The influx of research on machine learning and data science from the field of computer science into chemical engineering presents transformative opportunities for chemical engineering paradigms. Among them, physics-informed neural network (PINN) has gained wide attention because it embeds physical equations into neural networks so that the network output satisfies physical laws. This work begins by introducing the algorithm ideas and sampling strategies of PINN. It further discuss various treatment of the PINN loss function, mainly including cases with no observational data, equation reduction, equation discretization, and partial embedding of physical equations. Finally, it provides an overview of recent progress in the application of PINN to areas such as gas-liquid two-phase flow, two-phase flow in porous media, liquid-solid two-phase flow, and heat transfer in two-phase flow.

The sub-nanometer high-precision separation of molecules/ions by confined mass transfer separation membranes is a hot topic and difficulty in the current membrane research field. Clarifying the confined mass transfer effect within the membrane, forming a common mass transfer mechanism and manipulation methods, is a key way to break through the trade-off effect and achieve extraordinary membrane separation performance. This article reviews the research progresses of confined mass transfer separation membranes in recent years from three aspects: the construction of confined mass transfer channels, the confined mass transfer mechanism, and the application of confined mass transfer separation membranes. The future development direction of confined mass transfer separation membranes has also been proposed, which is expected to provide reference for the design and application of high-performance membrane materials.

The energy storage technology of liquid flow has the characteristics of high safety, high efficiency, long life, and environmental friendly. It is suitable for large-scale energy storage and distributed energy storage. Ion conducting membrane is one of key materials of a flow battery, upon which the properties and cost of ion conducting membranes directly affect the performance and cost of flow batteries. Among various ion conducting membranes, the compositions and structures of the selective layers and porous supporting layers of composite ion conducting membranes can be adjusted independently. Thus, composite membranes can exhibit high selectivity, high conductivity and high stability at the same time, which have been widely investigated and utilized in flow batteries. Moreover, by tuning the structures of the selective layers of composite membranes, their selectivity and conductivity can be further optimized, then improving the performance and lifespan of flow batteries. Therefore, this review will summarize the structure adjustment strategies of the selective layers of porous composite membranes based on their research progress in flow batteries, providing the theoretical instructions for the further development of ion conducting membranes in flow batteries.

Hydrogen energy is an important renewable energy source with the advantages of high energy density, high calorific value and environmental friendliness. The catalytic conversion of ortho-hydrogen (ortho-H₂) to para-hydrogen (para-H₂) is an essential step in hydrogen liquefaction which is generally regarded as the critical issue for the massive use of hydrogen energy. Many advances have been achieved regarding mechanism understanding as well as catalyst applications in ortho- to para-H₂ conversion, however, a comprehensive and systematic summary is still lacking. We have conducted a comprehensive review of research progress concerning catalytic conversion of ortho- to para-H₂, with emphasis on the catalyst technology, catalytic mechanisms, and reaction kinetics. Finally, a brief outlook and prospect on future research is outlined.

Lithium secondary batteries (LSBs) have attracted attention due to their low cost, high voltage platform and environmentally friendly nature. As application scenarios become more complex, the demands on the capacity, durability and safety of LSBs are increasing. To develop LSBs with higher performance and greater adaptability to different scenarios, it's essential to elucidate the relationship between material structure and battery performance under complex operating conditions, and to predict battery performance under different operating conditions. Finite element method (FEM) numerical simulation is an effective method to establish a numerical model of the battery by using physical fields such as electric field, temperature field and displacement field to describe the mass transfer, heat transfer and interfacial reaction process within the battery. FEM numerical simulation can reveal the intrinsic relationship between material structure and battery performance under different operating conditions, providing theoretical and technical support for the design and development of high-performance lithium batteries. This paper first introduces the algorithm basis, research scope and development history of FEM numerical simulation in battery system from the perspective of multi-physical field coupling, summarizes the research progress of FEM numerical simulation in the design of high-performance lithium secondary batteries, and looks forward to the future development direction and its application prospects in energy storage devices.

As one of the most important basic reaction types in industrial production, the nitration of aromatic hydrocarbons is bound to develop towards microscale with the requirements of safe, green and efficient production of chemicals. The key concern of major research projects is how to achieve high-quality development of microscale aromatic nitration. This article comprehensively reviews and analyzes the advancements and challenges of aromatic nitration in microreactors. Starting from the study of microscale nitration reaction kinetics, the direction for the design and intensification of aromatic hydrocarbon nitration microreaction process is pointed out. It summarizes current methods for kinetic study, process intensification and safety evaluation in the nitration microreaction technology. Future development directions of the aromatic nitration in microreactors will also be prospected.

Anisotropic microfibers have been widely used in many fields such as biomimetic materials, drug-controlled release and biomedicine due to their diverse structures and functions. Microfluidic technology, as a new type of micro-nano material preparation technology, can achieve controllable preparation of various shaped microfibers by adjusting channel structure, fluid properties and flow conditions. This review summarizes recent progress on the controllable fabrication of diverse functional anisotropic microfibers by microfluidics, for use in fields such as pharmaceuticals, chemical engineering, and environment. Fabrication strategies for the controllable fabrication of anisotropic microfibers, including solid-shaped, hollow-shaped, spindle-shaped and spiral-shaped microfibers by designing the structure of microfluidics are introduced. Important ideas for diversifying the functions of shaped microfibers based on their microstructure are discussed. The future development of microfluidics for the controllable fabrication of novel anisotropic microfibers is prospected,with a view to providing important references for the fabrication of highly bionic anisotropic microfibers by strengthening the study of flow mechanism and molding mechanism.

Droplet sieving is one of the basic operations of droplet microfluidic technology. Compared to the droplet sieving technology in traditional macroscopic equipment, the continuous operation of droplet sieving could be easily conducted in microfluidic equipment, and the whole process of droplet generation, sieving and collection could be continuously realized by using a microfluidic chip. This technology has been widely used in cell encapsulation, drug screening, gene analysis and other important fields. The droplet sieving based on microfluidic technology could be divided into active sieving and passive sieving. In this paper, the research progress of droplet sieving in microchannel in recent years is reviewed, and the future research directions and problems to be solved in this field are prospected.

Lightweight have become the development requirements of aircraft structure design and manufacturing in the field of aerospace. The lightweight and porous structure and excellent mechanical properties of negative Poisson’s ratio materials are new carriers to meet this demand. This review covers the types and deformation mechanisms of negative Poisson’s ratio materials, discusses the improved structures of the negative Poisson’s ratio materials and their properties in different dimensions, and summarizes the application prospects in the aerospace field. Also, the challenges and opportunities of the negative Poisson’s ratio materials for future research are proposed.

Substances have unique properties and reactivity under supercritical reactions and are often used as supercritical reaction media, but there are few examples of them being actually used as reactants in chemical reactions.This paper focuses on reactions where at least one reactant is a supercritical fluid, summarizing their applications in some industrially valuable reactions. This review particularly emphasizes the fundamental research and industrial applications of supercritical reactions where all reactants are in a supercritical state, while also looking ahead to future research directions and prospects for this technology.

Alkaline ion membranes (anion exchange membranes) are key materials in electrochemical processes such as water electrolysis to produce hydrogen and CO₂ reduction.They have important application value in transferring ions, separating anode and cathode, and blocking gas penetration. Originating from electrodialysis process, most commercial anion exchange membranes have low conductivity, which can’t meet the demand of high current density and high stability in electrochemical process. For demands of high flux, low resistance and low energy consumption in water electrolysis, this work investigates ions transport in membranes, combined with features of hydroxide ions, analyzes the structural characteristics of anion exchange membranes that meet the comprehensive performance requirements, and focuses on the strategies of enhancing ion transport. The latest research are summarized, and specific strategies such as cross-linking, directional alignment, microphase separations and micropore construction are discussed, indicating the direction of high-performance anion exchange membranes, and promoting the development of electrochemical progresses such as water electrolysis.

Eucommia ulmoides is a traditional and precious medicinal material in China, which has the functions of anti-tumor, anti-oxidation, anti-osteoporosis, anti-inflammatory and blood pressure regulation. Its active ingredients such as chlorogenic acid and flavonoids have high medicinal value. However, the traditional Chinese medicine has complex ingredients and backward production technology. Membrane separation technology has the characteristics of high separation efficiency, low energy consumption, simple operation and no secondary pollution, and shows a good application prospect in the separation and purification of traditional Chinese medicine. As Eucommia ulmoides is a unique medicinal material in China, there are few studies on membrane separation of Eucommia ulmoides active components in the world, and the domestic research on it is still in the initial stage. It is hoped that the extraction, detection, separation and purification methods of Eucommia ulmoides active components will be reviewed to provide theoretical support for the multipolar utilization of eucommia active components. In this paper, the separation mechanism of membrane was analyzed, the application of membrane in the separation and purification of Eucommia ulmoides was reviewed, and the factors affecting the separation process were discussed. Finally, the problems of membrane materials and membrane pollution in the separation and purification of Eucommia ulmoides active components were further pointed out, and the future research of membrane technology in the development of low-cost special membrane materials and systems and membrane pollution control was prospected.

Layered lithium nickel cobalt manganese oxide (LiNi_1-x-y Co _x Mn _y O₂, 0<x+y<1) is one of the most popular cathode materials for power lithium-ion batteries due to its high energy density and low cost. However, issues such as irreversible phase transitions and transition metal ion dissolution during lithium cycling, caused by lithium ion extraction and lattice oxygen loss, lead to capacity degradation, structural deterioration, and safety concerns. These issues severely limit its application in electric vehicles. Surface coating modification techniques aim to enhance the cycling stability and safety performance of the cathode materials by improving interface stability between the cathode material and electrolyte, suppressing micro-crack formation, and enhancing the thermal stability of the batteries. This article systematically introduces a series of innovative coating strategies developed by our research group to improve the electrochemical performance of high-nickel ternary cathode materials, based on the analysis of interface degradation mechanisms of high-nickel ternary cathode materials. The goal is to provide new insights for the development and application of high-performance lithium-ion battery cathode materials.

Biomanufacturing uses the functions of organisms to process and synthesize chemicals on a large scale. Compared to traditional approaches, biomanufacturing method is considered as a green and sustainable one because it normally consumes less energy, generates less wastes yet outputs higher added-value products. It is routine to design and construct microbial cell factories for biomanufacturing applications. However, microbial cell factories often fail to exhibit expected functions due to intrinsic crosstalk mediated by cofactors. This article briefly introduces conventional methods for regulating intracellular redox coenzyme levels and their limitations, highlights the necessity of creating non-natural coenzyme-mediated systems. Furthermore, with nicotinamide cytosine dinucleotide (NCD) and nicotinamide mononucleotide (NMN) as examples, we will discuss how to explore new biological components and redox modules to design new microbial cell factories. Finally, we predict the future directions and analysis the challenges of biomanufacturing based on non-natural cofactors.

Atomically dispersed catalysts (ADCs) combine the advantages of both homogeneous and heterogeneous catalysts, with high specific surface area, high atomic utilization, and clear structure. They exhibit excellent catalytic performance while being easy to separate and recover. Therefore, they have received widespread attention in the field of industrial catalysis and are considered the most promising catalysts. This review categorizes and summarizes the general synthesis methods of atomic level dispersed catalysts. In addition, it investigates the catalytic applications of atomic level dispersed catalysts in selective hydrogenation, carbonylation, dehydrogenation and other chemical reactions. Finally, the opportunities and challenges faced by the current application of ADCs were summarized, providing reference for its future development and application.

The energy security and environmental pollution issues brought about by the exploitation and utilization of large amounts of fossil resources have attracted widespread attention.The exploitation of renewable resources and the advancement of renewable energy and green chemicals are pivotal aspects of sustainable development. Biomass stands as the sole sustainable carbon resource, with its conversion and utilization representing a crucial pathway towards accomplishing the dual carbon goals. Chitin, being the second largest biomass, constitutes the sole nitrogen-containing polysaccharide. Hence, the process of converting chitin for the preparation of nitrogen-containing chemicals holds distinctive theoretical and practical significance. Remarkable strides have been made in recent years with regards to chitin conversion for the production of nitrogen-containing chemicals. This article primarily delves into the nitrogen-containing structural features of chitin, outlining the most recent research progress in chitin hydrolysis for the generation of oligomers and monosaccharide N-acetylglucosamine, the transformation of chitin and monosaccharides for the production of furan compounds, hybrid nitrogen-containing chemicals, and other nitrogen-containing chemicals. Particularly, the advancements and principles of catalytic conversion of chitin and monomers for the preparation of 3-acetylamino-5-acetylfuran are summarized. In addressing these advancements, the article also presents the existing issues and challenges, while offering a glimpse of the research direction in this field, in an effort to advance the high-quality development of chitin catalytic conversion for the preparation of nitrogen-containing chemicals and to aid in achieving the dual carbon goals.

The advancement of fluorescence labeling and imaging techniques is closely dependent on key emission and chemical properties of fluorescent dyes, such as brightness, photostability, and biocompatibility. The development of new fluorescent groups and the enhancement of fluorescence performance are also expected to propel the progress of fluorescence technology. The novel fluorescent properties of dyes are intricately linked to their molecular structure, with the main strategies for structural innovation including the discovery of entirely new fluorescent groups and the structural modification of traditional fluorescent group frameworks. This review delves into the fluorescent structure-activity relationship of fluorescent dyes, detailing a series of fluorescent dyes that have achieved significant improvements in luminous performance through molecular structural innovation. It discusses the outstanding performance exhibited by these dyes in cutting-edge applications, such as advanced bioluminescence imaging. The article concludes with a discussion of the challenges faced by the development of fluorescent dyes in the field of biological imaging.

The combination of ultrasonics and microreactor can solve the problems of conventional microreactors that can frequently be blocked by solid particles, poor operational elasticity, and difficult scale-up so that ultrasonic microreactor is expected to become a new generation of microreactor technology, which will be widely used in reaction processes, involving solid blockage and limited mass transfer of mixing, especially the synthesis of nanomaterials. Although there are many research reports on ultrasonic microreactors, most of them are limited to small reactors for laboratory use, and there are few studies on the amplification of ultrasonic microreactors. This review systematically introduces the structural composition of the ultrasonic microreactor system and the resonance matching and scale-up strategies between the components. Generally, the ultrasonic microreactor system consists of four parts: ultrasonic power supply, ultrasonic transducer, microchannel reactor, and fluid in the channel. The ultrasonic energy is generated by the power supply and transmitted to the fluid through the transducer and microchannel. To ensure the high energy transfer efficiency of the system, the resonant frequency corresponding to these four parts needs to be consistent and the impedance should be matched. The scale-up of the ultrasonic microreactor is divided into three aspects: ultrasonic power amplification, reactor radiation surface enlargement, and microchannel size expansion, and the core problems and solutions encountered in the magnification of each part are systematically expounded. Finally, the applications of ultrasonic microreactors in the field of nanomaterial synthesis are introduced in detail, and according to the mechanism of the synthesis process, it is divided into three types of nanomaterial synthesis: reaction nucleation growth control, molecular self-assembly control, emulsion and interface confinement control.

Flow chemistry, as an important frontier technology in chemical synthesis, has the characteristics of high efficiency, safety, controllability, and environmental protection. It is widely used in drug synthesis, fine chemicals, and materials science. Recent advances in automation and artificial intelligence (AI) have enabled flow chemistry to achieve full-process automation and intelligence. Automated systems integrate equipment and control systems to monitor and regulate reaction conditions in real-time, minimizing human error and enhancing stability and reproducibility. AI algorithms allow these systems to handle large data volumes, navigate high-dimensional chemical space, shorten experimental cycles, and improve efficiency and yield. This paper summarizes the development of intelligent flow chemistry systems, discusses the construction and application of the automated systems, and explores AI-based advancements, including machine learning algorithms and large language models. Case studies highlight the significant potential and application prospects of intelligent flow chemistry systems in chemical synthesis.

Carrier-free self-assembled nanomedicine has attracted wide attention and become one of the powerful strategies for cancer treatment due to its unique advantages such as simple preparation process, high drug loading, low cost and avoiding the toxicity caused by carriers. However, with millions of possible drug combinations, determining whether they can form self-assembling nanoparticles is a major challenge. With indomethacin as the model drug, different types of anti-tumor drugs were selected to explore their ability to form self-assembled nanoparticles with indomethacin, and different methods such as Hansen solubility parameters, machine learning model, binding energy calculation and COSMO-RS theory were utilized to study the self-assembly behavior. The self-assembly process was visualized by molecular dynamics simulation and quantitative chemistry calculation was used to analyze the molecular interaction to reveal the driving force of the self-assembly process. It was found that the machine learning model based on the training of high-throughput experimental values can quickly predict the probability of self-aggregation and co-aggregation with indomethacin molecules, and the combination of drug molecules can be preliminarily screened. In addition, through the study of thermodynamic mechanism, suitable drug molecule combinations can be selected from the perspective of energy and charge distribution, including the comparison of binding energy between the drug molecule itself and two different drug molecules, Hansen solubility parameter difference and surface charge density distribution. The self-assembly behavior is predicted using the Hansen solubility parameter model, COSMO-RS theory, and binding energy acquisition descriptors, and compared with the prediction of the machine learning model based on molecular fingerprints as descriptors. Based on molecular dynamics simulation, it was found that the self-assembly of drug molecules to form nanoparticles is a spontaneous aggregation behavior. Further analysis of the weak interaction between molecules revealed that hydrogen bond interaction is the key factor driving the self-assembly of drug molecules. Based on the research results of this paper, the different eigenvalues of drug molecules calculated by the thermodynamic model can be coupled into the machine learning model to enhance the physical meaning of the machine learning model, and an intelligent screening platform for self-assembled nanomedicine can be established, providing important guidance for the design and preparation of carrier-free nanomedicine delivery system with high delivery efficiency and combination therapy.

The inorganic particle-doped modified polyvinyl alcohol (PVA) membrane materials have promising industrial application prospects in pervaporation dehydration from esterification system. However, it is still lack of mechanism exploration in microscopic view and fundamental theoretical data. In this study, the molecular structure models of two types hybrid PVA materials doped with ZSM-5 and ZIF-67 respectively were constructed using molecular simulation method to elucidate distribution of inorganic particles in PVA chains. The Monte Carlo (MC) method was used to simulate the adsorption behavior of ethyl acetate and water in PVA hybrid materials, and the effects of doping ratio and temperature on adsorption amount and adsorption isotherm were investigated. The diffusion behavior of ethyl acetate and water in the hybrid materials and the fraction of free volume (FFV) within the hybrid materials were simulated by molecular dynamics (MD) method, and the influence of doping ratio and temperature on the diffusion coefficients of small molecules through the hybrid materials were investigated. The results showed that the adsorption of water in the two hybrid materials was significantly higher than that of ethyl acetate, and the adsorption of water in the ZSM-5/PVA was higher than that in ZIF-67/PVA. The diffusion coefficient of water in the two hybrid materials was significantly higher than that of ethyl acetate, and moreover, the diffusion coefficients of small molecules in ZSM-5/PVA were higher than those in ZIF-67/PVA because ZSM-5/PVA has higherFFV. It provides theoretical guidance for the modification of PVA materials and the mechanism of mass transfer separation.

The online mass transfer characterization technology was used to study the liquid-liquid two-phase mass transfer process of Newtonian/non-Newtonian fluid with polyacrylamide (PAAm) solution as the dispersed phase in the microchannel. The flow patterns were analyzed first. A unique sussage slug flow was observed and the effects of PAAm concentration on the flow patterns (slug flow, sussage slug flow and annular flow) were investigated. The research reveals that the mass transfer in both the Newtonian and non-Newtonian slug droplets was dominated by the convection and diffusion. However, the shear-thinning characteristics of the non-Newtonian fluid lead to significant change in the vortices and concentration distribution. The convection inside the slug droplets was affected by the flow rate, droplet length and capillary number. Based on the penetration theory, a modified correlation by relating the flow rate ratio and capillary number was proposed, which shows excellent prediction performance.

Reducing the bubble size is regarded as an effective method to enhance mass transfer of gas-liquid bubbling systems. However, in contaminated liquids, studies have shown that smaller bubbles may be more severely affected by contaminants within the system. The experimental study of the rising absorption process of single CO₂ bubbles in aqueous solution containing pollutants was carried out, and the influence of pollutant concentration and initial bubble size on the motion and mass transfer characteristics of single bubbles was investigated. The results indicated that an increase in contaminant concentration decreased bubble rising velocity and mass transfer efficiency, but there was an upper limit to this effect. The initial bubble size also affected the mass transfer efficiency. Under certain contamination conditions, larger bubbles exhibit an advantage at higher rising heights.

Annular flow in microchannels is widely used in the fields of chip heat dissipation and fine chemical synthesis due to its efficient thermal mass transfer. The on-line measurement of the thin liquid film thickness and flow pattern of annular flow was realized by using the Micro-LIF method with an accuracy of ±2 μm. The results show that as the gas phase shear force increases, the liquid film thickness decreases, and the wave shape changes from low-frequency and high-amplitude waves to high-frequency and low-amplitude waves. When dichloromethane liquid flow rate is 3 ml/min and the gas content is 0.7, the fluctuation frequency can reach up to 260 Hz. Under the same gas content, the liquid film morphology is determined by the viscosity and surface tension of liquids, the liquid film thickness increases with the fluid viscosity, and the frequency of liquid film fluctuation decreases with the liquid film surface tension. The prediction model of thin liquid film thickness for different fluids was constructed through the force analysis of thin liquid film, and the maximum deviation of the predicted value from the experimental value was ±15%. This study clarifies the effects of different fluids and gas velocities on the fluctuations and scales of the liquid film in the microchannel, and provides theoretical guidance for the enhanced heat and mass transfer of the thin liquid film.

A sieve microchannel with embedded structure was designed and the droplet generation process of water-silicone oil system was studied. The dripping and jetting flow were observed under different flow rates of continuous phase and dispersed phase. The effects of two-phase flow rates and interfacial tension on the active pore number distribution and droplet size were investigated. The results showed that the number of active pores increased with the increase of two-phase capillary number. The droplet size decreased with the increase of continuous phase flow rate and decrease of interfacial tension. The droplet size increased in waves with the increase in dispersed phase flow rate. Based on the obtained results, an empirical correlation was proposed to predict the droplet size with good prediction performance. In addition, the effect of the microporous membrane as a flow resistance on the active pore number distribution and droplet size in two-pore microsieve was investigated. The activation of pore became easily under low flow rate of dispersed phase at the presence of microporous membrane as a flow resistance, which led to a smaller droplet size.

In order to achieve high heat flux electronic device cooling, HFE-7100 was used as the working fluid to conduct an experimental study on the flow boiling characteristics of three wedge-shaped manifold microchannels and compared them with conventional rectangular manifold microchannels. The effects of two manifold configurations and two surface enhancement structures on the boiling heat transfer coefficients, critical heat fluxes and flow pressure drops under different flow rates and inlet subcooling are discussed. The experimental results show that the wedge-shaped manifold can promote the transition of flow pattern from churn flow to annular flow, and increase the fluid transport efficiency and vapor discharge efficiency, thus improving the heat transfer performance while reducing the flow pressure drop. Compared with the micro-pin-fin enhancement structure, the porous surface processed by femtosecond laser provides a simple and convenient method to enhance the boiling heat transfer, which can greatly expand the heat transfer surface, provide a large number of nucleation sites, and significantly increase the CHF. Combining the wedge-shaped manifold with porous microchannels, the average two-phase heat transfer coefficient of the manifold microchannels is increased by 21.6%, the critical heat flux is increased by 30.4%, and the two-phase pressure drop is reduced by 12.7%, which realizes a significant improvement in the comprehensive performance of manifold microchannel heat sinks.

In the process of preparing quantum dots in droplet-based microreactors, the perfluoropolyether oil as the continuous phase and the dispersed phase will change the motion behavior of droplets and affect the heat and mass transfer of the reaction due to the large density difference. The effects of the relative direction of buoyancy and flow and the two-phase flow on the dynamic behavior of the droplet were studied by using coaxial microchannels. The results show that the axial symmetry of the flow field in the horizontal droplet is affected by the buoyancy force, and the coaxiality of the droplet decreases to 0% in the early stage of shedding. By adjusting the relative direction of flow and buoyancy, droplet coaxiality stabilized to 100% at a low continuous phase flow rate (Q_c=1.514 ml/min), but at a high Q_c (3.666 ml/min) the droplet coaxiality (96.8%) decreased by only 3.2%. By adjusting the two-phase flow rate, the droplet size can be controlled within 537—980 μm. Based on the mechanism of promoting and inhibiting the horizontal/upward and downward droplet by buoyancy, the droplet size prediction model is established with the deviation less than ±10%. The experiment elucidates the effect of buoyancy on droplet behavior in microchannel and provides guidance for the design of droplet based microreactor.

As a new type of actively enhanced microreactor, micro continuous stirred reactor (micro-CSTR), has a strong ability to handle solid-related reaction systems. In this paper, a micro-CSTR based on magnetic stirring with a total volume of 3 ml and consisting of 16 micro cylindrical grooves was constructed. Its flow characteristics and micromixing performance were investigated by residence time distribution measurement and Villermaux-Dushman fast parallel competitive reaction experiments. The results demonstrated that the flow rate and rotational speed exerted weak influence on the degree of backmixing in the micro-CSTR. The overall Peclet number (Pe) was maintained between 20 and 30, indicating that the degree of backmixing was slightly higher than that of tubular microreactors frequently applied. However, the degree of backmixing remained relatively low. The micromixing efficiency of the micro-CSTR was superior to that of the tubular microreactor, particularly at low flow rates. The characteristic mixing time of this micro-CSTR was further determined using the incorporation model, with a value falling within the range of 0.5 ms to 1.0 ms.

Based on the preparation of supported catalytic packing (SCP) by polydopamine-assisted secondary growth method, a high-performance SCP preparation method was developed through multiple crystallization and alkali treatment synergistic modification. It was found that the loading of the active component layer on SCP increases linearly with the number of crystallization steps. However, the excessively dense structure of the active component layer hinders the utilization of active sites. Tetramethylammonium hydroxide (TMAOH) treatment, by dissolving silicon atoms to create mesopores, enhances the external specific surface area and diffusion efficiency, thereby improving the catalytic activity and coke accommodation capacity of SCP. Under the optimized modification conditions, that is, with 3 crystallization times, a TMAOH solution concentration of 0.05 mol/L, an alkaline treatment temperature of 80℃, and an alkaline treatment time of 120 min, the activity of SCP is increased by 3.74 times. Although the activity decreases during the synthesis of cyclohexyl acetate from acetic acid and cyclohexene, the activity can be restored through calcination regeneration. The coke resulting from the high-temperature polymerization of cyclohexene is the primary cause of activity reduction.

A new continuous operation process was proposed for in-situ sequestrating the by-product CO₂ of water-gas shift reaction (WGSR) by mineral carbonation (MC) in a packed fluidized bed. In addition to utilizing the high temperature, pressure, and humidity environment of WGSR to intensify MC, the continuous separation of sorbent powders by their fluidization through WGSR catalyst packed bed can cope with the rapid decay of MC absorption rate caused by thickening of the product layer. Based on the grain-scale solution-diffusion MC model and the WGSR apparent kinetics, a one-dimensional steady-state plug flow model of the reactor was established to analyze the technical and economic feasibility of applying this new process in a 750 MW integrated gasification combined cycle (IGCC) unit. The CO₂ mitigation cost is calculated based on the simulated conversion rates of CO₂ and MC sorbent, with given energy consumption, carbon tax, etc. It shows that obtaining added value from the carbonation product of MC sorbent as supplementary cementitious materials (SCM) is a prerequisite for the commercialization of this technology. Considering the conversion rates of CO₂ and MC sorbent powder and the grinding energy consumption, MC sorbent fine powders of about 10 μm in diameter is preferred.

Monopropellant energy belongs to gas energy. Unlike conventional energy that relies on oxygen combustion to release energy, it generates high-temperature and high-pressure gas by catalytic decomposition of energetic liquid chemicals without air, which flows through the Laval nozzle to generate thrust or blow the turbine output shaft power. The characteristics are high reliability, fast response, low cost, and unrestricted flight altitude. It is often used to maintain the satellite orbit and provide the emergency power unit for aerospace equipment. With start-up of this power system, the liquid monopropellant enters the packed bed and contacts with the catalyst particles, and then immerses into the micro/nano pores of the catalyst carrier under the action of capillary force. The high-temperature and high-pressure small molecule gas phase is generated with being activated and decomposed by precious metal nanoparticles. With the influence of catalyst pore structure, size, and surface activity, when the gas production rate of catalytic decomposition inside the pore is greater than the outward movement speed of the fluid, the internal pressure in the pore will sharply increase, and even damage the carrier to deactivate. In this paper, the Poiseuille flow is used to describe the flow of gas-phase products in catalyst pores, the Newton’s second law is employed to analyze the movement of gas-liquid interface driven by capillary force, and the gas production rate is predicted through reactant diffusion reaction model. The phenomena of flow, catalytic reaction and gas-phase pressure formation process in the catalyst micro/nano pores is investigated during the initiation of hydrazine propellant catalytic decomposition reaction. The physical phenomenon of catalyst destruction and deactivation caused by the excessive pressure in the pores is analyzed during the initiation process, a theoretical basis for designing and optimizing the catalyst pore structures is provided for decomposing monopropellant.

Succinic anhydride (SA) is the raw material for synthesizing biodegradable plastic-polybutylene succinate (PBS). The research on the preparation of SA catalyst by hydrogenation of maleic anhydride (MA) has important application value. In order to solve the problem of low activity and easy deactivation of the catalyst in maleic anhydride hydrogenation at low temperature, a series of yNi/MC catalysts with different nickel content were prepared by using a kind of mesoporous carbon as the carrier and their properties were characterized and evaluated. Due to the large specific surface area and pore volume of mesoporous carbon, an appropriate Ni loading [40% (mass)] can increase the number of metal nickel site, which is conducive to the high activity in the hydrogenation of maleic. When the Ni loading is relatively lower, increasing the number of active site for weak adsorption of hydrogen is beneficial for improving its catalytic activity in MA hydrogenation. When the load of Ni is higher than 20% (mass), the adsorption and dissociation capacity of H₂ is greatly enhanced so that the bridge adsorption of C=C bond on the catalyst surface becomes the bottleneck problem for further boosting the reaction activity. This work demonstrated that the 40Ni/MC catalyst with 40% (mass) Ni loading reduced at 500℃ had a remarkable performance, achieving 100% selectivity towards succinic anhydride and 80.1% conversion of maleic anhydride at a low temperature of 60℃ and high WHSV of 8.3 h^-1. Furthermore, this catalyst displayed superior stability during the five successive recycling operations. In addition, when the reaction temperature was increased to 90℃, both the conversion and selectivity are close to 100%. When the fixed bed reaction system was used for evaluation, 100% MA conversion and SA selectivity could be maintained after 150 h. Therefore, the as-prepared mesoporous carbon-supported Ni catalyst exhibited a prospective future in maleic anhydride hydrogenation from the viewpoint of industrial application.

Continuous chromatography is a promising technology for antibody production, which has significant advantages of improving process productivity, saving operation cost and enhancing product quality. However, continuous chromatography modes are diverse and there are many influencing factors, making traditional experiment-based process development methods difficult. In this study, model-assisted process development and optimization method was proposed and applied to continuous capture of monoclonal antibody. Different continuous capture modes (twin columns, three columns and four columns) were compared systematically, and the best mode and operating conditions were determined and further verified by experiments. It was found that the model prediction was consistent with the experimental results. Compared with batch chromatography, process productivity of continuous capture was increased by 27.2%, and the resin capacity utilization was increased by 50.1%. Moreover, there were no significant changes in product quality. The results demonstrated that model-assisted process development is useful to determine the optimal operating mode and conditions for continuous capture, promote process optimization, and accelerate the industrial applications of continuous process.

In view of the shortcomings of traditional chitosan preparation process such as high pollution and high water consumption, this paper proposes a new green method for preparing high-purity chitosan based on ionic liquids. The results showed that the [Emim]OAc and [Ch]Ms can respectively prepare chitin with purities of 90.7% and 97.4%, and yields of 38.1% and 63.9% through a two-step dissolution-regeneration method and a one-step dissolution-separation method. Compared with the 1-ethyl-3-methylimidazolium acetate ([Emim]OAc) extraction system, the water content has less influence on chitin extraction by choline methanesulfonate [Ch]Ms. When the water content increases to 50%, the chitin purity still reached 94.3%, and the yield remained at 60%. Additionally, the chitin structure obtained from the [Ch]Ms separation remained in the α form, while the chitin obtained from the [Emim]OAc separation transitioned to a semi-α form. The preliminary mechanism indicated that the synergistic action of the cations and anions in [Ch]Ms effectively removed protein and calcium carbonate, resulting in high-purity chitin. Compared to the [Emim]OAc system, the [Ch]Ms system offered advantages such as lower cost, easier separation, and shorter processing time, making it more suitable for large-scale applications.

Double reflux (DR) pressure swing adsorption (PSA) process has the advantage of not being affected by pressure ratio, and is expected to break through the thermodynamic limitations of traditional pressure swing adsorption (PSA) to obtain two high-purity gases at the same time. In this work, based on the two-bed four-step DR PSA process, we investigated the separation effects of activated carbon (AC), 13X and 5A molecular sieve composite adsorbents, and Cu(Ⅰ)/AC single adsorbent, achieving the simultaneous preparation of high-purity H₂ and CO products. A non-isothermal adsorption model consisting of mass, momentum and energy balance equations was developed using the Aspen Adsorption simulation platform, and its reliability was verified through fixed-bed adsorption experiments. The results demonstrated that the DR PSA process with AC, 13X, and 5A molecular sieve composite adsorbents exhibited unsatisfactory separation efficiency, but exhibited stronger CO desorption ability; using Cu(Ⅰ)/AC alone as the adsorbent can significantly enhance the separation efficiency, that is, using CO/H₂=0.5/0.5 (volume ratio) synthesis gas as the raw material, H₂ product with a purity of >99.999% could be obtained, the CO content is <0.20 ml/m³, and the yield is 96.69%. At the same time, the purity of CO product attains >97.00%, and the yield reaches 99.16%. Increasing the reflux ratio of light and heavy components could further improve the purity of H₂ and CO product gases, respectively.

The use of membrane separation technology for dye desalination is of great significance for the clean treatment and resource recovery of textile printing and dyeing wastewater. In this paper, poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP) hollow fiber porous membrane prepared by melt spinning was utilized as the base membrane. The surface hydrophilicity of FEP hollow fiber composite membrane was improved by co-deposition of catechol (CA) and polyethylenimine (PEI) on the membrane surface, and the interfacial polymerization process was optimized by polypyrrole (PPy) as the intermediate layer. Finally, the FEP hollow fiber composite membrane was fabricated. The results showed that the water contact angle of the membrane was reduced from 122° to 39° after modification, and the hydrophilicity was improved. When the concentration of pyrrole was 10%(mass fraction), the composite membrane had the best comprehensive performance. The rejection of dyes such as Coomath brilliant blue and Congo red were above 95%, while the rejection of salts such as NaCl and MgSO₄ were all below 8%, which could realize the efficient separation of dyes and inorganic salts. Furthermore, when the FEP hollow fiber composite membrane was tested at 80℃ and treated with organic solvent, the dye rejection remained stable, indicating excellent resistance to heat and solvents. In addition, FEP hollow fiber composite membrane was capable of achieving the separation of binary dyes.

With the increase of global plastics production, the problem of waste plastics disposal has become increasingly serious. Pyrolysis technology has attracted widespread attention as a method to convert waste plastics into high value-added products. The pyrolysis process of polyethylene (PE) was investigated by combining molecular-level kinetic model with machine learning methods. First, a large-scale pyrolysis dataset was generated for PE raw materials with different molecular weight distributions using molecular level kinetic model. Then, 9 machine learning models were constructed based on the large-scale dataset to evaluate their predictive ability and feature importance, and analyze the key factors affecting the product yields. The results show that reaction time and pyrolysis temperature are the main factors, and the KNN model performs the best in the prediction of gas and liquid phase products. The study also demonstrates that the simulation accuracy and efficiency of the pyrolysis process can be significantly improved by optimizing the machine learning model and expanding the dataset, which provides new ideas and methods for waste plastics resourcing.

To address the challenges of low gasification efficiency and poor hydrogen selectivity in the production of green hydrogen from biomass gasification, a decoupling process involving pyrolysis followed by chemical looping reforming of volatiles for hydrogen production is proposed. In the theoretical analysis of the above process, it was found that the complex relationship between the yield and composition of pyrolysis volatiles and the properties of biomass and pyrolysis operating conditions is difficult to be accurately associated with the traditional modeling method, which restricts the precise analysis and regulation of the above process. Therefore, this paper establishes a neural network model for the product distribution of the biomass fast pyrolysis process using machine learning methods and determines the optimal pyrolysis conditions using the particle swarm optimization algorithm. The goal is to maximize the hydrogen atom ratio and heating value of the pyrolysis volatiles while minimizing the oxygen atom ratio. Subsequently, the process of hydrogen production from chemical looping reforming of volatiles was analyzed and optimized through process simulation. The results show that the established neural network model can accurately predict the yield of the three-phase pyrolysis products, the detailed composition of the pyrolysis gas, the elemental distribution of the pyrolysis oil, and the higher heating value, etc. The average coefficient of determination of the predictions is 0.821, and the average root mean square error is 2.00, in the test set of the above output parameters. After optimization, the pyrolysis volatiles yield for herbaceous biomass (wheat straw, corn stover) and woody biomass (ficus, pine wood) ranged from 64.49% to 78.62%, with a hydrogen atom ratio between 3.77% and 4.39%. Under optimal conditions at a reforming temperature of 700 ℃ and a steam-to-biomass mass ratio of 0.71 to 0.88, wheat straw showed the highest hydrogen yield and CO₂ negative emission capability, with values of 0.60 m³/kg and -1.74 kg /m³, respectively. Using chemical looping reforming of biomass volatiles for hydrogen production, the hydrogen yield from the four types of biomass increased by 61%, 35%, 16%, and 34% respectively compared to conventional gasification. The research results provide effective foundational support for the production of green hydrogen from biomass.

Accurate prediction of gas solubility in liquid phase is of great significance for studying the stability and decomposition kinetics of gas hydrates. In this work, the Valderrama-Patel-Teja equation of state in conjunction with the Wong-Sandler mixing rule was adopted in correlating methane and carbon dioxide solubility data. In order to improve the predicting ability of gas solubility for saline solutions, the Debye-Hückel electrostatic contribution was taken into account. Moreover, the gas-solvent interactive parameters were evaluated via experimental data of gas solubility in water and the ion-gas interactive parameters were obtained by fitting low-pressure salting-out constants. The modified Patel-Teja equation of state was then integrated with the Chen-Guo hydrate model and was employed to predict gas solubility in water and saline solutions in the presence of hydrate. Comparing with experimental data, the empirical or semi-empirical correlations indicates that the proposed model is capable of predicting methane and carbon dioxide solubility in water and salt containing systems in equilibrium with their hydrate. The average relative deviations of predicted solubility for CH₄ and CO₂ in water coexisting with hydrate are 5.740% and 3.530%, respectively. When the proposed method is used for saline solutions, the average relative deviations of calculated solubility for CH₄ and CO₂ are 2.340% and 1.990%, respectively. The proposed model, therefore, presents potential applications for developing hydrate-based technologies in the fields of CO₂ replacement exploitation and carbon sequestration.

The distribution characteristics of water electrolysis have a significant impact on the performance of the electrolytic cell and its service life. Using partitioned printed circuit boards, the current density distribution and temperature distribution of the steady-state and dynamic processes of water electrolysis were in situ characterized, and the effect of mass transfer polarization on multiple physical fields under the influence of water flow and actual current density was analyzed. The results show that the current density distribution and temperature distribution are more uniform and stable when the electrolytic cell is in the control region of electrochemical polarization and ohmic polarization. When the cell is during the mass transfer limitations, the current density distribution is significantly different. The more severe the mass transfer limitations, the greater the difference in local current density distribution. The high temperature area of the corresponding temperature distribution gradually shifts from the inlet side to the outlet side with the increase of the water flow rate. In addition, the normalized current density distribution is used to analyze the variation of current density distribution in the dynamic process. The results show that the main reason for the change of distribution uniformity of the electrolytic cell is mass transfer polarization. During the occurrence of mass transfer polarization, the low current density region near the downstream outlet area gradually increases, and finally forms the distribution characteristics of stable mass transfer polarization.

During the extraction and transportation of crude oil in subsea or cold regions, gas hydrates can form and accumulate within pipelines under low-temperature and high-pressure conditions. This can subsequently lead to blockage in pipelines and valves, causing a significant threat to the safety of oil and gas transportation. Therefore, studying the formation of hydrates in oil and gas pipelines has always been the focus of attention of the oil and gas production and transportation departments. In this work, we applied a high-pressure microscopic experimental device of visualizing hydrate film growth to study the morphology and growth characteristics of methane hydrate film on the surface of microdroplets suspended in toluene, mixed oil phase of toluene and n-heptane (1∶1, volume ratio), and n-heptane by using the pendant droplet method, and the kinetics of methane hydrate film growth at different temperatures (274.15—277.15 K) and pressures (5.37—7.26 MPa) were determined. The experimental results show that the growth rate of hydrate film increases with the increase of methane solubility in different oil phases, the film growth rate (at 274.15 K, 6 MPa) in toluene (0.26 mm/s)>in mixed oil (0.23 mm/s)>in n-hexane (0.21 mm/s). During thickening growth of hydrate, water is transferred outward through the hydrate film causing the “grooves” between wrinkles on the hydrate film surface gradually filled with hydrate crystals, and the rough hydrate formed in toluene allows for the fastest thickening rate, while the smooth hydrate film formed in n-heptane allows for the slowest thickening rate. The decrease in temperature and the increase in pressure both lead to an increase in the lateral growth rate of hydrate films. The pressure has a more significant effect than temperature, and the growth rate is the slowest in toluene and the fastest in n-hexane. A model driven by pressure difference effectively predicts the kinetic data for methane hydrate film growth (AARD=6.12%).

Under the goal of carbon neutrality in 2060, the development of clean and renewable energy is imperative. However, it is challenging to overturn the energy foundation of the current industrial processes from fossil-based to renewable energy. The key problem lies in the unknown limits on material utilization and energy conversion of renewable energy. In this work, three questions on system and surrounding, heat and electricity, as well as the efficiency and rate were identified. Thermodynamics describing the process limits was used to analyze these questions and discuss the perspectives to achieve carbon neutrality. Based on green electricity converters, photoelectrochemical engineering, membrane separation and heat pumps, a conceptual blueprint of chemical industrial process reengineering was proposed, so as to provide a new perspective for chemical industry to understand and lay out the disruptive technologies required for carbon neutrality.