On the basis of summarizing the development of various nonlinear chemical kinetics, this paper focuses on the main contents of the latest research results on concentration field theory. Based on the law of mass action and the principle of general relativity, the theory has built the nonlinear complex reaction kinetics equation (i.e., the concentration field equation) and given the mechanism index of 9 basic kinetics types, such as diffusion, crystallization, adsorption, heat transfer, phase transformation, and so on. The new theory solves the problems of thermal analysis kinetics, such as non-convergence and faultiness of theoretical basis. The so-called “memory effect” and “reaction order of fractional level” of fracton kinetics were explained rationally. By means of mathematical equations and graphs, it can not only quantitatively express and explain various nonlinear chemical phenomena, such as chemical oscillations, chemical bifurcations, and multiple stationary states, but also give the important conclusions that the fundamental reason for producing various nonlinear chemical phenomena is the double-solution properties of three stage reaction. All these illustrate that the concentration field equation and the concentration field theory have important value in theoretical research and practical application.

Liquid-liquid dispersion process is one of the most typical chemical engineering processes, and the precise control of such processes is the key point for chemical engineering research. Micro-structured chemical systems perform multi-scale manipulation of liquid-liquid multi-phase flows, and have been regarded as one of the most promising techniques for liquid-liquid dispersion and droplet generation. In this paper, recent progresses in droplet generation mechanism, dynamic interfacial tensions (IFTs) and standard particle preparation were introduced. Dominant forces of droplet rupture, flow patterns of liquid-liquid micro-dispersion and micro-dispersion computational fluid dynamics (CFD) methods were firstly introduced. Then, the mechanism of dynamic interfacial tensions (IFTs) were analyzed. Micro-dispersion techniques for particle preparation were finally stated. This review also presents outlook to the future research areas of micro-dispersion and particle preparation.

In order to increase the mass/heat transfer area, the dispersed phases in multiphase reactors are usually dispersed into the continuous phase fluid in the form of particles (bubbles, droplets or solid particles). The interactions with the surrounding continuous phase and other dispersed phase particles make the particles and particle swarms present the complex temporal and spatial heterogeneous behaviors. It is the essential basis to describe accurately these heterogeneous characteristics for modeling accurately, diagnosing quantitatively and optimizing multiphase reactors. In this work, the complex temporal and spatial heterogeneous behaviors of particles and particle swarms in multiphase reactors are summarized and three main measurement problems, i.e., on-line, dense dispersed phase and multi-dispersed phase measurements are put forward in multiphase reactors. The progresses in the measurement techniques of multiphase reactors are summarized. It is pointed out that the optical fiber measurement techniques such as PC and PV probes are more economical for on-line measurement of the dense two-phase reactors, while the invasive photography technology is more accurate. It provides the feasibility to solve the above measurement problems and has a good applicable prospect. However, there are still some technical problems to be solved in order to realize the industrial on-line heterogeneous measurement of multiphase reactors.

During the free radical polymerization process, due to the interactions of mixing, transfer and polymerization, the complex multiscale flow fields, such as the macroscopic velocity, concentration and temperature distributions, the mesoscopic droplet size distribution, the microscopic polymerization rate, polymer molecular weight and polydispersity index distributions, exist within the reactor，thus making the modeling of polymerization reactors be a difficult issue. In this paper, the multiscale phenomena existing in the free radical polymerization reactors were systematically introduced. Modeling and simulation methods of flow field distributions of microscopic polymer properties were briefly described. The simulation research progress of mesoscopic droplet size distributions were introduced from two aspects of suspension polymerization and emulsion polymerization. At macroscopic scale, the research progress of multiphase flow field distributions were expounded from the perspective of non-ideal mixing. Finally, the coupled solution methods of multiscale models were analyzed. This review is our preliminary views, which can be used as a reference for the design, optimization and scale-up of polymerization reactors.

The devolatilization process follows different heat and mass transfer mechanisms due to different volatile contents in polymers. It is of great significance to develop efficient devolatilization technology and equipment based on its determining mechanism. In this paper, different theories, models and characteristics of three consecutive stages of polymer devolatilization process, namely, flash-devolatilization, foam-devolatilization and diffusion-controlled-devolatilization, have been systematically introduced. The intensification methods of devolatilization process have also been reviewed in both engineering and technology perspectives. Correspondingly, new technologies, such as grid falling film reactor, higee, supercritical fluid assistance and ultrasonic enhancement, and their applications were described in detail. Future research directions of polymer devolatilization theory and engineering practice were proposed as following: the coupling mechanism between diffusion-controlled-devolatilization and foam-devolatilization needs to be studied further to establish more precise and universal devolatilization mechanisms; and the grid falling film devolatilization technology is prospective in mass-scale industrial devolatilization process due to its energy efficiency advantages.

The separation of structurally-related compounds is one of the most challenging problems in chemical industry, and conventional separation methods usually suffer from low selectivity, large solvent consumption, and high energy cost. Based on the strong hydrogen-bonding/π-π interaction ability and good phase-forming ability of ionic liquids, ionic liquid-based liquid-liquid extraction can efficiently recognize the small differences in the physicochemical properties of structurally-related compounds, improve the separation selectivity, obtain high distribution coefficients and large extraction capacity, and resist emulsification. This review described the dipolarity/polarizability, hydrogen-bond acidity/basicity and liquid-liquid phase equilibrium of ionic liquids, introduced the research progress in the selective separation of various structurally-related compounds by ionic liquid-based liquid-liquid extraction, and discussed the existing problems and future work in research. Compared with hydrophilic compounds, ionic liquid-based liquid-liquid extraction is more suitable for separating hydrophobic or surface-active structurally-related compounds. The studies on ionic liquid-molecular solvent composite extractant offer a feasible way to address the problems of ionic liquids such as large viscosity and high cost.

Ionic liquids (ILs), comprised entirely of cations and anions, are classified as property-tunable and green solvents. Due to their special properties, such as high thermal stability, low volatility, as well as outstanding physical and chemical nature, ILs have shown great application prospects in many fields and become a research hotspot in recent years. However, the inevitable loss during the use of ILs and the problem of relatively high cost, the recycling and reuse of ILs have drawn great attentions with the scaling up of the ionic liquid-based technologies. Before the large-scale industrial application of ILs, the problem of IL recycling must be solved. This review aims to introduce methods of recycling ionic liquids, which have been investigated widely in recent years. We mainly discussed five methods applied in recycling and reuse of ILs, i.e. distillation, extraction, membrane separation, adsorption and phase separation. The advantages and disadvantages were summarized and analyzed. The results indicated that the recycling and reuse of ILs will greatly enlarge the application range of ILs, while there are still some other challenges need to be resolved. For example, the recycling scale is yet small and the methods reported in the literature are still in their infancy stage. Finally, the review puts forward the future research direction for recycling and reuse of ILs.

Gas-solid circulating fluidized bed (CFB) has been widely used in many fields due to its good mixing, heat transfer, mass transfer and reaction characteristics as well as advantages of large processing capacity and continuous production. CFB is a circulating loop composed of several units, and all the units are coupled and interacted with each other. Therefore, the full-loop simulation, in which the whole CFB system is chosen as the simulation object, is more conducive to obtain accurate and comprehensive results and has advantages in revealing the flow dynamics in the CFB system and in studying the interactions inside the unit between the unit and between the unit and the system. This kind of full-loop simulation has been emerged as a promising research method in the recent decade for the CFB system. The present work will conduct review on the research progress of full-loop simulation, and have in-depth introduction on the application of such simulation method and its relating model and model characteristics. For the CFB, a system with multi flow patterns, it is necessary to establish the multi flow physical model (e.g. interphase drag model, model for the solid pressure) for the full-loop simulation of the CFB system. With the improvement of computing capacity and the development of physical modeling, the full loop simulation method will play an increasingly important role.

Liquid-solid circulating fluidized beds (LSCFBs) have been developing for the past 30 years as a new type of fluidized bed reactor. It possesses many advantages, such as high mass and heat transfer efficiency, large operating intensity, small footprint, combining two independent reactions, etc., and has a broad application prospect in the integration and intensification of traditional chemical processes. In this paper, the development history, equipment structure and basic characteristics of LSCFBs were introduced. It mainly focuses on how to achieve the process integration and intensification of LSCFBs in the following applications: protein extraction, lactic acid fermentation and separation process, phenol removal from phenol-containing wastewater and biological treatment of wastewater. Finally, the future development of LSCFBs was prospected. It was proposed that in the future industrial production process, the reactor can be effectively integrated and improved according to the needs of the process and the properties of the reactor. Based on the integration and intensification of the reaction process, new ideas can be provided for future revolution in production patterns.

The gas membrane separation technology is limited by the properties of industrial membrane materials and often cannot meet the requirements of selectivity and permeability in the production process at the same time. The dual-membrane module integrates two gas membrane materials with different or even opposite permeation properties into one structure, which can well compensate for the poor selectivity of the membrane material and the low permeation rate. First, the research progress of the dual-membrane module is introduced, and the contributions of several main research teams from its generation to development are reviewed. Subsequently, the characteristics of enhanced mass transfer and separation are introduced, the basic principle of reducing concentration polarization on both sides of membrane is shown, and the influence of flow form on separation efficiency of components is analyzed. Then, the three coupling processes of dual-membrane + absorption, dual-membrane + reaction and dual-membrane + condensation +distillation based on the dual-membrane module are described in detail by examples. Finally, the prospects for the research and industrial application of the dual-membrane module are presented. Through the coupling with other separation methods, the dual-membrane module has shown certain potential and unique advantages in the fields of petrochemical industry and natural gas industry. The study on the dual-membrane module is still in the development stage, and the experimental study on separation sequence and operation condition of membrane module needs to be strengthened.

Safety valves, as major safety accessories of pressure systems, play a very important role in ensuring safe operation of chemical and energy installations. More precision and strict requirements have been put forward on the performance of safety valves as the result of harsher condition such as increased pressure and temperature. In order to develop advanced design, manufacturing and maintenance technology for safety valves, the state-of-the-art of safety valves was reviewed and key science and technology progresses were summarized, which include precision design of action and displacement, sealing design, seismic design, reliability design, high temperature mock-up testing verification and structural integrity and health monitoring and so on. On this basis, several future technical challenges were identified, including computer simulation of dynamic responses of safety valves under extreme fluid flows (higher temperature, higher pressure, earthquake, fire), testing setup and methods under extreme conditions, multi-scaling methods for determining the coefficient of flow, smart safety valve technology and structural integrity assessment of safety valves under extreme conditions.

The highly chaotic entropy dissipation across solids bed will trigger non-uniform fluidization, although distributor plays an important role in obtaining homogenous gas stream. For dense gas solids flow, total solids pressure loading (Φ _T), the pressure drop ratio between solids bed and distributor, were introduced here to present the gas solids interaction. The boundary between uniform and non-uniform fluidization can be detected by stability analysis based on Prigogine’s minimum of extra entropy production principle since the dense solids bed is far from equilibrium state and contains inelastic dissipation. Based on the framework of stability analysis of uniform distribution for dense gas solids flow, a phase diagram, illustrating the effects from operational parameter (Φ _T), geometrical characteristics of distributor (C _d) and property of solids (Ga) on instability of uniformity, were attained to draw some useful conclusions of robust uniform fluidization. Besides, the gas tracer method and pressure analysis have been provided to verify the effect of total solids pressure loading on the stability of uniform distribution in cold flow fluidized bed (ID 300mm). The framework has been also applied to calculate the critical point and provides guideline to find better operational conditions and design principle for various industrial fluidized bed reactors.

Xinjiang, the autonomous region in the northwest China, has contained abundant resources of oil, coal and natural gas. Since the 21st century the advancement of exploitation technique has brought the rapid progress petroleum and chemical industries in Xinjiang. With the construction of the New Eurasian Continental Bridge, the transport services of the Eurasian Railways, the operation of China-Kazakhstan crude oil pipelines and the development of the Central Asia natural gas pipelines, Xinjiang has constantly displayed a significant role in the cooperation between China and Central Asian countries. This paper analyzes the current situation of the development of petroleum and chemical industries in Xinjiang and the current and prospective view of energy cooperation between China and Central Asian countries. Based on the SWOT analysis on the future development of petrochemicals and new coal chemical industries, it is proposed that in the new environment of the Belt and Road Initiative, the development of petroleum and chemical industries in Xinjiang still has great advantages. It is concluded that by broadening the sources of resources, focusing on the transition to chemicals and materials, planning modern petrochemicals along the G30 expressway, exploiting coal resources in east Junggar Basin in order to develop modern coal chemical industry, and cooperating with Central Asian countries to produce methanol chemicals, Xinjiang will remain the sustainable development in its petroleum and chemical industries.

Carbon monoxide/carbon dioxide (CO/CO₂) utilization，as the central part of C1 chemistry and carbon capture and utilization，becomes one of the most severe challenges for human society nowadays. For CO₂ utilization，it is very important to achieve CO₂ activation and C—C precise coupling simultaneously. It is a great challenge to control C—O activation，C—C coupling carbon chain growth and termination effectively for syngas conversion. We provide an overview of the significant breakthrough on CO/CO₂ hydrogenation to lower olefins (C₂ ⁼—C₄ ⁼)，which are widely used in the chemical industry and direct CO₂ hydrogenation to gasoline-range hydrocarbons (C₅—C₁₁) with high selectivity. Currently，Fischer-Tropsch (FT) synthesis and oxide/zeolite bifunctional catalysis routes can be utilized to produce lower olefins or gasoline fuels directly from CO/CO₂ hydrogenation. For FT to C₂ ⁼—C₄ ⁼，the product distribution over cobalt carbide nanoprisms deviates markedly from the classical Anderson-Schulz-Flory (ASF) distribution. In addition，acidic zeolites have been exploited to construct the bifunctional FT catalyst，and CO/CO₂ can be directly transformed into C₅—C₁₁ hydrocarbons with good selectivity owing to the catalytic function of acidic zeolite in the hydrocracking/oligomerization/isomerization reactions. On the other hand，the integration of the reduced oxide，which is responsible for the activation of CO or CO₂ to methanol，and SAPO-34 or HZSM-5 zeolite responsible for the selective C—C coupling can also realize the direct synthesis of lower olefins or gasolines from CO/CO₂ hydrogenation with excellent selectivity at a high conversion. In the future，the main objective is to maximize the selectivity of the target hydrocarbons and to reduce methane production significantly by adopting new methods in nano-synthetic areas which deviates from the classical ASF distribution.

To meet the technical requirements of reducing sulfur and olefin contents in the increasingly stringent clean gasoline standards, extensive researches have been carried out in the field of gasoline cleaning technology over the world. In this review, the recent progresses were summarized from the following three aspects: (1) the distributions of sulfides and olefins in fluid catalytic cracking naphtha, the octane numbers of different hydrocarbons, and the hydrogenation reactivity of various olefins and their suppressing effects on hydrodesulfurization; (2) the advantages and disadvantages of the various fluid catalytic naphtha hydroupgrading processes, including selective hydrodesulfurization processes, the combined processes of selective hydrodesulfurization and directed olefin conversion, adsorption desulfurization, and the combined processes of selective hydrodesulfurization and solvent extraction; and (3) the typical models for active metal sulfides and the recent advances in catalyst development. The aim of this review is to provide a brief but comprehensive reference for researchers in the field of clean gasoline production technology.

To meet the“strictest in history”national Ⅵ gasoline quality standards, the development of low sulfur, olefin, and octane number clean gasoline production technology has become a hot research topic. The mainstream technology of clean gasoline production is selective hydrodesulfurization technology. This article expounded the research on the relationship between the octane number loss of FCC gasoline and the hydrogenation saturation law of olefins with different carbon numbers and structures in FCC gasoline. And the status of hydrodesulfurization technology under the background of Ⅵ upgrading in China was also analyzed in detail. The research progress of the hydrodesulfurization catalysts about the desulfurization selectivity and octane number recovery performance was reviewed. Based on the current status and problems of refinery development, the future development of the clean oil was suggested. Adhering to the concept of "molecular refining", the knowledges of the gasoline composition need to be improved so the continuous separation and efficient conversion of various hydrocarbons in gasoline composition will be realized, which can meet the upgrading requirements of clean oil products and the structural adjustment of future oil products.

Coal-based crude oil refers to initial liquid products obtained from thermal chemical reactions, chemical engineering processes of coal, which includes coal tar, coal direct liquefaction oil, and Fischer-Tropsch oil etc. Accurately analyzing the chemical composition and characteristics of coal-based crude oil is beneficial to its fine processing, downstream industrial processing and conversion of the objective products with a product-demand-oriented mode. At the same time, an intensive study of the composition of coal-based crude oil also contributes to the improvement of coal processing techniques. However, due to the complexity of coal-based crude oil, no exact composition and content of coal-based crude oil have been reported, and there is no national or industry standard for corresponding analysis methods so far. Particularly the problem of material balance during the whole production process in the qualitative and quantitative analysis has not been solved yet. Therefore, a more precise qualitative and quantitative analysis of coal-based crude oil with material balance as a constraint, and the establishment of a comprehensive and systematic analysis method in the whole production process is still an urgent issue to be solved. The paper points out that the combination of gas chromatography and infrared spectroscopy, liquid chromatography separation and ultraviolet spectroscopy, synchronous fluorescence spectroscopy, and other spectral analysis methods can quickly obtain the content of coal-based crude oil group-components, or qualitative description of coal-based crude oil properties; Nuclear magnetic resonance spectroscopy can achieve accurate qualitative and quantitative determination of phenolic compounds; Chemical analysis is only suitable for qualitative and quantitative analysis of specific components of coal-based crude oil; Analysis and characterization combination of infrared spectroscopy, nuclear magnetic resonance spectroscopy, gel permeation chromatography and elemental analysis can systemically acquire some important structural parameters of coal-based crude oil; Chromatographic analysis can separate complex mixtures by chromatographic separation function, and use different detectors to achieve qualitative and quantitative of samples. The qualitative methods mainly use mass spectrometer, spectrometer, nuclear magnetic resonance spectrometer, etc. The quantitative methods include normalization method, internal standard method, external standard method and response factor prediction method. For the qualitative and quantitative determination of the light weight fractions of coal-based crude oil (boiling point <350℃), gas chromatography-mass spectrometry (GC-MS) technology provides the possibility of this analysis process. Especially the detection principle and quantitative method of flame ionization detector (FID) detector was reviewed at length and deduced the FID response factor prediction formula. The formula will be combined with area normalization method to establish the FID quantitative method system, and results from the standard addition recovery experiment (recovery rate is 99.07 wt%) indicate that the method system is accurate and effective, and can be widely applied to the quantitative analysis of complex organic mixtures. In the end, the key to the material balance in the whole production process lies in the prompt, accurate and large-scale quantification of complex organic compounds was pointed out. Preliminary analysis results showed that the combination of instruments, especially GC-MS/FID, would be one of the main ways to achieve qualitative and quantitative analysis of composition of light weight fractions constrained by material balance for the time being. It was inferred that the key to the qualitative and quantitative analysis of the light components of coal-based crude oil was the accurate acquisition of the response factors of each component in the complex mixture.

Carbon dioxide is a kind of low toxic, non flammable, cheap and abundant C1 resource. The effective conversion of carbon dioxide to high value-added chemicals has become an attractive research topic. From the point of view of energy utilization and economy, the utilization of carbon dioxide as carboxylation reagent together with energetic materials to synthesize carboxylic acids or esters is an important way and has been attracted much attention. In this paper, the recent progress on the carboxylation of carbon dioxide is reviewed, and the feasibility and application prospect of the carboxylation route are discussed from the respect of reaction thermodynamics, mechanism and the improvements of catalyst and reaction process. And the problems and limitations of this research field are summarized. In the end, the future development direction is prospected. Establishment of CO₂ chemical industry relies on the breakthrough of fundamental research. Highly active and cheap transition metal catalysts with wide application are urgently needed, in order to activate and utilize CO₂.

The design of supercapacitor with high energy density requires a deep understanding of the contribution factors of the total capacitance. This article reviews the recent progress on predicting the capacitive performance of supercapacitors by using classical density functional theory (CDFT). Comparing to the conventional molecular simulations, the CDFT is superior in calculation speed, especially for electrolytes in porous electrodes. CDFT could be developed and applied to study the electrode/electrolyte interface behaviors, to understand the pore size effect, curvature effect, and the surface modification of porous materials and the electrolytes parts (the concentration effect, the solvent and impurity effect, and the ionic liquid mixture effect) on the capacitive performance. Further development of CDFT for electrode/electrolyte interface would allow researchers to design better supercapacitors.

Operando characterization is a cutting-edge technique for revealing the catalytic reaction mechanism and the dynamic structure evolution of industrial catalysts under the conditions close to industrial reaction. The development of operando technique and its application on heterogeneous catalysis have been reviewed, and the latest progress on operando infrared spectroscopy (IR), operando Raman, operando X-ray diffraction (XRD), operando M?ssbauer, operando X-ray adsorption spectra (XAS), and operando X-ray photoelectron spectroscopy (XPS) have been summarized. In addition, the coupling of various operando characterizations has also been introduced. Through this technique, the overall structure of the catalyst during reaction process can be characterized more deeply, and thus can realize the rational design of industrial catalysts. Therefore, we believe this coupling technique will become an important and prospective way to study heterogeneous catalysis. Nevertheless, the time and space resolution of current operando technique needs to be improved, and its enormous potential still requires to be further developed.

Hydrogen is regarded as an ideal energy carrier for its light quality, high energy density and eco-friendly combustion emission. Hydrogen can be used as fuel for PEM fuel cells and energy storage media to regulate the energy output from wind turbine and solar power, therefore it is expected to play a crucial role in future energy system. In order to develop the technology and devices for water electrolysis, high efficient electrocatalysts are the key. We systematically introduce the recent progress in MoS₂-based electrocatalysts for hydrogen evolution reaction (HER), categorize the electrocatalysts into powder-type and binder-free electrocatalysts, and discuss two methods of regulation of active sites and the improvement of electric conductivity. Different types of MoS₂ and MoS₂-based electrodes for HER were compared and evaluated using the overpotential and Tafel slopes, and the results demonstrate promising potential of MoS₂ as HER electrocatalysts. For developing MoS₂ HER electrocatalysts, it should further increase the stability of MoS₂ crystal, regulate the electronic properties and optimize the electrode structure.

The Fischer-Tropsch (FT) synthesis is a key technology for producing high quality ultra-clean fuels from syngas produced from coal, natural gas, and biomass. Cobalt is one of the most effective and industrially important catalysts for the FT synthesis due to its high activity, high resistance to deactivation, and low water-gas shift activity. Although the cobalt-based catalysts for the industrial application have been developed, the large-scale and wide application of Co-based catalysts is still in need of developing a more efficient catalyst with a higher activity, improved stability, and higher selectivity to desired products such as α-olefins. In this work, the recent advances on the study of Co-based catalysts for FT synthesis, i.e., the structure sensitivity, breaking the dependence between the dispersion and extent of reduction of cobalt, deactivation mechanism, and tuning the product selectivity, are reviewed. The effects of Co particle size, crystal structure, and the interactions between Co and support on the FT activity are analyzed . Besides increasing the Co dispersion and extent of reduction through adjusting the interactions between Co and the support, the controlled synthesis of Co-based catalysts with a hexagonal close packed (hcp) phase, of which a higher intrinsic activity for FT synthesis has been revealed, is an effective strategy to improve the mass-specific activity of Co catalysts. The resistance to the sintering of Co and coke deposition is revealed as the key factor for improving the lifetime of Co-based catalysts for FT synthesis. Finally, recent developments of bifunctional FT catalysts for one-step synthesis of clean liquid fuels from syngas are highlighted, and the further developing trends are to improve the stability of bifunctional catalysts and to solve the engineering problems for large-scale manufacture of the catalyst.

p-Chlorobenzaldehyde is an intermediate for many fine chemicals and it is widely used in the production of pharmaceuticals, agricultural chemicals, and dyes. It is significant but also very challenging to develop a green process for the catalytic synthesis of p-chlorobenzaldehyde. Herein synthesis of p-chlorobenzaldehyde by catalytic oxidation of p-chlorotoluene was reviewed. Emphasis was put on the oxidation of p-chlorotoluene with H₂O₂, air/O₂ or electro-oxidation, and biomimetic catalytic method. The advantages and disadvantages of these methods were described systematically, and the feasibility and existing problems in their industrial development were pointed out. In addition, the selective oxidation of p-chlorobenzene to p-chlorobenzaldehyde by photocatalysis was also introduced. After comparison of different synthesis methods, we point out that the liquid phase oxidation of p-chlorobenzene by using H₂O₂ and molecular oxygen as oxidant shows good industrial application prospect. Meanwhile, the electro-oxidation and biomimetic catalytic oxidation will provide new techniques for the preparation of p-chlorobenzaldehyde.

Zirconium dioxide (ZrO₂) is an excellent catalytic material, due to its high-temperature resistance, corrosion resistance and high mechanical strength. Besides, it has both acid and basic sites on the surface and is able to produce oxygen vacancy. However, ZrO₂ prepared by conventional methods has low surface area and pore volume, which may limit its broad applications. The recent preparation methods or techniques of high-surface-area ZrO₂, including templating methods, MOF pyrolysis, and electrostatic spinning,so as to improve its thermal stability and to extend its applications in catalysis are reviewed. The studies showed that the porous ZrO₂ can improve the dispersion of the supported metal and the metal-support interaction, giving rise to the enhanced activity and stability of the catalysts. Meanwhile, its particle size, morphology and pore structure also have effects on the catalytic performance. The high-efficient and low-cost preparation methods of thermal stable high-surface-area ZrO₂, and the accurate regulation of its morphology or structure, will give it a broader catalytic application prospect in the future.

Cyclohexylbenzene can be oxidized to produce phenol and cyclohexanone. Besides, it can be used as an additive in the electrolyte of lithium ion batteries and as a blend to tune the cetane number of diesel oil, and thus it is a fine chemical with high added value and market potential. The progress in the synthesis of cyclohexylbenzene by alkylation of benzene with cyclohexene and the catalysts used are reviewed. The mechanism and reaction path of benzene hydroalkylation are summarized, including the source of hydroalkylation activity, the inference of carbocation intermediates, and the formation of all reaction products. Based on the hydroalkylation mechanism, the design concepts and the development process of hydroalkylation catalyst were reviewed. Finally, it is pointed out that new catalysts, such as B-acid, B-L-acid, and immobilized ionic liquids, can be developed for the alkylation of benzene with cyclohexene. It is suggested that the hydroalkylation mechanism can be improved by means of the latest research methods of carbocation, and hierarchical porous zeolite can be used as the acidic support of hydroalkylation catalyst.

Due to the excellent catalytic performance, the multicomponent bismuth molybdate catalysts have attracted much attention in oxidative dehydrogenation of butene. This review describes the recent progress about the crystalline phases and its relationship with the reaction performance for both single and multicomponent bismuth molybdates. The results indicate that in bismuth molybdate, α-Bi₂(MoO₄)₃ provides adsorption sites because of the presence of more lattice defects, and γ-Bi₂MoO₆ provides lattice oxygen because of higher oxygen mobility. The synergistic effect of the two phases enhances the activity of the catalysts. In multicomponent bismuth molybdate catalysts, the added elements combine bismuth and molybdenum to form new crystalline phases, resulting in more lattice defects and oxygen donors, and thus improving the catalytic performance. As for the further improvement of multicomponent bismuth molybdate catalysts, it is believed that, on the basis of the method of adding components, the surface structure of the catalysts can be further explored.

The superhydrophobic surface have been studied for decades， and the applications of superhydrophobic metal materials in chemical engineering are quite promosing. In this work， the latest progress in the preparation of superhydrophobic metal surface materials and their applications are reviewed. On the basis of fundamental wetting models， the preparation methods of constructing rough micro- and nano-structure on metal for obtaining superhydrophobic surface are introduced. Applications of superhydrophobic metal surface in conventional chemical engineering such as self-clean， drag reduction， heat exchanging intensification， anti-icing， anti-corrosion， water/oil separation， and new applications including anti-scaling， rolling granulation， and evaporation crystallization， are summarized. Finally， the developing tendency is proposed as one-step preparation of stable and high-performance superhydrophobic metal surface with the features of pollution-free， low-cost， and quickness.

Membrane-based filtration is the current leading technology for high-end water treatment processes. Nevertheless, the high energy consumption, the “trade-off”relationship between permeability and selectivity, and the low antifouling/antibacterial properties of membranes are challenges that hinder their widespread industrial-scale application. This review summarizes state-of-the-art nanomaterials and the selection principles of them for the fabrication of nanocomposite membranes. An overview on the desalination properties, including separation performance, antifouling/antibacterial characteristics, chlorine resistance, concentration polarization effect, are compared and summarized. Challenges, future research directions, and perspectives on developing high performance nanocomposite membranes are illustrated in detail. It is implicated that more efforts are still needed for the development of next-generation desalination membranes, particularly in the agglomeration, dispersibility, and compatibility of the nanomaterials.

Due to the lack of an efficient online monitor technology for the component concentration in the fermentation, more and more researches are working on the development of the fermentation biosensors. This review mainly focuses on the recent research progresses on the fermentation biosensors, especially on the progress of the recent synthesized novel nanomaterials for the construction of the fermentation biosensor. The various nanomaterial design strategies and preparation methods have been introduced for the different fermentation systems, including metal, metal oxide, coordination compound, organic compound, and carbon based nanomaterials. The mechanisms of these nanomaterials and their practical biosensing performance were also discussed. According to the sensitivity, working potential and anti-inteference ability, the advantages and disadvantages of these materials were evaluated, and the future development of the biosensing materials for the fermentation detection had also been analyzed. The review provides an important reference to the biosensor fabrication for the wide range and multiple fermentation components detection.

Functional oligosaccharides have been widely used in the fields of food and biomedicine due to their appealing characters of anti-tumor, anti-inflammatory, anti-coagulation, anti-radiation, and other health functions. As an efficient separation technology, nano-filtration has attracted more and more attention in the separation and purification of functional oligosaccharides. In this paper, the separation mechanism of nano-filtration membranes for functional oligosaccharides was analyzed. Recent progress in their applications for the separation and purification of functional oligosaccharides was reviewed. The factors affecting the nano-filtration process were discussed, including the properties of feed solution, the operating parameters of membrane process, and the characters of membrane materials. The factors of feed solution mainly included its composition, concentration, viscosity, etc. The operating parameters were mainly reflected in the following: temperature, pressure, membrane surface velocity, pH, etc. The characters of membrane materials included both the microstructure and the surface properties. Finally, the challenges that the nano-filtration technology for the separation and purification of functional oligosaccharides is facing, such as the cost of equipment, the characters of membrane materials, and the membrane fouling, were presented. To promote the further application of nano-filtration, it is necessary to develop special membranes with low-cost and high performance, to focus more on the optimization of membrane system and the fouling control of membrane.

Porous carbon materials have attracted great attention due to their advantages of adjustable pore structure, superior chemical stability and outstanding electron accessibility, which have been made a great research progress in the field of energy storage. Here, combined with the research work of our group, we summarize the synthetic method and method principles of the pore structure design. The research progress of porous carbon with different morphology, such as carbon nanospheres, carbon nanofibers, carbon sheets, monolithic carbon is briefly introduced. Moreover, this article summarizes the application of porous carbon materials in the field of electrochemical energy storage (supercapacitors, lithium ion/sodium ion batteries, lithium-sulfur batteries, etc.) and point out the disadvantages of porous carbon materials for energy storage. Finally, we propose some important aspects for the future development of porous carbon applied for energy storage.

The functions of microscale functional materials are determined by an accurate and synergistic combination of their structures and the constitute components. However, how to accurately manipulate diverse structures, and synergistically integrate diverse components in micro-space still remains challenging. This review summarizes recent progress on the microfluidic fabrication of novel microscale functional materials. Emphases are placed on the new strategies for fabricating microscale functional materials with unique structure and function, through accurate and synergistic combination of the structures and the constitute components. First, controllable fabrication of functional microparticles and microfibers with diverse structures, respectively from microdroplet templates and microflow jet templates is introduced. Then, in situ fabrication of functional membrane-in-chip and microvalves using confined microscale interfacial systems in microchannel as templates is introduced. Further study should focus on the creation of microscale interfacial systems with more diverse structures and their scale-up techniques.

Lignin is the second most abundant natural organic polymer in plants. Industrial lignin derived from paper-making and biorefinery processes is utilized to develop functional materials, which plays a great role for the mitigation of fossil resource crisis and environmental pollution and so on. Various lignin-based functional materials have been prepared, including drug-loaded capsules, UV blockers, antioxidants, catalyst carriers, carbon electrodes and so on. This review introduced recent research progresses of lignin-based functional materials, summarized the preparation methods and application fields. The influence of the lignin microstructures and preparation methods lignin on the properties and application performance of the functional materials were also reviewed. Developing lignin-based functional materials is a frontier topic of multidisciplinary. However, how to prepare lignin-based functional materials with controllable structures and excellent performance is still a challenge. Future researches should focus on the microstructures of lignin and its regulation mechanisms, so that it can better use its three-dimensional and aromatic structures to prepare functional materials.

The high efficient separation of CH₄-N₂ can greatly promote the use of the conventional and unconventional natural gas which is a kind of green and low carbon energy. Zeolite-based adsorbents and membrane materials have excellent gas separation characteristics and great potential for CH₄-N₂ separation. In this review，the state of the art of zeolite adsorbents and membranes for CH₄-N₂ separation was discussed from two aspects：N₂-selective separation（high-concentration methane purification） and CH₄-selective separation（low-concentration methane enrichment）. The structure-activity relationship between the framework and cations of zeolite and its adsorption and separation performance of CH₄-N₂ was analyzed in detail. Combining with the previous work of our group, we proposed that the electroneutral (near-neutral) framework molecular sieve has better separation of CH₄-N₂. Finally, the future trend of molecular sieve adsorbents and membrane materials for CH₄-N₂ separation is summarized and prospected.

Carbon capture/storage (CCS) is of great significance to solve the problems of greenhouse effect, climate warming, environmental pollution and energy crisis. More attention has been paid on Ca-based sorbents because their high adsorption capacity and lower cost. The characteristics and adsorption mechanism of calcium-based CO₂ sorbents are introduced. This paper focuses on two modification methods of calcium-based sorbents, including incorporation of refractory metals into CaO and morphology modification, which are effective to improve the stability. Single and co-doping by metal oxides with high Tamman temperatures or more oxygen vacancies, such as Zr, Ce, Mn, Mg, Al, are introduced. The influence of synthetic methods, conditions of adsorption-desorption, content of inert material, and the precursor on the performance of calcium-based sorbents is discussed. The hollow and solid spherical particles of calcium-based sorbents prepared by polystyrene beads, carbon aerogels, and carbon sphere, have favorable adsorption capacity and stability. However, there is still a long way to go for realizing the industrial application. It is urgent to explore the relationship between the structure and the performance, so as to provide the theoretical guidance.

Membrane-based separation is considered to be one of the most promising separation technologies due to its high efficiency and low energy consumption. Owing to the small difference in the mixtures’ physical properties (such as molecular sizes), it is extremely challenging to finely separate them. Metal-organic frameworks are featured to have good adjustability on aperture sizes and high porosity, thus are expected as ideal membrane materials to sieve molecules precisely. In this review, traditional porous membrane materials are compared and the metal-organic framework based membranes are classified into supported metal-organic framework membranes and mixed matrix membranes. Simultaneously, the fabrication methods and their developments of these two types of membranes are introduced and the more advanced fabrication methods are forecasted. Additionally, the applications of metal-organic framework membranes in gas separation, nanofiltration and desalination, and pervaporation are discussed. Finally, several directions to improve the permeability and selectivity of supported metal-organic framework membranes are proposed.

In natural environment, multilevel and multidimensional, and multi-scale natural hard template structure from long-term evolution and some "soft" natural biological molecules with multi-level, multi-dimensional structure provide a new venue for hierarchically structural design and preparation of nanomaterials. Metal oxides are usually employed as an important component of the catalyst. Therefore, their preparation and catalytic applications have received much attention. Bio-templated synthesis provides a simple, green and efficient synthetic route to the metal oxide. This review summarized the research progress in recent ten years from the aspects of preparation methods based on bio-templates, the roles of biological templates in the oxide preparation process and in catalytic application of metal oxides. The preparation method based on hard template is simple and efficient and can perfectly duplicate metal oxide materials with similar structures, while the soft template can flexibly regulate the size and dispersibility of metal oxide particles. Based on the bio-templated synthesis, the formation of metal oxide often experiences multi-steps of "adsorption-nucleation and growth-assembly", where bio-template plays important roles in the surface adsorption, confinement, orientation, etc. For catalytic applications of the metal oxide, bio-templated synthesis offers the advantage to enable the elemental self-doping of metal oxide, effectively improve mass transfer, and special surface structure of metal oxide endows the resulting catalyst with excellent catalytic performance.

The g-C₃N₄-based materials with special morphologies have the characteristics of hierarchical structure and adjustable short-range electron transfer pathway etc., and thus could well overcome the problems of traditional g-C₃N₄-based materials such as small specific surface area, low visible-light utilization efficiency, and high recombination rate of photo-generated carriers. Consequently, they demonstrate broad development prospect and great application potential in the photocatalysis field. This review highlights the recent advances of g-C₃N₄-based materials with special morphologies, such as tube/rod/array, porous microsphere, gel and biomimetic morphology, and discusses the structure-function relationship between their morphologies and the photocatalytic performance. At present, the research for this kind of materials is in their infancy and they still exhibit a few problems, such as limited morphology types, few synthetic methods and insufficient understanding of the structure-function relationship. Therefore, the investigation should be focused on the expansion of the morphology type, regulation of the energy band position, the transfer mechanism of photo-generated carriers and the molecular modeling in the future, so as to afford better ideas for the exploration of high-performance photocatalytic materials.

High-purity magnesia is an important heat-resistant material and magnesium oxide ceramics are widely used in the field of transparent materials. It has great theoretical and practical significance to study the production process of the two materials. Various technologies of producing high-purity magnesia and magnesium from magnesite and brine, sintering methods of magnesium oxide ceramics and the influence of sintering additives on the sintering process are systematically reviewed. The preparation technologies of high-purity magnesia from magnesite, the preparation technologies of high-purity magnesia by brine precipitation method and by direct pyrolysis of brine method and the preparation technologies of high-purity magnesia by electrical fusion method are introduced. The advantages and disadvantages of each production technology and the research and development directions in the future are pointed out. Various sintering methods and research progress of magnesium oxide ceramics are introduced, including conventional sintering, hot pressing sintering, hot isostatic pressing sintering, spark plasma sintering, microwave sintering and vacuum sintering. The influence of sintering additives on the sintering process and the influence mechanism are summarized. The future research emphases of magnesium oxide ceramics such as powder synthesis technology, densification sintering technology and sintering additives are pointed out.

Three-dimensional (3D) printing is a rapid prototyping technique. The applications of 3D printing for the preparation of catalyst and adsorbent have recently received increasing attentions. 3D printing can extend the range of monolithic catalysts and adsorbents, optimize the structure design and the active component distribution, which can enhance the mass and heat transfer during the catalytic reactions and adsorption processes. As a convenient and reliable modeling method, 3D printing is suitable for both laboratory operations and industrial applications. In this review, a general overview of the commonly available 3D printing methods is given for the preparation of catalysts and adsorbent. Recent works on printing strategies and new materials for catalysis and adsorption are also discussed. Polymers, carbon, metals and metal oxides, zeolites and many other materials can be incorporated into monolithic catalytic system by the help of 3D printing. The catalytic and adsorption performances can be controlled by the structure and distribution of the materials. Therefore, 3D printing is a promising technology for the preparation of catalysts and adsorbents. It is also pointed out that future developments have been discussed including the microstructure control of the material, the standardization of printing feedstocks and processes, and the design of the structures and active component distributions.

Sulfonated poly(phthalazinone ether sulfone ketone)(SPPESK), a novel non-fluorinated polymer, possesses the advantages of low methanol permeability, high chemical and thermal stability, but the obtained high conductivity needs high degree of sulfonation, resulting in the loss of membrane dimensional stability due to the excessive swelling. The introduction of inorganic nanoparticles can effectively improve the membrane performance. However, due to the lack of functional groups on the surface, the inorganic particles often show poor organic compatibility. Besides, the membrane’s anti-methanol permeability and proton conductivity cannot be easily improved simultaneously. The sulfated nanoparticles with acidic sites and sulfate groups on the surface can effectively overcome this problem. The SPPESK based composite proton exchange membranes were prepared by doping sulfated SnO₂ (SSnO₂) nanoparticles. The SSnO₂ showed good organic compatibility when the content was not more than 7.5%. Compared with the pristine membrane, the composite membrane containing 7.5% SSnO₂ showed higher water uptake (improved by 19%) at 80℃ in, and the swelling ratio (19.6%) was close to that of Nafion115. The nanoparticles induced the aggregation and expansion of the ion clusters in the membrane, which led to the low-resistance transfer of protons. Compared with pristine SPPESK and Nafion115, the composite membrane showed conductivity increases of 48% and 30% at 80℃, methanol permeability reductions of 46% and 71% and power density enhancements at 0.5V of direct methanol fuel cell of 205% and 50%, respectively.

The global climate change due to the accumulation of greenhouse gases has attracted great attention. Therefore, scientists have carried out many explorations and researches on CO₂ fixation through different methods, such as chemical conversion, enzyme catalysis, and microbial transformation. The versatility of microbes has the advantage of using biomass, biological waste and carbon dioxide as raw materials to produce biofuels and chemicals. In this paper, the ways of immobilizing CO₂ naturally occurring in microorganisms were summarized, and the related work of converting carbon dioxide into chemicals or biomass energy by biological or bio-electrochemistry methods were extensively discuused. In addition, the first (using food as raw material) and second (using non-food biomass as raw material) generations of bio-manufacturing’s methods and effects were evaluated, and the concept of the third generation of bio-manufacturing was introduced. Finally, the key technologies and development trends needed in the future development of carbon dioxide for biotransformation were suggested.

Diabetes mellitus is an endocrine and metabolic disease with high morbidity and complications, which so far cannot be healed. The patients not only have economic burden but also have poor quality of life. Those with serious illness also face long-term life threats. In recent years, the increasingly serious problem of diabetes has gradually become one of the major concerns of the society and the related fields. This article started from the introduction of human blood glucose regulation system, describing the causes of the two types of diabetes. From the chemical engineering point of view, the human body can be analogized to a control system for the blood glucose metabolism. The main mechanisms of the blood glucose control in diabetic patients and the key role of blood glucose prediction were pointed out. The paper introduced two main physiological models of blood glucose prediction in detail: the glucose-insulin metabolism model and the glucose absorption model. The important role of the chemical engineering modeling strategy in the construction of the absorption model was highlighted, and the advantages of the method as well as the deficiency of the existing models were analyzed. The suggestions on improved modeling approaches were further discussed based on the in vivo and in vitro experiments in recent years. Finally, the future work of blood glucose prediction was proposed. It is suggested to improve understanding themechanism and combine the blood glucose prediction model with the chemical engineering modeling strategy to better understand the effect of diet on blood glucose regulation. In addition, the long-term prediction model and the personalized model need to be improved.

The continuous-flow micro-reaction technology based on micro-reactors is an emerging technology in drug synthesis. It offers many advantages, as compared to the conventional batch-wise synthesis, including excellent heat- and mass-transfer characteristics, inherent safety, high process reproducibility, consistent product quality, facile automation, and exceptional space-time efficiency. Its advantages are increasingly appreciated by the drug synthesis community. In this review, the recent research progress of end-to-end continuous-flow synthesis and preparation of active pharmaceutical ingredients (APIs) and final dosages from starting materials were highlighted. The technologic advantages and significance of continuous-flow micro-reaction technology were further illustrated by means of analyzing typical research examples. The limitations of this technology applied to drug synthesis were summarized. In general, drug synthesis comprises multiple steps, and is constantly faced with issues such as system inconsistency, solvent replacement, separation and purification and the sequence of raw-material addition, etc. The connection between consecutive reaction steps and coupling of post-processing steps presented difficulties and challenges for end-to-end continuous-flow synthesis and preparation of active pharmaceutical ingredients (APIs) and final dosages from starting materials, which needs to be addressed. Therefore, the development of new technology and equipment to connect multiple reaction steps and for post-processing which can be effectively coupled with micro-reactors is gradually becoming a hot research topic in this field.

Product capture from a cell culture broth is a key step in the production of antibodies and Fc-fusion proteins. With a rapid increase of large-scale animal cell culture techniques, capture techniques in antibody production have become the key technical bottleneck in monoclonal antibody productions. In this paper, core antibody capture methods, including protein A chromatography and cation exchange chromatography, have been reviewed in term of their history and applications. At the same time, peptide affinity chromatography, mixed-mode or multimodal chromatography, expanded-bed adsorption and sequential multi-column adsorption have been introduced to exhibit their great potentials in high-efficient antibody captures. Moreover, the factors affecting the capture and purification processes were analyzed while the problems that need to be solved to improve the technologies were discussed. Finally, perspectives into the development of antibody captures were discussed with focusing on the technological aspects of the chromatographic methods.

Bioethanol production through syngas fermentation has many advantages, such as mild reaction conditions, higher end-product tolerance, rich source of raw carbon materials and so on, which is a novel method for fuel ethanol productions. In this paper, the types of microorganisms for syngas fermentation, the characteristics of growth, metabolism and substrate utilization of the main microorganisms, Wood-Ljungdahl pathways, the key enzymes of formate dehydrogenase and carbon monoxide dehydrogenase/acetyl-CoA synthase, the influence factors of culture medium, reducing agent, pH, gas composition, products, medium composition and culture methods on syngas fermentation, and the types of syngas fermentation reactor were reviewed. The prospect of future development direction of syngas fermentation was proposed.

Terpenoids have a wide range of physiological activities and important economic value, and using Saccharomyces cerevisiae for terpenoids synthesis has the advantages of low cost and high efficiency. However, due to the low expression and catalytic efficiency of many key enzymes for terpenoids synthesis in S. cerevisiae, it is difficult to realize industrial applications. The regulation strategies of key enzymes, metabolic pathways, CRISPR gene editing system and synthetic chromosome technology used in S. cerevisiae were elaborated. And the advantages of key enzymes screening, modification, rational and irrational design; regulation strategies for MVA pathway, acetyl-coenzyme A synthesis pathway and subcellular structural modification were summarized. To achieve efficient synthesis of terpenoids in S. cerevisiae, combinatorial regulation strategies should be adopted, and the development of the CRISPR gene editing system and synthetic chromosome technology will provide a powerful tool for the in-depth development and utilization of the S. cerevisiae.

Enzymatic catalysis plays an increasing role in the development of bio-industry. However, there are still many problems in the application of some enzymes, which hinder the development of biocatalysis. This paper focused on the enzyme substrate specificity and reviewed the advantages of enzymes, such as high specificity, increased efficiency, and environmentally-friendly process. The applications of enzymes in fine chemistry and pharmaceutical synthesis were introduced. The paper also summarized the current methods used in engineering of enzyme substrate specificity, including chemical modification, irrational and rational design. Chemical reaction was a direct-viewing method applied in enzyme modification. Irrational design was often employed to obtain the better mutants with increased substrate specificity through error-prone PCR and DNA shuffling. In the rational design, enzyme engineering was based on their sequences and structures. Starting from reshaping the active pockets for increasing the substrate specificity and changing the enzymatic reaction type, this paper elaborated the methods of rational design to enhance the substrate specificity and provided a reference for future substrate specificity engineering.

Charge control agent (CCA), as an important additive in toner to change the charging characteristics of the toner and the rate of electrification to complete the printing, has drawn more and more attentions. This review summarized the development history of typical CCA used in toners. According to the difference in electrical properties, CCA can be divided into positive CCA and negative CCA. The traditional positively charged CCA includes aniline black and quaternary ammonium salt. The aniline black cannot be applied to color printing because of its own color while the quaternary ammonium salt is the most commonly used positively charged CCA because of its simple synthesis and light color. Negative CCA includes azo metal complex and tert-butylsalicylic acid metal complex, where in the latter has become the most widely used traditional CCA due to its stable charge, good dispersibility in the resin and colorlessness. In recent years, no metal-complex type CCA has become a hot research topic due to the instability of high temperature for metal complex type CCA. In addition, biomaterial-based CCA and CCA synthesized by polymerization have drawn more attention due to the demand for environmental concern and high image quality. All over the world, the Oriental Chemical Industry Company (Japan), Baotu Valley Chemical Industry Company (Japan) and Hubei Dinglong Chemical Company (China) are the three largest CCA producers. Two Japanese companies have more than 80% of the world's share. The research and development of high quality imaging information chemicals in China is still an important task, such as how to solve the problem of high cost for the CCA without metal ions and to develop price-competitive, colorless, and fully charged CCA.

Energy and environment had been become the two major global challenges in the present world. The production fuels and chemicals from lignin may be an important part of the low-carbon solution to both issues. This paper took the energy and environmental problems as the starting point, the feasibility and necessity of the production of fuel and chemicals via catalytic pyrolysis lignin were described, and then the status of the research on the catalytic pyrolysis behavior, catalytic pyrolysis process and catalytic products at home and abroad were systematically introduced. A brief introduction of the structure and transformation process of lignin was presented. Then the catalytic pyrolysis behavior, catalytic pyrolysis products, and the research status of the used catalysts were systematically elaborated, and the existing mechanism of catalytic pyrolysis lignin was discussed. The assessment of the challenges and opportunities, mitigating technical, environmental, and logistical issues in the process of catalytic pyrolysis lignin for the fuel and chemicals production showed that improving product productivity and energy efficiency in the conversion of lignin into fuel and chemicals will be the overall goal in the future, and the raw material supply and production, catalyst development, product separation and purification, reaction mechanism and kinetics, and computational simulation will be important research fields for further study on effective utilization of lignin.

The elimination of chrome discharge is a key technical issue that needs to be urgently solved in leather industry. However, chrome is inevitably released into effluents during chrome tanning and post-tanning processes by using existing technologies accompanied with the production of chrome-containing leather solid waste, which makes it almost impossible to eliminate chrome discharge from leather processing. In this paper, an inverse chrome tanning technology aiming at eliminating chrome discharge is introduced. The research progress of several unit processes in this technology, including chrome-free pretanning, post-tanning, terminal chrome tanning and chrome-containing wastewater treatment, is reviewed. The shortcomings as well as development trends of these unit processes are discussed. The inverse tanning technology, mainly composed of chrome-free pretanning, post-tanning and terminal chrome tanning, was developed by reassembling and coupling the unit processes of leather manufacture. The use of this technology resulted in a significant reduction of chrome-containing pollutants, a convenient and complete recovery and treatment of chrome from tannery wastewater and high quality of resultant leather. This paper is expected to provide a reference for eliminating chrome pollution from leather industry.

In view of the separation and resource utilization of heavy oils such as ectopic unconventional petroleum and sludge, this paper systematically introduces the basic problems of unconventional petroleum resources and sludge separation. Several major resource utilization methods have been summarized and discussed. The heavy oil-solid systems are mainly composed of oil, minerals and water. However, their properties are highly dependent on the physical and chemical properties of the minerals, the properties of the oil components, the moisture, and the additives (flocculants), which further directly affect the selection of oil-solid separation method, as well as the separation efficiency. Accordingly, this paper summarizes the research status of three types of heavy oil-solid separation processes, such as washing, solvent extraction and pyrolysis, from the basic engineering principles, traditional processes and new processes. Although great progress has been made on these processes, there are still different challenges for each method, which needs further exploration, such as condition and equipment optimization, additive screening and optimization, raw material system modification, energy comprehensive utilization, etc. In addition to the technology itself, it is also necessary to conduct a comprehensive analysis of the resource-based process in terms of engineering site conditions and separation economy to reduce the cost.

The low resource efficiency and high carbon emission are severe in coal chemical industries. A great number of co-feed processes of coal and hydrogen-rich gas were proposed to achieve carbon reduction at source. The integrated hydrogen-rich gas includes natural gas, coke-oven gas and shale gas. The representative co-feed processes can be divided into the co-feed process integrated with methane partial oxidation (MPO) and the co-feed process integrated with dry/steam methane reforming (DMR/SMR) according to the differences in process. Tech-economic analysis was conducted for these two processes by means of resource utilization and economic performance, compared with the conventional coal to methanol (CTM) process. The co-feed process with MPO has higher carbon elemental utilization ratios up to 57.9%. It emits 1.50t CO₂ per ton methanol, giving 37.5% reduction. It has a slightly lower production cost. The process integrated with DMR/SMR has the highest carbon utilization ratios of 83.7%. The carbon emission reduction effect is the most obvious. This process emits 0.90t CO₂ per ton methanol, which is 62.5% lower than the traditional process. It has a slightly higher production cost brought by the energy consumption of CO₂ conversion. With the carbon tax higher than 65CNY/t, the advantage of these co-feed processes is emerging on economy due to its carbon reduction.

Recently, high-salinity wastewater “zero liquid discharge” has become a seriously environmental issue for many companies, while the salts in high-salinity wastewater can be separated, concentrated, and reutilized by ion exchange membrane electrodialysis due to its special separation mechanism, resulting in the recycling of water and salts. In this paper, an application of ion exchange membrane electrodialysis in high-salinity “zero liquid discharge” for recent years was reviewed. Additionally, the potential of electrodialysis for treating high-salinity-high-COD wastewater was prospected, as well as the opportunity of the novel electrodialysis such as selective electrodialysis and bipolar membrane electrodialysis for separation of mixed salts and reutilization of the separated salts. Meanwhile, many challenges were point out in consideration of the large-scale application of electrodialysis, such as the advancement of ion exchange membrane properties, optimization of electrodialysis process, and the decrease in investment and running cost for electrodialysis apparatus. The progress proposed in this paper will provide a new method for the high-salinity wastewater “zero liquid discharge”. Besides, this progress will lay the foundations for large-scale application of ion exchange membrane electrodialysis in the high-salinity wastewater “zero liquid discharge” .

Water treatment technology is one of the main aspects of environment protection and green chemical industry. The removal of nitric acid pollutants in waste water has already been the focus on industrial water treatment research. In this paper, the current treatment technologies of nitric acid-containing waste water, including biological denitrification, chemical reduction and neutralization, were briefly introduced. The drawbacks of these methods, such as high cost, secondary pollution and low level of nitrogen resource reuse, were revealed, leading to the point of view that there was still a lack of perfect treatment technology for nitrate polluted water. Subsequently, the fundamental mechanism and technical routine of removal of nitrate in waste water by microalgae were emphasized, and the influence of microalgae strains, characteristics of industrial effluent and treatment procedure were demonstrated. After a preliminary technical-economical analysis on microalgae treatment, it was proposed that further decrease of the operating cost of environment-protecting installation could be achieved by a novel combination of sewage treatment and the production of microalgae-originating products. With further improvement, the microalgae treatment, a promising waste water treatment technology, would play a more and more significant role in solving the conflict between environment protection and economic development.

In the past decades, biochar has received considerable attention due to potential environmental applications and advantages of low cost, environmental friendliness and renewability. In this paper, the concept, applications and properties of biochar were summarized, as well as research advances on adsorption of heavy metals. Biochar is the porous carbonaceous materials produced by thermochemical conversion of biomass in zero or limited oxygen atmosphere and it is suitable for soil amendment. Biochar can improve crop yields, realize carbon sequestration and mitigate climate change, and also has potential applications in catalysis, energy production and wastewater treatment. Biochar can be prepared by pyrolysis, gasification and hydrothermal carbonization, and its properties depend on biomass feeds, thermochemical process and technical parameters. Adsorption of heavy metals onto biochar was surveyed, including affecting parameters, adsorption mechanism and modifications of biochar. Adsorption mechanism can be revealed by adsorption kinetics, isotherms, thermodynamics and advanced characterizations. Recent advances focus on improving adsorption performance of biochar by surface modifications, which are achieved via physicochemical activations or impregnating metal oxides, functional organics or nano particles. There exist some challenges and wide gap for treatment of real wastewater by biochar.