The Taylor flow and bubbly flow in gas-liquid two phase systems in microchannels have the advantages of uniform bubble size, narrow residence time distribution, easy control, high specific surface area, and so on. These advantages facilitate them various applications and important implications. Based on the bubble dissolution and mass transfer process during Taylor flow and bubbly flow, this paper systematically reviews the research progress of bubble dissolution, mass transfer process and mass transfer/dissolution model at microscale, and introduces the above flow pattern in reaction or process. Finally, an outlook is given for further research directions in this field.

Traditional catalytic reaction kinetics studies focus on macroscopic variables and properties (such as temperature and concentration sensitivity) and can be used to guide the optimal design of industrial reactors, but pay little attention to the effects of catalyst microscale structures and properties. It cannot therefore be used to guide the optimal design of the catalyst. This review mainly discusses the development and application of multifaceted kinetics analysis method, which can discriminate the dominant active sites of supported metal catalysts, and the possibility to use the activation entropy (ΔS^0*) as an experimentally measurable descriptor of catalytic reaction rate, which can be fine-tuned by tailoring the electronic properties of supported metal nanoparticles in terms of the surface chemistry and properties of carbon supports. It can extend the application of the kinetics analysis from the reactor design to the catalyst design.

Chirality is a ubiquitous property in nature and organisms. More than half of the active pharmaceutical ingredients contain at least one chiral center. Because of the stereoselectivity of chiral molecules, the chiral enantiomers often exhibit higher activity with lower side effects than racemates. The precise manufacturing of chiral enantiomer is, therefore, of great significance. At present, chiral resolution of racemate is one of the most efficient and convenient way to harvest enantiomer, whereas chiral resolution by crystallization is of key importance and widely applied technology to obtain pure enantiomer. Here, the recent progress on chiral resolution of pharmaceuticals by crystallization is summarized. Firstly, the history and development of chiral resolution by crystallization is briefly introduced. The enantiomeric resolution approaches based on classical resolution methods(diastereomeric salt resolution and preferential crystallization) and some recent developed novel chiral resolution methods including preferential enrichment and Viedma ripening, as well as their process intensification, are reviewed in detail. Then, other racemate separation methods such as chromatography and membrane separation are also briefly reviewed. Finally, the future study and development on pharmaceutical chiral resolution by crystallization are discussed and prospected.

The rotating packed bed (RPB) reactor is a typical process strengthening device, which has an active effect on the mass transfer and mixing process. The fluid flow behavior as one of the most fundamental property in a rotating packed bed reactor is essential to the study and optimization of the RPB reactor. Optical imaging technology and numerical simulation have been developed rapidly in recent years as important means to study hydrodynamic characteristics in RPB reactors. In this work, the visualization researches of RPB reactor in recent 30 years have been reviewed. The visualization research of RPB gradually develops from the surface of the packing zone to the inside of the packing zone. Up to now, the fluid flow in the packing and cavity zones can be described, but the simulation of mass transfer and mixing processes and accurate visual experiment still need to be developed deeply.

Interfacial transfer at mesoscale is a common issue for all the multi-phase chemical processes, and the related study remains as a scientific challenge due to the complexities. Investigating the interfacial interactions at mesoscale to find out the regulation strategies is the key to realize process-intensification of mass-transfer and reaction for the advanced chemical industries. To accurately describe the behavior of fluids at the interface, a new molecular thermodynamic model that can describe the complex fluid-solid interface interaction. When the molecular thermodynamic modeling method is extended to the nano-micro interfacial transfer needs to be developed, calling for the coordination of advanced experiments at nano-micro scale and molecular with molocular thermodynamic modelling. Atomic force microscopy (AFM), which possess the sensitivity down to nanoscale, can directly obtain the interfacial interaction at nano-micro scale. The quantification of AFM-measured forces can be used to construct the coarse-grained molecular model and describe complex interfacial interaction. Then, the coarse-grained molecular model can reveal the molecular thermodynamic mechanism of nano- and micro- interface transfer, realizing quantitative prediction.

Aspergillus niger has a strong ability to secrete proteins, and its secreted lignocellulose degrading enzymes, amylases, proteases, and lipases are widely used in related industries such as food, feed, and biotechnology. We describe its great potential as cell factory for secretory proteins based on the production of homologous and heterologous secretory proteins by A. niger. Firstly, the prospect of A. niger as cell factory for secretory proteins is ascertained based on the superiority of its expression system. Then the standard procedure for construction of A. niger cell factory for secretory proteins is introduced. Subsequently, the advances on A. niger as cell factory for homologous secretases in the past decade are summarized. It is proposed that the directed expression of inherent secretases in A. niger is an ideal strategy to study their properties, functions and structures. Finally, the advances on A. niger as cell factory for heterologous secretory proteins in recent years are summarized, and based on the difficulties encountered in the expression of heterologous proteins, the countermeasures to improve the production of heterologous proteins by further improvement of A. niger cell factory are introduced.

The type of dyes, dyeing objects, dyeing principles and dyeing properties which are physically combined with fibers are reuiewed. Then it discusses in detail the dyeing principles, properties and development of the reactive dyes which are chemically bounded to the fibers in terms of types of reactive group, monofunctional reactive dyes, bifunctional reactive dyes and the effects of chromophore structures on dyeing properties of bifunctional dyes. Finally, it introduces in brief the molecular structure of macromolecular crosslinking dyes and their dyeing properties which can well meet the needs of modern digital inkjet printing.

Cell factories can use microbial cells to produce the energy, drugs, and chemicals that humans need. The adaptation of chassis cells to exogenous metabolic pathways is a core challenge in building efficient cell factories. Genome synthesis refers to the bottom-up construction of a genome from chemically synthesized nucleotides. Genomic induced rearrangement refers to the customized regulation of DNA sequences and structures in genome scale. Genome synthesis and inducible rearrangement have enabled the creation of organisms, enhanced the flexibility of model chassis. Proper genome simplification and codon simplification improve the utilization efficiency of substrates and energy, and improve the predictability and controllability of cell physiological performance. Genomic rearrangement can generate structural variations such as random deletion, replication, translocation and inversion. The rearrangements of synthetic genome accelerate the rapid evolution of chassis and the optimization of metabolic pathways, and improve the adaptability between chassis and pathway. The genome synthesis and inducible rearrangement provide a new strategy for the construction and optimization of cell factories.

Carbon materials are a class of magical materials. Carbon atoms can be hybridized by sp, sp² or sp³ to construct carbon materials with different microstructures. The allotropes of carbon that have been found so far are graphite, diamond, fullerene, carbon nanotube, carbon nanoring, graphene and graphdiyne. Due to the excellent properties and broad application prospects, the discoverers of fullerene and graphene have been honored by the Nobel Prize in 1996 and 2010, respectively. Since carbon nanorings have special structure, excellent mechanical strength with unique physical and chemistry properties, they have attracted much attention. Initially people have carried out some theoretical calculations to predict the properties of carbon nanorings, Up to now, carbon nanorings with different sizes have been successfully prepared through chemical vapor deposition, laser irradiation, ultrasonic self-assembly, etc., and their properties and applications have also been explored. This paper summarizes the growth mechanism, controllable synthesis, properties and applications of carbon nanorings for nearly 30 years. Furthermore, suggestions and prospects for the large-scale synthesis and application of carbon nanorings are presented.

Shaped functional microparticles are widely used in industrial and clinical medicine due to their unique characteristics of scattering, rheology and condensation. Compared with other fabrication methods, microfluidics technology has the advantages of precise control, easy adjustment and continuous fabrication process. Moreover, the microscale materials prepared by microfluidics have uniform morphologies and diverse functions. Therefore, the preparation of anisotropic microparticle functional materials by using microfluidics has become a research hotspot. This paper reviews recent progress in fabrication of anisotropic polymer microparticle functional materials by microfluidics.The controllable fabrication of microparticles with polyhedral structures by combining the laminar flow produced in the PDMS microfluidics with controllable lithography, rod-like microparticles by combining the droplet microfluidics with confinement of microchannel or second manipulation, bullet-shaped microparticles by varying the flow rate of continuous fluid and the structure of microchannels, core-shell and multicompartment structure microparticles by surfactant-assisted dewetting of immiscible fluid droplets, helical microparticles by combining the microfluidics with rope coiling effects are highlighted. This review provides guidance for the further design and fabrication of anisotropic microparticle functional materials as well as their applications in industrial applications and clinical pathologies.

As a new type of framework material with three-dimensional pore structure, metal-organic frameworks (MOFs) has been widely used in the fields of catalysis, energy storage and separation. However, the water stability of MOFs is always a barrier to its application expansion. With the continuous emergence of water stable MOFs materials and the deepening understanding of the water stable mechanism of MOFs, many scholars begin to pay attention to the separation application of the MOFs separation membrane in the water system. This review focused on the separation and application of MOFs separation membranes in water system environment, summarized the factors affecting the water stability of MOFs, the preparation methods of MOFs separation membranes, and the application of MOFs separation membrane in dye wastewater, desalination and removal of heavy metal ions and ion selective separation. The future development trend of MOFs separation membrane was prospected.

Anion exchange membrane(AEM) fuel cells have the advantages of using non-precious metal catalysts and fast catalytic kinetics. It is a clean and efficient source of energy, but its commercialization has been subject to the development of high performance anion exchange membranes. Up to now, there are two major obstacles stand in front of AEM which are low ion conductivity and low stability. Substantial works have been done to increase the conductivity while maintain the mechanical stability, and improve the alkaline stability of AEM. Among them, construction of high efficient ion transport channels is verified to be an efficient way to solve the dilemma between ion conductivity and mechanical stability. This paper reviews the main methods to construct ion channels in AEM, including nanocomposites, microphase separation, interpenetrating polymer networks and form ion clusters.

Metal organic framework materials (MOFs) are a class of inorganic metal centers and organic ligands formed by self-assembly of crystalline porous materials. MOFs combine high crystallinity and electron mobility of inorganic materials with high specific surface area, porosity and modifiability of organic materials, thus exhibiting broad application prospects in the field of photocatalysis. The research on MOFs photocatalytic materials in recent years is reviewed centering on the regulation of physical and chemical microenvironment. The regulation of physical microenvironment has been focused on micromorphology regulation, noble metal deposition and heterostructure construction, meanwhile the regulation of chemical microenvironment has been focused on metal site regulation and organic ligand regulation. In addition, in order to provide ideas for rational design and controllable preparation of high-performance MOF photocatalysts, the future development of MOF photocatalytic materials is also prospected.

Carbon dioxide capture and utilization is a hot spot in the global academic and industrial circles, as well as a frontier and difficulty in the field of combustion science and technology. Oxy-fuel combustion of solid fuels in fluidized beds, which combines many advantages of both fluidized bed combustion and oxy-fuel combustion, is widely recognized as one of the most promising carbon capture technologies in combustion for industrial applications. To fully grasp the latest developments in this field, the research on oxy-fuel combustion in fluidized beds in recent years was reviewed systematically. Based on a brief description of the basic technical principles of oxy-fuel combustion, the research trends were analyzed, and the recent advances were summarized, including single fuel oxy-fuel combustion in fluidized beds, mixed fuels oxy-fuel combustion in fluidized beds, pressurized fluidized bed oxy-fuel combustion and new fluidized bed oxy-fuel combustion. Finally, the future development trend and research focus for oxy-fuel combustion of solid fuels in fluidized beds were discussed.

Plant-derived natural products are a class of secondary metabolites with complex structures and diverse properties, which are widely used in food, medicine, cosmetics and other fields. At present, the main source of plant-derived natural products is direct extraction from plants, which is time consuming and farming land occupying. Microbial synthesis has been studied to produce plant-derived natural products for the advantages of short growth cycle, mature manipulating methods and controllable large-scale fermentation. Nowadays, it has attracted many attentions to achieve biosynthesis and transformation of plant-derived natural products employing microbial cells. Many kinds of natural products such as terpenoids, flavonoids, alkaloids and saponins have been successfully synthesized in microbes. In this review, the applications of microbial cell factories in the synthesis of plant-derived natural products have been summarized as well as different strategies, which will be helpful for the systematic and in-depth study in the synthesis and transformation of plant-derived natural products.

Based on the history of cellulose fiber development, the progress of three kinds of fibers, i.e. viscous fiber, Lyocell fiber and ionic liquid fiber (Ioncell) with natural cellulose as raw materials are summarized. Firstly, the development history of regenerated cellulose fiber manufacturing technology is summarized, and the development status of viscose fiber, Lyocell fiber and ionic liquid fiber (Ioncell) with natural cellulose as raw material is summarized. In this work, the performance, application field, and market prospect are mainly introduced, and their technologies including spinning technology, the preparation of spinning solution, and the methods of solvent recovery are compared. In comparison with viscous fiber, both the dissolution of cellulose and the dry-jet wet spinning for the other two fibers show unique advantages. But their key points lie in the continuous preparation of spinning solution and efficient recovery of solvent. Compared to the NMMO solvent used by Lyocell fiber, ionic liquids (ILs) used by Ioncell fiber have the advantages of negligible volatility and properties tunable. Therefore, this kind of ILs with high solubility but without degradation ability of cellulose, high thermal stability to water and metal ions, and little environmental impact can be designed, which provide a new approach for the development of green spinning technology. In addition, the existing problems of Ioncell fiber are analyzed, and some research direction for the two kinds of fibers produced by solvent method are pointed out.

The hydrogenation reaction is a type of reaction which is very common in organic synthesis. The conventional batch hydrogenation reactor has the problems of low reaction efficiency, cumbersome operation and poor safety. The method of heterogeneous hydrogenation in a continuous microreactor can provide higher mass transfer performance, easy recycling of the catalyst and the purification of the product are more convenient, which can greatly improve the production efficiency and reduce the loss of precious metal catalysts. With these advantages, continuous hydrogenation technology in microreactors has received more and more attention. The research progress of commonly used microreactors and solid metal catalyst types, as well as heterogeneous high-efficiency catalytic hydrogenation of different functional groups in continuous microreactor are described in this paper. On this basis, the application of this technology in the field of fine chemicals is prospected. The continuous microreactor technology enables the hydrogenation process under safer, more efficient and more environmentally friendly conditions. It has high industrial application value and is one of the key development directions in the chemical industry in the future.

Triterpenoid saponins are usually composed of one or more glycosyl groups attached to hydrophobic aglycones, which are widely used as active ingredients in traditional Chinese herbal medicines. The traditional method for obtaining triterpenoid saponins is extracted from plants, due to the low content of triterpenoid saponins in plants and the limitation of plant growth by land resources, climate and environment, it has greatly restricted its large-scale promotion and application. Thus，it’s hard to be applied and popularized on large scale. The use of synthetic biology principles to design and construct microbial cell factories to synthesize triterpenoids is considered to be the most promising alternative and has become a new research hotspot. Glycosyltransferases play a key role in the synthesis of triterpenoid saponins. This article will describe the research progress in the synthesis of triterpenoid saponins using glycosyltransferases, and provide a reference for the further application of triterpenoid saponins.

The determination of the corrosion rate of metallic materials is an important indicator for evaluating the corrosion resistance of materials in service environments. However, one of the crucial issues that limit the application of EN is that EN data is not interpreted quantificationally. Quantitative evaluation of corrosion is mainly achieved by noise resistance and spectral noise resistance, with the precondition that they much have rigorous physical significance. This paper reviews several important theoretical models regarding with quantitative analysis, including models based on electrochemical kinetics, equivalent circuit approach, shot noise theory etc. The advantages and drawbacks of each model is discussed in depth. Finally, the future directions in this field are pointed out.

Based on two-dimensional hard disk fluid, a molecular thermodynamic model for a two-dimensional square-well chain fluid with variable range(SWCF-VR-2D) was established with the help of modern molecular thermodynamic research methods. The established model is used in the correlation calculation of gas adsorption at the solid interface, and the model parameters of the corresponding adsorbate and adsorbent are obtained. It is found that the model can reproduce the adsorption isotherms of nitrogen, methane, ethane, ethylene at different solid interfaces, such as silica gel, activated carbon, zeolite and metal organic framework (MOF), with a total average absolute deviation of 3.42%. The energy parameter ε _w reflects the interaction between the adsorbate and the adsorbent.

Separation of aromatic hydrocarbons in catalytically cracked diesel by solvent extraction is an effective way to reform catalytic diesel. Liquid-liquid equilibrium data provides basic data and theoretical guidance for the simulation, design and optimization of solvent-extracted aromatics process. The liquid-liquid equilibrium data of 1-methylnaphthalene-n-decane-1-tetradecene-sulfolane system at 323.15, 333.15 and 343.15 K were determined at atmospheric pressure. The ternary phase diagram of this system was obtained. The correlation coefficient of Hand equation and Othmer-Tobias equation was over 0.99, which indicated that the phase equilibrium data have good consistency. The binary interaction parameters were obtained by correlation with NRTL equation, the root mean square deviation between the calculated value and the experimental value was small, indicating that the NRTL model was suitable for the system. The selectivity coefficient of 1-methylnaphthalene to non-aromatic hydrocarbons was maintained between 2 and 55, it showed good separation performance.

In the jet bubbling reactor, as the liquid jet velocity increases, the gas-liquid dispersion shows three states including the flooding, loading, and complete dispersion. In this work, the liquid velocity near the wall above the gas distributor of the jet bubbling reactor was measured by the Pavlov tube to identify the aforementioned three dispersion states. It was found that the standard deviation of liquid velocity and the average liquid velocity both appeared four stages with the increase of jet velocity, which included the first plateau, the ascending stage, descending stage and second plateau. Wherein, the first plateau corresponded to the flooding state, the ascending and descending stages corresponded to the loading state, and the second plateau corresponded to the complete dispersion state. Therefore, the criterion for the critical jet velocity was proposed. The jet velocity at the intersection of the first plateau and the ascending stage was the flooding velocity u _jf, and the jet velocity at the intersection of the descending stage and the second plateau was the complete dispersion velocity u _jcd. Compared with the visual observation method, the average relative deviation of u _jf obtained by liquid velocity standard deviation analysis was 5.82%, the average relative deviation of u _jcd was 18.2%; the average relative deviation of u _jf obtained by time-averaged liquid velocity analysis was 5.86%, and the average relative deviation of u _jcd was 12.1%. The study also found that the blunt jet velocity increases as the superficial gas velocity increases.

The upflow reactor is a key pre-reactor of fixed bed residual hydrocracking process, which improves the applicability to residual materials and prolongs the run time of the device. Experimental bench of upflow reactor for the mass transfer process between gas and liquid was built. The industrial catalysts particles with the shape of pentagonal cylinder are packed in the reactor, and air simulates hydrogen and aqueous solution for oil. Based on physical absorption of oxygen into water and chemical absorption into sodium sulfite, the gas-liquid mass transfer characteristics in the upflow reactors are explored under the condition of high gas liquid flux ratio. The influences of superficial gas velocity, superficial liquid velocity, packing particle dimension, internal component, catalyst packing gradation and the ratio of height to diameter on volumetric liquid-side mass transfer coefficient and gas-liquid interfacial area were investigated. The experimental data show that the volumetric liquid-side mass transfer coefficient increases with the increase of gas and liquid superficial velocity. The smaller the particle diameter, the greater the volumetric liquid-side mass transfer coefficient is. Installing proper internal components in the bed layer can enhance gas-liquid mass transfer and the larger aspect ratio of the reactor is beneficial to the gas-liquid mass transfer process. Based on the experimental data, the empirical correlation formula suitable for the volumetric liquid-side mass transfer coefficient and gas-liquid interfacial area of upflow reactor are established, and the maximum fitting errors are 12% and 24% respectively. That the empirical correlations of gas-liquid mass transfer may well describe the characteristics of gas-liquid mass transfer in upflow reactor.

The flow behaviors of droplets breakup in the three-dimensional (3-D) pore-throat microchannel were investigated using a high-speed camera. A glycerin-water solution of different viscosity was used as a dispersed phase, and a mineral oil containing 4%(mass) of a surfactant (Span 20) was used as a continuous phase. Three flow patterns were observed when the droplets flowed out the pore-throat structure: spherical breakup, non-spherical breakup and non-breakup. Except extremely low capillary number of continuous phase, the increase of the viscosity of the dispersed phase or two-phase flow rates is not conducive to droplet breakup. Generally, the breakup position of the droplets approaches to the throat outlet. The spherical breakup of the droplets was further studied, the results indicate that the average daughter droplets size decreases with the increase of the viscosity of the dispersed phase and the flow rate of the continuous phase. The variation of the average size of daughter droplets with capillary number could be scaled with a power-law relationship, and the predicted result agrees well with the experimental data.

Mix-settler is the earliest extraction equipment which is still widely used at present. This paper studies on mixing and settling characteristics in a mixer-settler according to the limitation. The research process uses the SOPAT droplet measurement platform to measure the droplet size. The relationship between the droplet size distribution, the average droplet size, the liquid holding capacity, the size of the dispersion belt and the entrainment amount of different system mixing chambers, clarification chambers is discussed. The results show that Sauter diameter of droplet, D ₃₂, is linear with the agitation speed. D ₃₂ and liquid holdup were satisfied with the Calderbank model in the mixing chamber. And in the settling chamber, the settling performance was mainly affected by droplet size, organic/aqueous phase density difference, viscosity, mass transfer, temperature and interfacial tension. The drop studies will lay the foundation for optimizing or improving the structure of the mixer-settler.

The MoS₂/Si-ZrO₂ catalyst was prepared by an equal volume impregnation method, and the catalytic activity stability of CO for sulfur-tolerant methanation was evaluated. The CO conversion of the MoS₂/Si-ZrO₂ catalyst decreased by 11% under the following condition: molar ratio of feed gas composition was 2H₂∶2CO∶1N₂; concentration of H₂S was 0.01%; weight hourly space velocity was 6000 ml/(g·h); reaction temperature was 450℃ and reaction pressure was 2.5 MPa. The catalysts were further characterized by hydrogen temperature programmed reduction (H₂-TPR), X-rays photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), Raman spectra (RS), inductively coupled plasma emission spectra (ICP-OES), thermogravimetric analysis (TGA) and elemental analysis. The results demonstrated that little carbon deposited on the surface of spent catalyst, which did not cause catalyst deactivation. The minor cause was that MoS₂ slabs grew longer and stacked more layers after long-term reaction and then covered the active sites. The root deactivation cause was attributed to parts of catalytic active bridging {\mathrm{S}}_{\mathrm{2}}^{\mathrm{2}-} ^{species converting to less active S2- species and H₂S, which resulted in the loss of active sites and sulfur element.}

Y zeolite was modified with Zr by equal volume impregnation method. The effects of different amounts of Zr on the structure of modified Y zeolite, the physicochemical properties of the catalyst and the performance of hydrocracking reaction were investigated systematically. The modified Y zeolite and catalyst were characterized by X-ray diffraction (XRD), NH₃ temperature programmed desorption (NH₃-TPD), H₂ temperature programmed reduction (H₂-TPR) and transmission electron microscopy (TEM). The results show that Zr modification decreased the amount of acid sites of Y zeolite, and the trend became larger with an increase of Zr content. Moreover, Zr modification availably weakened the relation of metal species and support in the catalyst with Y zeolite, and improved the dispersion of W species on the catalyst surface. The hydrocracking reaction results suggested that VGO conversion over the catalyst with Y zeolite modified with Zr decreased compared with that with Y zeolite, and middle distillates increased about 20%(mass), as well as VGO conversion gradually decreased and the middle distillates slightly increased as the Zr content increased.

The high-efficiency adsorption purification of organic pollutants such as methylene blue in textile printing and dyeing wastewater is an important research topic in the environmental field. The unique lamellar structure of molybdenum oxides has great potential for adsorption application. Molybdenum oxides with different oxygen vacancies concentration were prepared by one-step microwave assisted hydrothermal method. The prepared molybdenum oxides with different negative surface charge distribution were applied to the efficient selective adsorption of organic pollutant cationic azo dye methylene blue. The relationship between oxygen vacancies concentration and adsorption performance was explored. It is found that molybdenum oxide with oxygen vacancies concentration is relative to its adsorption rate. The adsorption process conforms to Langmuir isotherm model and pseudo second order kinetic model, indicating that the adsorption process belongs to monomolecular adsorption. Therefore, it provides a potential for the development and application of metal oxides in the field of dye adsorption.

A systematic study on the catalytic oxidation of Ag(111) and Ag(211) on the surface of Ag(111) was carried out by density functional theory. It was found that atomic O* is necessary to initiate the reaction at the ambient conditions. The O—H bond in the ethanol is activated with the help of adsorbed atomic O* to form ethoxy, which then further transfers hydrogen in α-C—H to adsorbed O* forming the acetaldehyde (E _a<38 kJ/mol), which, in turn, reacts with atomic O*/OH* to form final product CO₂. To generate CO₂, C—C bond breaking (CCOO \stackrel{}{\to } C+ CO₂ on Ag(111) and CH₂COO \stackrel{}{\to } CH₂+ CO₂ on Ag(211)) exhibits the highest barriers (E _a>95.5 kJ/mol), which indicated it is the rate-determining step. The results indicate that the catalytic oxidation of ethanol on silver surfaces is structural sensitive. Selectivity towards value-added products like acetaldehyde would be improved by reducing the density of defected sites.

Based on the polymerization mechanism and process analysis of polyphenylene sulfide (PPS) and reasonable assumptions, a kinetic model of PPS polymerization based on Monte Carlo method was proposed. The fitting regression of the model parameters was performed through literature data, and the results show that the calculated value based on the kinetic model is in good agreement with the corresponding experimental data, and the extrapolation prediction based on the model is consistent with experiments, with the deviation less than 2%. The effect of the reactants ratio on the polymerization reaction was calculated based on kinetic model, and the results is in accordance with the literature value. Finally, by establishing the reactor model of industrial PPS polymerization, the industrial production process was simulated, and the results show that the tanks-in-series mode should be adopted for this process. The relevant results in this work will provide theoretical basis to the kinetic modeling of PPS polymerization reaction and the design and optimization of industrial PPS production.

In this work, the effect of support materials on the kinetic behaviors of indium-based catalysts in carbon dioxide hydrogenation was studied. A series of supported indium-based catalysts were prepared and tested. Only group ⅣB metal (Ti, Zr and Hf) oxide supported indium-based catalysts had substantial catalytic activity. Particularly, In₁/HfO₂ and In₁/ZrO₂ catalysts showed high methanol selectivity, while In₁/TiO₂ mainly catalyzed the reverse water-gas shift reaction. Steady-state kinetics, in-situ diffuse reflectance infrared Fourier transform spectroscopy and temperature-programmed experiments indicate that the key surface reaction intermediate over In₁/HfO₂ and In₁/ZrO₂ are formate and methoxy species, and methanol is produced via stepwise hydrogenation of the surface formate. In₁/HfO₂ possesses the strongest hydrogen splitting and hydrogenation ability, thus favoring methanol synthesis. Over In₁/TiO₂, no significant surface carbonaceous species was detected under reaction conditions. The improved CO production might be related to interfacial oxygen defects facilitating the redox cycle and decomposition of formate intermediate.

The zeolite Al-beta coating was fabricated on the stainless steel mesh by secondary growth method. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and contact angle (CA) measurements were used to characterize the zeolite Al-beta coatings. The cross-linked zeolite Al-beta crystals with spherical morphology on the stainless steel mesh constituted a micro/nanoscale hierarchical structure. The as-synthesized stainless steel mesh supported zeolite Al-beta coatings exhibited superhydrophilic and underwater superoleophobic characteristics. The stainless steel mesh supported zeolite Al-beta coating was applied to the separation of various oil/water mixtures. It could maintain the high separation efficiency above 97.1% after 100 separation cycles. The stability of zeolite Al-beta coatings was checked by using corrosive and ultrasonic treatments. The treated stainless steel mesh supported zeolite Al-beta coatings exhibited almost the same surface morphologies and separation efficiencies as the untreated sample. In addition, the zeolite Al-beta coating displayed a strong attachment to the stainless steel mesh surface. Self-cleaning stainless steel mesh supported zeolite Al-beta coatings with superior durability and stability would show great application potentials in actual oil/water separation processes.

Double reflux pressure swing adsorption is a pressure swing adsorption process in which the feed is carried out in the middle of the adsorption tower, and the top and bottom of the tower are respectively reflowed with light and heavy components, and two high purity and high recovery product gases can be simultaneously produced. In this paper, a LiLSX zeolite synthesized by the laboratory was used as the adsorbent, meanwhile, numerical simulation of a two-bed dual-reflux pressure swing adsorption air separation process was carried out with feed mixture (78%N₂/21%O₂/1%Ar) using the commercial software Aspen Adsorption. The adsorption and desorption pressure are 2 bar and 0.3 bar, the feed flow rate is 0.4 m³/h, the light and the heavy component reflux flow rate are 0.095 L/min and 5.22 L/min. Ultimately, the purity of O₂ and N₂ reach 95.67% and 98.25% in their respective product gas, and the recovery rates are 94.60% and 99.91%, respectively. Besides, effects of operating parameters (the feed position, duration of feed step, light reflux flow rate, heavy product flow rate) on the process performances were investigated, which was more helpful for understanding this process.

Hydrogen is an important reaction component in the oil hydrogenation process, and its solubility in petroleum fractions is a key factor affecting the hydrogenation process. Nevertheless, the sets of data for hydrogen solubility in heavy oils are scarce in literatures, and especially no attention has been paid on the influence of asphaltene on the hydrogen solubility in heavy oils. The solubility of hydrogen in four heavy oil feedstocks was systematically studied by high pressure stirred tank. The variation of hydrogen solubility in heavy oil with temperature and pressure was obtained. The effect of asphaltene content on hydrogen solubility was investigated. It was found that hydrogen solubility in certain oil increased with temperature and pressure under the present measurement conditions. The hydrogen solubility was influenced more significantly by temperature under higher pressure and pressure under higher temperature. The Flash module in Aspen Plus is combined with the PR state equation to establish a hydrogen solubility calculation model, and the hydrogen solubility under high temperature conditions is predicted. The results indicate the contradiction between hydrogen solubility and hydrogen consumption in vacuum residue of Canadian oil sand bitumen is much serious under conventional hydrogenation conditions. The hydrogen solubility of the deasphalted oil is greatly improved, and the removal of resin and asphaltene alleviates the contradiction between hydrogen dissolution and hydrogen consumption.

The low energy density of electrochemical double layer capacitors limits its application in the field of energy storage power. Organic electrolytes, as a key factor in improving the energy density of devices, are of great significance in studying the properties of conductive electrolytes. Ion size and diffusion coefficient in organic electrolyte are the critical factors in determining the energy density of electrochemical double layer capacitors. A dynamic model of electrochemical double layer capacitors was established to simultaneously account for transport process, Stern and diffuse layers and the saturation phenomenon of dielectric permittivity. The cyclic voltammetry measurement of electrochemical double layer capacitors was numerically simulated for different ionic solvation sizes and diffusion coefficients. The simulation results indicated that the specific capacitances were only affected by ionic solvation sizes at low scan rates, increasing significantly with decreasing ionic solvation size, whereas the ionic diffusion coefficients had no effect on the specific capacitances which were mainly controlled by the Stern layer at low scan rates. However, the specific capacitances, which were mainly controlled by the ionic transport within the diffuse layer at high scan rates, were simultaneously affected by ionic solvation sizes and diffusion coefficients. The specific capacitances increased considerably with increasing ionic solvation size or diffusion coefficient at high scan rates. Finally, the strategies for rational design of electrochemical double layer capacitors is proposed based on the simulation results.

To mitigate climate change and reduce CO₂ emissions, a systematic study on the capture of CO₂ from dry flue gas by temperature vacuum swing adsorption (TVSA) was conducted. With zeolite 13X as adsorbent, a four-bed TVSA with continuous feeding was designed, and a mathematical model was established for numerical simulation. Results showed that with the productivity of 1.7 mol·(kg ads)^-1·h^-1 and energy consumption of 3.14 MJ· ( \mathrm{k} \mathrm{g} \text{?} \mathrm{C} {\mathrm{O}}_{\mathrm{2}} {)}_{}^{-\mathrm{1}} _,, CO₂ purity of 97.54% and CO₂ recovery of 96.79% can be obtained by the four-bed TVSA process. The effect of feed flowrate, recycle time and vacuum level on purity, recovery, productivity and energy consumption was investigated. Additionally, the pressure and temperature behaviors in the column were analyzed, and the distribution of gas phase and adsorbed phase concentration in the axial direction was discussed in detail. The good performance indicated that TVSA will have the potential to be a cost-effective process capable of producing high purity and high recovery CO₂ product.

Using four different soft segments, i.e. polyterahydrofuran diol (PTMG), polycaprolactone diol (PCL), hydroxyl-terminated polybutadiene with high cis-1,4 content (HTPB), and commercial hydroxyl-terminated polybutadiene produced by free radical polymerization (FHTPB), four kinds of polyurethane elastomers (PUE) were prepared by a two-step solution polymerization. The effects of soft segment structure on mechanical properties and thermal properties at room temperature and low temperature were investigated by tensile test, dynamic mechanical property analysis (DMA), differential scanning calorimetry (DSC) and thermogravimetric analysis. It has been found that the tensile strength and elongation at break of the four PUEs at low temperature (-30℃) are superior to those at room temperature. This is not only related to the autofrettage effect induced by crystallization of soft segment at low temperature, but also to the increase of the degree of micro-phase separation between the soft and hard segments. Compared with the other three kinds of PUE, the soft segment in HTPB-PUE has lowest polarity and glass transition temperature (T _g), so the micro-phase separation is in highest degree, and the elastomer has the most excellent flexibility. Even at -30℃, elongation at break of the HTPB-PUE is up to 660%. PCL-PUE and PTMG-PUE are rigid because their soft segments are easy to crystallize and their degree of micro-phase separation between soft and hard segment is low. The cyclic tensile testing indicated that HTPB-PUE and FHTPB-PUE still have excellent elasticity at -30℃. The results from DSC and DMA showed that the T _g of HTPB-PUE is much lower than the other three PUEs, and the value from DSC is about -103℃. The initial thermal decomposition temperatures of the four PUEs are very similar, and are all around 270℃.

A series of modified alumina (Al₂O₃) nanoparticles (NPs) were synthesized by grafting heptanoic acid, stearic acid, cyclohexanecarboxylic acid and benzoic acid onto Al₂O₃ NPs. The effect of organic structures and grafting yield on the nucleation effect of modified NPs in isotactic polypropylene (iPP) matrix was investigated. The results show that the benzoic acid modified particles (BA-Al₂O₃) have excellent nucleation effect compared with linear alkyl and cycloalkyl carboxylic acids. The crystallization temperature and flexural modulus of nucleated iPP with 0.1% (mass) BA-Al₂O₃ increase by 9.4℃ and 21.9% compared with that of virgin iPP, respectively. The crystallization temperature and mechanical properties of composites are heavily affected by the grafting yield of the benzoic acid on the modified NPs BA-Al₂O₃. When the grafting yield is smaller than 1.3 mmol/(g Al₂O₃), the nucleation effect of BA-Al₂O₃ increases significantly with increasing grafting yield; however, when the grafting yield is higher than 1.3 mmol/(g Al₂O₃), the nucleation effect increases slightly. By regulating the surface structures of modified NPs, it can effectively improve the crystallization behavior and mechanical properties of iPP.

Fe₃O₄@TiO₂ magnetic nanocomposites with photocatalytic activity were successfully prepared by sol-gel, hydrothermal methods and calcination method. Combine superparamagnetism Fe₃O₄ and TiO₂, which can not only realize the rapid recovery of materials but also made the materials have visible light response capability. The Fe₃O₄@TiO₂ magnetic nanocomposites were further applied to the removal of Cr(Ⅵ). The results show that when Fe₃O₄@TiO₂ has a TiO₂ content of 1.0 g/g and the addition of formic acid as a hole remover and the solution pH=2, Fe₃O₄@TiO₂ has the best removal ability of Cr(Ⅵ). Under this condition, Cr(Ⅵ) removal rate reached 99.85%, and the catalytic performance remained high even used 4 times. In addition, Fe₃O₄@TiO₂ has good removal ability for Cr(Ⅵ) in the range of 5—500 mg/L. Fe₃O₄@TiO₂ has excellent removal ability for Cr(Ⅵ) magnetic nanocomposites and has a good application prospect.

Graphene oxide/poly(N-isopropylacrylamide-maleic acid) (GO/P(NIPAM-MA)) hydrogel was prepared by freeze polymerization and non-freeze polymerization, and the preparation method was compared to GO/P(NIPAM-MA) hydrogel La³⁺ adsorption capacity. It was found that the hydrogel synthesized by freeze polymerization method has an excellent swelling-shrinking and adsorption properties. With an equivalent molar ratio of 10∶1 for NIPAM∶MA and 370 mg/L of LaCl₃ solution, the equilibrium adsorption capacity of hydrogel synthesized by freeze polymerization method was (29.87±0.073) mg/g, while that of by non-freeze polymerization method was only (20.29±0.395) mg/g. Fitting parameter, n, of the Freundlich isotherm increased linearly with the increase of MA content for hydrogel synthesized by freeze polymerization method, and the increasing degree was larger than that of by non-freeze polymerization method. After five repeated adsorption-desorption cycles, it was found that there was no significant deformation and the adsorption capacity was not obviously decreased for hydrogel synthesized by freeze polymerization method, while it was broken after three repeated adsorption-desorption cycles for hydrogel synthesized by non-freeze polymerization method. The GO/P(NIPAM-MA) hydrogel synthesized by the freeze polymerization method has the advantages of large La³⁺ equilibrium adsorption capacity and reusability.

A series of molecular weight-controlled, narrow molecular weight distributions of 3-trimethoxysilyl methacrylate (MPS) and N-isopropyl acrylamide (NIPAM) block copolymers were synthesized by reversible addition-fragmentation chain transfer (RAFT) living radical polymerization. Temperature-sensitive silicon-containing nanoparticle are prepared by dispersing in aqueous solution. With the same chain length of hydrophobic segment PMPS, by changing the chain length of hydrophilic segment PNIPAM and the pH of the water solutions, the critical aggregation concentrations, the diameters and morphologies of the nanoparticles, and the phase separation behavior happening in the process of temperature variation were studied. Thermo-responsive and spherical nanoparticles were attained. The nanoparticles possessed advantages of both organics and inorganics. And they may have wide applications in many fields such as biomedicine, chemical catalysis, nanoreactors, dyes, coatings and so on.

To explore the mechanism and law of liquid superheating and boiling caused by tank leakage, a small device was established to study the bubble evolution, pressure and medium superheat response during the bumping process. Upon the typical features of medium superheat degree, overheat time was further introduced to characterize the delay degree of boiling. The results show that a large number of bubbles were generated and grew rapidly in the medium after the vessel rupture. Bubble-growth process could be divided into a relatively stable stage and an accelerated stage, and the obvious pressure recovery was attributed to the accelerated growth of bubbles. According to the response of temperature sensors in the medium, the boiling occurred and spread from top to bottom and from the inner wall to the inside of the medium. And the medium underwent a cycle of supercoiling—saturation—superheat—saturation—supercooling during boiling. In addition, it was found that the increase of initial pressure and the decrease of initial liquid level could both improve the maximum superheat degree of medium, especially a maximum superheat of 9. 4℃ with the initial liquid level of 50%. What’s more, the ascent of the initial pressure or the initial liquid level also hold a significant lower overheat time. And the rise of the initial liquid level would contribute to a more serious rebound phenomena of pressure. On the basis of the overheat time obtained by experiments, the mathematical model of the overheat time was also verified. The results showed that the calculation of the mathematical model was basically consistent with the experimental data.