 wt% NaCl). The study revealed that CO2 hydrate forms faster in quartz sand achieving about 87% CO2 to hydrate conversion in pure water as opposed to 55% CO2 to hydrate conversion in the brine system. The high hydrate conversion achieved in pure water is promising to provide a potential storage capacity of CO2 in sediments. However, visual confirmation revealed that a high percentage of the hydrates in the pure water system formed at the top of the sand bed within the reactor which is unusual and undesired for practical CO2 storage field applications. Interestingly, the hydrate formed in the brine system was within the porous media pore spaces. The results thus suggest that hydrate storage techniques experimental testing should be conducted in reactors with visual capabilities to gain a proper understanding of the location of the hydrates within the porous media.

Study on the growth kinetics of methane hydrate in pure water system containing ZIF-8.

The hydrate formation rate is the key to the implementation of solid gas storage and transportation technology by the hydrate method. As a MOF material with strong hydrothermal stability, ZIF-8 has been proved to play a significant role in promoting the nucleation and growth of hydrate. However, the growth kinetics promotion mechanism and growth law of methane hydrate in the ZIF-8 promoter system have not been clarified at present. Therefore, the growth kinetics experiment of methane hydrate in the ZIF-8 promoter system was carried out in a high-pressure visualization reactor to systematically study the effects of the ZIF-8 concentration, undercooling degree, and pressure on the growth law of methane hydrate. The experimental results showed that: (1) the concentration of ZIF-8 had a significant shortening effect on the induction period of methane hydrate. With the increase in the ZIF-8 concentration, the induction time of methane hydrate was shortened from 5.85 h to 0.85 h. The methane gas consumption showed a gradually increasing trend at first, and then with the reaction going on, a dense hydrate film was formed at the gas–liquid interface, which increased the mass transfer resistance, resulting in the increase in the methane gas consumption gradually becoming stable. There were four stages in the growth process of hydrate, namely rapid formation, slow formation, secondary formation, and end formation and the optimal dosage of ZIF-8 promoter exists, and the optimal critical specific content was 0.02 mg mL−1. (2) With the increase of undercooling, the induction time of methane hydrate decreased significantly, and the increase in the methane consumption also showed an increasing trend at first and then decreased. (3) With the increase of the system pressure to 7 MPa, the induction time of methane hydrate decreased from 1.02 h at 6 MPa to 0.2 h at 7 MPa, and the decrease rate was 80.8%, which was mainly due to the presence of “OPEN GATE” in the ZIF-8 accelerator. With the increase of the system pressure, the pore opening of the ZIF-8 material increased, the adsorption of methane increased, and the nucleation and growth of methane hydrate were promoted.

Boosting O2 Reduction and H2O Dehydrogenation Kinetics: Surface N‐Hydroxymethylation of g‐C3N4 Photocatalysts for the Efficient Production of H2O2

Abstractg‐C3N4 photocatalysis is a safe and green approach for H2O2 production, but the activity of pristine g‐C3N4 photocatalysts is unsatisfactory. At present, most of the modifications on g‐C3N4 photocatalysts for H2O2 production have focused on thermodynamic processes, few have considered the kinetic aspects. Herein, the surface N‐hydroxymethylation of g‐C3N4 photocatalysts for the efficient kinetic production of H2O2 is reported. Through the reaction of formaldehyde with the amino moieties (–NH2) on the g‐C3N4 surface, N‐hydroxymethyls groups (‐NH‐CH2‐OH) are introduced on typical g‐C3N4 photocatalysts. Relative to the pristine g‐C3N4 photocatalysts, the modified g‐C3N4 photocatalysts have over 1280% higher activity for H2O2 production in pure water system, and impressive solar‐to‐chemical conversion efficiency. The experimental investigations and theoretical calculations reveal that the introduction of ‐NH‐CH2‐OH on the g‐C3N4 photocatalysts does not change their morphology, light absorption intensity and edges, band positions, charge separation and transfer properties, but markedly improved the H2O dehydrogenation and O2 adsorption properties of g‐C3N4. As a result, the reduction kinetics of O2 to H2O2 on the g‐C3N4 photocatalysts with ‐NH‐CH2‐OH is more energetically favorable. This work provides a useful reference and inspiration to achieve the effective modification of g‐C3N4 or other metal‐free photocatalysts from the kinetic perspective.

UV/VIS absorption properties of metal sulphate polymer nanocomposites

In this study, the nanoparticles of CaSO4, SrSO4, and BaSO4 were synthesized by precipitation method. Metal chlorides were used against the (NH4)2SO4 for the synthesis of nanoparticles by using pure water and water-ethanol solvent system. The average particle size was calculated as 25.26/ 22.13 nm, 19.29/ 29.35 and 26.93 / 27.93nm for BaSO4, CaSO4 and SrSO4 in ethanol-water/ pure-water system respectively. These nanoparticles were utilized for the preparation of PVAc nanocomposites films with 1-3 wt/wt% composition. These films were subjected to absorption of UV-Vis radiation and SrSO4 composite found the best one for the absorption of UV light.

Precipitation of sodium sulfate and sodium carbonate during supercritical water oxidation/gasification of ethanol

Reactor plugging induced by salt precipitation in supercritical water (SCW) is a major problem during the hydrothermal treatment of hypersaline waste. Considering that current investigations have focused strictly on pure water systems, a continuous tube reactor was designed herein to study the precipitation of Na2SO4 and Na2CO3 in a complex SCW environment, which was generated using C2H5OH and H2O2 in order to reproduce real SCW conditions. Results indicate that salt precipitation was accelerated in the presence of C2H5OH and H2O2. The passage rate was only 87% for Na2SO4 and 43% for Na2CO3 in an aqueous solution of 0.1 wt% C2H5OH and 0.5 times of H2O2, compared to the solubility of these salts in pure water at 385 °C and 25 MPa. Organics and gases reduce the fluid density and further aggravate salt precipitation. Salt precipitation occurred mainly in the area around gas inlet and mixer in a real SCW process.

Methane hydrate production using a novel spiral‐agitated reactor: Promotion of hydrate formation kinetics

AbstractTo enhance hydrate formation kinetics, we presented a novel spiral‐agitated reactor, where hydrates were synthetized in pure water systems, and fast hydrate kinetics was observed under extremely mild conditions. Hydrates can nucleate within 4 min under 3.5 MPa and 275.15 K at a rotating speed of 60 rpm, and large water‐to‐hydrate conversion (>85%) was obtained at a moderate condition of 4.85 MPa, 275.15 K, and 30 rpm with an average methane uptake of 139.78 V/V, demonstrating that pure water systems are feasible for hydrate‐based solidified natural gas (SNG) technology. Numerical simulations of flow fields inner the reactor were carried out, and four mechanisms behind the excellent promotion were proposed, dual‐agitation, two‐way convection, interfacial impact and micro bubbles, which significantly improve mass transfer, giving rise to fast hydrate nucleation and growth kinetics. These findings suggest extraordinary performance of spiral agitation, and this may pave way on the industrial application of hydrate‐based SNG technology.