Based on bibliometric analysis of bio-hydrogen published 2004 to 2020 indexed by Web of Science, dark fermentation as one of the four methods of bio-hydrogen, has received the highest attention for its assets such as high hydrogen-production rate without light, low energy consumption and comprehensively available microorganism and substrate. At the same time, some metal nanoparticles (Fe, Ni, Co, and Ag) that exhibit excellent promotion for dark fermentation has been spotlight in this research field. Nanoparticles equipped with the properties and characteristics of small volume, surface effect and quantum size effect can enhance the rate of electron transfer of cells and present good biocompatibility. The mechanism of metal nanoparticles (MNPs) interacting with enzymes and microoganisms has been illustrated. Particularly, impacts of MNPs are elaborated in details on different mechanisms of enhancing the hydrogen production process through dark fermentation by promoting hydrolysis of lignocellulose, immobilization of cellulase enzymes, and activity of hydrogenase, respectively. On one hand, MNPs assist pretreatment process of removing of lignin, and improve stability of enzymes by immobilizing them; on the other hand, MNPs enhance the rate of electron transfer, thus make a promotion of activity of hydrogenase, and finally lead the increase of hydrogen production. In addition to the impact of nanoparticles on enzymes, the role of nanoparticles on bacterial metabolism, interspecies electron transfer and synergistic hydrogen production of mixed culture are discussed. The difficulties and prospects of the application of metal nanoparticles in dark fermentation for hydrogen production are also prospected.

A stable solid electrolyte interface (SEI) is the key to improving the electrochemical performance of the lithium-ion battery. Electrolyte additives are one of the most economical and effective methods to improve the performance of the lithium-ion battery. The existence of additives significantly improves the recyclability and service life of lithium-ion batteries, so it has been widely studied by researchers. This paper evaluates the research progress and action mechanism of unsaturated ester compounds, sulfur compounds, lithium salts and inorganic compounds as electrolyte film-forming additives in lithium-ion batteries in recent five years, evaluates their advantages and disadvantages and finally combines them with prospects. The future development trend of film-forming additives is proposed: (1) It is a general trend to use multiple additives or design new additives with multiple functional groups to make up for the shortcomings of a single additive in some aspects and facilitate the complementarity of functional advantages. (2) Quantum chemical calculation is an efficient method to screen film-forming additives, which is helpful to understand the action mechanism between additives and electrodes and speed up the research and development efficiency. (3) The characterization method of the SEI membrane needs to be further improved. To further study the action mechanism of additives, the in-situ analysis method can be considered in the future characterization process. The main ideas for developing film-forming additives in the future include: (1) The additives shall be mainly organic species, which can form SEI film with small elastic modulus, to adapt to the expansion behavior of anode materials. (2) The additive should try to ensure that the formed SEI film and graphite and other anode materials have good adhesion, so the polymerization degree of the polymer formed by the additive should not be too small. (3) Before there is no film-forming additive with excellent performance, the molecular structure of the additive should be similar to the current film-forming additive as far as possible, to facilitate industrial production. (4) Focus on the application of current additives, improve the synthesis technology of additives, reduce the synthesis cost, facilitate large-scale use, and benefit society.

Oxygen conductor, such as perovskite oxide (ABO₃-type), are widely applied to fuel cell, oxygen sensors and oxygen permeable membranes. Improving the oxygen transport performance within perovskite oxide lattice is the key to increasing the efficiency of the oxygen conductor equipment. The transport performance of perovskite oxygen ions is affected by complex factors such as crystal structure, A/B site ions, anions and oxygen vacancies, which brings great challenges to the development of perovskite materials with high oxygen ion conductivity. This article first analyzes the mechanism of oxygen transport in the perovskite, and summarizes in detail the common factors that control the oxygen transport in the perovskite, including the crystal structure, the concentration of oxygen vacancies and the distribution of oxygen vacancies. Then focus on the analysis of the way and mechanism of these influencing factors on the oxygen transport process of the perovskite, and introduces the simple means and principles of regulating these influencing factors. This article further clarifies the prediction method for the oxygen transport performance of perovskite and the corresponding characterization method, such as O₂-temperature programmed desorption, X-ray absorption spectroscopy, high-resolution transmission electron microscopy and theoretical calculations. Combining theoretical calculations and experimental results, we can directly observe the internal microscopic properties of the material to promote the understanding of the oxygen ion transport process of the perovskite oxide. This paper aims to find a more accurate and convenient design strategy to rapidly screen perovskite oxides with high oxygen ion conductance.

Thermodynamic properties of CO₂ gas hydrates were essential for the design and operation of seawater desalination, biogas purification, CO₂ capture and storage systems, energy utilization, natural gas storage, etc. In this study, four different quaternary ammonium salts were employed to accelerate the CO₂ hydrate formation in the temperature range from 272.75 K to 294.35 K at pressures 0.35—4.50 MPa by the constant volume temperature search method. The results showed that under the same conditions, the CO₂ hydrate phase equilibrium temperature under the action of quaternary ammonium salt can be summarized as below:tetrabutylammonium fluoride (TBAF) > tetrabutylammonium bromide (TBAB) > tetrabutylammonium chloride (TBAC) > benzyl-triethyl-ammonium chloride (TEBAC). The phase enthalpy of CO₂ hydrate in different quaternary ammonium salt solutions was calculated by using the Clausius-Clapeyron equation, and the influence of its hydrate stability was explored. The logarithm of the pressure versus the reciprocal (absolute) hydrate formation temperature was also found to be nearly linear. The phase enthalpy of CO₂ hydrate under the action of TBAF and TBAB was close to and significantly higher than other quaternary ammonium salts, indicating that its promotion effect was the best, the corresponding hydrate formation conditions were also the mildest. Using the Chen-Guo model, combined with the PR equation of state and the improved Joshi empirical activity model, the thermodynamic phase equilibrium data of CO₂ hydrate under the action of TBAF, TBAB, TBAC and TEBAC were calculated respectively. The calculated results were in good agreement with the experimental data, and the maximum average relative error was 7.50%.

CO₂ mixed working fluid has the characteristics of high efficiency and environmental friendliness, and has received extensive attention in the new generation of heat-power conversion cycle. Vapor-liquid equilibria properties for mixtures is the foundation of cycle analysis and calculation, so in order to improve the calculation accuracy of the vapor-liquid equilibria model for CO₂-based mixtures, the vapor-liquid equilibria properties of seven CO₂+HFCs/HFOs and four CO₂+HCs mixtures are calculated by combining the PR equation of state with three mixing rules (vdW, WS, MHV1). The results show that the vdW mixing rule can achieve better results for CO₂+HCs mixtures. For the CO₂+HFCs/HFOs system, the calculation accuracy is similar in the subcritical region, but in the supercritical region, the WS mixing method improves the calculation accuracy obviously. MHV1 calculation accuracy is lower than WS and the calculation result of vdW is the most unsatisfactory. Finally, a differential model is proposed to predict the vapor-liquid equilibria properties of CO₂-based mixtures. The predicted AARD(p) value is 2.03%, and the AAD(y) value is 0.0120, with high prediction accuracy.

The critical temperature is a very critical thermophysical property, and its theoretical prediction has always been a hot topic in thermophysical property research. However, the previously reported models cannot effectively distinguish the isomers in working fluids. To solve this problem, the new structure description ‘molecular fingerprints + topological index’ was considered in the predicted model, the average absolute deviation between the predicted and experimental values is 3.99%, which proves the reasonable prediction performance of the proposed model. Then the estimation accuracy of the model was compared with previous models, the results indicated that the proposed model can not only effectively distinguish the isomers of working fluids, but also surpass other existing models with respect to accuracy.

The wall wettability of microchannel plays an important role in the gas-liquid flow hydrodynamics. The microchannels with the surface contact angles of 10°, 40°, 70° and 110° were prepared by a plasma-induced graft polymerization technology, in which the methylacryloethyl sulfonyl betaine (SBMA) or the 1H,1H,2H,2H-perfluoro-decyltriethoxysilane was grafted onto the surface of polymethyl methacrylate (PMMA). The effects of the wall wettability of microchannel on the gas-liquid two-phase flow patterns, bubble length and pressure drop were investigated. The results indicated that the break-up position of the bubble moved downstream with the increase of the contact angle. Meanwhile, the expansion time of the bubble was shortened, and the squeezing time of the bubble became longer. As a result, the bubble length increased with the increase of the contact angle at low flow rate zone, and decreased at high flow rate zone. The prediction model of the bubble length associated with the contact angle of water on the microchannel surface was established, in which prediction accuracy was higher than the Garstecki's model. For θ<90°, the pressure drop decreased with the increase of the contact angle of microchannel surface; for θ>90°, the three-phase contact line appears on the microchannel surface, which would increase the flow resistance and the pressure drop.

Calcium carbonate fouling in industrial circulating cooling water is always an important problem for industrial producers. Fouling on the heat transfer surface increases the fouling resistance of heat exchanger and reduces the heat transfer efficiency of heat exchanger. Adding scale inhibitor to circulating cooling water is an effective method to control the fouling of heat exchanger. The inhibition of calcium carbonate fouling by carboxymethyl dextran of different concentrations was studied by fast controlled precipitation(FCP) method. The FCP method is a general method for evaluating scale inhibitors, which is very suitable for the research and control of scale inhibition treatment in heat exchanger. At present, the FCP method is widely used in the evaluation of water quality resources and the measurement of scale inhibition effect of scale inhibitors. By measuring the real-time pH and resistivity in the solution, the fast controlled precipitation method can reflect the inhibition effect of scale inhibitor in the nucleation and growth process of calcium carbonate. The concentration of Ca²⁺ in the solution was 200 mg/L, and the concentration of carboxymethyl dextran was 0.5, 1, 2 and 4 mg/L, respectively. The results show that carboxymethyl dextran has a significant effect on slowing down the nucleation process of calcium carbonate. In addition, it also significantly reduces the growth rate of crystals after calcium carbonate nucleation. When the concentration of Ca²⁺ was 200 mg/L, 4 mg/L carboxymethyl dextran could inhibit the nucleation and crystal growth of CaCO₃. It is of great significance to the anti-scaling of calcium carbonate and the improvement of heat transfer efficiency in industrial application.

The heat transfer of supercritical water in a side-heated square channel with auxiliary coolant is numerically investigated, and the mechanisms of heat transfer deterioration and recovery are explained in terms of boundary layer thickness and turbulent kinetic energy in the near-wall region. The heat transfer correlations for supercritical water heat transfer in a side-heated square channel under different conditions (pressure, inlet temperature, heat flux, mass flow, flow direction and pipe diameter) are examined and the Fan correlation achieves the highest prediction agreement. The PEC factor is employed to evaluate different enhanced heat transfer structures (dual channels and grooves). It is found that the PEC factor of upper and lower dual channel is generally less than 1, and the overall heat transfer enhancement is low. The PEC factor of the downstream asymmetric chamfered groove is in the range of 1.13—1.51, and the maximum value is achieved under different working conditions. The field synergy analysis also proves that the down stream asymmetric chamfered groove structure has the best comprehensive heat transfer performance.

The heat transfer characteristic of supercritical CO₂ in tubes is the key factor affecting the overall performance of heat exchangers. In recent years, square microchannels have shown broad application prospects in compact and efficient printed circuit heat exchangers. The SST k-ω turbulent model was used to simulate the heat transfer characteristics of supercritical CO₂ in square microchannels under uniform heating conditions. The effects of flow channel shape, heat flux, mass flow rate and inclination angle on heat transfer performance in microchannels were studied by comparing three average heat transfer coefficients, buoyancy parameter and secondary flow intensity. The results show that the overall heat transfer performance of horizontal square microchannels is better than that of semicircular microchannels with the same hydraulic diameter. The temperature distribution, velocity distribution and turbulent kinetic energy distribution of typical sections in the fluid domain can well explain the non-uniform heat transfer phenomenon in horizontal microchannels. The overall heat transfer level of square microchannels can be improved by decreasing the heat flux, increasing the mass flow rate or decreasing the angle between the flow direction and the gravity direction. The simulation results have certain theoretical significance for the design and optimization of microchannel heat exchangers using supercritical CO₂ as working medium.

Cell culture technology is the pillar of the biopharmaceutical industry. T-flasks as single-use consumables are typically used in single-layer static cultivation which produces limited cell density. In order to achieve high-throughput and high density cell culture in T-flasks, this study systematically investigates the hydrodynamics and mass transfer characteristics of a T25 flask placed on a rocking platform under different operating conditions. The results show that shaking can significantly increase the mass transfer rate of the square bottle and reduce the mixing time, making high-density culture possible. But the air filter on the bottle cap becomes the limiting factor for the mass transfer rate at high rotation speeds. The horizontal and vertical distances of the flask relative to the rocking axis had negligible effects on mass transfer and mixing, but placing the flask at a 45° angle and effectively using the walls of the flask as baffles, drastically reduces the mixing time at the same rocking speed. A user-defined function is used to implement a dynamic mesh to simulate the rocking movement of the T-flask in a CFD model. The CFD model enables the analysis of the shear stress and energy dissipation rates in the flask under different rocking speeds. This study provides the data and theoretical support for the further development of a T-flask-based high-throughput, single-use microbioreactor systems.

Enhancement of nucleate boiling heat transfer using wettability modification on porous or micro-structured surfaces has been studied extensively. The CFD-VOF method is used to accurately study the nucleate boiling enhanced by surface temporary modulation in the growth and the departure regimes of single bubble boiling on silicon micropillar structured surface. To comparatively study the effect of wettability temporary modulation on bubble dynamics and heat transfer performance, initial contact angle is set at 48°, 60°, 90° and 110° respectively, then is modulated to 20° at t = 0.152 ms. The results show that the hydrophobicity can increase the bubble growing rate, the adhesion force between the bubble and micropillars, and promote the bubble spreading along the gaps between the micropillars. At t = 0.150 ms, the contact area between the bubble and the surface with the contact angle at 110° is increased by 1.3 times, and the microlayer evaporation rate is increased by 1.2 times. The hydrophilicity reduces the proportion of the detachment time in the whole cycle， the average evaporation power at the detachment time increases by 33.3%， and the surface heat transfer performance is enhanced throughout the process.

Ultrasound can enhance heat transfer due to the mechanism of cavitation and acoustic flow. In order to study its effect on the heat transfer characteristics of spray cooling under high heat flow, an immersed spray cooling experimental platform with H₂O as the working fluid was designed and built. The effect of the ultrasonic field on the spray cooling heat transfer performance under different spray heights, pressures and heat fluxes was investigated in the non-boiling regime. Studies have shown that the heat transfer effect of ultrasonic immersed spray cooling is better than that of immersed spray cooling, which is more obvious in the case of large heat flux 152 W/cm². The enhanced heat transfer effect will decrease with the increase of spray pressure, and the immersed ultrasonic spray cooling has the highest increase of 14.4% compared to the immersed type under the optimum spray height 10 mm and spray pressure 0.1 MPa condition. The improvement of ultrasonic on heat transfer will increase with the increase of spray height, and the highest enhancement ratio is 29.1% when spray height is 18 mm.

The Ni₃S₂@Mo₂S₃ self-supported catalyst for oxygen evolution reaction in water electrolysis was in situ synthesized on MoNi foam (MNF) by one-step hydrothermal method with MNF as the sources of Ni and Mo. The morphology, composition and OER electrocatalytic performance of the as-prepared catalyst were characterized by the corresponding characterization techniques and electrochemical methods. The catalyst was consisted of irregular nano-slabs with the composition of hexagonal Ni₃S₂ and monoclinic Mo₂S₃ in a ratio of 5∶1. The as-prepared Ni₃S₂@Mo₂S₃ only needed an overpotential of 170 mV (after IR compensation) to drive a current density of 10 mA·cm^-2 in 1 mol·L^-1 KOH with negligible degradation during the 50 h stability test, which was superior to the commercial catalyst IrO₂ and other Ni-Mo based catalysts reported. The excellent electrocatalytic performance of Ni₃S₂@Mo₂S₃ can be attributed to the synergistic effect of different transition metal compounds, self-supporting in situ growth, large electrochemically active area, and aerophobicity under liquid.

Analyzing the morphology evolution of polyolefin particles during the growth process is crucial for understanding the polymerization mechanism and regulating product properties. The complex particle growth of polyolefins leads to a large morphology difference and an extremely wide range of particle size distribution. However, existing studies focus on the process of primary polyolefins growing from the fragmentation of homogeneous catalysts, but lack of systematic studies on the subsequent growth and morphology evolution of primary polyolefins with different morphologies. Besides, a method of batch sorting polyolefin with different morphologies is needed to support statistical analysis of morphology evolution. An electrostatic-morphology co-separation method for polyolefin particles was developed based on the morphology-dependence of same-material particles with the same size. Through this method, batch sorting of polyolefin particles with similar sizes but different morphologies was achieved and the morphology evolution during polyethylene particle growth was investigated. The results show that there is a general phenomenon of morphology deterioration during polyethylene particle growth. As the particle size increases, the particle morphology gradually deviates from the sphere. The coupling analysis of particle size, morphology and crystallinity indicates two possible modes of particle growth as well as morphology deterioration: the particle fragmentation caused by excessive crystallization rate, and the replication of catalyst morphology. The method and results in this paper provide important support for the study of polyolefin morphology and the development of high-performance polyolefin catalysts.

Porous adsorbents are widely used in separation and purification, gas storage, and industrial catalysis, and the determination of adsorption isotherms is of great significance for studying adsorption properties. Aiming at solving the difficulty that the traditional volumetric method is easily affected by the temperature distribution along the pipeline, the paper introduces an adsorption measurement method based on flow calibration. The error transfer of both methods is analyzed, and the influence of the structure parameters, physical parameters and instrument accuracy on the adsorption measurement is compared. The results show that increasing the calibration ball volume and sample chamber volume can improve the adsorption measurement accuracy of the traditional volumetric method, and increasing the sample volume, excess adsorption amount, skeleton density and instrument accuracy can improve the measurement accuracy of both methods. Compared to the traditional volumetric method, the method based on flow calibration has fewer error factors and can achieve lower measurement errors. The results can help improve the measurement accuracy of the volumetric method.

The kinetics of extraction of tetravalent cerium from nitric acid solution by ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide (C₄mimNTf₂) in 1,2-dichloroethane was studied by the constant interface cell method. The molecular dynamics (MD) simulations were performed to reveal the effect of the interface on the extraction kinetics. In the experimental section, the extraction rate regime was analyzed according to the dependences of extraction rates on the stirring speed, interfacial area, and temperature. The effect of solution compositions on the extraction rate was also investigated. The experimental results show that a mixed diffusional-kinetic regime occurs, where the diffusion resistance is in the aqueous phase, and chemical reactions occur at the interphase. The aqueous nitric acid concentration significantly influences the extraction rate, because it affects the coordination behaviors of tetravalent ceric ions. The apparent rate constant under the experimental condition was determined as 0.094 L·cm·mol^-1·min^-1 by fitting the experimental data. It also indicates that the additional tri-n-butyl phosphate (TBP) in the organic phase exerts the antagonistic effect on the kinetic with C₄mimNTf₂. The MD simulations employed the general AMBER force field (GAFF) combined with the restrained electrostatic potential (RESP) atom charge. The scaled charge scheme with a scaled factor of 0.8 was adopted for ionic liquids to avoid overestimating the interaction energy between cations and anions. A mixed dissociation model of nitric acid was employed to consider the state of nitric acid molecules in the aqueous phase. In simulations, the number and charge density distribution along the axial, the radial distribution functions (RDF), and diffusion coefficients were calculated. The simulation results show that C₄mimNTf₂ in the organic bulk tends to adsorb at the interface with the polar groups toward the aqueous phase. The center-of-mass RDF between C₄mim⁺ and \mathrm{N}\mathrm{T}{\mathrm{f}}_{\mathrm{2}}^{-} depicts that C₄mimNTf₂ exists in the form of ion pairs or clusters. With the addition of TBP in the organic phase, C₄mimNTf₂ can bond with TBP by the hydrogen bonds between the imidazolium ring and the terminal oxygen atom of the P\stackrel{\text{????}}{?}O group in TBP. Meanwhile, the simulated diffusion coefficients of C₄mimNTf₂ and TBP decrease with the increased organic phase TBP concentration. The hydrogen bond interactions and the variation of diffusion coefficients lead to the antagonistic effect. This study demonstrates that the interface behavior significantly affects the extraction of Ce(Ⅳ) from nitric acid solutions, which provides some reference for the extraction process and mechanism of the ionic liquid-based extraction system

Adjustments in production decisions or changes from working statuses may lead to multi-modal production process. Commonly used data clustering methods have difficulty in parameter selection or need prior knowledge when recognizing multi-modal process. Therefore, a method is proposed that combines the kernel density estimation of heat diffusion determining density peak technology in the field of artificial intelligence with the Gaussian mixture model. It can effectively overcome the shortcomings of the current methods. The method first uses the kernel density estimation of heat diffusion determining density peak technology to estimate the local density of every data sample and its distance from higher local density to obtain the number of cluster centers and cluster the data set. Secondly, the characteristic parameters of different working conditions are obtained by using Gaussian mixture model: average, covariance and prior probability, so as to accurately describe the historical process of multiple operating conditions. Finally, two examples of Tennessee Eastman process and simulation data in literature were used for verification, and compared with K-means and Gaussian mixture model improved by F-J, it is proved that the proposed method can be more convenient and effective to accurately recognize the historical operating conditions.

Under the overall idea of the refinery scheduling model considering optimal operating mode switching of units, a refinery plant-wide scheduling optimization discrete-time model structure is constructed with a matching program framework. The object-oriented modeling method is adopted, and expressions such as modal indication matrix are introduced, which provides a clear reference idea for the generalized oil refinery production scheduling modeling. Through the data interaction between GAMS and MATLAB, the complementary advantages of the two are realized, which provides convenience and lays a foundation for further research on the refinery production scheduling model. The case study verifies the effectiveness of the proposed model structure and program framework.

A stochastic programming modeling framework based on mass transfer mechanism was proposed, which took the uncertainty of crude oil properties into consideration, to achieve the simultaneous optimization of economic performance and disturbance rejection ability of refinery hydrogen network. The framework integrated process units such as atmospheric and vacuum distillation, hydrofining and flash separation to analyze the impact of crude oil properties fluctuations on network operation microscopically; adopted surrogate-assisted techniques to embed desulfurization unit and used the two-stage stochastic programming approach to retrofit network, so as to optimize hydrogen network macroscopically to meet production requirements. To verify the effectiveness and applicability of the proposed method, studies on the optimization design of an industrial hydrogen system were presented. The results show that the multi-scenario optimization strategy integrated process units can effectively improve the economic performance of hydrogen network. And it can flexibly respond to changes in operating scenarios caused by fluctuations in crude oil properties.

Chemical process is generally a multivariable system, but its main control scheme is decentralized multi-loop PID conventional control. Since there are different degrees of coupling in the multivariable system, there are mutual influences between the control loops. When the other control loops switch between the manual/automatic modes, the equivalent controlled object of this loop will mutate so that the original control parameters of this loop will be inappropriate and the control performance will become worse even the closed-loop system is unstable. In order to avoid this situation, the stability of the control loop mode switching should be studied from the perspective of the whole system, so the multivariable frequency domain Nyquist array design method is adopted. Based on the Nyquist stability criterion under diagonal dominance, the stability changing of each control loop before and after mode switching is quantitatively analyzed from the Gershgorin circle boundary points, so as to determine the adjustment direction and size of the controller gain for each loop. The controller parameter self-tuning of each loop at the moment of control loop mode switching is realized to compensate the disturbance caused by the control loop mode switching and ensure the closed-loop stability of the whole system. The multi-loop PID control system of Shell heavy oil fractionator is used as an example, when the three PID control loops are put into use in turn, the control parameter self-tuning according to the boundary points of Gershgorin circle makes the closed-loop system still maintain certain control performance, otherwise the closed-loop system will be unstable.

Global warming has become increasingly serious over the last decade. As one of the greenhouse gas (GHG) emission contributors, petroleum refineries are now encountering high GHG emissions and annual costs due to the increase of hydrogen demand. Light hydrocarbons recovery(LHR) unit can effectively reduce GHG emissions and improve resource utilization through recovering hydrogen and hydrocarbons components. Therefore, it is necessary to consider the light hydrocarbon recovery unit in the optimization of the hydrogen network. To avoid the high computational cost of rigorous process, this paper proposed surrogate models as approximations to the rigorous LHR process. Meanwhile, the environmental impact was added to the optimization goal. Finally, a hydrogen network multi-objective mathematical programming model was established. The proposed approach was applied to a case study taken from a real refinery. The results showed that the proposed method can effectively reduce the annual cost and GHG emissions of the hydrogen network, and reveal the trade-off relationship between the economic performance and the environmental impact of the hydrogen network integrated LHR unit. Hence it can provide a certain theoretical basis for further industrial application.

The electrowetting behavior of captive bubble/oil-droplet in the surfactant solution in a low-voltage electric field is investigated experimentally. The effect of the surfactant on the electrowetting characteristics was analyzed, and the evolution of immersed bubble/oil-droplet under electric field was explored. The experimental results show that by adding N,N,N-trimethyl-1-dodecanaminium bromide(DTAB) or sodium dodecyl sulfate(SDS), contact angle reduction and bubble slip can occur in low-voltage (0 — -6 V). In addition, the increase of the surfactant concentration could reduce the voltage required for bubble slip. In a concentration of 0.05 CMC to 0.10 CMC, the captive oil-droplet in the DTAB solution presents good electrowetting performance, and the silver surface could achieve underwater superoleophobic property with θ < 30° at -3 V. Moreover, in the process of electrowetting, the contact angle and contact diameter of the bubbles/oil-droplets both gradually decrease in form of “slow-fast-slow”. The shape of the captive oil-droplet is found to be affected by the electrostatic force caused by the adsorption and charging of the ionic surfactant at the interface.

Compliant foil gas seal is a new structural form of cylindrical gas film seal. This structure can be applied in hydrogen compressor. The combination of gas film dynamic and the compliant foil achieves high performance seal. In order to analyze the influence of surface topography and turbulence on sealing characteristics of compliant foil gas seal, this paper solves the Reynolds equation by periodic condition. This equation includes the factor of surface roughness. The result is compared with the experimental. The influence of surface roughness on compliant foil gas seal includes leakage, gas force, gas stiffness and sealing hysteresis. Meanwhile, the influence of surface roughness on the cycle test of compliant foil gas seal is observed. The results show that the factor of surface roughness has important effect on the leakage and seal hysteresis. With the surface roughness and speed increases, the mid-surface pressure fluctuation largely. Meanwhile, the leakage and the gas force increases obviously with the increase of surface roughness, but the gas stiffness decreases. This casues the instability of gas film seal. Under the full cycle test, there is sealing hysteresis in the gas film seal. The increase of surface roughness leads the increase of the sealing hysteresis energy. Moreover, there is anti-hysteresis phenomenon under different surface roughness. This is caused by elastic element and the transient variation of friction and speed. Therefore, it is important to control the surface roughness for compliant foil gas seal.

Utilizing abundant and readily available solar and seawater resources to provide sustainable and clean energy to mankind is a far-reaching exploration. In this work, we have designed and synthesized the self-floating solar photothermal composite (Cu/TiO₂/C-Wood) that possesses efficiently full-spectrum solar energy capture and photothermic properties for highly targeted interfacial phase transition reactions that are synergistically favorable for both seawater desalination and hydrogen production. Among them, carbonized wood with abundant microchannel and extremely light mass is used as self-floating carrier to rapidly transports liquid water to localized heating interface by capillary and photothermal effects to achieve effective seawater desalination and water steam production. The plasmonic Cu loaded TiO₂ nanoparticles as catalytic active components trigger surface-dominated photothermally catalytic hydrogen evolution of water steam, realizing the dual-function seawater desalination and synergistic hydrogen production. The hydrogen evolution rate of Cu/TiO₂/C-Wood composite is 179 μmol·h^-1·cm^-2 (35.8 mmol·h^-1·g^-1) under 15 kW·m^-2 and remains basically unchanged after being used 5 times. More importantly, the experimental results show that the main component in seawater-sodium chloride can promote the hydrogen production performance by synergistically concentrated irradiation and self-floating phase transfer process, which breaks the bottleneck of seawater hydrogen production technology, confirming the promising application potential of the self-floating two-phase photo-thermo-catalytic system in large-scale, green and sustainable solar hydrogen production from seawater.

The removal of tar is a problem for the large-scale application of biomass gasification. Ionic liquids have the advantages of lower saturation vapor pressure and designable molecular structure, which are widely used in catalysis and absorption, but there is little research in the tar removal. Based on the improved COSMO-RS method, the infinite dilution activity coefficients for benzene, toluene, phenol and naphthalene are calculated by COSMOtherm software. The effects of imidazole cations and strong electronegative anions on absorption properties are further investigated by partial molar excess enthalpies. The results show that the infinite dilution activity coefficients of the preferred double substituent imidazole ionic liquids for the four tar simulants are between 0.4—1, which is expected to have excellent absorbing performance. When the anions are the same, the absorbability of the double substituent imidazole cation becomes better with the increase of alkyl side chains at R₁ position, and [C₈MIM][NTf₂] shows a better absorbing performance. The infinite dilution activity coefficients of benzene, toluene and naphthalene are 0.95, 1.24 and 1.36, respectively, but the viscosity of the ionic liquid is higher. For phenol system, [BF₄]^- anion performance is better.

In the context of “Emission peak, Carbon neutrality”, high CO₂ emission intensity, and low carbon utilization efficiency greatly restrict the development of the coal to methanol(CTM) process. A novel CTM process is proposed in the paper,which is near zero carbon emission by pulverized coal gasification integrated green hydrogen. In this case, the air separator and water-gas shift units can be eliminated, and acid gas removal unit also can be simplified. The key parameters are analyzed on the basis of established model of the two processes. The advantages of novel process are manifested in detail in comparison with the CTM process. The results show that the carbon utilization rate of the CTM process and the novel process are 41.50% and 95.77%, and the CO₂ direct emission intensity is decreased from 1.939 to 0.035 t·(t MeOH)^-1. An analysis of the impact of hydrogen prices and carbon taxes on product costs reveals that when the hydrogen price and carbon tax are 10.36 CNY·(kg H₂)^-1 and 223.3 CNY·(t CO₂)^-1, the production cost of two processes is equal. The new technology not only reduces carbon emissions from the CTM process, but also improves the on-site absorption capacity of renewable energy, which has good application prospects.

Calcium oxide(CaO) was used as additive to regulate the thermal desorption process of oil-based drilling cuttings to reduce the low quality and severe smell of oil and gas. The results showed that: (1) The higher CaO addition ratio, the higher yield of oil and the lower yield of water and gas. The yield of residue increased at first and then decreased. (2) Higher desorption temperature resulted in lower yield of residue and higher yield of oil, water, and gas. (3) The addition of CaO significantly increased oil yield and decreased the yield of oil and gas by different degrees under every temperature. (4) The yield and saturation of hydrocarbons of oil increased, the sulfur content in oil decreased after adding CaO. Therefore adding CaO improved the additional economic value of recycled oil and reduced the water and gas yield, especially the yield of CO₂ and H₂S. The introduction of CaO as an additive reduces the atmospheric pollution of the thermal desorption process to the operating environment, as well as the desulfurization burden of the subsequent process, reduces the high energy consumption caused by water evaporation, and creates favorable conditions for the reuse of oil products and non-condensable gas.

The synergistic removal technology of ozone oxidation pollutants utilizes the strong oxidizing property of ozone to oxidize various pollutants such as NO _x, Hg, VOCs and other pollutants with low solubility in flue gas into high valence or easily soluble forms, and combined with the tail wet spray system to achieve simultaneous removal of pollutants. Due to its advantages of low temperature window, high denitration efficiency, fast reaction rate and less difficulty in transformation, it is widely used in industrial boilers, kilns and non-electric industries. However, the actual transformation path of pollutants in this process, especially the input/output balance of NO _x, has not been verified in detail by experiments. Therefore, for the typical ozone oxidation denitrification process, this paper analyzes NO _x input/output balance and nitrogen flow direction in the process of pollutant removal. The experimental results show that the NO input in the gas phase is gradually converted into nitrate and nitrite in the liquid phase after ozone oxidation coupled with wet spraying. Under different O₃/NO molar ratios, the reduction of nitrogen in the gas phase is converted into the increase of nitrate and nitrite in the liquid phase, and there is no other nitrogen- containing form. At the same time, the conversion rate of nitrate and nitrite in the absorption slurry is also matched with the NO _x removal rate in the flue gas. Under the condition of simultaneous oxidation of NO/SO₂, adjusting the O₃/NO molar ratio, combined with the wet absorption system, it can achieve simultaneous and high-efficiency removal of NO _x /SO₂, and the system can satisfy the nitrogen input/output balance. It can provide a basis for the engineering application and popularization of ozone oxidation pollutant synergistic removal technology.

Efficient and stable CeO₂/CNT composites were prepared by impregnation-calcination method. The structure of the material was characterized by means of X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectroscopy, and the degradation performance of sulfisoxazole(SIZ) by activated peroxymonosulfate(PMS) of the composite was studied. The introduction of CeO₂ increases the defects content of carbon nanotubes, and the Ce³⁺/Ce⁴⁺ provides active sites for the reaction, which effectively improves the performance of carbon nanotube when activating PMS. The catalyst performance was studied by investigating the effects of CeO₂ doping amount, catalysts dosage, PMS dosage and initial pH on the degradation system. The results show that when the dosage of catalysts is 75 mg·L^-1, the dosage of PMS is 0.3 mmol·L^-1 and the initial pH is 5.36, the removal rate of SIZ can reach more than 90% in 30 min and 100% in 50 min, and the reaction process conforms to the pseudo first-order reaction kinetic model. After 5 cycles, the catalyst can still maintain 77% degradation. Electron paramagnetic resonance experiments indicated that SO₄?^-, ?OH and ¹O₂ were produced in the degradation of SIZ. The surface defects of carbon nanotubes may be related to the formation of ¹O₂. At the same time, the direct electron transfer mediated by carbon nanotubes was existed in the system. The cycle of Ce³⁺/Ce⁴⁺ in the system promotes the activation of PMS.

Based on the in-situ visualization features of electrical impedance tomography (EIT), yeast and kaolin are used as model pollutants, the different fouling characteristics of ultrafiltration (UF) membranes were studied under different cross flow velocity, the flux, average voltage, EIT image and three-dimensional image reconstruction were obtained, and the correlation model between membrane flux and average voltage was established. The results show that the EIT can visually display the membrane fouling interface. The membrane fouling formed by the yeast presented a spatially uneven distribution, while the fouling formed by the kaolin was relatively uniform, and the fouling formed by the mixed solution lies between the two. The information about the thickness of the contamination layer was obtained from the reconstructed image of the EIT signal. The results showed that the contamination layer formed by yeast was the thickest, followed by the mixed solution of yeast and kaolin, and the thinnest contamination layer was the kaolin solution.

Capacitive deionization (CDI) is a new desalination technology based on the principle of electrosorption, which has the advantages of low cost, no secondary pollution, and low energy consumption. The hydrophilic binders carboxymethyl cellulose sodium (CMC), polyvinyl alcohol (PVA) and sulfonated carboxymethyl cellulose sodium (SCMC), quaternized polyvinyl alcohol (QPVA) were used to prepare the activated carbon electrodes, which further enhanced the hydrophilicity and ion selectivity of activated carbon (AC) electrodes. The hydrophilic charged polymer binder can effectively inhibit the anodic oxidation reaction and enhance the driving force of ion adsorption by virtue of its own charge. In 500 mg/L NaCl salt solution at 1.2/0 V, AC-CMC//AC-PVA and AC-SCMC//AC-QPVA can obtain 14.58 and 17.39 mg/g of desalination, respectively, And after 100 cycles at 0.8/0 V, the retention rates of desalination were 65.48% and 80.53%, respectively.

Metal-organic framework (MOF) has been developed rapidly in the fields of gas adsorption and storage in recent years, but they are unsatisfactory in the adsorption of strong corrosive gas ammonia (NH₃) due to structural instability. Considering NH₃ is the only carbon-free chemical energy carrier, developing efficient ammonia storage technology to carry hydrogen is an effective technology to reduce carbon dioxide emissions. MOFs exhibit great prospects for adsorption and storage of NH₃ due to their high surface area and structural diversity advantages. NH₃ has a lone pair of electrons, which will attack the coordination bond formed between the metal ion and the ligand, resulting in the structural destruction of MOFs. Herein, the structural characteristics, stability, and NH₃ adsorption properties of Zr-based metal-organic frameworks, including UiO-66, NU-1000, MOF-801, and MOF-808, were investigated by experiments and computational simulations. The results showed that UiO-66 has excellent structural stability in NH₃ adsorption with a high uptake of 13.04, 6.38 and 9.65 mmol/g. However, Due to the limited stability and low adsorption capacity, NU-1000 and MOF-801 are not suitable for ammonia adsorption under the humid environment. Conversely, the structure of UiO-66 and MOF-808 is very stable, which can be used in NH₃ adsorption and storage applications both in dry and humid NH₃ environments.

Based on the fact that the 18-crown-6 ether ring cavity can form a 1∶1 stable complex with K⁺, 4,4'-diamino-dibenzo-18-crown-6 (A18C6) was introduced into the ion-exchange membrane-based material and formed into a membrane, and then A18C6 molecules were cross-linked and immobilized with 1,3,5-benzenetricarbonyl chloride (TMC) to obtain a series of modified cation-exchange membranes. By changing the content of A18C6 and the reaction time of TMC to adjust the matrix structure of CEMs, the ED permselectivity to K⁺ for the modified membranes in binary systems of K⁺/Mg²⁺, K⁺/Na⁺ and K⁺/Li⁺ were systematically investigated. At a constant current density of 5.0 mA·cm^-2, the modified membrane M-A18C6-10%-T30 shows prominent permselectivity to K⁺ in K⁺/Mg²⁺ and K⁺/Li⁺ binary systems (P_{\mathrm{M}{\mathrm{g}}^{\mathrm{2}+}}^{{\mathrm{K}}^{+}}=\mathrm{6.96},P_{\mathrm{L}{\mathrm{i}}^{+}}^{{\mathrm{K}}^{+}}=\mathrm{3.73}), which is superior to commercial monovalent selective cation exchange membrane (MSCEM) CIMS (P_{\mathrm{M}{\mathrm{g}}^{\mathrm{2}+}}^{{\mathrm{K}}^{+}}=\mathrm{5.36}). The introduction of A18C6 improves the compactness of membrane matrix (pore-size sieving effect) and further provides new ion transport channels for K⁺ (ion-dipole interaction).

Coal resources in China are rich, diverse, inexpensive and widely distributed. Converting coal into new materials is an effective way to improve its added value and technical content. Coal has high carbon content and rich aromatic ring structure, and pyrolytic carbonization can prepare hard carbon anode materials for sodium-ion batteries. This paper uses Xinjiang bituminous coal as the carbon source, adopts a two-step process of low-temperature pyrolysis and high-temperature carbonization, and adjusts the corresponding process conditions. The effect of the development process of bituminous coal mesophase on the structure of hard carbon and its sodium storage electrochemical behavior was studied. We have found that changing the temperature range, carrier gas flow rate, and heating rate of low-temperature pyrolysis can adjust the decomposition and depolymerization reactions in the formation stage of colloids, then adjust the degree of volatile matter generation and escape, and the degree of colloidal solidification, so as to adjust the specific surface area, graphitization degree and heteroatom content of the obtained hard carbon. The result of electrochemical performance test demonstrated that the carbonized anode electrode material under low-speed heating range of 350—550℃, carrier gas flow rate of 60 ml·min^-1, and heating rate of 1℃·min^-1 has the best reversible specific capacity and initial coulombic efficiency, reaching 314.3 mA·h·g^-1 and 82.8% at a current density of 0.02 A·g^-1, respectively. These excellent performances should be attributed to the coordination between the ordered carbon structure and the defect structure of the coal-based hard carbon material.

Zuomu-based activated carbon was prepared by different activation methods. The structure of activated carbon was investigated by N₂ adsorption, FT-IR, XPS, XRD, and Raman spectra. And the structure-property relationship of activated carbon was discussed. The results show that activated carbons prepared by different activation methods have different microstructure and electrochemical performance. Activated carbons prepared by KOH and H₃PO₄-KOH have well-developed micropores, abundant content of defective sites and heteroatoms on the surface of carbon matrix, which provide more energy storage space and active sites to increase the specific capacitance at low current density. The activated carbon prepared by H₃PO₄-KOH has better capacitance retention due to its wider micro mesopore distribution and pore connectivity. Activated carbons prepared by CO₂, H₃PO₄ and H₃PO₄-CO₂ activation possess well-developed mesopores, small micropore volume, poor connectivity, relatively complete carbon matrix, and fewer defects and heteroatoms exposed on the surface of the carbon matrix, resulting in the higher capacitance retention rate and lower specific capacitance. The microstructure of activated carbon has a great influence on the performance of supercapacitors. The developed microporous will provide abundant energy storage sites. The good connectivity will provide channels for fast ion transport to improve the capacitance retention. More exposed defects and heteroatomic groups on the surface or edges of the carbon matrix will be beneficial to improve the pseudo capacitance. These enable the supercapacitor to exhibit high specific capacitance and good cycling stability. Therefore, high-performance activated carbon electrodes for supercapacitors should have a well-developed microporous structure, a wide distribution of micro-mesopores, a smooth micro-mesoporous connected structure. At the same time, it contains more structural defects and heteroatom groups exposed on the surface of the carbon structure, thereby improving the energy density of the supercapacitor.

The low thermal conductivity and poor shape-stability of organic paraffin as phase change material have limited their applications. In order to improve the thermal conductivity and anti-leakage performance of paraffin, wood was modified by chitosan and carbonized at high temperature to prepare hierarchical porous carbon skeleton, which can not only firmly adsorb paraffin but also greatly improve the thermal conductivity of phase change composite (PCC). The morphology, phase change cycling stability, thermal conductivity and photothermal conversion performance were tested. The results show that with the introduction of multi-scaled porous structure, PCCs have good shape-stability without obvious leakage. The phase change enthalpy of the PCC is 126.9 J/g. The phase-transition temperature and enthalpy of the PCC have no obvious change over the 100 cycles of melting and solidification, indicating that the PCC has good cyclic stability. The thermal conductivity of PCC is also greatly improved and presents obvious anisotropic thermal conductivity. The out-of-plane and in-plane thermal conductivity of PCC are 0.67 and 0.41 W/(m·K), respectively. The great improvement of the out-of-plane thermal conductivity is conducive to improve the thermal management application of PCC. In addition, it is also found that PCC has good photothermal conversion performance. The composite phase change materials developed in this paper have application prospects in the fields of heat storage and thermal management.

In order to investigate the combined burning characteristics of soaked porous media sand bed under different combustible liquid layer heights, a series of burning tests with different sand sizes and liquid layer heights were conducted. The characteristic parameters, fuel (ethanol) mass loss rate, flame height, internal temperature of porous media (quartz sand) and plume temperature were measured, and the effect mechanism of liquid layer height was analyzed and studied. The results show that the existence of combustible liquid layer has a certain effect on burning characteristics of quartz sand infiltration layer. When there is a liquid layer above the sand layer (h=20—60 mm), the mass loss rate of quartz sand infiltration layer increases obviously, which can be attributed to the preheating effect of liquid layer burning. The flame height increases firstly and then stabilizes with the increase of liquid layer height, which shows the similar trend with mass loss rate. The temperature growth retardation occurs inside sand bed within 78.7—79.0℃ (which is close to fuel boiling point), so the vapor zone movement speed inside sand bed can be evaluated. As the height of the liquid layer increases and the particle size of the quartz sand decreases, the velocity of the vapor zone in the sand layer gradually increases. In addition, based on previous scholar's plume relationship and current experimental data, an empirical formula is obtained to describe axial temperature of flame and plume for combustible liquid-soaked inert porous media sand bed.

In order to study the inhibiting effect of C₆F₁₂O on the combustion of aviation kerosene, the combustion mode of cup burner is changed from liquid level combustion to wick combustion, which overcomes the difficulty of ignition in the fire extinguishing performance test of gas extinguishing agent due to the high flash point of aviation kerosene. It can be seen from the experiment that with the increase of the concentration of C₆F₁₂O in the air, the height of aviation kerosene flame experienced a process of slow increase and then rapid decrease. That means the effect of C₆F₁₂O on combustion changes from promotion to inhibition at different concentrations. In order to further explore the reason of that transformation, the mechanism of inhibiting RP-3 aviation kerosene combustion by C₆F₁₂O with 1403 species and 7496 reactions was constructed. According to the chemical kinetics analysis, the inhibition effect of C₆F₁₂O on combustion at low temperature is better than that at high temperature. The inhibition effect of C₆F₁₂O at low concentration increases mainly because the reaction rates of promoting combustions are much faster than other reactions after the temperature rising. One of the ways to reduce the combustion temperature of RP-3 aviation kerosene is through endothermic reactions such as thermal decomposition. And with the increase of the concentration of C₆F₁₂O, the reaction path changes, resulting in a decrease in the production of H, O and OH free radicals and a large increase in consumption, which macroscopically weakens the promotion effect of C₆F₁₂O on combustion as a fuel, and enhance the inhibition effect as an extinguishing agent. The results can provide theoretical guidance for the prevention and control of aviation kerosene fire by using C₆F₁₂O, and provide reference for the development of new extinguishing agent.