It is known that salt ions are abundant in the natural environment where natural gas hydrates are located; thus, it is essential to investigate the self-preservation effect of salt ions on methane hydrates. The dissociation behaviors of gas hydrates formed from various NaCl concentration solutions in a quartz sand system at 268.15 K were investigated to reveal the microscopic mechanism of the self-preservation effect under different salt concentrations. Results showed that as the salt concentration rises, the initial rate of hydrate decomposition quickens. Methane hydrate hardly shows self-preservation ability in the 3.35% (mass) NaCl and seawater systems at 268.15 K. Combined the morphology of hydrate observed by the confocal microscope with results obtained from in situ Raman spectroscopy, it was found that during the initial decomposition stage of gas hydrate below the ice point, gas hydrate firstly converts into liquid water and gas molecules, then turns from water to solid ice rather than directly transforming into solid ice and gas molecules. The presence of salt ions interferes with the ability of liquid water to condense into solid ice. The results of this study provide an important guide for the mechanism and application of the self-preservation effect on the storage and transport of gas and the exploitation of natural gas hydrates.

In this work, we utilize a cocrystallization technique to solve the problem of high hygroscopicity of the high-energy oxidant ammonium dinitramide (ADN). For this purpose, a non-hygroscopic oxidant, triaminoguanidine nitrate (TAGN), is selected as the cocrystallization ligand. The ADN/TAGN system is simulated by using Material Studio 5.5 software, and the DFT of ADN and TAGN molecules are calculated by Gaussian09 software. The most stable molar ratio of the ADN/TAGN cocrystallization is determined to be 1:1, and the hydrogen bonding between the H atom of ADN and the O atom in the TAGN is the driving force for the formation of cocrystals in this system. Moreover, the electrostatic potential interaction pairing energy difference (△E_pair) < 0 kJ·mol^-1 (-12.71 kJ·mol^-1) for n_ADN:n_TAGN = 1:1 again indicates cocrystallization at this molar ratio. The crystal structure and crystal morphology is predicted. And the hygroscopicity of ADN/TAGN cocrystal at 20 °C and 40% relative humidity is calculated to be only 0.45%. The mechanism of hygroscopicity is investigated by examining the roughness of each crystal surface. Overall, the more hygroscopic it is in terms of surface roughness, with the roughest crystal surface (0 1 $\overline{2}$) having a hygroscopicity of 1.78, which corresponds to a saturated hygroscopicity of 0.61%. The results show that the (0 0 1) crystal surface has the smallest band gap (1.06 eV) and the largest sensitivity. Finally, the oxygen equilibrium value for the ADN/TAGN system is calculated to be -8.2%.

This work provides an overview of distillation processes, including process design for different distillation processes, selection of entrainers for special distillation processes, system integration and intensification of distillation processes, optimization of process parameters for distillation processes and recent research progress in dynamic control strategies. Firstly, the feasibility of using thermodynamic topological theories such as residual curve, phase equilibrium line and distillation boundary line to analyze different separation regions is discussed, and the rationality of distillation process design is discussed by using its feasibility. Secondly, the application of molecular simulation methods such as molecular dynamics simulation and quantum chemical calculation in the screening of entrainer is discussed for the extractive distillation process. The thermal coupling mechanism of different distillation processes is used to explore the process of different process intensifications. Next, a mixed integer nonlinear optimization strategy for the distillation process based on different algorithms is introduced. Finally, the improvement of dynamic control strategies for different distillation processes in recent years is summarized. This work focuses on the application of process intensification and system optimization in the design of distillation process, and analyzes the challenges, prospects, and development trends of distillation technology in the separation of multicomponent azeotropes.

Acetic acid and furfural are known as prevalent inhibitors deriving from pretreatment during lignocellulosic ethanol production. They negatively impact cell growth, glucose uptake and ethanol biosynthesis of Saccharomyces cerevisiae strains. Development of industrial S. cerevisiae strains with high tolerance towards these inhibitors is thus critical for efficient lignocellulosic ethanol production. In this study, the acetic acid or furfural tolerance of different S. cerevisiae strains could be significantly enhanced after adaptive evolution via serial cultivation for 40 generations under stress conditions. The acetic acid-based adaptive strain SPSC01-TA9 produced 30.5 g·L^-1 ethanol with a yield of 0.46 g·g^-1 in the presence of 9 g·L^-1 acetic acid, while the acetic acid/furfural-based adaptive strain SPSC01-TAF94 produced more ethanol of 36.2 g·L^-1 with increased yield up to 0.49 g·g^-1 in the presence of both 9 g·L^-1 acetic acid and 4 g·L^-1 furfural. Significant improvements were also observed during non-detoxified corn stover hydrolysate culture by SPSC01-TAF94, which achieved ethanol production and yield of 29.1 g·L^-1 and 0.49 g·g^-1, respectively, the growth and fermentation efficiency of acetic acid/furfural-based adaptive strain in hydrolysate was 95% higher than those of wildtype strains, indicating the acetic acid- and furfural-based adaptive evolution strategy could be an effective approach for improving lignocellulosic ethanol production. The adapted strains developed in this study with enhanced tolerance against acetic acid and furfural could be potentially contribute to economically feasible and sustainable lignocellulosic biorefinery.

Electrode materials with high desalination capacity and long-term cyclic stability are the focus of capacitive deionization (CDI) community. Understanding the causes of performance decay in traditional carbons is crucial to design a high-performance material. Based on this, here, nitrogen-doped activated carbon (NAC) was prepared by pyrolyzing the blend of activated carbon powder (ACP) and melamine for the positive electrode of asymmetric CDI. By comparing the indicators changes such as conductivity, salt adsorption capacity, pH, and charge efficiency of the symmetrical ACP-ACP device to the asymmetric ACP-NAC device under different CDI cycles, as well as the changes of the electrochemical properties of anode and cathode materials after long-term operation, the reasons for the decline of the stability of the CDI performance were revealed. It was found that the carboxyl functional groups generated by the electro-oxidation of anode carbon materials make the anode zero-charge potential (E_pzc) shift positively, which results in the uneven distribution of potential windows of CDI units and affects the adsorption capacity. Furthermore, by understanding the electron density on C atoms surrounding the N atoms, we attribute the increased cyclic stability to the enhanced negativity of the charge of carbon atoms adjacent to quaternary-N and pyridinic-oxide-N.

Glycerol monolaurate (GML) is a widely used industrial chemical with excellent emulsification and antibacterial effect. The direct esterification of glycerol with lauric acid is the main method to synthesize GML. In this work, the kinetic process of direct esterification was systematically studied using p-toluenesulfonic acid as catalyst. A complete kinetic model of consecutive esterification reaction has been established, and the kinetic equation of acid catalysis was deduced. The isomerization reactions of GML and glycerol dilaurate were investigated. It was found that the reaction was an equilibrium reaction and the reaction rate was faster than the esterification reaction. The kinetic equations of the consecutive esterification reaction were obtained by experiments as k₁ = (276+92261X_cat)exp(-37720/RT) and k₂ = (80 +4413X_cat)exp(-32240/RT). The kinetic results are beneficial to the optimization of operating conditions and reactor design in GML production process.

As promising catalysts for the degradation of organic pollutants, metal–organic frameworks (MOFs) often face limitations due to the particle agglomeration and challenging recovery in liquid-catalysis application, stemming from their powdery nature. Engineering macroscopic structures from pulverous MOF is thus of great importance for broadening their practical applications. In this study, three-dimensional porous MOF aerogel catalysts were successfully fabricated for degrading organic dyes by activating peroxymonosulfate (PMS). MOF/gelatin aerogel (MOF/GA) catalysts were prepared by directly integrating bimetallic FeCo-BDC with gelatin solutions, followed by freeze-drying and low-temperature calcination. The FeCo-BDC-0.15/GA/PMS system exhibited remarkable performance in degrading various organic dyes, eliminating 99.2% of rhodamine B within a mere 5 min. Compared to the GA/PMS system, there was over a 300-fold increase in the reaction rate constant. Remarkably, high removal efficiency was maintained across varying conditions, including different solution pH, co-existing inorganic anions, and natural water matrices. Radical trapping experiments and electron paramagnetic resonance analysis revealed that the degradation involved radical (SO₄^-·) and non-radical routes (¹O₂), of which ¹O₂ was dominant. Furthermore, even after a continuous 400-min reaction in a fixed-bed reactor at a liquid hourly space velocity of 27 h^-1, the FeCo-BDC/GA composite sustained a degradation efficiency exceeding 98.7%. This work presents highly active MOF-gelatin aerogels for dye degradation and expands the potential for their large-scale, continuous treatment application in organic dye wastewater management.

The particle residence time distribution (RTD) and axial dispersion coefficient are key parameters for the design and operation of a pressurized circulating fluidized bed (PCFB). In this study, the effects of pressure (0.1-0.6 MPa), fluidizing gas velocity (2-7 m·s^-1), and solid circulation rate (10-90 kg·m^-2·s^-1) on particle RTD and axial dispersion coefficient in a PCFB are numerically investigated based on the multiphase particle-in-cell (MP-PIC) method. The details of the gas-solid flow behaviors of PCFB are revealed. Based on the gas-solid flow pattern, the particles tend to move more orderly under elevated pressures. With an increase in either fluidizing gas velocity or solid circulation rate, the mean residence time of particles decreases while the axial dispersion coefficient increases. With an increase in pressure, the core-annulus flow is strengthened, which leads to a wider shape of the particle RTD curve and a larger mean particle residence time. The back-mixing of particles increases with increasing pressure, resulting in an increase in the axial dispersion coefficient.

It is quite important to ensure the safety and sustainable development of nuclear energy for the treatment of radioactive wastewater. To treat radioactive wastewater efficiently and rapidly, two multi-amine β-cyclodextrin polymers (diethylenetriamine β-cyclodextrin polymer (DETA-TFCDP) and triethylenetetramine β-cyclodextrin polymer (TETA-TFCDP)) were prepared and applied to capture uranium. Results exhibited that DETA-TFCDP and TETA-TFCDP displayed the advantages of high adsorption amounts (612.2 and 628.2 mg·g^-1, respectively) and rapid adsorption rates, which can reach (88 ±1)% of their equilibrium adsorption amounts in 10 min. Moreover, the adsorbent processes of DETA-TFCDP and TETA-TFCDP on uranium(VI) followed the Langmuir model and pseudo-second-order model, stating they were mainly chemisorption and self-endothermic. Besides, TETA-TFCDP also showed excellent selectivity in the presence of seven competing cations and could be effectively reused five times via Na₂CO₃ as the desorption reagent. Meanwhile, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy illustrated that the enriched multi-amine groups and oxygen-containing functional groups on the surface of TETA-TFCDP were the main active sites for capturing uranium(VI). Hence, multi-amine β-cyclodextrin polymers are a highly efficient, rapid, and promising adsorbent for capturing uranium(VI) from radioactive wastewater.

In response to the lack of reliable physical parameters in the process simulation of the butadiene extraction, a large amount of phase equilibrium data were collected in the context of the actual process of butadiene production by acetonitrile. The accuracy of five prediction methods, UNIFAC (UNIQUAC Functional-group Activity Coefficients), UNIFAC-LL, UNIFAC-LBY, UNIFAC-DMD and COSMO-RS, applied to the butadiene extraction process was verified using partial phase equilibrium data. The results showed that the UNIFAC-DMD method had the highest accuracy in predicting phase equilibrium data for the missing system. COSMO-RS-predicted multiple systems showed good accuracy, and a large number of missing phase equilibrium data were estimated using the UNIFAC-DMD method and COSMO-RS method. The predicted phase equilibrium data were checked for consistency. The NRTL-RK (non-Random Two Liquid-Redlich-Kwong Equation of State) and UNIQUAC thermodynamic models were used to correlate the phase equilibrium data. Industrial device simulations were used to verify the accuracy of the thermodynamic model applied to the butadiene extraction process. The simulation results showed that the average deviations of the simulated results using the correlated thermodynamic model from the actual values were less than 2% compared to that using the commercial simulation software, Aspen Plus and its database. The average deviation was much smaller than that of the simulations using the Aspen Plus database (>10%), indicating that the obtained phase equilibrium data are highly accurate and reliable. The best phase equilibrium data and thermodynamic model parameters for butadiene extraction are provided. This improves the accuracy and reliability of the design, optimization and control of the process, and provides a basis and guarantee for developing a more environmentally friendly and economical butadiene extraction process.

In-site soil flushing and aeration are the typical synergetic remediation technology for contaminated sites. The surfactant present in flushing solutions is bound to affect the aeration efficiency. The purpose of this study is to evaluate the effect of surfactant frequently used in soil flushing on the oxygen mass transfer in micro-nano-bubble (MNB) aeration system. Firstly, bio-surfactants and chemical surfactants were used to investigate their effects on Sauter mean diameter of bubble (d_BS), gas holdup (ε), volumetric mass-transfer coefficient (k_La) and liquid-side mass-transfer coefficient (k_L) in the MNB aeration system. Then, based upon the experimental results, the Sardeing's and Frössling's models were modified to describe the effect of surfactant on k_L in the MNB aeration. The results showed that, for the twenty aqueous surfactant solutions, with the increase in surfactant concentration, the value of d_BS, k_La and k_L decreased, while the value of ε and gas-liquid interfacial area (a) increased. These phenomena were mainly attributed to the synergistic effects of immobile bubble surface and the suppression of coalescence in the surfactant solutions. In addition, with the presence of electric charge, MNBs in anionic surfactant solutions were smaller and higher in number than in non-ionic surfactant solutions. Furthermore, the accumulation of surfactant on the gas-liquid interface was more conspicuous for small MNB, so the reduction of k_L in anionic surfactant solutions was larger than that in non-ionic surfactant solutions. Besides, the modified Frössling's model predicted the effect of surfactant onk_L in MNB aeration system with reasonable accuracy.

The separation of aromatic/aliphatic hydrocarbon mixtures is crucial in the petrochemical industry. Pervaporation is regarded as a promising approach for the separation of aromatic compounds from alkanes. Developing membrane materials with efficient separation performance is still the main task since the membrane should provide chemical stability, high permeation flux, and selectivity. In this study, the hyperbranched polymer (HBP) was deposited on the outer surface of a polyvinylidene fluoride (PVDF) hollow-fiber ultrafiltration membrane by a facile dip-coating method. The dip-coating rate, HBP concentration, and thermal cross-linking temperature were regulated to optimize the membrane structure. The obtained HBP/PVDF hollow-fiber-composite membrane had a good separation performance for aromatic/aliphatic hydrocarbon mixtures. For the 50%/50% (mass) toluene/n-heptane mixture, the permeation flux of optimized composite membranes could reach 1766 g·m^-2·h^-1, with a separation factor of 4.1 at 60 ℃. Therefore, the HBP/PVDF hollow-fiber-composite membrane has great application prospects in the pervaporation separation of aromatic/aliphatic hydrocarbon mixtures.

Biochar is a reactive carrier as it may be partially gasified with steam in steam reforming, which could influence the formation of reaction intermediates and modify catalytic behaviors. Herein, the Ni/biochar as well as two comparative catalysts, Ni/Al₂O₃ and Ni/SiO₂, with low nickel loading (2% (mass)) was conducted to probe involvement of the varied carriers in the steam reforming. The results indicated that the Ni/biochar performed excellent catalytic activity than Ni/SiO₂ and Ni/Al₂O₃, as the biochar carrier facilitated quick conversion of the -OH from dissociation of steam to gasify the oxygen-rich carbonaceous intermediates like C=O and C-O-C, resulting in low coverage while high exposure of nickel species for maintaining the superior catalytic performance. In converse, strong adsorption of aliphatic intermediates over Ni/Al₂O₃ and Ni/SiO₂ induced serious coking with polymeric coke as the main type (21.5% and 32.1%, respectively), which was significantly higher than that over Ni/biochar (3.9%). The coke over Ni/biochar was mainly aromatic or catalytic type with nanotube morphology and high crystallinity. The high resistivity of Ni/biochar towards coking was due to the balance between formation of coke and gasification of coke and partially biochar with steam, which created developed mesopores in spent Ni/biochar while the coke blocked pores in Ni/Al₂O₃ and Ni/SiO₂ catalysts.

In this work, several HZSM-5 catalysts with different Si/Al ratios treated with acids are selected as catalysts and used for hydration of cyclohexene to cyclohexanol. The results indicated that HZSM-5 (Si/Al = 38) modified with 4 mol·L^-1 nitric acid was selected as an efficient catalyst for improving the hydration efficiency of cyclohexene. Furthermore, the microstructures and properties of fresh, used and regenerated acid-modified catalysts have been characterized by X-ray diffraction, scanning electron microscopy, nitrogen adsorption/desorption isotherm, Fourier transform infrared, thermal gravimetric analyzer, ammonia temperature programmed desorption and pyridine adsorbs Fourier transform infrared. The characterization results indicated that the total surface areas and pore volume of HZSM-5 zeolite increased after nitric acid treatment due to the formation of mesoporous structure. This benefits the diffusion rate of reactants and products, which improves the hydration efficiency and stability of the catalyst. Under the catalysis of HZSM-5, the conversion of cyclohexene was found to be 9.0%. However, treatment of HZSM-5 with nitric acid enhanced the conversion of cyclohexene to 12.2%, achieving a selectivity of 99.7% for cyclohexanol under optimal reaction conditions. This work affords a mild and efficient approach for improving the hydration efficiency and has potential industrial application value.

Ensuring the consistency of electrode structure in proton-exchange-membrane fuel cells is highly desired yet challenging because of wide-existing and unguided cracks in the microporous layer (MPL). The first thing is to evaluate the homogeneity of MPL with cracks quantitatively. This paper proposes the homogeneity index of a full-scale MPL with an area of 50 cm², which is yet to be reported in the literature to our knowledge. Besides, the effects of the carbon material and surfactant on the ink and resulting MPL structure have been studied. The ink with a high network development degree produces an MPL with low crack density, but the ink with high PDI produces an MPL with low crack homogeneity. The polarity of the surfactant and the non-polarity of polytetrafluoroethylene (PTFE) are not mutually soluble, resulting in the heterogeneous PTFE distribution. The findings of this study provide guidelines for MPL fabrication.

Fabric multifunctionality offers resource savings and enhanced human comfort. This study innovatively integrates cooling, heating, and antimicrobial properties within a Janus fabric, surpassing previous research focused solely on cooling or heating. Different effects are achieved by applying distinct coatings to each side of the fabric. One graphene oxide (GO) coating exhibits exceptional light-to-heat conversion, absorbing and transforming light energy into heat, thereby elevating fabric temperature by 15.4 ℃, 22.7 ℃, and 43.7 ℃ under 0.2, 0.5, and 1 sun irradiation, respectively. Conversely, a hydrogel coating on one side absorbs water, facilitating heat dissipation through evaporation upon light exposure, reducing fabric temperature by 5.9 ℃, 8.4 ℃, and 7.1 ℃ in 0.2, 0.5, and 1 sun irradiation, respectively. Moreover, both sides of Janus fabric exhibit potent antimicrobial properties, ensuring fabric hygiene. This work presents a feasible solution to address crucial challenges in fabric thermal regulation, providing a smart approach for intelligent adjustment of body comfort in both summer and winter. By integrating heating and cooling capabilities along with antimicrobial properties, this study promotes sustainable development in textile techniques.

Micromixing efficiency is an important parameter for evaluating the multiphase mass transfer performance and reaction efficiency of microreactors. In this work, the novel curved capillary reactor with different shapes was designed to generate Dean flow, which was used to enhance the liquid-liquid micromixing performance. The Villermaux-Dushman probe reaction was employed to characterize the micromixing performance in different curved capillary microreactors. The effects of experiment parameters such as liquid flow rate, inner diameter, tube length, and curve diameter on micromixing performance were systematically investigated. Under the optimal conditions, the minimum value of the segmentation factor X_S was 0.008. It was worth noting that at the low Reynolds number (Re < 30), the change of curved shape on the capillary microreactor can significantly improve the micromixing performance with X_S reduced by 37.5%. Further, the correlations of segment index X_S with dimensionless factor such as Reynolds number or Dean number were developed, which can be used to predict the liquid-liquid micromixing performance in capillary microreactors.

Magnesium-ion batteries (MIBs) have attracted extensive attention due to their high theoretical capacity, superior safety, and low cost. Nonetheless, the development of MIBs is hindered by the lack of cathode materials with long cycle life and rate capability. MXene stands out as a prime choice for MIB cathode or collector for anode-free magnesium batteries (AFMBs) because of its larger surface area, adjustable surface properties, and good electrical conductivity. In this paper, we summarized the preparation and layering methods of MXene and discussed the prospects of MXene as a cathode or collector for MIBs. This review will be immensely beneficial in critically analyzing the synthesis techniques and the applications of MXene material as MIB cathode or AFMB collector. In addition, the challenges of the preparation and layering were concluded, along with raising the research strategies of MXene for storing Mg ions.

The dynamics of vapor-liquid-solid (V-L-S) flow boiling in fluidized bed evaporators exhibit inherent complexity and chaotic behavior, hindering accurate prediction of pressure drop signals. To address this challenge, this study proposes an innovative hybrid approach that integrates wavelet neural network (WNN) with chaos analysis. By leveraging the Cross-Correlation (C-C) method, the minimum embedding dimension for phase space reconstruction is systematically calculated and then adopted as the input node configuration for the WNN. Simulation results demonstrate the remarkable effectiveness of this integrated method in predicting pressure drop signals, advancing our understanding of the intricate dynamic phenomena occurring with V-L-S fluidized bed evaporators. Moreover, this study offers a novel perspective on applying advanced data-driven techniques to handle the complexities of multi-phase flow systems and highlights the potential for improved operational prediction and control in industrial settings.