It is one of the hot topics in the field of process engineering to accurately understand and predict the complex hydrodynamics, transport phenomena, and reaction characteristics in multiphase reactors. In recent years, with the rapid development of experimental detection technology and high-performance computer, researchers can obtain high-precision multidimensional transient flow field data sets. In the last decade, machine learning, as a new interdisciplinary subject, is widely applied in data mining, image recognition, intelligent control, etc. This article summarizes several common machine learning methods, including neural network model, support vector machine model, decision tree model, clustering algorithm model, etc. Afterward, a summarization of the construction process of the machine learning model, including data set establishment, feature variable selection, algorithm framework selection, model parameter optimization, model validation, and testing, etc, is also provided. Subsequently, the application progress of machine learning assisted multiphase reactors in constitutive model construction, flow field image reconstruction, flow pattern identification, prediction and optimization of key parameters in the flow field, uncertainty analysis, and digital twin technology platform are reviewed. Finally, we analyze the challenges in the field of coupling machine learning with multiphase reactors, meanwhile, the possible development direction of machine learning in multiphase reactors is prospected.

The highly integrated microfluidic system has been widely used in many scientific fields due to its advantages such as large specific surface area, short transfer distance, and fast mixing speed, etc. However, the interaction and dynamic behavior of multiphase flows in microchannels are affected by many aspects, hence, it is difficult to fully understand the multiphase mass and heat transfer process, obtain flow field characteristic parameters, and reveal the interaction of multiphase flows only through experimental observation techniques and theoretical prediction methods. Compared to the formers, the rapid development of CFD-numerical simulation technology provides a more intuitive, effective, and accurate alternative approach for the prediction and analysis of multiphase flow characteristics in microfluidic channels. In this paper, the application process of numerical simulation technology for multiphase flow characteristics study in droplet-microfluidic systems is comprehensively reviewed, covering the structure and evolution of droplet-microfluidic devices, the method, and optimization of numerical simulation, as well as the process and interaction of multiphase flow in the microchannel.

The separation of waste lye is the key processing step in the preparation of cyclohexanone by the cyclohexane oxidation method. If the separation is incomplete, it will directly cause the scaling of the reboiler of the alkane distillation tower, resulting in increased material consumption and greatly short operating cycle of the cyclohexanone unit. Therefore, how to efficiently reducing the waste alkali content in cyclohexane oxidation decomposition liquid has always been a difficult problem faced by various enterprises. This article reviews the progress of advances in lye separation technology of cyclohexane oxidative decomposition liquid, and analyzes the principle, characteristics and application effects of the gravity sedimentation+inclined plate separation process, the gravity sedimentation+coalescence separation process, the gravity sedimentation+hydrocyclone separation+coalescence separation process, and the inclined plate separation+hydrocyclone separation+coalescence separation process. With the upgrading of deep separation technology, the Na⁺ content in the material entering the alkane distillation tower has dropped from 50—100mg/kg to less than 0.2mg/kg, and the start-up cycle of the cyclohexanone unit has been extended from 2—3 months to more than 24 months. From the perspective of industrial application effect, the gravity sedimentation + hydrocyclone separation+coalescence separation process has the highest lye separation efficiency and the best industrial application effect, which is worthy of vigorous promotion and application. In addition, the inclined plate separation+hydrocyclone separation+coalescence separation process is a novel combined separation technology, and its separation effect needs further industrial verification.

Chemical industries are continuously transferred to the manufacture of necessary commodity chemicals and high value-added chemical-based products. The development of these chemical products needs not only corresponding design/screen methods but also their sustainable manufacturing processes, their marketing, and environmental impacts. Therefore, the development of chemical products is a systematic and multi-scale product. In this paper, model-based chemical product design methods are reviewed. With model-based chemical product design methods, it is possible to carry out a virtual screen of a large number of product candidates in a short time, which could significantly reduce the experimental costs. However, for different product types, it is still hard to obtain accurate models, data, design rules, and methods, therefore, the wide application of model-based design methods is restricted. Additionally, the multi-scale and multi-disciplinary nature of chemical product design makes it complex. Hence, to find innovative chemical products, systematic computer-aided methods, and tools, which could manage the complexity becomes one of the research topics in recent years. In this paper, various model-based design methods and tools are reviewed, including experiment-based, knowledge-based, rule-based, and model-based approaches. The perspectives, including challenges and opportunities, are discussed.

The data-driven method is a black-box model, which has the advantage of autonomously mining and constructing the internal relationship of data. The development of perception equipment and the improvement of computing power highlight the advantages of the data-driven method, which can better independently mine and build the internal relationship of data. This paper introduces the principles and functions of various data-driven methods, analyzes the advantages and disadvantages of the methods and the practical application direction, and draws the conclusion that deep learning and integrated learning are the key research points of data-driven methods in the future. This paper reviews the research and application of data-driven methods for fault diagnosis in chemical processes in the recent five years, and finally comprehensively analyzes the current research situation in this field. The analysis shows that it is effective to solve problems in chemical processes by combining multiple data-driven methods. Furthermore, the research direction of data anomaly and time lag is provided. In this paper, it suggested that the mechanism of the method should be studied and optimized. In the future, the development and research of data-driven methods for fault diagnosis in chemical processes should focus on two points, namely “practicality” and “timeliness”.

With the rapid development of artificial intelligence and the corresponding supporting data system, chemical process modeling technology has been developed to a new and high level. The hybrid modeling method combining multiple mechanism models and data-driven models in a reasonable structure can fully use the first principle and process data of chemical process. With the help of artificial intelligence algorithms, the hybrid modeling can achieve simulation, monitoring, optimization, and prediction in chemical process in the form of series, parallel or hybrid. It is an important development trend for process modeling technology in recent years because the modeling purpose is clear, the model development is flexible, and the resulting hybrid model is in high performance. This work summarized the recent advances on intelligent hybrid modeling in chemical process, including the application of machine learning algorithms, hybrid structure design, and structure selection. The application of hybrid model was discussed in different task scenarios. Through literature review and analysis, it was concluded that the key of hybrid modeling lies in the matching of problem and model structure. More fruitful results can be achieved for the hybrid modeling technology by improving the performance of mechanism sub-models, acquiring high quality data in a wide range, deepening the understanding of process mechanism, and establishing a more efficient hybrid modeling paradigm.

In recent years, for sustainable development, large-scale applications of clean and renewable energy such as solar energy are an urgent need. To overcome the disadvantages of solar energy is easily affected by the variety of weather or day and night so that energy cannot be supplied continuously, researchers have proposed integrating the energy storage system into the solar power generation system. In this way, solar energy can be stored in some medium and released when required. Then the system can operate continuously. Among many energy storage methods, thermochemical energy storage has high energy density, and the materials can be transported and stored for a long time. These advantages turn it into a new research hotspot. Materials choice is variable in thermochemical energy storage, in which CaCO₃/CaO and Ca(OH)₂/CaO system is promising because of their high security, low cost, and availability. This article introduced the reaction principle and materials and summarized advanced reactor design and system integration and control of these two calcium-based thermochemical energy storage systems. Moreover, the challenges and opportunities existing in the research are discussed. Some suggestions can be provided for future research and development of calcium-based thermochemical energy storage technology.

Etherification reaction is a significant way to produce fuel addictive, which is important to the national economy and the people's livelihood. Reactive distillation (RD) plays a key role in this reaction. This study reviewed the application of RD in etherification, which is advantageous not only to the development of RD but also to the technology upgrade of fuel additive production. The application progress of RD in the etherification reaction was introduced in detail from fundamental research to industrial application for several important fuel addictive, including methyl-tertiary-butyl-ether (MTBE), ethyl-tert-butyl-ether (ETBE), tert-amyl-methyl-ether (TAME), tert-amyl-ethyl-ether (TAEE), and dimethyl-ether (DME). The contents contained raw choice, process development, and multiple steady states. The advantages and disadvantages of different reaction routes and technology processes were analyzed. The fundamental issues and concludes were concluded for the multi-steady-state of RD. The opportunity and challenge of the application of RD for the synthesis of polymethoxy dimethyl and translation of several biomass platform chemicals, such as glycerol, hydroxymethylfurfural, and furfuralcohol, into fuel addictive via etherification, were analyzed. The common issues of technological process development and catalytic packing design were discussed for the application of RD in etherification, and related suggestions were provided.

Supersonic swirl separation technology is a major technological innovation in the field of natural gas processing and treatment. It combines expansion and cooling, gas/liquid swirl separation, recompression and other processing processes in a closed and compact device. The types, principles, advantages and disadvantages of supersonic swirl separator were summarized, and the research status and the latest progress of the theory of low temperature condensation of condensable gas and supersonic swirl separation technology were reviewed from the aspects of theoretical analysis, numerical simulation, experiment and field application. A large number of experiments and field applications show that the supersonic swirl separator has the advantages of compact and light structure, energy conservation and environmental protection, safety and reliability. At the same time, the application of the technology is becoming more and more diversified. It is gradually expanding from the traditional dehydration and heavy hydrocarbon removal to the field of deacidification and natural gas liquefaction, which has broad application prospects. However, there are also problems such as secondary evaporation and large energy loss in the application process. The next research work can start from the interaction mechanism of the multi-component mixture condensation process, the movement characteristics and the collision and coalescence mechanism of condensate droplets. On this basis, effective ways can be explored to improve the condensation efficiency and reduce the energy loss, so as to promote the industrial application of the supersonic swirl separation technology.

Speeding up the development of independent and controllable industrial software is an urgent task for China's petrochemical industry to achieve high-quality development, and finding out the shortcomings is the premise of accurate policy implementation. Based on the comparative analysis of several mainstream intelligent manufacturing reference models, this paper puts forward a three-chain model for petrochemical industry in terms of product chain, asset chain and value chain. The paper divides petrochemical industrial software into five categories: process engineering and design, manufacturing execution and control, petroleum supply chain, asset management, operation management, then draws the panoramic map and classification map of petrochemical industry software. The software maturity evaluation index is designed based on three aspects of function, technology and business. Then through the investigation of the three state-owned petrochemical group enterprises, some large private petrochemical enterprises and more than 60 independent software suppliers, the paper evaluates the market share and maturity of domestic petrochemical software, compiles independent software maturity map and suppliers map, forms a systematic understanding of petrochemical industrial software, and provides decision-making basis for the high-quality development of domestic petrochemical industrial software.

Zeolite catalysts are widely used in oil refining, petrochemical and environmental catalysis etc. With decades of development, the preparation of zeolite catalysts are relatively mature. However, traditional routes usually involve the production of ammonia-nitrogen wastewater and nitrogen exhaust gas, which also inevitably lead to high production cost. Therefore, it is rather important to design and develop new clean and efficient preparation technology to reduce the cost and satisfy the increasingly restricted environmental demand. From the aspects of efficiency, environmental protecting, and economy, the problems in the preparation of zeolite catalysts are discussed as well as the corresponding solving tragedies such as avoiding or replacing organic template, sodium ion, solvent and binder, and recycling useful components. An outlook regarding the development trend of clean and efficient preparation of zeolite catalysts is also presented, which suggests that fundamental research should be strengthened and combined with its industrialization. In addition, the integration of various green preparation techniques with the aim to achieve high catalytic performance are the most important key to realize the eventual high efficient, low cost routes for preparation of zeolite catalysts.

Hierarchical zeolite materials, which inherit the excellent catalytic activity and shape selectivity from microporous zeolites, could substantially enhance the mass transfer and diffusion efficiency, therefore, the catalyst deactivation due to carbon deposition could be greatly improved. Herein, a general overview of hierarchical zeolite materials in the preparation methods and catalytic application is provided. According to the difference in pore size, three types of zeolite materials with hierarchically porous structures are particularly dwelled on, including micro-mesoporous zeolite materials, micro-macroporous zeolite materials, and micro-meso-macroporous zeolite materials. Moreover, this review gives a comprehensive analysis of the pros and cons of the materials mentioned above from the perspectives of performance, cost, operability, and applicability, and points out the future improvement direction of hierarchical zeolite materials. The rational design and controllable preparation of the zeolite materials with hierarchical pore systems, which are well-communication inside to maximize the catalytic efficiency, will be a vital research focus in the field of hierarchical zeolite materials.

Zeolite is the key component of hydrocracking catalyst, and its properties affect the hydrocracking reaction efficiency and product distribution. The microporous structure of zeolite reduces the diffusion efficiency of macromolecular reactants and the accessibility of acid sites, hence, it is not suitable to be used as the carrier of hydrocracking catalyst directly. In this paper, the properties of zeolites with hierarchical pore structure and zeolites with core-shell structure are introduced from the view of pore structure and acid site accessibility. Compared with the corresponding reference catalysts, the hierarchical pore structure of the zeolite can greatly improve the diffusion efficiency of the reaction species and the accessibility of acid sites, showing better catalytic activity, stability, and selectivity of the target product. In addition, the reasonable combination of the active sites of metal hydrogenation and zeolite cracking is also a challenge for the application of hierarchical zeolite in heavy oil hydrocracking.

The catalytic dehydrogenation of ethylbenzene (EB) to styrene (ST) in the presence of excessive overheated steam (EBDH) is one of the most important industrial processes. However, because of the thermodynamics limitation and the high energy consumption of EBDH, alternative process with more efficiency is continuously pursued. Among the possible alternative routes, the oxidative dehydrogenation of ethylbenzene with carbon dioxide (CO₂-ODEB) characterizes the alleviated thermodynamics limitation of EBDH, high ST selectivity, energy-saving, and the efficient utilization of greenhouse gas of carbon dioxide. Moreover, by using carbon dioxide as a soft oxidant, it might open up new directions for oxidation reactions. Thus, CO₂-ODEB is intensively investigated as an environmentally benign process. After analyzing the characteristics, problems, and development directions of EBDH in industry, in this review, the characteristics and reaction mechanism of CO₂-ODEB and discuss the key reasons for the generally observed rapid deactivation of existing catalyst systems were concentrated on. It indicates that the research of high-performance catalysts is still critical to advance the industrial application of CO₂-ODEB. In view of the high activity of vanadium-based oxide catalysts, it has become the research focus on CO₂-ODEB in recent years. Therefore, we comprehensively analyzed the relevant research progress on the understanding of the active center structure and reaction mechanisms from the perspectives of the content of vanadium species and its aggregated structure, redox and acid-base properties of catalysts, surface carbon of the catalyst and its functions. It revealed that the isolated state V⁵⁺ and its content might be the key factors in determining the activity of the vanadium oxide catalyst. Moreover, its stability mainly depends on the oxidation-reduction characteristics of the catalyst. The effect of carbon deposition on the activity and stability of the catalyst is closely related to its composition and graphitization degree. Combining these understandings, it is believed that the efficient enhancement for the activation of CO₂ and the suppression of the deep reduction of V⁵⁺ are the key development directions for the research of vanadium oxide catalysts. Furthermore, the process optimization by using the moving fixed bed or riser reactor has important research value for accelerating the industrial application of the CO₂-ODEB.

The recent discovery of boron-based catalytic system, especially represented by boron nitride catalyst, exhibits high activity and selectivity to olefins with negligible formation of CO₂ in oxidative dehydrogenation of light alkane reactions and has become a new hotspot worldwide. Herein, the recent progress of boron-based materials in oxidative dehydrogenation of light alkanes was summarized. The effects of different boron-based catalysts, such as hexagonal boron nitride, silicon boride, boron carbide, and elemental boron, were clarified. Combining the evidence of spectrum (IR, XPS, NMR, SVUV-PIMS, etc.) and kinetics (partial pressure, kinetic isotope effect, isotope labeling, etc.) and theoretical calculation, the active sites of boron-based catalysts, namely the surface of the tricoordinated boroxol species (B—OH/B—O) and the reaction mechanism containing surface and gas-phase radical reaction were highlighted. The opportunities and the challenges of using boron-based materials in oxidative dehydrogenation of light alkanes were summarized. It indicates that the design of the boron-based materials with highly promoted olefin selectivity is the main topic in further researches. Several suggestions were proposed for the rational design and practical application of boron-based catalytic materials.

With the rapid development of propane dehydrogenation for the production of propylene, it is urgent to develop a new generation of high-performance catalysts. In this review, recent progresses of supported Pt nanoclusters, metal oxides, and carbon materials in propane dehydrogenation are discussed. The dispersion and stability of Pt nanoclusters are the key factors affecting the dehydrogenation performance. The catalytic activity of Pt nanoclusters can be improved by developing new synthesis techniques and adjusting the properties of supports. The unsaturated metal cations in metal oxides are the active sites for dehydrogenation reaction. The catalytic activity can be significantly improved by adjusting the properties of supports, optimizing the preparation methods, and structural doping. The oxygen-containing functional groups in carbon materials are considered to be active sites for propane dehydrogenation reaction. The catalytic performance of carbon materials can be enhanced by tuning the surface area, pore property, and the number of oxygen-containing functional groups. Future studies should be focused on improving the anti-resistant ability of Pt nanoclusters, enhancing the intrinsic activity of oxides, and increasing the thermal-stability of carbon materials, which leads to breakthroughs in the development of propane dehydrogenation catalyst.

Production of liquid fuels or chemicals via Fischer-Tropsch synthesis (FTS) from coal- or biomass-derived syngas meets national resource characteristics and strategic demand. The development of high-performance iron-based catalysts promotes this process. The support structure and electronic environment affect the properties of the catalysts significantly. Carbon supports have attracted much attention in Fe-FTS catalysts. We review the recent advances in carbon-confined materials (e.g. carbon nanotubes, mesoporous carbon, organic derivatives, graphene, etc.) for FTS, and focus on the confinement effect from two aspects: geometric and electronic effects, such as gas diffusion and local concentrations, reduction and carbonization of iron species, the stability of phase and particle size, etc. The key points of the future work will be aimed at the controllable preparation of catalysts, the high stability of carbon materials under industrial conditions, and a clear mechanism of carbon-confined materials on iron carbide formation and reaction.

Methane is the main constituent of natural gas and its utilization is of curial importance. This work first introduces methane conversion processes and then makes a comparison between traditional methane oxidation and chemical looping methane oxidation processes which builds a versatile platform to convert fuels in a clean and efficient manner. Then, the main advances in the recent development of the catalysts for chemical looping methane oxidation are presented, among which perovskites are focused because of their high oxygen storage, reactivity, and low synthesis cost. Moreover, the machine learning method for high-throughput screening of perovskites is briefly introduced. Furthermore, the way by which perovskites catalyze chemical looping methane oxidation as well as the factors that determine the reactivity and selectivity, including particle size, metal valence, oxygen vacancy formation energy, and oxygen concentration, are systematically discussed, which provides a foundation for the screening of perovskite catalysts for methane oxidation.

d-Block transition metals (d-TMs) are considered to be an ideal candidate for electrocatalytic nitrogen reduction reaction (NRR) catalysts because they are easy to be modified. Meanwhile, they possess unfilled valence d orbitals, which are conducive to adsorbing nitrogen (N₂), as well as separated d electrons can donate into N₂ Consequently, considerable progress of d-TMs in NRR has been acquired in in-depth research. This article reviewed the latest researches on the applications of d-TMs based materials, which were designed and synthesized by different modification strategies to NRR. The NRR mechanisms based on d-TMs catalysts were briefly described. Moreover, the d-TMs based NRR catalysts designed by modification strategies such as surface/interface engineering, crystal facet regulation/amorphization, defect engineering, as well as the construction of bionic site, were summarized in detail and the influence of each modification strategy on NRR performance was analyzed. Finally, this article prospected the development prospects of this field and proposed the problems that need to be paid attention in the future from a series of perspectives, e.g., theoretical calculation model, catalyst modification strategies, electrochemical system, testing and characterization methods, and ammonia (NH₃) detection methods, so as to provide references for the design of modified d-TMs based efficient NRR catalysts.

Recently, biomass has been intensively employed as an ideal carbon raw material to prepare carbon materials due to its rich carbon, natural abundance and renewability, environmental friendliness, and low-cost. This review summarizes the recent progress in design and preparation of carbon materials derived from various biomass feedstocks and in their application as catalysts for organic transformations. The focus was placed on those carbon catalysts prepared by heteroatoms-doping and metal-hybridization strategies and their applications in liquid-phase catalytic hydrogenation, oxidation, and coupling reactions. Meanwhile, the correlation between catalyst's structure and catalytic performance was elucidated accordingly. Lastly, the merits of biomass-based carbon catalysts in organic synthesis were summarized, and the current challenging and future perspectives for the design and preparation of biomass-based catalysts and their applications in organic transformation are provided.

Phosphorus-containing porous organic polymers with a flexible porous structure, high surface area, and diversified modification potential show a promising prospect in heterogeneous catalysis. For the lack of review on the preparation of phosphorus-containing porous organic polymers and their applications in heterogeneous catalysis, herein, we retrospect their developments and advances in the past decade. Phosphorus-containing porous organic polymers have a great progress in preparation, including coupling polycondensation, organolithiation route, Friedel-Crafts polycondensation, solvothermal olefin polymerization, scholl polycondensation, phenolic polymerization, aldimine condensation, phosphating of poly-pyrylium salts, and multi-stage polymerization, etc. Due to the excellent coordination ability of phosphorus-containing porous organic polymers, metal nanoparticle or even metal single-atom (or single-site) catalysts can be prepared by loading these polymers with different metal species. In phosphorus-containing porous organic polymers based catalytic systems, phosphorus can not only induce the distribution of metal species but also modify their electronic and steric properties, thus they can regulate the activity and selectivity of catalysts.

In recent years, a new route to acrylic acid (acrylate) production through the condensation reaction between formaldehyde and acetic acid (methyl acetate) received substantial attention from both academic and industrial communities. This reaction route is technically simpler and the feedstock can be obtained from natural gas and coal, which is economically favorable for sustainable acrylic acid production. So far, multifarious types of catalysts have been studied, including vanadium phosphorus oxide (VPO), supported alkali metal/alkaline earth metals, and ionic liquid, etc. This paper reviewed the recent achievements on the above catalysts and commented the advantages and disadvantages of the applied catalysts. The ionic liquid catalyst can be operated at rather low temperature with low energy consumption and high target product selectivity, whereas the nature of non-continuous homogeneous catalytic reaction causes the difficulties in product separation and catalyst recycling as well as the low process efficiency. The VPOs and alkali metal/alkaline earth metals are operated continuously at high temperatures (320—400℃), and the products can be readily separated from the system with higher catalytic efficiency. Compared to the VPOs, the alkali metal/alkaline earth metals involve less side reactions and thus show relatively higher product selectivity, though the overall efficiency could be lower, and the regeneration of deactivated catalyst is difficult. The latest study reveals that the typical fabrication of VPO precursor in an organic phase can be replaced by a more facile, lower-priced, and environmentally friendly approach operated one-pot in an aqueous phase. The activation of the precursor obtained in the new approach can be simply finished in air-atmosphere. The accomplishment not only greatly simplifies catalyst fabrication but also significantly enhances catalytic performance of laboratory scale, and lays a solid base for further application.

Acrylic acid (AA) is an important industrial chemical intermediate and polymer monomer, which is in great demand. The rich coal resources and renewable biomass resources in China provide a solid material guarantee for the coal-based and biomass-based synthesis routes of acrylic acid. The two main routes were reviewed, including the synthesis routes of acrylic acid from coal-based chemicals, such as CO, low carbon alcohols (methanol and ethanol), formaldehyde, acetic acid, ethylene, and so on, and the synthesis routes of acrylic acid using glycerol, 3-hydroxypropionic acid, lactic acid, fumaric acid, and muconic acid. These routes are compared to provide a reference for the route selection. In order to provide a theoretical reference to the design and development of efficient, stable, and cheap catalysts for practical coal-based and biomass-based acrylic acid production in the future, the active sites in the catalytic reactions, side reactions analysis, the types and characteristics of catalysts, the catalytic performance and the deactivation mechanism of the catalysts are emphasized.

Vinyl chloride monomer (VCM) is an important monomer used in polymer chemical industry, which is obtained by ethylene method and acetylene method. VCM is produced by the pyrolysis of dichloroethane (EDC) in the process of ethylene oxychlorination, which usually requires high temperature, and the energy consumption problem needs to be solved urgently. Mercuric chloride catalyst (HgCl₂) is commonly used in acetylene hydrochlorination to synthesize VCM, which has strong toxicity and volatility, causing serious pollution and harm to the environment and human beings. Although the noble metal catalyst substituted for HgCl₂ has high activity, it still needs to solve the problem of high cost to realize large-scale commercial application. This paper focuses on the recent research progress of noble metal catalyst, non-noble metal catalyst and carbon-based metal free catalyst in VCM synthesis, and the active site, deactivation reason of the catalyst and how to design the catalyst through reasonable regulation structure were emphatically introduced. In the future research, explore an efficient, pollution-free and low-cost catalyst to replace mercuric chloride catalyst in acetylene hydrochlorination and to develop a new catalyst in ethylene oxychlorination would be the key issue.

Hydrocarbon oxidation and nitridation are widely used to produce basic organic chemicals and high value-added products. Though the traditional industrial oxidation and nitridation processes have made outstanding contributions in enriching human life, they also cause serious environmental issues, which urges them to be more environmentally friendly. As a well-known green oxidant, hydrogen peroxide has been widely used in green chemical production, such as oxidation or nitridation of hydrocarbon. The article here briefly introduces the current status of hydrogen peroxide industry in China and foreign countries, with the focus on the slurry reactor technology for hydrogen peroxide production exploited by Research Institute of Petroleum Processing (RIPP), SINOPEC. Specifically, the article, by taking caprolactam, propylene oxide and epichlorohydrin as examples, introduces the applications of hydrogen peroxide in oxidation or nitridation of hydrocarbon, and reports the research progresses and industrial experimental results of RIPP in green chemical industry. The successful exploitation of several green chemical technologies have broken through the technical blockade of foreign countries against China, provided the whole process of green chemical technologies to a plurality of chemical industrial bases, and effectively ensured the green transformation of the chemical industry in China.

Hydrogen peroxide (H₂O₂) is a green oxidant with high efficiency (above 47.1% active oxygen), and is widely used in the production of fine chemicals, bleaching of textile and pulp, treatment of wastewater, and green chemical synthesis metallurgy. Recently, the direct synthesis of H₂O₂ (DSHP) from H₂ and O₂ has attracted great attention because of its environmentally friendly process and simple, atom-efficient route. In this paper, the catalytic mechanism for DSHP and the influence of catalytic performance for different structures and properties of different metals in recent years are summarized. The support acid sites, support structure, the interaction between active sites and acid sites are discussed. Finally, the catalytic performance of catalysts for DSHP in recent years are compared. It reveals that the industrial application of catalysts for DSHP with high selectivity and high productivity in the future is still the development direction.

Catalytic oxidation is a basic process for the bulk chemicals production such as synthetic resin, synthetic fiber and synthetic rubber, as well as various fine chemicals, which plays an important role in the chemical industry. At present, the industrial hydrocarbon oxidation process generally in conducted under high temperature and pressure conditions. Molecular oxygen is activated, and free radicals could be generated from the cleavage of C—H bond under such harsh conditions. In this paper, the research progress of catalytic oxidations in recent years were reviewed from homogeneous, heterogeneous and biomimetic catalysis etc. The mechanisms of free radical in catalytic oxidation were analyzed. The developments of free radical stability and directional regulation mechanism in biomimetic catalytic system were summarized. It was proposed that the design of efficient catalyst, the transfer and regulation mechanism of free radical would be the significant research in the field of catalytic oxidation.

The requirements and control of catalytic cracking/pyrolysis products are gradually refined to the molecular level due to increasingly stringent environmental regulations and continuous upgrading of refined oil standard quality. A reliable molecular-scale reaction kinetics model is the key to achieve molecular management of the catalytic cracking/pyrolysis process. This article briefly describes the catalytic cracking/pyrolysis reaction mechanism and reaction types. The research progress in the construction of the reaction network and molecular-scale reaction kinetics model of catalytic cracking/pyrolysis process by different methods in the past 30 years were reviewed. This study focused on the detailed comparative analysis of the advantages and disadvantages of different model building technologies. It also pointed out the research direction of the construction of the catalytic cracking/pyrolysis reaction molecular level kinetic model, including the development of more refined petroleum molecular analysis and characterization technology, building a molecular level reaction kinetic model combined with catalyst deactivation and reactor model, and the realization of the design and process engineering scale-up of catalytic cracking/pyrolysis reactor based on molecular management. In addition, the establishment of an integrated platform for molecular set construction, reaction network construction, and kinetic parameter solving is an inevitable trend in the development of molecular-level reaction kinetic.

2,5-Dimethylfuran (DMF) is known as one of the potential biomass-derived liquid fuel and is of great significance to alleviate the current energy crisis. In view of its excellent property and wide application prospect, the preparation of DMF using biomass resources as raw materials through green and economic methods has gradually become a hot spot in scientific research. The recent advances in catalytic conversion of biomass carbohydrates into DMF at home and abroad are summarized in this paper. Based on the structure-activity relationship between the active center and the support, the catalytic effects of various metal catalysts are compared, and the key factors affecting the multiphase reaction system, including the different reaction routes and synthetic methods are analyzed. A highly efficient catalytic system for direct conversion of biomass carbohydrates into DMF is an important basis for technological breakthrough in the field. Some suggestions are given for further research and development to the catalytic conversion of biomass carbohydrates into DMF by one-pot reaction. In addition, it provides scientific basis and innovative ideas to explore efficient, economical, green and sustainable DMF synthetic pathway, which will guide the development of industrial technology for the catalytic conversion of biomass resources into DMF.

The research of temperature sensitive polymer had become one of the important research directions of emerging new materials. It is a kind of material which changes chemical properties or physical structure according to the change of external temperature. And these two changes eventually lead to the change of its own performance. New temperature sensitive materials had been applied in various industries. In oil and gas exploitation, temperature sensitive polymer is used as oilfield additives because of their unique temperature sensitive properties. The problems of viscosity reduction, channeling and pollution during oil and gas exploitation were solved by temperature sensitive polymer. In this paper, the research and application of temperature sensitive polymer in oil and gas production preparation, water injection and sewage treatment were reviewed. And the properties and synthesis methods of the thermosensitive agents were analyzed. The application of temperature sensitive polymer in oil and gas production in the future was prospected. The problems of temperature sensitive polymer had also been pointed out. For example, the sensitivity of temperature sensitive products was insufficient, the adjustment of LCST was difficult, and the ability of temperature and salt tolerance was poor. Thus, the further studies of the temperature sensitive polymer were proposed.

Zhundong coal is a kind of high-quality power coals. However, the high content of Na and Ca in Zhundong coal causes contamination and slag which restrict the large-scale industrial application. In this paper, Zhundong Wucaiwan coal was selected, and the phosphorus-rich mineral struvite was used as an additive. The simultaneous thermal analysis (STA) was performed on raw coal ash and coal ash (doped with 5% struvite) treated at 500℃. Combustion experiments of raw coal and treated coal were performed at different temperatures in a tube furnace under air atmosphere. The ash samples were analyzed by XRF, XRD, and ICP-OES. Supporting evidence for the chemical transformations occurring was obtained from FactSage. The results showed that struvite additives had an obvious effect on the release of Na and Ca. A large amount of Na and Ca were accumulated in the form of phosphate complex salt in the treated coal ash during combustion. The struvite additive had a better trapping effect on Na and Ca before 1000℃, but the capture effect weakened after the temperature continues to rise.

Ethylene tar pitch with high aromaticity and good physical-chemical properties has been widely used as the raw materials for the production of artificial carbon materials. To fully understand the thermal conversion behaviors of ethylene tar pitch is important to the production of high-quality carbon materials from the ethylene tar pitch. In this paper, the thermal conversion of the ethylene tar pitch (ETP) and two atmospheric air oxidation modified pitches (MP1 and MP2) was examined and monitored by elemental analyzer, FTIR, TGA, polarized microscope, SEM, XRD and Raman spectroscopy. The results showed that the thermal-stability and content of C\stackrel{\text{????}}{?}O and C—O groups of the modified pitches were significantly higher than those of the ethylene tar pitch. The C\stackrel{\text{????}}{?}O groups functioned as the reactive site can initiate the thermal reactions. The constant temperature treatment conditions were beneficial to the formation of fibrous structure in the pitch coke, and the content of leaflet structure was relatively higher in the pitch coke under the variable temperature treatment conditions. The regularity of the carbon microcrystallites of the modified pitch coke was lower than that of the ethylene tar pitch coke.

Naomaohu raw coal and washed coal were pyrolyzed in a vertical tube furnace. By means of inductively coupled plasma-atomic emission spectrometry (ICP-AES) and X-ray diffraction (XRD), the precipitation characteristics of alkali metal sodium and the migration and transformation rules between different deposit forms of Naomaohu coal at different pyrolysis temperatures were studied. The results show that in the pyrolysis process of ammonium acetate washed coal and hydrochloric acid washed coal, insoluble sodium are converted to ammonium acetate soluble sodium and acid soluble sodium, in which the volatility of sodium shows an increasing trend with the release amount of 3%—24%; while during the pyrolysis process of water washed coal, sodium migrates and transforms from water-soluble, ammonium acetate-soluble and acid-soluble states to insoluble and gaseous phases. Sodium in raw coal is mainly water-soluble. In the pyrolysis process, water-soluble sodium transforms into other forms, in which the volatility of sodium first decreases and then increases, reaching the lowest at 600℃. At low temperature, the sodium volatilization comes from the decomposition of ammonium acetate soluble sodium. At high temperature, water soluble sodium and acid soluble sodium enter the gas phase, which makes the sodium volatilization rate of raw coal and washed coal increase at 800℃.

Raw coal is still used in the vast rural areas of China, which seriously pollutes the atmospheric environment. Providing high-quality coal-based clean fuel is one of the important means to solve the environmental problems caused by low-quality coal burning at the source. However, the traditional civilian stoves are layer-fired, so the fuel used has the requirements of strength and lumpiness. Therefore, how to guarantee the forming and strength of fuel is a key problem. Based on this, in this paper, long-flame coal and the composite auxiliary agent are firstly cold-pressed, and then pyrolyzed to prepare the clean coke. At the same time, the effects of the amount of compound binder and pyrolysis temperature on the strength of clean coke are studied. The results show that by adding 1% polyvinyl alcohol (PVA) and 30% washing oil residue (WOR), and keeping the carbonization temperature at 800℃, civil clean coke with a crushing strength M₂₅ of 94.7% can be obtained, which fully meets the strength requirements of civil clean coke. The PVA in the composite additive is a cold binder and forms a high viscosity reticular colloid between coal particles when it meets water, which promotes the adhesion between coal particles and ensures its cold strength. The WOR is a hot binder, which is converted into a colloidal substance with high adhesion in the high-temperature pyrolysis process. The originally loose and non-adhesive inert particles are bonded to form a high strength civil clean coke. The research provides theoretical guidance for the preparation of high strength civil clean coke.

Based on the Gibbs free energy minimization method of Aspen Plus software, the coal gasification model in the Shell entrained flow bed was established. The model predicted the gasification temperature and gas composition, which was in good agreement with experimental results. The sensitivity analysis module of Aspen Plus was used to research the effects of oxygen-to-coal ratio, oxygen concentration and oxygen preheating temperature on the gasification results, and an orthogonal simulation calculation was designed to research the results of the above three factors. The results show that with the increase in the oxygen-to-coal ratio, the carbon conversion rate increases, and the cold gas efficiency increases initially and then decreases, and reaches a maximum value of 77.72% when the oxygen-to-coal ratio is 0.9kg/kg; the increase in oxygen concentration makes the gas calorific value, carbon conversion rate, and cold gas efficiency increase, and when the oxygen-to-coal ratio is 0.8kg/kg and the oxygen volume fraction is 50%, the cold gas efficiency can reach 82.6%; the increase in oxygen preheating temperature increases the carbon conversion rate and the cold gas efficiency, and when the oxygen-to-coal ratio is 0.8kg/kg and the oxygen preheating temperature is 600℃, the cold gas efficiency can reach 82%. The comprehensive analysis of orthogonal simulation calculation shows that the effect of oxygen-to-coal ratio on the efficiency of cold gas and carbon conversion rate takes the first place; the effect of oxygen volume fraction on the gas calorific value, effective gas volume fraction, and gas yield takes the first place; and the oxygen preheat temperature has little effect on coal gasification index. Within the experimental range, when the oxygen-to-coal ratio is 0.8kg/kg, the oxygen volume fraction is 100%, and the oxygen preheating temperature is 300℃, the gas calorific value reaches the maximum value of 3011kcal/m³; when the oxygen-to-coal ratio is 0.8kg/kg, the oxygen volume fraction is 60%—100%, and the oxygen preheating temperature is 300—500℃, the cold gas efficiency reaches the maximum value of 83.46%.

Transition metal disulfide has stable electrochemical performance, high theoretical specific capacity, and mature preparation method, and is one of the most widely used cathode materials in lithium thermal batteries. But at the same time, there are also several problems such as low electrode potential and weak high-power discharge capability, which limit its further development. At present, the optimization and modification of transition metal disulfides is a core subject in the field of lithium thermal batteries. This review provides a summary of the extensive research on main transition metal disulfides such as FeS₂, CoS₂ and NiS₂ in terms of discharge mechanism, preparation technology and electrochemical performance, and introduces the research progress of bimetal disulfides and transition metal disulfide composites containing carbon-based substances. In addition, through the analysis of the current studies, the key issues that hinder the further development of transition metal disulfide cathode materials are clearly pointed out, the main modification methods for transition metal disulfides are briefly described, and some ideas and suggestions about the subsequent research are also specifically proposed.

Nickel-rich ternary cathode materials have low cost and high specific capacity, which are suitable for the sustainable development of lithium-ion batteries and have been considered as the mainstream of next-generation cathode material. However, nickel-rich materials need to used together with suitable electrolytes to effectively give their best performance, which is however paid little attention. Selecting suitable electrolytes is particularly important for nickel-rich lithium-ion batteries. This paper briefly described the general types and composition of the electrolytes for lithium-ion battery. Next, we focused on the application of organic electrolytes, solid electrolytes and ionic liquid-based electrolytes in nickel-rich ternary material batteries, which were assessed through quantitative calculations. The results showed that the ionic liquid-organic solvent hybrid electrolyte presented very good circulation performance in nickel-rich NCM batteries, while meeting the requirements of the battery on safety and stability, and therefore was more suitable for nickel-rich NCM battery. Finally, the molecular dynamics studies on the interaction mechanism and Li⁺ transport between different solvents of hybrid electrolyte were prospected.

In the current era, the development of human society increasingly depends on huge amounts of energy, which contradicts the limited reserves of non-renewable resources. The development of green, clean, efficient and sustainable new energy and energy utilization technologies is extremely urgent. As an important member of transition metal phosphides, cobalt phosphides have been widely used in electrochemical energy storage and conversion fields such as electrolysis of water, supercapacitors and secondary batteries due to its excellent performance of absorption/desorption of H and its special crystal structure. However, cobalt phosphides have also many shortcomings. In the process of electrolysis of water, the active components are easily decomposed and the structural stability is poor. When used in the supercapacitor, cobalt phosphides electrode materials suffer from the insufficient exposure of the active site and the lower conductivity. As anode materials for lithium / sodium ion batteries, the huge volume change results in poor cycle stability. In this review, the crystal structure, preparation methods and improved methods of cobalt phosphides were summarized, and the effective mechanism and development status of cobalt phosphides used in electrolysis of water, supercapacitor and lithium/sodium ion battery were summarized. In addition, the existing problems and future development directions for cobalt phosphide materials were also discussed.

Pickering emulsion refers to an emulsion that is stabilized by micro-nano solid particles instead of traditional surfactants as an emulsifier. It has strong stability and an ultra-high oil/water interface, which can provide an efficient and stable place for multi-phase interface reactions and mass transport. The structure of emulsion droplet and properties of Pickering emulsion depends on the size, morphology and surface properties of the solid particles. Pickering emulsions can be endowed with specific responsive functions via adjusting the properties of the solid particles or their surfaces, resulting in wide application fields. This paper reviewed the main research results of Pickering emulsions with different response types (magnetic, CO₂, pH, light, temperature and other response types), focusing on the stability principle of Pickering emulsions, the preparation methods and structural regulation of response Pickering emulsions, and the recent application research progress of Pickering emulsion in matter separation. Finally, the development trend of the application research of Pickering emulsion was prospected.

Several chemical, physical and mechanical methods could be used in the traditional preparation of nanomaterials. In recent years, the preparation of metal nanoparticles by biotechnology has attracted widespread attention due to its economic and environmental advantages. This review describes the principles of microbial synthesis of metal nanoparticles, the conditions that affect nanoparticle biosynthesis, the biosynthetic nanoparticles and their advantages of stable dispersion in biomass. Then the use of pollutants as biosynthetic nanoparticles is discussed. When metal precursors come from pollutants and contaminated wastewater, microbial synthesis of nanoparticles reduces production costs and treats waste liquids. The impact of the application of nanoparticles on the environment and human health is analyzed, and it is emphasized that the environmental feasibility should be assessed principally before the application. In addition, the discussion focuses on the catalytic effect of metal nanoparticles on the catalytic viscosity reduction of heavy oil, the hydrogenation and oxidation reactions of nano-catalyzed heavy oil viscosity reduction. The thermal recovery method of metal nanoparticles-assisted in-situ heavy oil recovery is also introduced. Finally, the application of synthetic biomimetic composite nano-catalytic materials are prospected.

Battery-grade iron phosphate was prepared by precipitation method using iron powder and phosphoric acid as raw materials. The effects of reaction temperature, reaction time and the amount of hydrogen peroxide on the quality of the produced iron phosphate were explored. The crystal morphology, structure and chemical composition of the prepared iron(Ⅲ) phosphate were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), laser particle size analysis, thermal gravimetric analysis (TG/DTA) and inductively coupled plasma atomic emission spectrometer (ICP-AES). Experimental results showed that the optimal experimental parameters were: reaction temperature of 70℃, reaction time of 1h, 10% excess of H₂O₂, H₂O₂ dropping time of 60 minutes. The particle size of iron phosphate prepared under the optimum conditions was 1—4μm, with good crystallinity and high purity. The iron and phosphorus content test showed that the iron content of the sample was 36.37%, the phosphorus content was 20.86%, and the molar ratio of iron to phosphorus was 0.97, satisfying the requirements of battery grade of FePO₄ precursor and lithium iron phosphate anode material precursor.

A salt-responsive cation exchange membrane (PTA-GS) was developed by grafting poly(3-sulfopropyl methacrylate potassium salt) (PSPM) onto the surface of polyethersulfone ketone membrane containing abundant tertiary amines (PTA) with excellent chemical stability via a simple and controllable “one-pot” method. The positive-charged lysozyme (Lys) and negative bovine serum albumin (BSA) in neutral environment were used as model proteins, and the static adsorption, adsorption kinetics and the salt-responsive adsorption performance of the PTA-GS membrane toward protein were studied systematically. Moreover, the experimental results were fitted by isothermal adsorption model and adsorption kinetics model. The results showed that the Lys adsorption on PTA-GS membrane was in line with Redlich-Peterson and Langmuir isothermal adsorption models, and pseudo-second-order kinetic equation. The results discovered that the equilibrium adsorption capacity of Lys and BSA on PTA-GS membrane was much different in neutral buffer solution at 25℃, and their saturated adsorption capacity were (174.2±22.8)mg/g and (8.1±2.5)mg/g, respectively. The adsorption capacity of PTA-GS membrane toward Lys declined with the increase of salt concentration, and the desorption ratio of protein reached 79.3% after regeneration in buffer solution with 1mol/L sodium chloride. The results provided a new strategy for the simple preparation of salt-responsive cation exchange membrane with excellent adsorption performance and guidance for the protein adsorption behavior on the cation exchange membrane.

Langmuir-Blodgett (LB) technology was used to assemble a highly b-oriented silicalite-1 seed monolayer on porous alumina disk surface. Then, a continuously and highly compact ZSM-5 (Si/Al=120) membrane was fabricated after 48h crystallization at 175℃ by using dimer-TPABr as the structure direct agent during the secondary growth procedure. The SEM results showed that the thickness of ZSM-5 zeolite membrane was about 2.6μm. XRD results revealed that the ZSM-5 zeolite membrane was highly b-oriented and the crystallographic preferred orientation (CPO) indices was 0.858. The gas separation performance test results showed that the prepared ZSM-5 zeolite membrane would produce defects in the calcination process of organic template removal at high temperature. The ZSM-5 membrane showed excellent selective gas separation performance for H₂ after tetramethoxysilane (TMOS) modification for defects. The separation selectivity of H₂/CO₂ mixture was as high as 68 (T=25℃,p=0.1MPa), and the corresponding H₂ permeation rate was 1.36×10^-8mol/(m²·s·Pa).

Lipstatin is a β-lactone molecule which controls the digestive activity of pancreatic lipases and thus controls the absorption of fat in the small intestine. Lipstatin is supposed to inhibit the catalytic activity of pancreatic lipase by acylation of the serine residue present in the active site. A binding study suggests that one molecule of lipstatin binds with one molecule of lipase. Lipstatin is a natural product produced from Streptomyces toxytricini. The chemical structure is introduced,and the current application situation is reviewed. The progress in production of lipstatin fermentation is presented with a discussion on existing problems. Technology of metabolic engineering used in fermentation is introduced especially.The mechanism of lipstatin biosynthesis in bacteria is not yet clear, however acyl-coenzyme A carboxylase (ACCase) complex is playing key role in lipstatin biosynthesis. Furthermore, prospect for future research is proposed.

Agar is a kind of seaweed polysaccharide widely used. In the process of agar extraction, the raw materials Gracilaria for agar production need to be cleaned after being treated with alkali. At present, the water consumption of the process is large, which is an important factor affecting the wastewater discharge for industrial productions of agar. In this paper, countercurrent cleaning process was investigated to reduce the wastewater in cleaning process of Gracilaria after alkali treatment. The ratio of liquid to solid was optimized and the effectiveness in reducing wastewater was measured. The optimized ratio of liquid to soild was 18.1∶1, which was 9.47% lower than that of traditional process. The water consumption in the production of high-strength agar meeting GB 1975—2010 agar quality was greatly reduced by adopting countercurrent cleaning with the optimized liquid to soild ratio. The water consumption was reduced by 77.4%, and 562t water and 1282CNY were saved for producing 1t agar. The scaled-up test showed similar water consumption and agar property to those of the bench scale experiment. The results show that the water consumption and cost can be greatly reduced by using countercurrent cleaning technology with the optimized liquid to solid ratio, indicating an practicable references for the industrial production of agar from Gracilaria.

The effect of water content (w₀=0.12, 0.23, 0.47, 0.74, 1.0, 1.28) on physicochemical properties such as density, dynamic viscosity and electric conductivity of HHexam(Tf₂N) composed of hexylamine(Hexam) cation and bis(trifluoromethylsulfonyl) imide (Tf₂N) anion was studied in the temperature range of T = 303.15~353.15K. In this study, Hexam was Br?nsted base and HTf₂N was Br?nsted acid. HHexam(Tf₂N) dissolved a small amount of water 6.33% (corresponding to w₀=[H₂O]/[PIL]=1.44) as it was hydrophobic. The density, dynamic viscosity decreased and the electric conductivity increased with increasing water content at the same temperature range. Meanwhile, the density linearly decreased, dynamic viscosity exponentially decreased, and the electric conductivity exponentially increased with increasing temperature at the same water content. The Walden lines for HHexam(Tf₂N) with w₀=0.12—1.28 water content were in ΔW=0.5—1.0 range, implying that they could offer a better ionicity. The maximum transconductance (2.79mS) of PEDOT OECT fabricated in HHexam (Tf₂N) was 3.4 times as that (0.832mS) of PEDOT:PSS OECT fabricated in aqueous solution at -0.6V of the drain potential.

As an efficient and advanced wastewater treatment technology, membrane technology has a unique advantage in particle, organic matter, and microorganism removal. However, the removal capacity of membrane will decline gradually as the accumulation of membrane fouling. The water treatment effect will be affected by the membrane fouling, and further result in a high maintenance cost in membrane. This paper focused on the issue of membrane fouling, introduced the influence factors, types, and mechanisms of membrane fouling, and reviewed the improvement process of membrane fouling mechanisms. The methods of alleviating membrane fouling were also discussed, and then mainly introduced the pretreatment technology of membrane fouling.

With the widespread application of reverse osmosis (RO) technology in water treatment, millions of spent RO membrane modules are disposed as ordinary waste every year, resulting in environmental pollution and resource waste. This review systematically summarizes the possible recycling schemes of spent RO membranes and gives related application cases. Then, in order to compare the environmental impact of different recycling methods, it summarizes the research progress of evaluating the environment benefit and material input of different recycling methods by means of full life cycle analysis (LCA). The results show that the recycling of spent RO membrane is one of the end treatment methods of RO membrane, which includes the direct use of the spent RO membrane after cleaning as a new one, chemical transformation into other porous membrane material, and dismantling and cleaning RO membrane. In addition, the LCA in membrane technology still mainly focuses on evaluating the use process, while that on other key processes such as membrane design, membrane modification and membrane recovery is rare.

In recent years, new biological denitrification technologies have been widely concerned in the treatment of high-salt wastewater containing nitrogen. It can tolerate certain salinity and remove nitrogen from wastewater at the same time, which overcomes the drawbacks of traditional biological denitrification, such as large floor space, long process flow and high operating cost. This paper reviews the effects of salinity on new denitrification technologies based on nitrification and denitrification biochemical processes [simultaneous nitrification-denitrification and shortcut nitrification-denitrification) and new denitrification technologies based on anaerobic ammonium oxidation (anaerobic ammonia oxidation, partial nitrification-anammox process, completely autotrophic nitrogen-removal over nitrite (CANON), oxygen-limited autotrophic nitrification-denitrification (OLAND)]. Through literature research, it is found that within the salinity tolerance range, the new technologies have little influence on the denitrification performance, even improve the denitrification performance, and when it exceeds a certain range, it significantly inhibits the nitrogen removal performance of the new technologies. This is mainly due to the influence of salinity on the interaction of multiple microorganisms and their own activities in the new technologies. Adding halophilic bacteria and microorganisms acclimated to a certain salinity in the reactor can treat nitrogen-containing wastewater with higher salinity. Finally, it is pointed out that strengthening the study on the influence of salinity on the microbial community structure and metabolic pattern in the new denitrification process, screening and applying of the salt-tolerant denitrifying microorganisms, and the response mechanism of microorganisms for salt tolerance are the fundamentals to improve the treatment performance of their own processes, which have become the research directions for treatment of high-salt wastewater containing nitrogen.

The accumulation of antibiotics in environmental water is a global problem threatening human health and ecological security. It is urgent to remove the residual antibiotics in the environment. In this paper, the main sources and hazards of antibiotic residues in the environment were firstly reviewed by summarizing the relevant literature on the treatment of antibiotic wastewater by microalgae in recent years. Then, according to the characteristics of microalgae in the treatment of antibiotic wastewater, five possible removal mechanisms of microalgae for antibiotic removal were described, including biodegradation, bioaccumulation, bio-surface adsorption, photosynthetic degradation, volatilization and hydrolysis. The contributions of these mechanisms in the related experimental studies were compared. Besides, this article clarified the necessity to optimize the selection of algae species and culture conditions in order to improve the removal efficiency of antibiotics by microalgae. Finally, the problems of incomplete removal, unclear degradation products and lack of large-scale application in the removal of antibiotics by microalgae were discussed. It was pointed out that the full removal of antibiotics could be achieved by combining chemical, physical and biological methods; the degradation products of antibiotics could be comprehensively analyzed through omics data; the pilot test data were accumulated to lay the foundation for further large-scale application.

In order to avoid the negative impact of greenhouse effect, the reduction of CO₂ emissions has become an urgent task. As a potential CO₂ emission reduction technology, CO₂ mineral carbonation has attracted extensive attention. CO₂ mineral carbonation methods mainly include the direct dry carbonation route, direct aqueous carbonation route, and indirect carbonation route. At present, the key challenge in CO₂ direct or indirect carbonation methods is to improve the kinetic characteristics of CO₂ carbonation. The slow reaction rate and low carbonation efficiency are the main problems of the current technology. The traditional CO₂ amine chemical absorption method has the advantages of fast absorption rate, large absorption capacity, and absorbent recycling, but the energy consumption and operating cost are high. The integrated CO₂ absorption-mineralization technology (IAM) developed by the combination of the CO₂ amine chemical absorption and CO₂ carbonation process not only solves the problems of high energy consumption and low conversion rate of the traditional process but also simplifies the process flow and reduces the cost, which is beneficial to industrialization. This paper summarizes the research progress of CO₂ mineralization technology in recent years and compares the different characteristics of various technological routes. It points out that strengthening the research on the reaction mechanism of the IAM process and the development of efficient and economical absorbent and mineralized raw materials are the key of the future research of this process.

SCR technology is widely used in treating coal-fired flue gas due to its high denitrification efficiency and good selectivity. However, SCR catalyst will oxidize the SO₂ in flue gas to SO₃, which will subsequently react with NH₃ to generate ammonium bisulfate (ABS) and ammonium sulfate (AS). When the flue gas temperature is lower than the precipitation temperature of ammonium sulfate, it will deposit on the catalyst, air preheater and other attached equipment, which has caused many serious problems and brought a negative impact on the operation and environment of power plant. In this paper, the characteristics and control methods of SO₃ and ammonium bisulfate formation in coal-fired flue gas are reviewed. The formation mechanism and migration transformation characteristics of SO₃ in boiler and SCR system are analyzed. The effects of different active components on the generation of SO₃ and ammonium bisulfate on catalyst’s surface are introduced. Finally, it is proposed that the development of new catalysts is the key research direction for the control of SO₃ and ammonium bisulfate formation in coal-fired flue gas.

Anaerobic biological treatment technology has the advantages of energy saving and resource recovery, but in the treatment of low-strength sewage (COD<1000mg/L), its application is severely limited due to low sludge activity and low treatment efficiency. In order to promote the development of anaerobic treatment technology for low-strength sewage, the mechanism of anaerobic treatment was elucidated on the basis of introducing the types of electron transfer between microorganisms and anaerobic functional bacteria. Then, based on the principle of anaerobic digestion, the effects of temperature, pH, VFA and ammonia nitrogen on anaerobic treatment were discussed.Then, the methods of strengthening anaerobic biological treatment of low-strength sewage were summarized from three aspects: anaerobic membrane bioreactor, anaerobic microorganism activity and direct interspecies electron transfer. Finally, the development trend and research direction of anaerobic biological treatment of low-strength sewage were prospected from the perspective of screening of “hunger resistant” bacteria and strengthening of microbial activity, in order to provide reference for promoting anaerobic biological treatment of low-strength sewage and accelerating resource utilization of organic matter in sewage.

The effects of iron/carbon ratio, absorbent dosage, and acid pretreatment of urine on the synergistic adsorption of α-Fe₂O₃ and activated carbon (AC) were investigated. Its removal efficiency on urine treatment and characteristics were analyzed and discussed. The results showed that the removal rates of total organic carbon (TOC), PO{}_{\mathrm{4}}^{\mathrm{3}-}-P and TP were 39.51%, 71.03% and 76.79%, respectively, when the iron/carbon ratio was 0.6. The removal of TOC mainly depended on the adsorption of AC, while the removal of PO{}_{\mathrm{4}}^{\mathrm{3}-}-P relied on α-Fe₂O₃. Acid pretreatment of urine greatly improved the adsorption of PO{}_{\mathrm{4}}^{\mathrm{3}-}-P. The adsorption processes of TOC and PO{}_{\mathrm{4}}^{\mathrm{3}-}-P were both in accordance with the Redlich-Peterson adsorption isotherm, specifically, the synergy of monolayer adsorption and multilayer adsorption. The results of kinetic analysis showed that the adsorption of TOC and PO{}_{\mathrm{4}}^{\mathrm{3}-}-P could reach the equilibrium within 24h. The adsorption process of PO{}_{\mathrm{4}}^{\mathrm{3}-}-P can be explained by Elovich model, which is multi-layer adsorption occurred on the inhomogeneous interface. However, the adsorption of TOC is mainly controlled by the diffusion rate. Meanwhile, the removal rate of chromophoric dissolved organic matter (CDOM) was 72.16% with the best adsorption effect of humic acid. The adsorption of tyrosine, tryptophan, and soluble microbial products could be reduced by acid pretreatment. The removal of P was due to the coprecipitation between P and α-Fe₂O₃ and inorganic ions in urine. Then, it was attached to the pore of AC in the form of inorganic salt deposition.

In order to investigate the removal characteristics of organic pollutants during the treatment process of cephalosporin pharmaceutical wastewater, the removal efficiencies of COD, TOC, ammonia nitrogen, total nitrogen, total phosphorus, and residual antibiotics in wastewater were analyzed. Then, liquid-liquid extraction/gas chromatography-mass spectrometry (GC-MS) methods were employed to analyze the organic pollutants qualitatively. The results showed that the removal efficiency of cefazolin in wastewater achieved 99.1%, while the removal efficiencies of COD, TOC, ammonia nitrogen, total nitrogen, and total phosphorus were between 50.0% and 97.4%. The effluent met the "Discharge standards of water pollutants for pharmaceutical industry chemical synthesis products category" (GB 21904—2008). The qualitative analysis results of GC-MS identified 52 kinds of organic pollutants, containing many kinds of acids, esters, amines and heterocycles, among which trichloromethane, and phenol were listed in the black list of priority pollutants in water. Triethylamine, tetrahydrofuran, N, N-dimethylpivalamide, butanoic acid, 2-thioimidazole, 5-methyl-1,3,4-thiadiazole-2(3H)-thione, etc. were derived from the raw materials and intermediates during the production of cephalosporins. Considering the potential environmental toxicity of the above organic pollutants, it is urgent to optimize the existing treatment processes for these pollutants and pay attention to their corresponding residual concentrations and migration-transformation process in the environment.