Energy conversion and energy storage processes based on anion exchange membranes (alkaline ion membranes) are very important, including alkaline membrane fuel cells, alkaline membrane electrolysis of water to produce hydrogen, etc. This type of electrical membrane process will have a profound impact on the future energy structure influences. Existing anion exchange membranes often suffered from problems of poor alkali resistance and short life span, which severely restrict the development of efficient energy storage and conversion technologies. Recently, researchers have carried out a lot of novel molecular design for alkaline membrane materials of highly chemical stability. This review is based on the two perspectives of alkaline anion exchange membranes and the polymer backbone and cationic groups, focusing on the molecular design strategies including polyolefin and poly-aryl backbone structure, as well as non-metal or metal cationic groups. Moreover, regular methods and current deficiencies of high-stability alkaline anion exchange membranes structural design is summarized, and new ideas for synthesis of next generation high-performance materials for energy conversion processes is also proposed.

As a green and efficient separation technology, melt crystallization has the advantages of high selectivity, low energy consumption, and no need for solvents. However, it remains several challenges in theoretical research on crystallization, continuous production, specific targeted crystallizer design and industrial scale-up. Moreover, its separation efficiency is limited by the nature of the system, the purity of raw material and crystal growth rate. Therefore, a reasonable design and process optimization for melt crystallization is of great significance to improve its energy and process efficiency. Based on the actual demand and applying prospects of melt crystallization technology, the intensification methods of crystal nucleation and growth during melt crystallization include three aspects that are: process optimization, surface design of crystal layer growth and coupling technique, which providing the feasible guidance to realize higher efficiency and lower energy consumption. Finally, the critical concerns of melt crystallization are outlined and the development directions are prospected.

Nitrogen-doped carbon materials have a wide range of applications in the field of catalysis due to their unique properties. The nitrogen doping process can introduce defects and nitrogen species, improve the physical and chemical properties, acidity and alkalinity and wettability of the catalyst, and interact with active species to enhance the catalytic performance. Besides, the existence of nitrogen species could act as anchoring sites which could enhance the stability of active species such as metal and metal oxide components. With above mentioned, not only would the catalytic performance largely be increased, but also the stability and dispersion of active species would be improved. Up to now, there are several strategies for nitrogen-doped carbon materials preparation, which are post synthesis, in-situ synthesis, etc. For the post synthesis, well-prepared carbon materials and nitrogen precursors would be treated together, forming nitrogen species in carbon. During the synthesis process, the modulation of precursor type, treatment method and synthesis condition could effectively vary the pore structure, nitrogen type and content, interaction between support and active species, etc. Though great progress has been made, nitrogen-doped carbon materials still need investigation in the development of low cost, simple, environment friendly preparation routes. Moreover, in-depth research on influence of nitrogen species on defect construction and interaction between nitrogen and active sites is also urgently needed. In all, nitrogen-doped carbon materials exhibit excellent catalytic performance, which may pave a way for industrial catalytic technology.

The gaseous pollutants and particulate matters produced during coal gasification and combustion will be transferred to syngas and air, resulting in problems such as equipment corrosion and environmental pollution. Electrospun nanofibers have the advantages of controllable and ultra-fine diameter, porous structure, ultra-high specific surface area, designable morphology, and easy to be modified on the surface, and thus have great application value in gas pollutants removal. The basic principle, development history and current situation of electrospinning were introduced, and the application and research status of electrospun nanofiber materials in the removal of gas pollutants such as PMs, CO₂, NO_x, H₂S, SO₂ and VOCs were summarized and analyzed. Finally, more extensive and depth perspectives of nanofibers material synthesized by electrospinning in the applications of gas pollutants removal were also discussed and expected.

The anti-/de-icing of impact droplets is of great significance in practical engineering applications. It is a research hotspot in the field of icing to seek an economical and efficient anti-/de-icing method. In view of the icing problem of impact droplets, the author firstly reviews the dynamic characteristics, icing characteristics and theoretical research of impact droplets icing. On this basis, a comprehensive analysis of the current commonly used anti-/de-icing methods and existing problems was carried out. Then, based on the new idea that the rebounding characteristics of impact droplets can suppress icing from the source, a new method to reduce contact time and increase nucleation/rebright time is proposed. The proposal of these methods will help to solve the problem of icing of impact droplets in essence, and will greatly expand the application scope of “using the rebound characteristics of impact droplets to suppress icing”, and actively promote the development of anti-icing technology. Finally, the research on the use of the rebound characteristics of droplets to suppress icing is expected.

As a new method for ethanol synthesis from coal, dimethyl ether carbonylation with CO to methyl acetate and its further hydrogenation to ethanol has attracted much industrial attention. This route requires mild reaction condition and the catalysts can be easily prepared. In this work, we reviewed the advancement of the catalyst in the field of dimethyl ether carbonylation and methyl acetate hydrogenation. In addition, we summarized the effect of proximity of zeolite and Cu-based catalyst for ethanol synthesis. We especially focused on the development of dimethyl ether carbonylation and deactivation mechanism over zeolite as well as the modification methods of zeolite. The new coal-to-ethanol technology provides an important way for the clean and high-value-added utilization of coal resources in China.

The organic amine aqueous solution absorption method is one of the most commonly used and mature methods for CO₂ capture, but key issues such as high regeneration energy consumption and severe degradation of the absorbent hinder its large-scale promotion and application. Water as a co-solvent in this technology is considered to be the weak point because of its large specific heat capacity and enthalpy of vaporization. These associated energy consumption takes up about 60% of the total energy for CO₂ desorption. The replacement of the strong polar water using organic solvents to develop non-aqueous absorbents has potential to reduce the regeneration energy consumption, degradation as well as equipment corrosion. Therefore, non-aqueous absorbents have attracted much attention in recent years. Research on the kinetics of CO₂ absorption by amines in organic solvents is helpful to understand the reaction mechanism and the effect of different structures or types of amines and co-solvents on the reaction kinetics, and also to design the CO₂ absorption process from the lab to industry. In this review, possible reaction mechanisms in non-aqueous solvents are summarized, and the typical experimental methods and principles for reaction kinetics reported in the literature are introduced. Research works and results on the kinetic properties for amine systems with various organics in the open literature are summarized and remarked. Moreover, further analysis on the correlation between solvent characteristics and the collected kinetic data is conducted. It has been found that roughly linear relationships between solvent characteristics and the reaction order and kinetic parameters are presented. For a specific amine, the second-order rate constant increases as increasing the solubility parameter of the co-solvents. However, the partial reaction order with respect to the primary and secondary amines increases with the increasing solvent polarity. Finally, some further research directions for reaction kinetics of CO₂ absorption in non-aqueous solvents are proposed based on critical analysis of the existing research.

This article introduced a basic but high valued carrier material--microbubble. In this paper, the preparation method of microbubbles, the control of morphology, size and stability of microbubble as well as the functionalization were reviewed point by point. The recent applications of microbubbles in different areas were also introduced in detail. The studies on the characteristics of microbubbles for innovative applications by researchers from various research fields were reviewed comprehensively. Finally, the research trends and existing problems of the preparation and functionalization of microbubble materials are discussed.

Rebaudioside A is an extremely important new sweetener. Nevertheless, there are some quality problems of its crystal products obtained by existing crystallization process such as too many fine crystals and large crystal size distribution. In order to solve the above problems, a comprehensive study about crystallization of rebaudioside A was carried out. Firstly, the solubility of rebaudioside A in several binary mixed solvents including methanol-water, ethanol-water, n-propanol-water and acetone-water as well as the metastable zone width in methanol-water mixed solvents were determined by means of laser dynamic technology and the experimental solubility data was verified by Wilson model subsequently. Besides, the influences of solvent composition, agitation rate and cooling rate on metastable zone width were explored and the result showed that the metastable zone width would increase with the increment of the content of methanol in mixed solvents or the increment of cooling rate while would become narrow with the incensement of initial saturation temperature and stirring rate. In addition, on the basis of the classical nucleation theory and corresponding metastable zone model, the nucleation parameters such as interfacial energy between solid and liquid γ and critical Gibbs free energy \mathrm{\Delta }{G}_{\mathrm{c}\mathrm{r}\mathrm{i}\mathrm{t}} of rebaudioside A were calculated. Furthermore, according to the calculated value of apparent nucleation order m, progressive nucleation was the dominant nucleation mechanism of rebaudioside A when the initial crystallization temperature was higher than 318.15 K. At last, the crystallization process was optimized and the high quality rebaudioside A product with uniform particle size was obtained.

Superconducting energy pipeline is a forward-looking energy transmission technology that cools superconducting cables with liquefied natural gas (LNG) and realizes the simultaneous transmission of two energy sources. The economic operating temperature of superconducting energy pipelines is generally 77—100 K, and LNG has a risk of solidification in this temperature range, so it is necessary to study the solid-liquid equilibrium characteristics of the main components of LNG. This article focuses on five binary mixtures of methane+ethylene, methane+ethane, methane+propane, methane+n-butane, and methane+n-pentane, using the equation of state represented by the Peng–Robinson (PR) equation of state with the simple van der Waals (vdW) mixing rule. The activity coefficient method represented by models such as NRTL (non-random two liquids), WILSON and UNIQUAC (universal quasi–chemical). Based on the binary data of vapor-liquid equilibrium for the studied system and the regressed binary interaction parameters, the solid-liquid equilibrium of five binary mixtures was predicted, and the results were compared with the literature data. The results show that the PR-vdW equation has the best prediction results for the solid-liquid equilibrium of the five binary mixtures containing methane. Furthermore, the effects of the binary interaction parameters in the PR-vdW equation on the calculation results of the vapor or solid-liquid equilibria of the five binary mixtures were studied, and the dependence of the model on temperature was analyzed.

In order to improve the product distribution of FCC process, on the basis of the traditional single-layer upward feedstock nozzle feed structure, two symmetrical and downward “sub-nozzles” have been added. The gas-solid flow characteristics of the double-layer nozzles were experimentally investigated in a large-scale cold model. The occurrence of the secondary flow of the downward nozzle jet in the riser was analyzed by using “secondary flow” theory. The results showed that, the double-layer nozzle structure can improve the matching of oil & catalyst particles and improve the gas-solid contact efficiency compared with the traditional single-layer nozzle structure. Furthermore, the secondary nozzle can shorten the mixing height of riser by 1/3, reduce the mixing time of oil & catalyst particles, accelerate the uniformity and stabilization of gas-solid phase, realize the purpose of restraining over-cracking of oil, improving the target product yield and reducing coke generation.

Residence time distribution (RTD) in the spiral microchannel (MC) was determined by the impulse response method using polypropylene glycol with low molecular weight as the fluid carrier and N,N- dimethylmethylacetamide solution of acid orange as the tracer. The fittingness between parallel tanks-in-series (PTIS) model and RTD experimental data was verified. The influence of MC's length and Reynolds number (Re) on RTD was systematically studied. Additionally, the change law of radial velocity index y and Peclet number (Pe) of the fluid was thoroughly discussed. The results indicated that RTD became narrower with the increase of MC's length. When Re was increased by reducing viscosity, RTD became narrowed with Re increasing. When Re was increased by increasing flow rate, RTD would also become narrower as Re grew if the MC's diameter was large. However, if the MC's diameter was small and length was short, RTD would be widened as Re increased; on condition of longer length, RTD could become widened first and then narrowed with the increase of Re (or velocity). That is, there was a critical Reynolds number (Re_c). These changes of RTD indicate that secondary flow and radial molecular diffusion have a significant effect on the RTD of MC with small diameters.

In order to study liquid flow structure of scrubbing cooling chamber, two-head conductance probe was used to measure the gas holdup distributions, the Pitot tube-differential pressure transmitter speed measuring system was used to measure the axial and tangential liquid velocity distributions in a scrubbing cooling chamber cold model apparatus. The results showed that the axial velocity flowed downward near the outer wall of the descending tube, while the inner wall of the liquid pool flowed upward at the outlet of the descending tube and the bottom of the bubble breaking plate. The turning points of the liquid phase are r/R=0.7 and r/R=0.6 respectively. The existence of the bubble breaker makes the axial liquid velocity distribution be parabolic. The average tangential velocity is smaller than the axial velocity and fluctuates within the range of -0.15—0.1 m/s. The velocity distribution of liquid phase under different apparent gas velocities is similar, and the velocity of liquid phase increases with the increase of apparent gas velocities. By normalizing the velocity distribution of liquid phase at h =523 mm, the U_z/U_c model correlation equation was obtained. After the inspection, the change of the center velocity of the annulus with the tower diameter and the apparent gas velocity can be approximately described by the Nottenkaemper correlation.

The fluidity characterization and hopper discharge experiments were carried out with glass beads, fluidized bed cracking catalyst particles, lignite and PVC particles as experimental materials. The study found that the fluidity of different powders is quite different, and the corresponding gravity discharging results are also different. The flow rate of the powder used in the experiment is much lower than that predicted by the traditional Brown and Richards model. The analysis shows that the cohesion and agglomeration caused by the interaction between particles is the main reason that hinders the flow of fine powders. Based on the above analysis, the tensile strength of the bed is obtained by shear test combined with the theory of molar stress circle. Meanwhile, with the help of the model between the interaction between particles and the bed stress of powder constructed by Rumpf equation, the interaction force between particles can be obtained. Finally, the Bond number is used to modify the voidage of the powder bed, and the influence of the interaction between particles on the structure of the powder bed is revealed. On the basis of that the prediction model of powder mass flow rate is established. The newly established powder flow rate model coupled with the force between particles has effectively improved the disadvantage of the traditional model for the high prediction value of the fine particle powder flow rate, and significantly reduced the flow rate prediction deviation.

Aiming at the problem of heat transfer enhancement outside the tube of immersed coil heat exchangers, the ultrasound is imposed into the heat exchanger by means of vibration surface, and the influence of ultrasonic field on the flow pattern, cavitation phenomenon and heat transfer enhancement outside the tube of immersed coil heat exchanger is studied. The cavitation and ultrasound propagation phenomenon are generated by ultrasonic technology. The cavitation phenomenon induces liquid-vapor phase transition near the vibration surface, while the expansion of tiny bubbles occurs away from the vibration surface. The average vapor volume fraction of the heat exchanger without the ultrasound is 0.01302, which increases to 0.01359 with the ultrasound. The ultrasound propagation makes the flow velocity of the fluid outside the tube have the same pulsating change characteristics as that of the ultrasonic wave, by which the fluid flows towards both sides of the heat exchanger with high-low velocity interval distribution. The fluid has the lowest velocity near 0, and the highest velocity of 4.93 m·s^-1, the average velocity of the whole heat exchanger increases from 0.0248 to 0.102 m·s^-1 under the significant influence of the ultrasound. Under the dual effects of cavitation and acoustic flow, the average value of turbulent kinetic energy on the outer surface of the heat exchange tube increased from 2.090×10^-4 to 0.01847 m²·s^-2, indicating that the fluid on the outer surface of the heat exchange tube was disturbed and enhanced , the convective heat transfer coefficient of the outer surface of the heat exchange tube increased from 1634.533 to 2031.069 W·m^-2·K^-1, and the heat transfer enhancement ratio reached 24.26%. This research is of great significance to the application of ultrasonic technology in immersed coil heat exchanger.

Taking advantage of the fixed-temperature energy storage characteristics of phase change materials, a latent heat energy storage system with water as the heat exchange fluid and microencapsulated phase change material (MPCM) slurry as the energy storage medium was built. In this experimental system, water worked as heat transfer fluid and MPCM slurry acted as the energy storage medium. The cooling discharging characteristics of this system were characterized by the cooling rate, phase transformation completion rate, volumetric thermal release capacity and convective heat transfer coefficient. Through the comparisons between this latent thermal energy storage system and the sensible thermal energy storage system using pure water as the working medium, the influences of different flow rate of circulating water and stirring rate on the cooling discharging performance of this system was analyzed. The results indicated that the phase transformation of MPCM mainly occurred in the range of 17—19℃, and the phase transformation completion rate is approximately 90% when the slurry temperature was 20℃. The cooling discharging rate increased with the increasing the circulating water flow rate. When the flow rate of circulating water is 6 L·min^-1, the maximum cooling discharging rate of MPCM slurry reached 1.52 kW in the phase transition region, which is 70% higher than that of the sensible thermal energy storage system. In the range of 0—200 r·min^-1, the volumetric thermal release capacity and convective heat transfer coefficient of MPCM slurry can be increased by increasing the stirring rate. At the stirring rate of 200 r·min^-1, the volumetric thermal release capacity and convective heat transfer coefficient of MPCM slurry are 73.86 MJ·m^-3 and 2176 W·m^-2·K^-1, respectively, which are 1.66 and 1.87 times higher than that of sensible thermal storage system.

The gas temperature in the oscillating tube changes periodically, and the wall surface of the tube bundle will perform the same frequency pulsation heat transfer with the gas in the tube, which will have a certain impact on refrigeration. The static experimental platform of oscillating tube was built to measure the wall temperature. At the same time, the numerical model of unsteady flow and heat transfer was established to study the convective heat transfer. The experimental results show that a certain temperature distribution is formed on the wall of the tube bundle, and the temperature distribution on the stable wall will be steeper by thinning the outer wall thickness of the oscillating tube bundle to change the axial heat conduction area. The numerical calculation shows that the convection heat transfer between the cold end wall and the cold air will make the cold air heated, and finally reduce the refrigeration depth. The experimental results show that the maximum cooling depth increases by 0.2 K (1.6 expansion ratio), 0.5 K (1.8 expansion ratio) and 0.4 K(2.0 expansion ratio) when the wall thickness of tube bundle is reduced from 10 mm to 5 mm, which verifies the effect of pulsating wall heat transfer on refrigeration performance.

The pore structure is widely used in mass transfer tower packing, which has a great influence on the liquid film flow and mass transfer behavior on the packing. However, no relevant research has been conducted on the wetted area and wave characteristics of the porous plates. In this work, three-dimensional simulations of the liquid film flow on the vertical smooth and porous plates were carried out and verified by experimental results. The effects of the holes on the liquid film flow behavior were studied. The results show that the flow patterns on the vertical porous plates and the smooth plate are almost the same, namely droplet, rivulet, and closed film flow. Dry holes will hinder the spreading of the liquid film, while the wet holes will promote it. Compared to the smooth plate, the liquid film on porous plates has sinuous waves, which will affect the distribution of film thickness and the wave velocity. The sinuosity of liquid film thickness and the horizontal velocity will increase with the increase of hole diameter, while the vertical flow velocity will decrease with the increase of hole diameter. When the hole diameter increases to certain value, capillary waves will appear on the liquid film in the hole, which will greatly enhance the horizontal wave velocity and reduce the vertical velocity in the hole. When the hole depth is 0.5 mm, a hole with a diameter of 4 mm will produce capillary waves. However, if the hole diameter continues to increase to a critical value, the liquid film will rupture. There are vortices on the in-hole and gas side of the porous plate, which can promote the internal liquid exchange and enhance the gas side disturbance, thus enhance mass transfer.

The laser ablation method is used to prepare four superhydrophobic/hydrophilic regular microarray structure surfaces on the polished copper without coating modification. In this work, visualization and temperature processing calculations were applied to analyze the effects of surface wettability and subcooling on flow boiling heat transfer performance, then the active nucleation site density between experimental data and predicted value were compared. The results show that the hydrophobic surface has a negative effect on single-phase flow heat transfer and presents an outstanding heat transfer coefficient (HTC) by 75.5% compared with the bare copper surface. Simultaneously, it has an early appearance of onset of nucleate by 3.5 K, and the number of nucleation sites was increased by more than 5 times compared with the bare copper surface, but has a lower critical heat flux. The super hydrophilic surface could enhance the single-phase flow heat transfer and slightly increased the flow boiling heat transfer. Comparing the bubble growth process on the hydrophilic and hydrophobic surface, the bubbles at the end of the hydrophobic surface were easy to coalesce and the growth period was longer, while the growth period of bubbles on the hydrophilic surface was shorter, and no obvious bubble coalescence occurred.

Catalytic cracking reactor is an important reactor for deep processing of petroleum. In this paper, the gas-solid two-phase flow characteristics in a novel fast fluidized bed catalytic cracking reactor were studied by experimental method, and the particle concentration in the bed was measured, the effect of gas flow rate on the axial and radial distribution of particle concentration was investigated. The results show that the axial particle concentration in the bed presents a dense and sparse distribution in the lower part, an S-shaped distribution of axial particle concentration when the gas flow rate is low, and an exponential distribution when the gas flow rate is high, the particle concentration distribution in the upper part of the reactor has little effect, and the particle concentration distribution in the radial direction of the bed has the characteristics of sparse center and dense side wall, and the radial distribution tends to be uniform with the increase of air flow rate. Under a certain operating condition, the solids concentration of the novel fast fluidized bed is significantly increased compared with the conventional riser.

The structure of pool boiling heat transfer surface has an important influence on its boiling heat transfer performance. In order to further enhance the pool boiling heat transfer performance at lower surface superheat, a new type of pool boiling heat transfer trapezoidal microchannel surface was proposed, and the pool boiling heat transfer performance of deionized water on the surface at saturated temperature was studied by the visualization experiment method. The results show that the trapezoidal microchannel surface can reduce the superheat of initial boiling surface compared with smooth surface. At the same surface superheat, with the increase of the bottom length and the decrease of the bottom angle, the heat flux and heat transfer capacity of the trapezoidal microchannel surface increase. The trapezoidal microgroove with a bottom length of 1.2 mm and a bottom angle of 45° has the lowest initial boiling surface superheat (1.4 K). When the surface superheat is 8.3 K, the heat flux can reach 1.2×10⁶ W·m^-2, which is 24.0 times as much as that of the smooth surface at the same surface superheat. The larger bottom length and the smaller bottom angle are beneficial to enhance the pool boiling heat transfer performance of the trapezoidal microchannel surface.

Considering local non-thermal equilibrium in porous region and using the Brinkman-extended Darcy model with stress jump conditions, the heat transfer characteristics in a partially filled porous media channel are analyzed. The analytical solutions of temperature fields and Nusselt number in fluid and solid regions are obtained, and the influences of different parameters on temperature fields and Nusselt number are analyzed. The results show that when interfacial convection heat transfer coefficient, H_s, is small, the increasing of the interfacial stress jump coefficient, β, and Darcy number, Da, will reduce the two phases temperature difference between fluid and solid phases. While at a high H_s, decreasing of Da will also decrease two phases temperature difference. When Da, H_s and thermal conductivity ratio, K, are large, hollow ratio, S (ratio of the free region height to the channel height), and Biot number, Bi, are small, there is a maximum temperature difference between fluid and solid phases occurs near the core of porous region, and this maximum temperature difference will move to the interface region with the increase of S, and the decrease of Da and H_s. For different K and Bi, the curves of the relationship between Nusselt number Nu and S have different types for model C (the heat flux distribution of solid phase at the interface is related to the heat exchange of the fluid phase in the free fluid region) in this study and the curves' type is related with H_s, which is different from model A (the total heat flux division between the solid and fluid phases is based on their effective conductivities and the corresponding temperature gradients). When K is small, the influence of β on Nu is greater than that of H_s on Nu. When K is large, the influence of H_s on Nu is much greater than that of β on Nu, and the increase of H_s will significantly increase Nu in the channel.

According to the operation principle of the coaxial tubes type deep borehole heat exchanger (DBHE), a three-dimensional unsteady state heat transfer model coupled inside and outside of the borehole was established, based upon hydrogeological conditions of water-rich hot reservoirs with the buried depth of 1000—3000 m in Bohai Basin. The transient analytical solutions were obtained by applying Laplace and Fourier transform methods to calculate the vertical temperature profiles in the inlet (outlet) pipe and the grout of the DBHE and the excess temperature in aquifers. The mathematical model and the analytical solutions were validated by the experimental data determined from a demonstration project and the numerical simulation of the finite volume method (FVM). Based on the dual-continuum spatial coupling approach, the influence was performed to examine the seepage process of underground water on the heat transfer performance of the DBHE in water-rich hot reservoirs. The simulated calculation indicates that the average heat exchange capacity increment of the DBHE is up to 55 kW, when the quantity of the circulating water is stable at 30 m³/h and the Darcy velocity of underground water increases from 0 to 5×10^-6 m/s in water-rich hot reservoirs. However, the average heat exchange capacity increases 34 kW meanwhile the circulating pump power consumption increases 20.6 kW, ignoring the seepage process, when the quantity of the circulating water is enhanced from 30 m³/h to 60 m³/h. Studies have shown that as the seepage velocity increases, the heat transfer mechanism in the thermal reservoir changes, thereby enhancing the heat transfer process of the deep well heat exchanger; at the same time, it reduces the influence of the circulating water flow on the heat transfer performance of the deep well heat exchanger.

Based on the phase-change thermosiphon effect of the working fluid, a bidirectional thermal management system for power battery was proposed. By changing the charging amount of the working fluid, the bidirectional thermal management performance of the system was tested at 60—220 g, and the system was optimized accordingly. The results show that there is a minimum charge amount for the normal operation of the thermal management system. Before the optimization of the system, the heating condition and the heat transfer power of the system are less affected by the charging amount. In the heat dissipation condition, the heat transfer power of the system increases with the increase of the charging amount and the initial temperature of the battery box, and the forced heat dissipation effect is better than the natural heat dissipation. With the same charging amount, the maximum temperature difference on the surface of the heat exchange plate increases with the increase of the initial temperature of the battery box. At the discharge rate of 3C, the surface temperature of the battery cannot be controlled below 45℃. After the system optimization, the heat transfer effect of the circular tube heat exchanger plate system is better than that of the rectangular tube heat exchanger plate system, and the surface temperature of the battery can be reduced to 43.4℃ at the 3C discharge rate, and the surface temperature of the heat exchanger plate is more consistent.

Ionic liquid catalytic reactive distillation is a green and effective method to improve the conversion rate of the transesterification equilibrium reaction. The mixture of 1-propylsulfonate-3-methylimidazolium trifluoromethane sulfonate ([PSO₃HMIm][OTf]) and 1-octyl-2,3-dimethylimidazolium bis((trifluoromethyl)sulf-onyl)imide ([OMMIm][Tf₂N])) were utilized as the catalyst for transesterification of methyl acetate with n-hexanol, and the reaction kinetics of the transesterification were measured. The effects of mixing ratio, reaction temperature, initial molar ratio of reactants and concentration of catalyst on reaction rate and the conversion of methyl acetate, and recovery performance of the catalyst were investigated. The reaction kinetic equation of the transesterification catalyzed by mixed ionic liquids was obtained by the correlation of experimental data. Based on the reaction kinetics, the reactive distillation process for transesterification of methyl acetate and n-hexanol was simulated, and the effects of theoretical stage number, reflux ratio, feed position, theoretical stages in reaction section, catalyst amount and liquid holdup on the reactive distillation column were analyzed. Under the optimized operating conditions, hexyl acetate product with purity of 0.9993 was obtained by the reactive distillation process.

Under the premise of ensuring selectivity, high-efficiency photocatalytic oxidation of benzyl alcohol to benzaldehyde is still a huge challenge. g-C₃N₄ has a moderate valence band position and mild oxidation ability. It has been developed for photocatalytic oxidation of benzyl alcohol to ensure the selectivity of the reaction, but the high electron-hole recombination rate makes it difficult to increase the conversion rate of the reaction. In this work, alternate \mathrm{B}{\mathrm{i}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{2}}^{\mathrm{2}+} and \mathrm{C}{\mathrm{O}}_{\mathrm{3}}^{\mathrm{2}-} orthogonal symbiotic layer within Bi₂O₂CO₃ can not only increase the specific surface area of catalyst to form more active center, but also can construct local electric field to separate electronic-hole pair more efficiently. Therefore, we build the Bi₂O₂CO₃/g-C₃N₄ heterojunction structure to speed up the carrier separation to enhance the reaction rate. The best photocatalyst can achieve both 100% selectivity and conversion after 9 h reaction, which reduces the cost of separation and has a huge development prospect. In this paper, the in-situ construction of the heterojunction accelerates the charge separation to promote the reaction. Its preparation method, reaction mechanism, energy level structure, etc., all have a certain guiding role in organic conversion reactions.

Aldehydes can undergo a rapid reversible nucleophilic addition reaction with sodium bisulfite, which can be used to remove aldehydes from the mixture. The kinetics of these reactions mostly focused on low carbon aliphatic aldehydes and aromatic aldehydes, lacking of kinetic studies on high carbon aliphatic aldehydes, besides, the commonly analytical methods such as iodine titration and ultraviolet spectrophotometry had many limitations in application. In this paper, heptaldehyde was taken as the research object, and the reaction processes between heptaldehyde and sodium bisulfite were monitored by means of ReactIR at 283.15—298.15 K. Through the calculation and fitting of the experimental data, the rate constants and equilibrium constants of the reaction at different temperatures were obtained, and the kinetic equation of the reaction was determined, which provided a theoretical basis for the separation of heptaldehyde. The results show that as the reaction temperature increases, the reaction rate of heptaldehyde increases, while the equilibrium conversion rate decreases. The addition reaction of heptaldehyde and sodium bisulfite is an exothermic process, and the reaction heat is -60.01 kJ?mol^-1. The activation energy of the forward reaction is 34.68 kJ?mol^-1, and the pre-exponential factor of the forward reaction is 1.369×10⁷ L?mol^-1?min^-1. The activation energy of the reverse reaction is 94.69 kJ?mol^-1, and the pre-exponential factor of the reverse reaction is 2.500×10¹⁵ min^-1.

As a fundamental industrial operation, the granular air classification is widely used in mineral processing, filter material regeneration, powder cleaning and other industrial areas. However, most of the static air classifiers cannot take into account industrial requirements such as high particle dispersion, low pressure drop, easy operation, and regular flow field. And relevant reports are based on particle mixture with better fluidization properties. There is no research on particle mixture which is difficult to fluidize and has large differences on diameter. This research proposes a new type of large-difference-particle air classifier, which enables the mixture to be fully dispersed, while regulating the flow field and controlling the pressure drop. The specific situation is as follows: a cone Johnson screen internal with high opening rate and smooth surface are arranged in the classification chamber to disperse the materials. Meanwhile, a frustum-shaped Johnson screen is set at the outlet of large particles to rectify the gas and realize dust removal, which can enhance the effect of air flow on the separation of particles. Microsilica powder is used as dust and molecular sieve adsorbent as the large particle. This study investigated the classification characteristics of novel air classifier before and after setting the dispersed Johnson screen. Two important classification parameters (the pressure drop and the classification efficiency) were explored under different operating parameters including the superficial gas velocity U, the granular circulation rate W and the dust/large particle ratio R. It is found that in a free bed, with an increase of the superficial gas velocity, the pressure drop of the equipment increases simultaneously, and the classification efficiency reaches a maximal value 87% when U=0.27 m/s. The influence of granular circulation rate on the pressure drop is not so clear, but the classification efficiency decreases continuously with an increase of W. When the dust/large particle ratio R is relatively low, the pressure drop does not change obviously. As it exceeds the tolerance of the Johnson screen, however, the dust deposited in the Johnson screen forms an ash layer, which results in an exponential increase in pressure drop and a sharp decline in efficiency. Compared to the free bed, setting a dispersed Johnson screen, the equipment pressure drop and classification efficiency are not sensitive to the variation of the operating parameters due to its rectification and distribution function. The dispersed Johnson screen extends the operating dust/large particle ratios whereas limits the superficial gas velocity. The actual pressure drop of the equipment is divided into three parts: Johnson network pressure drop, particle friction pressure drop, and gas outlet pressure drop. Based on the experimental results, a model for calculating the pressure drop is given.

Focusing on the important need for the recovery and separation of low-concentration CH₄ from low-grade coalbed methane, it mainly explores the development of granular carbon adsorbents with excellent CH₄/N₂ separation performance using biomass as a carbon source. Granular rice grains were chosen as carbon source to prepare granular rice-based carbon materials (GRCM) by carbonization and then CO₂ activation. The resulting granular carbon material exhibited a relatively narrow micropore distribution, and its BET specific surface area reached 938.529 m²/g. FT-IR analysis results show that the surface of rice-based granular carbon contains oxygen-containing functional groups such as hydroxyl and carbonyl groups. The CH₄ adsorption capacity and CH₄/N₂ adsorption selectivity of the sample GRCM-900 are as high as 1.32 mmol/g and 5.68 (298 K and 100 kPa), respectively, comparable to most of the reported powdered carbon materials and MOF. Molecular simulation revealed the different contributions of surface hydroxyl/carboxyl/aldehyde groups of GRCM to the adsorption selectivity of CH₄/N₂, and the mechanism of methane and nitrogen adsorption in the slit pores of GRCM. Fixed-bed experiments confirmed that the application of GRCM carbon materials can effectively separate CH₄/N₂ mixtures at normal temperature, and the prepared granular GRCM have potential application prospects in recovering CH₄ from low-concentration CH₄ coal mine gas.

Normal alkenes and normal alkanes with the same carbon number are similar in structure, which makes their relative volatility less and more difficult to separate. As a designable green separating agent, deep eutectic solvent (DES) is widely used in the separation of such mixtures recent years. Additionally, the complexation between transition metal ions and double bond of olefin is focused on the separation of olefins and paraffins. In view of the above two aspects, a novel silver-based deep eutectic solvent (Ag-DES) was prepared and used in the separation of 1-hexene and n-hexane. The separation performance of 1-hexene was investigated systematically by a series of reactive extraction experiments on the effect of olefin concentration in the initial feed, molar ratio of silver ion to olefin and separating temperature. The results showed that Ag-DES had significant effect on the separation selectivity of 1-hexene to n-hexane within the range of 3.5—18 and exhibited excellent circulation stability. Furthermore, the chemical complexation and strong hydrogen bonds between Ag-DES with 1-hexene rather than n-hexane investigated by FT-Raman and quantum mechanical calculation are the essential reasons for the separation of 1-hexene and n-hexane. The study indicates that the reactive extraction separation intensification process using Ag-DES is of great significance for the efficient and green separation of 1-hexene from Fisher-Tropsch synthesis products.

Aiming at the uncertainty of operating condition in the batch process, an unfixed terminal time economic optimization method is proposed. Firstly, the economic model predictive control method is adopted, with terminal constraints replaced by economical maximum item in objective function, and add the batch length of the batch process into the optimization degree of freedom. Duration of batch production is included in optimized variables to establish a dynamic economic optimization problem. Through the different parameterization of each control variable which is updated with time, the dynamic optimization problem is transformed into an NLP problem. Then the interior point penalty function method is used to solve the optimization problem with nonlinear constraints, the obtained optimal control sequence and optimal batch production cycle can minimize the loss caused by uncertain disturbances. The control structure adopts the receding horizon control method, which not only improves the cooperative control ability of the multivariable system, but also adjusts the control curve according to the real-time forecast of the terminal product output, which flexibly optimize trajectory of manipulated variables and operating time. Finally, this method has been tested on the batch optimized control for the aniline hydrogenation process, and the performance is significantly better than that controlled by complex PI method based on selection-splitting. The test results show that the economic optimized control of unfixed terminals optimizes the operating conditions of each batch production from the perspective of the total production efficiency, and realizes the optimal management of the production time and economic efficiency of the batch reaction process.

In complex large-scale industrial process system, real-time process monitoring, computational optimization and reduction of running memory are the most critical and challenging tasks to achieve final product quality, so an adaptive fault detection algorithm for online reduced kernel entropy component analysis (ORKECA) is proposed. First, the kernel matrix of the training samples is calculated. The representative observation values are selected according to the retained eigenvalues and eigenvectors to construct a reduced set that conforms to the global data information characteristics. The square prediction error (SPE) of monitoring statistical data is calculated, and the control limit is determined by kernel density estimation. For the real-time data collected online, the statistic of the data is calculated and compared with the control limit of the reduced set. Whether the kernel entropy component analysis (KECA) model needs to be updated is analyzed according to the process state. This method can improve the performance of real-time monitoring process data. Finally, a non-linear numerical case and TE process data are used to simulate and numerically analyze the method. The simulation results show that the proposed method is effective and feasible.

The proper selection of heat transfer model between fluid film and sealing ring plays an important role in the accurate calculation of temperature and pressure distribution and steady state performance of dry gas seal. At close critical point of CO₂, a comparative study on the heat transfer model, including isothermal model, adiabatic model and conjugate heat transfer model, on temperature-pressure distribution, opening force and leakage rate of supercritical CO₂ dry gas seal was conducted. The applicability of the isothermal model and the adiabatic model under different rotating speed and film thickness was discussed. Moreover, the difference between supercritical CO₂ and air dry gas seal on temperature-pressure distribution and steady-state performance were studied. The results show that compared with conjugate heat transfer model, the isothermal model assumption is suitable for the low-speed flow with small film thickness, while the opening force is lower and the leakage rate is higher. However, the adiabatic model assumption is suitable for the high-speed flow with large film thickness. The temperature distribution of supercritical CO₂ dry gas seal under the small film thickness is similar to that of the air dry gas seal, and the pressure distribution of them two at large film thickness is just the same. However, compared to the air dry gas seal, the temperature of supercritical CO₂ dry gas seal at large film thickness is much lower, while the pressure of which at small film thickness is larger.

The non-uniform surface wettability can affect the movement behavior of the droplet after droplet impacts the surface. When the droplet impacts the wettability-patterned surface, the lateral bounce of the droplet can be achieved by using the hydrophobic surface decorated with ahydrophilic stripe. During the experiment, the influence of different surface properties and impact conditions on the lateral bounce behavior of the droplet was explored, which provided a new idea for the realization of the directional bounce of the droplet. The results showed that the wettability pattern mainly affected the retraction process of the droplet after it impacted the surface. And the pattern size, droplet velocity, and droplet impact position can affect the splitting and lateral bounce of the impacting droplet. Through experiments, the influence of the above parameters on the mass and distance of the droplet's lateral bounce is obtained.

Due to the frequent occurrence of slip flow caused by ultra-thin gas film and high-altitude rarefied gas in air-space field, a new type of cylindrical spiral groove air floating seal is designed in this paper. Based on the micro-scale characteristic size of the seal and the mechanism of airflow lubrication, the modified Reynolds equation of rarefied gas lubrication is established by simultaneously linearizing Boltzmann equation (F-K model) and introducing flow factor. The high-precision eight-point difference method and Newton-Raphson iterative method are used to solve the gas film pressure, and the F-K slip flow model is constructed, which solves the influence of the coupling of surface groove-step jump, radial eccentricity and ultra-thin gas film on the solution divergence and calculation accuracy. Then, the calculated results are compared with the existing studies, and the internal relationship between gas slip flow effect and operation parameters is investigated. The results show that the new cylindrical spiral groove air floating seal has obvious slip flow effect at high speed, low pressure, small film thickness and large eccentricity. At the same time, the dynamic pressure effect of cylindrical spiral groove air floating seal is caused by the dynamic pressure wedge caused by groove blocking effect and groove-step change, and the convergence wedge caused by eccentricity.On the other hand, the increase of groove depth, groove number and groove length increases the buoyancy of gas film but enhances the response of slip flow in the groove. The research results provide a theoretical basis for broadening the application range of dynamic seal.

The end-face contact during the start-stop process of the dry gas seal is inevitable.In order to reveal the mechanical characteristics when the end faces are in contact, the dry gas seal can operate stably. Using statistical contact theory and equivalent damping ideas, considering the material properties of the seal ring, an analytical model suitable for analyzing the normal dynamic contact stiffness and dynamic contact damping of the dry friction interface of the dry gas seal is derived. The real surface morphology of the seal ring was measured through experiments, and the initial parameters of the contact model were determined. The results show that the dynamic contact stiffness increases with the increase of contact pressure and disturbance amplitude. The effect of disturbance frequency on dynamic contact stiffness is much smaller than contact pressure or amplitude effect. Dynamic contact damping increases with the increase of contact pressure and decreases with disturbance frequency or amplitude. The current calculation results are closer to the GW model by comparing it with various contact models. The sealing rings' pairing is silicon carbide as the rotating ring and graphite as the stationary ring. When the end face is not worn, the contact surface's dynamic characteristics are mainly dynamic contact stiffness, and the dynamic contact damping is weak. The change of normal contact is mainly considered in the contact stage before the 50% critical detachment speed.

In order to explore the influence of turbulence effect on the performance of S-CO₂ dry gas seal, the spiral groove dry gas seal was taken as the research object. The Reynolds equation considering centrifugal inertia force effect was cited,the Ng-Pan turbulence coefficient expression was selected,and the real physical properties of carbon dioxide were calculated by using software REFPROP. Then, according to the universal energy equation, the simplified energy equation of the compressible fluid was established by introducing the average velocity including the turbulence effect and the centrifugal inertia force effect. By coupling the Reynolds equation and the simplified energy equation, the influence of the turbulence effect on the sealing performance under different working conditions and average film thickness was analyzed and discussed. The research has shown that the turbulence effect causes significant changes in the pressure and temperature distribution in the gas film flow field, hich cannot be ignored when calculating the flow field. Under different inlet pressure and inlet temperature, the opening force and leakage rate in turbulence show the same trend as that in laminar flow. Under different mean film thicknesses, the opening force after considering the turbulence effect shows a different variation rule from laminar flow, while the leakage rate shows the same variation trend as laminar flow. Under different inlet pressure, inlet temperature and average film thickness, the opening force and leakage rate in turbulent flow are lower than that in laminar flow, and the difference between the two flow states increases with the increase of inlet pressure, inlet temperature and average film thickness. At different rotational speeds, the opening force and leakage rate in turbulent flow show different trends from that in laminar flow. The results provide support for further research on the effect of turbulence on S-CO₂ dry gas seal.

To research heterogeneous nucleation of water vapor condensed on the rough surface of the fine particles, a heterogeneous nucleation model was proposed, which based on Fletcher's classical nucleation theory and molecular kinematics theory, considered the effects of surface diffusion mechanism of water vapor molecules, line tension and roughness. The accuracy of the established model was verified by comparing the simulation results of critical supersaturation with the experimental results in existed literature. The effects of line roughness factor and surface roughness factor on critical nucleation free energy, nucleation rate and critical supersaturation were analyzed by numerical simulation. The results show that compared with the fine particles with smooth surface, the microscopic contact angle between the fine particles with rough surface and water vapor is smaller, the wettability of the fine particles is better, and the possibility of heterogeneous nucleation is greater. When the line tension is negative, the rougher the fine particles surface is, the smaller the nucleation free energy and critical supersaturation are, and the higher the nucleation rate is, the more favorable the heterogeneous nucleation of water vapor molecules on the surface of fine particles is. The surface roughness factor has a greater effect on the heterogeneous nucleation and condensation of water vapor on the surface of fine particles than the linear roughness factor.

Campesterol, as an important synthetic precursor of steroid drugs (progesterone, androstenedione, hydrocortisone, etc.), has received extensive attention from domestic and foreign researchers. First, through bioinformatics analysis, 10 different sources of 7-dehydrocholesterol reductase DHCR7 encoding gene DHCR7 were isolated, and the endogenous ERG5 gene of Saccharomyces cerevisiae was inactivated by using the CRISPR/Cas9 gene editing technology to construct the recombinant strain for producing campesterol. The results showed that the Zw507, integrated Pangasianodon hypophthalmus DHCR7, obtains the yield of campesterol 216.93 mg/L. Then, 10 yeast endogenous strong promoters were selected to combine with PhDHCR7. The results showed that when TEF1p was used as the promoter of PhDHCR7, the production of campesterol was up to 253.35 mg/L. In order to further increase the output of campesterol, the copy number of the PhDHCR7 expression cassette in the yeast genome was increased. When the copy number is 3, the output of campesterol reaches the highest 302.27 mg/L. Finally, fed-batch fermentation was carried out in a 5 L fermentor, and the yield of campesterol was 916.88 mg/L. Thus this strain can be used as an excellent chassis cell for subsequent biosynthesis of steroidal drugs.

Using Dagang oil slurry as the raw material and fluidized coking powder as the carrier, the investigation of its conversion reaction characteristics provides guidance for the development of high-value utilization technology of oil slurry. First, a thermogravimetric analyzer was used to study the thermal decomposition characteristics of Dagang slurry oil and fluid coke. Afterwards, quartz sand and fluid coke were used as heat carriers to explore the thermal conversion reaction law of Dagang slurry oil at different temperatures. When the temperature was about 500℃, the quartz sand cracked oil yield was 85.54%, and the gas yield was 1.24%. Correspondingly, the oil and gas yield over fluid coke was 84.02% and 1.77%, respectively, indicating that the fluid coke had the effect of promoting thermal conversion. Combining FTIR and GC-MS to analyze the slurry oil and its pyrolysis oil, the results show that fluidized thermal conversion had achieved the enrichment of the aromatics components of the oil slurry, and the pyrolysis oil obtained from fluid coke as the heat carrier was richer in aromatics than that of silica sand. Finally, the circulation characteristics of fluid coke were investigated and verified the feasibility of fluid coke as a heat carrier due to its catalytic stability.

Natural gas hydrate (NGH) is a type of ice-like compounds formed by natural gas and water at low temperatures and high pressures. It is widely distributed in the sediments of the seabed and frozen soil. It has huge resources and is expected to become a replacement energy in the future. Among the resources, NGH in the shallow layer or directly exposed on the seafloor has been widely discovered, and its formation process and stability law are still unclear. In order to reveal its stability law, the dissolving process of methane hydrate in quartz sand was experimentally studied. The dissolving efficiencies of methane hydrate in silica sand have been studied by injecting water and oil, respectively. The results show that both water and mineral oil can effectively dissolve methane hydrate in quartz sand, with the gas-to-liquid volume ratio about 2 for water injection and about 10 for oil injection. The cumulative gas production of water dissolving generally increases logarithmically with time, and the gas production rate fluctuates greatly, but it decreases gradually as a whole, and the gas-liquid ratio is stable at first and then decreases gradually; the cumulative gas production of oil dissolving generally increases in S shape with time, and the gas-liquid ratio increases first and then decreases gradually. At the same injection rate, the gas production rate and gas-liquid ratio of oil dissolving are significantly higher than those of water dissolution. The dissolving rate of hydrate is mainly affected by the type of dissolving medium (water or oil, in this work) and the contact status between dissolving medium and hydrate. Water and oil are easily channeled into quartz sand, forming a dominant seepage channel. The gas-to-liquid ratio decreases when water/oil forms dominant seepage channel. The results provide theoretical basis for stability studies of NGH in the shallow layer or directly exposed on the seafloor. It seems feasible in principle to exploit gas hydrate in the shallow layer or exposed to the sea floor by dissolving. It is suggested that systematic experimental and numerical simulation studies should be continued in the future.

In this study, a one-dimensional axial dispersion reactor model and a two-substrate biodegradation kinetic model were established for the removal of high concentration H₂S waste gas by biotrickling filter (BTF). The simulation results of one-substrate model and two-substrate model were compared with each other under different inlet H₂S concentrations, proving the validity and feasibility of the two-substrate model. Then the dynamic removal process of H₂S in the biofilm was investigated. Furthermore, the two-substrate model was applied to investigate the deodorization performance of BTF under varying liquid phase H₂S concentrations and empty bed retention time. Studies have shown that when the H₂S concentration on the surface of the biofilm is 7589.3 mg/m³, the mass transfer-biodegradation process in the biofilm needs 0.75 s to reach a steady state. A thicker biofilm may lead to an increase of the internal diffusion resistance and the nonuniformity of biodegradation rate. Thus, the O₂ concentration has a significant effect on the biodegradation rate. The inlet velocity and spray concentration can significantly affect the removal rate of H₂S in BTF.

Thermal regeneration process is an important part of the thermal regenerative ammonia-based battery (TRB) system. In this study, the effect of the thermal regeneration process of TRB on the power generation is studied, and the thermal regeneration performance is enhanced by reducing the liquid height in thermal regeneration process. The results show that the maximum power density of TRB with regenerated electrolyte is only 12 W/m², which is 59% lower than that of TRB with initial electrolyte (29.6 W/m²); the average thermal resistance and temperature difference of regeneration electrolyte can be reduced by decreasing the height of liquid, and the thermal regeneration performance can be effectively enhanced; when the liquid height is reduced to 1 cm, the maximum power density of TRB is significantly improved (27.0 W/m²), only 8.7% lower than that of the original TRB. In the future, it is expected to further strengthen the thermal regeneration process and improve the thermal regeneration performance of the battery by constructing a thin liquid film thermal regeneration reactor.

Based on the second-order RC equivalent circuit and internal working mechanism, the direct current (DC) internal resistance model, alternating current (AC) impedance characteristic model and U-I output characteristic model of aluminum-air battery were established to study the influence of operating conditions on the performance of the battery. By studying the variation of DC internal resistance characteristic curve, electrochemical impedance spectroscopy and U-I output characteristic curve under different operating conditions and current density, the influence of operating conditions on the total internal resistance and output performance of battery was analyzed. The simulation and experimental results show that the model has high accuracy; the operating conditions have obvious influence on the AC impedance characteristics and U-I output characteristics of the battery; the AC impedance map and U-I output characteristic curve of the battery under different operating conditions have corresponding changes and quantitative relationships. Through the study of the influence of operating conditions on these two characteristics, the subsequent operating conditions can be optimized, which lays the foundation for the improvement of battery output performance.

Chemical-looping reforming of methane coupled with CO₂ reduction technology can not only produce syngas, but also reduce CO₂ to generate CO. In this paper, a series of Ce_1-xNi_xO_{y(x = 0, 0.2, 0.4, 0.6, 0.8, 1) oxygen carriers with different Ce/Ni molar ratios were prepared by co-precipitation method. The physical and chemical properties of oxygen carriers were characterized by means of XRD, BET, XPS and CH4-TPR. The performance of Ce1-xNixOy oxygen carriers in chemical-looping reforming of methane coupled with CO2 reduction reaction was systematically investigated. Compared with single metal oxide NiO and CeO2, Ce1-xNixOy composite oxygen carriers have higher activity and thermal stability in this reaction. During the partial oxidation of methane, Ce0.2Ni0.8Oy and Ce0.4Ni0.6Oy oxygen carriers have higher CH4 conversion. After 20 redox cycle experiments, the CO2 conversion rate of the Ce0.2Ni0.8Oy oxygen carrier remained almost unchanged, indicating that the Ce0.2Ni0.8Oy oxygen carrier has high thermal stability.}

By gradually reducing the carbon to nitrogen (C/N) ratio, the phosphorus accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) were acclimated in a sequencing batch with anaerobic-limited oxygen operation mode. The simultaneous nitrification-denitrification and phosphorus removal(SNDPR) process of low C/N ratio domestic wastewater was accomplished. The competition between PAOs and GAOs, as well as the N₂O release at different C/N ratio, was studied. The results showed that the simultaneous nitrification and denitrification (SND) nitrogen removal and phosphorus removal efficiency of SNDPR were 83.5% and over 90% respectively at the C/N ratio of 7.0. The N₂O emission was 0.54 mg/L. The SND and phosphorus removal efficiency decreased to 60.1% and 80.5% respectively at C/N ratio of 3.0—3.5. Meanwhile, the N₂O emission reached 1.09 mg/L and the N₂O yield was 7.68%. The decrease of PHA accumulation, coupled with the increase of denitrification by GAOs, resulted in the higher N₂O emission at the lower C/N ratio of domestic wastewater. The variation of endogenous substance in different stage of SBR showed that PAOs-GAOs coexisted at each C/N ratio. GAOs tended to be enriched in SNDPR with the decreasing of C/N ratio. The extracellular polymer (EPS) increased from 43.4 mg/g VSS to 50.5mg/g VSS and the sludge volume index(SVI) increased from 99 ml/g to 127 ml/g with the decrease of C/N ratio. In loose EPS (LB-EPS), the ratio of protein (PN) to polysaccharide (PS) (PN/PS) decreases as C/N increases, and the hydrophilicity of sludge increases, which is not conducive to sludge dewatering.

Deep eutectic solvents (DESs) are widely used in oxidative desulfurization. It is great significance to develop novel DESs and further improve the desulfurization performance. ChCl/2Ph type DESs was synthesized using choline chloride (ChCl) as hydrogen bond acceptor and phenol (Ph) as hydrogen bond donor. The hydrogen bonding interaction between Ph and ChCl was confirmed by FT-IR and ¹H NMR. Dibenzothiophene (DBT) was removed from the model oil using ChCl/2Ph as extractant, hydrogen peroxide as oxidant and Ti(SO₄)₂ as catalyst. The effects of reaction temperature, V(ChCl/2Ph)/V(Oil), n(H₂O₂)/n(S), the amount of catalyst and different sulfur compounds on the desulfurization rate were investigated. The results show that the optimum reaction conditions are as follows: 5 ml model oil, V(ChCl/2Ph)/V(Oil) =2∶10, n(H₂O₂)/n(S) = 6, and catalyst dosage of 0.01 g, reaction temperature of 40℃, reaction time of 180 min. Under above conditions, the desulfurization rate can reach to 98.2%. The apparent activation energy of the system is 41.9 kJ/mol. The deep eutectic solvent phase containing catalyst can be reused for 5 times without significant decrease in activity. The study of desulfurization mechanism shows that the formation of Ti peroxides and Br?nsted acid is the key to the high desulfurization activity of the system.

A novel hydrogel-based composite sorbent was prepared by in-situ polymerization with acrylamide monomer, carbon nanotubes and anhydrous lithium chloride. The sorbent was characterized by scanning electron microscope and synchronous thermal analyzer. The dynamic adsorption / desorption performance and equilibrium adsorption performance of the composite adsorbent were tested in a constant temperature and humidity chamber. The results showed that the equilibrium adsorption capacity of the hydrogel-based sorbent was as high as 1.75 g/g at 25℃ and 75% relative humidity, more than 2.5 times of silica-based sorbent; moreover, hydrogel-based sorbent could desorb 70% of the adsorbed water under 45℃; the dynamic adsorption rate of hydrogel-based sorbent was calculated by fitting linear driving force model under the same conditions. Compared with other composite adsorbents at home and abroad, the adsorption rate coefficient and adsorption capacity of the adsorbent were greatly improved.

SAPO-34 zeolite membrane has been favored by many scholars because of its unique pore structure and excellent stability. Most of the studies focused on catalysis, adsorption and gas separation, while there are few studies on liquid separation. In this paper, SAPO-34 zeolite membranes were prepared through primary and secondary synthesis on the surface of Al₂O₃ hollow fiber support, respectively. The effects of four different Si-Al ratios on the structure and performance of the SAPO-34 zeolite membranes were investigated. The obtained membranes were used for the pervaporation dehydration of ethanol solution. The effects of operating temperature, ethanol concentration and synthesis times on the separation properties of the obtained membranes were investigated. The results showed that the SAPO-34 zeolite membrane with Si-Al ratio of 0.5 and secondary synthesis had a continuous and dense separation layer, resulting in the best pervaporation performance. The separation factor of ethanol (90%) - water (10%) at 60℃ was 1170, and the flux was 0.9 kg/(m²·h).

Using polyimide as the precursor and TiO₂ sol as the dopant, hybrid carbon membranes were prepared through membrane formation and carbonization. The thermal property of precursor, the microscopic morphology, microstructure, surface functional groups and gas permeation of carbon membranes were characterized by thermogravimetric analysis, electron microscope, X-ray diffraction, infrared spectroscopy and permeation testing, respectively. The effects of TiO₂ sol dosage, permeation temperature and permeation pressure on the structure and property of carbon membranes were investigated. Results show that the incorporation of TiO₂ sol obviously improves the permeability and selectivity of final carbon membranes. For hybrid carbon membranes prepared by the precursor containing 10% TiO₂, the permeability can respectively reach to 1993.8 Barrer for H₂, 1555.6 Barrer for CO₂ and 266.9 Barrer for O₂, along with the selectivity of 93.6 for H₂/N₂, 73.0 for CO₂/N₂ and 12.5 for O₂/N₂.

It is a common method to improve the thermal conductivity of paraffin-based phase change materials that adding expanded graphite (EG) to paraffin (PA). It is valuable for the application of PA-EG composite to predict its thermal conductivity accurately. Through the analysis of the microstructure characteristics of PA-EG composite phase change materials with EG mass fraction less than 20%, a micro model based on the uniform dispersion of EG fibers in PA was established, the phase change process of uniformly dispersed structural units was numerically simulated, the influence of EG mass fraction and its particle size on the equivalent thermal conductivity of uniform dispersion unit was analyzed, and a prediction model was proposed for the thermal conductivity of the PA-EG phase change materials suitable for different preparation methods. The experimental results of PA-EG composite phase change materials with EG mass fraction less than 20% are in good agreement, with the maximum error of 15.1%.

To study the failure mechanism of a large fixed-roof Q345 steel tank under coupling effects of the fragment impact and pool-fire heat radiation, finite element models of thermal and dynamic response analysis under coupling effects of the high-velocity fragment perforation and heat radiation of a burning tank was established by Abaqus. The dynamic behaviors of a fixed-roof tank subjected to high-velocity fragment perforation were investigated. And the effect of the heat radiation on the thermal buckling behaviors of a perforated tank was analyzed. Moreover, the stress distribution and variation on the cylindrical shell was studied. The results indicated that the thermal buckling of the tank begun from the connection of the cylindrical shell and dome under the single effect of the heat radiation. And the cylindrical shell wrinkled along the circumferential direction with the temperature increasing at the post-buckling state. The reason was that circumferential and meridional stresses alternated between tension and compression to maintain the balance. The tank was perforated, and the thermal buckling of the perforated tank started from both sides of the perforation under coupling effects of the perforation and heat radiation. Moreover, perforation led to stress concentration in the plastic deformation zone and its vicinity. Compared with the unimpacted storage tank, the wall of the perforated storage tank was at a higher stress level and was more prone to instability. Therefore, the fire resistance of the perforated storage tank reduced, and the thermal buckling mode also changed.