Most industrial chemical processes involve thermochemical reactions, that are primarily induced or driven by heat (or heating). These reactions are found in many industrial sectors, including waste management, metallurgy, power generation, heat supply, building material manufacture and so on. Thermochemical reactions are also the earliest chemical reactions that humans have recognized. They are essential to the processing of resources, the conversion of energy, and the technologies required for a circular economy. Additionally, thermochemical reactions are the main source of CO₂ emissions, accounting for 90% of the total carbon emissions. For the goal of “carbon neutrality”, the innovation of thermochemical reaction science and technology should play major roles. The concept of “thermochemical reaction engineering” was proposed to refer to the science and technology for engineering chemical reactions. A highlight was made to identify the major advancements in science or technology for typical and great industries created based on thermochemical reactions. An analysis was also made to understand the opportunities for further techno-scientific innovations in“thermochemical reaction engineering”and their potential contributions to the strategy of“carbon neutrality”. Through carbon reduction, carbon substitution, and carbon recycling enabled by various innovatively new thermochemical reaction technologies, it was shown that an annual cut of up to 6 billion CO₂ was potentially possible in the industrial sectors of China, especially from those“super emitters”of carbon dioxide.

Petroleum thermal processing technology employs heat that indues thermal cracking and condensation of petroleum and its derivatives, resulting in the formation of various products. This technology includes a wide range of processes involved in petroleum refining and chemical synthesis and belongs to one of the branches of “thermochemical reaction engineering”. The ongoing third energy transition has led to a significant restructuring of the petroleum refining industry with a shift from producing fuel oil to manufacturing chemicals. This has driven continuous advancements in petroleum thermal processing technology, which is primarily based on thermochemical reactions. The main objectives of petroleum processing technology are heavy oil upgrading and low-carbon olefins production. The former includes processes such as visbreaking, delayed coking and heavy oil fluidized thermal cracking, while the latter involves steam cracking technology. In order to more efficiently convert petroleum into low-carbon olefins, researchers have further coupled thermochemical reactions with catalytic reactions, leading to the development of thermochemical-catalytic coupling thermal processing technology. This technology can be divided into light oil catalytic pyrolysis and heavy oil catalytic pyrolysis techniques. This article comprehensively analyzed the evolution process, technical characteristics, current situation and prospects of the above six typical petroleum thermal processing technologies, and conducted a comprehensive comparison. Through comparison, it was found that different petroleum thermal processing technologies can be distinguished based on whether there was recycling of heat carrier. The use of heat carrier recycling can effectively solve the coking problem and can also combine catalytic reactions to significantly enhance the adaptability of raw materials, flexibility of products and environmental friendliness in various technologies such as heavy oil fluidized thermal cracking, light oil catalytic pyrolysis, and heavy oil catalytic cracking. Therefore, future development would focus on these areas. In addition, by further integrating electrification technology with steam cracking and other related thermal processing technologies, the environmental friendliness and energy efficiency of the entire field can be effectively improved.

Introduction to the history of human manufacturing and utilization of carbon black (CB) as well as the characteristics of CB, this paper simulated and calculated a series of parameters related to the formation of quasi graphite microcrystals (GMCs) and the final formation of CB particles during the process of hydrocarbon pyrolysis, where carbon atoms formed a six carbon ring and undergo one-dimensional (1D), two-dimensional (2D) and three-dimensional (3D) growth. The latest achievements for the growth mechanism of quasi graphite microcrystals in CB and basic research on particle structure as well as its relationship with properties such as particle hardness and conductivity were introduced. Based on the research results of carbon atomic structure and basic physicochemical properties in CB, the molecular formula of CB was proposed. The structural reasons why CB had a hardness of up to 30GPa, the activity of reinforcing rubber and unique conductivity were interpreted based on testing data. This article also calculated the chemical reaction heat of several typical hydrocarbons used to produce CB through thermal cracking from the perspective of bond energy changes. It explained the reason why the yield of coal-based feedstock oil was 10% higher than that of petroleum based-feedstock oil during CB production. The article focused on introducing the engineering technology of modern hydrocarbons pyrolysis to produce CB in terms of raw materials, reactors, refractory materials, large-scale equipment, comprehensive resource utilization technology with equipment achieved and the development process of China becoming the largest country in CB manufacturing. This article summarized the latest requirements for energy conservation and environmental protection in the CB industry, looked forward to the future of the industry, and put forward suggestions for the key directions and research content of its technological progress.

In this paper, the development process of iron and steel metallurgy technology and discipline is sorted out, and its development process is divided into five main periods. In the new era, the iron and steel metallurgical industry will change from the pursuit of efficiency priority to the direction of energy conservation and environmental protection, this paper summarizes the green and low-carbon development path of the iron and steel industry, and focuses on the development direction of hydrogen-based low-carbon ironmaking technology. Hydrogen-rich blast furnace technology represented by COURSE50, ULCOS, and tkH₂Steel can be used as the preferred direction for blast furnace process improvement at this stage. In terms of non-blast furnace processes, this paper introduces the development of hydrogen-based shaft furnace direct reduction ironmaking processes such as MIDREX and HYL/ENERGIRON, and also introduces the hydrogen-based direct reduction ironmaking processes of iron ore powder using fluidized beds, such as H-Iron, FIOR, Circored and HyREX. In the new era, China's iron and steel industry should make full use of low-carbon energy sources such as coke oven gas, coal-to-gas, natural gas and green hydrogen while developing traditional energy-saving and emission reduction technologies, so as to reduce carbon consumption and CO₂ emissions.

Yellow phosphorus production is classified as a “high energy consumption” and “high pollution” industry. Currently, the electric furnace method stands as the sole industrialized approach for yellow phosphorus production. However, this method faces challenges such as excessive power consumption and the complexity of efficiently utilizing yellow phosphorus tail gas. Against the backdrop of the “peak carbon dioxide emissions” and “carbon neutrality” initiatives, it is an inevitable choice to fight the battle of pollution prevention and to realize the synergistic effect of pollution reduction and carbon reduction. Therefore, there is a pressing need for innovation in yellow phosphorus production technology. This paper summarizes the mechanism of phosphorus rock thermal reduction to produce yellow phosphorus and elucidates the influence of SiO₂, Al₂O₃, and MgO fluxes, as well as carbonaceous reductant activity, on phosphorus rock reduction. The technical principles, characteristics, and existing issues of the production of yellow phosphorus through blast furnace method, electric furnace method, fluidized bed method, molten electrolysis method, low-temperature carbon thermal reduction of phosphoric acid method, silicothermic process, and the phosphorus-coal coupled production of yellow phosphorus and carbon monoxide method are elucidated. It is emphasized that the overarching objective for future yellow phosphorus production technology is to achieve energy efficiency and optimize the utilization of carbon resources. Significantly, the advancement of technologies for utilizing low-grade phosphate rock and recovering phosphorus from waste with low phosphorus content holds immense importance in realizing the sustainable development and utilization of phosphorus resources.

Coal is the cornerstone of our energy security in China, and coal gasification, as a core technology for the clean and efficient utilization of coal, plays a crucial role in achieving the strategic goals of “peak carbon emissions” and “carbon neutrality”. Based on dynamic in-situ characterization to reveal the mechanism of coal gasification reactions and establish a coal gasification model has significant theoretical guidance value for expanding the applicability of carbon-containing materials such as coal and biomass as gasification feedstocks, and developing new efficient gasification technologies. Additionally, the flow properties of coal ash are a critical factor affecting the long-term stable operation of gasification furnaces. This paper provides a detailed review of the kinetics models, thermodynamics models, bed models, and predictive models for coal gasification processes. It compares the advantages and disadvantages of various models, their applicable conditions, and their abilities to describe gasification process performance. Furthermore, it identifies issues with the different methods used to establish models and offers prospects for future research focuses on reaction models in coal gasification processes.

Pyrolysis, as one of the most important fields in Engineering Thermochemistry, is an important route to realize the efficient utilization of coal. It is vital to the efficiency and economy of the pyrolysis to improve the yield of tar or chemicals. Coal pyrolysis follows the free radical reaction mechanism, so the key to high tar yield is to stabilize the free radicals produced from coal pyrolysis. Based on the pyrolysis mechanism of coal and its low H/C atom ratio, a strategy to improve tar yield was constructed by coupling the catalytic activation of H-rich small molecules with traditional coal pyrolysis. The H-rich active free radicals generated by catalytic activation of small molecule gases such as methane and ethane, were used to stabilize the free radicals cracked from coal pyrolysis, which can inhibit further polymerization or cracking of these free radicals to form char and gas, and achieve the obvious increase in tar yield. The studies show that tar yield is remarkably improved when coal pyrolysis is integrated with methane activation by catalytic reforming or plasma, and tar quality is enhanced. The strategy is universal. The coupling effect is influenced by methane activation methods, catalyst, coal properties and so on. Isotopic tracer techniques confirm that small H-rich molecule free radicals participate in the formation of tar. In addition, these small H-rich molecule gases can be extended to pure methane, ethane, pyrolysis gas, and so on. Based on this strategy and the fact that organic solid wastes such as biomass, waste plastics and waste tires have a higher H/C atom ratio than coal and H-rich active species will be produced during the pyrolysis process, co-pyrolysis of coal with biomass, waste plastics and waste tires is further developed. It is found that the heating rate and their mixing model can strengthen the synergistic effect, further improving the tar yield in coal pyrolysis and the resource utilization of the waste. This integrated technology provides an important idea and method to solve low tar yield in traditional coal pyrolysis, and a new route to develop the advanced coal pyrolysis technology. More attention should be paid to the development of integrated reactors and high-performance catalysts for the activation of small molecules in the future.

In response to the challenge of carbon neutrality, scholars in China have proposed the emerging discipline of “Engineering Thermochemistry”. Coal pyrolysis is an important industrial thermochemical reaction, which is an important research content in the field of engineering thermochemistry. In the face of increasing energy demand and deteriorating world environment, the clean and efficient utilization of coal has become a major strategic need in China. A comprehensive understanding of the coal pyrolysis process, improvement of coal pyrolysis theory and accurate description of the kinetic mechanism of coal pyrolysis are the basis for the development of efficient pyrolysis of coal. This paper firstly introduced the concept, classification and pyrolysis process of coal pyrolysis, and then summarized the research progress of coal pyrolysis mechanism, and conducted a detailed analysis of the ReaxFF MD molecular dynamics as well as thermal analysis kinetics of coal pyrolysis. The main reactions occurring in the pyrolysis process, the influencing factors of the reactions, and the effects of the reactions of minerals and heteroatoms in the process of thermal action were described. Finally, the development history and demonstration application of coal pyrolysis process were summarized.

Magnesium aluminum spinel transparent ceramics have the advantages of high transmittance, high strength, high thermal conductivity, resistance to environmental erosion and low dielectric constant, etc. It can be widely used in the military and civilian fields such as transparent armor, infrared window, substrate and so on. After more than 50 years of research, spinel transparent ceramics have developed a mature preparation process (powder-forming-sintering), which heavily relies on the commercial spinel powder with high purity and high activity. In this paper, the development of spinel transparent ceramics at home and abroad was briefly introduced and the work of the preparation of spinel transparent ceramics by reactive sintering by our team was focused on. The effects of raw powder crystal type, composition, sintering process and sintering additives on the microstructure evolution and properties of the material were analyzed, which can provide theoretical guidance for the optimization of material properties. In order to push forward the development of the manufacture process and application of spinel transparent ceramic, the relevant for different application fields was introduced for the first time, i.e. large-sized plate and hyper-hemispherical dome.

The development of high-temperature industry is closely related to the development of refractory materials, and the technological progress without exception depends on the research and development of high quality refractories. In the process of preparation and application, refractories are closely related to thermochemical reactions. This paper first briefly reduces the development of refractory, and secondly taking silica brick, synthetic mullite as examples, the thermochemical reactions in the preparation of these refractories are introduced. The thermochemical corrosion reactions of mullite-SiC brick, magnesia-spinel brick and magnesia-carbon brick in service is introduced, and the application of thermochemical simulation in the reactions between refractories and slag/gas is introduced. Taking alumina-carbon filter as an example, the adsorption mechanism of inclusion in its application process is introduced. Finally, the common calcining equipments for refractory are introduced.

Two-dimensional metal carbonitride (MXene) materials are a new two-dimensional material family composed of transition metal elements such as aluminum, titanium, niobium, molybdenum, and carbon and nitrogen elements, which have broad application prospects in energy storage and conversion, electromagnetic shielding, sensors, catalysis and other fields. The structure and physicochemical properties of MXene are determined by the combination of transition metal M and X element and the type of surface functional group T _x . Therefore, in the preparation and application of materials, it is a hot and difficult point to develop a controlled synthesis method to prepare MXenes with tunable element combination. Molten salt synthesis is one of the methods to prepare MXene, which makes full use of the characteristics of high temperature, high solubility and wide electrochemical window of molten salt. As a result, some special MXene materials that cannot be synthesized with conventional aqueous solutions can be synthesized with molten salt, thus expanding the application range of materials. In this paper, the latest research progress of MXene materials prepared by high temperature molten salt as oxidation etchant or solvent was reviewed, and the influence mechanism of different eutectic salts, reactants and reaction conditions on the structure of MAX and MXene materials was discussed. At the same time, the future development direction and main challenges of molten salt method were also prospected.

Heat-driven hydrothermal conversion technology is a typical thermochemical reaction engineering technology, which can simultaneously achieve the organic waste treatment and resource recovery, providing a vital way to achieve the goal of carbon peaking and carbon reduction. Taking organic waste as the object, this study first combs the overall development of hydrothermal technology, introduces the typical categories and characteristics of hydrothermal conversion technology in organic waste conversion, and expounds the properties of subcritical water and supercritical water. Then, the development of hydrothermal conversion equipment is reviewed. The typical hydrothermal conversion equipment in engineering application is emphasized and the potential problems that need to be focused in equipment development are analyzed. The typical cases of hydrothermal conversion technology in organic waste treatment and resource recovery are dissected. Finally, the existing challenges of hydrothermal conversion of organic waste are discussed, and the equipment corrosion caused by complex water quality in the actual environment, the development of highly efficient catalysts for specific products, the production of process pollutants and the technical and economic feasibility are still the restrictive conditions of this technology. This paper aims to provide theoretical and technical reference for the engineering practice of hydrothermal conversion of organic waste.

Biomass pyrolysis can produce high-grade energy products such as biochar, biogas and bio-oil, which has the advantages of high efficiency and multi-product utilization. However, the products obtained from direct pyrolysis with poor quality are inconducive to realizing high-value utilization. It is urgent to regulate and optimize the process of biomass pyrolysis. Starting from the optimization strategies for pyrolysis reactions, this review systematically outlined the influences of feedstock selection, pretreatment, pyrolysis parameters, reactor types, catalysts, and auxiliary techniques on the pyrolysis conversion process. Additionally, the methods for pyrolysis reaction optimization and product regulation were comprehensively summarized. To realize the green, low-carbon and value-added utilization of biomass, the regulation of pyrolysis products was reviewed from three parts: directional preparation of hydrogen-rich syngas, selective tuning of hydrocarbon liquid fuel, biochar structure tailoring and high-value utilization. Finally, the challenges and development prospects of biomass pyrolysis were summarized. The introduction of mhachine learning methods to accelerate the development of pyrolysis was also discussed, providing an important reference for the efficient pyrolysis conversion of biomass.

Microalgae has the advantages of short growth cycle and high photosynthetic carbon fixation efficiency, which is mainly comprised of three carbon-containing compounds (namely carbohydrates, proteins and lipids). Microalgae is a renewable biomass resource with great potential for energy production. Supercritical water gasification technology can directly convert wet microalgae (with high moisture content) into hydrogen-rich syngas without the drying of microalgae. It can avoid massive energy consumption in microalgae dehydration and has the advantages of high reaction rate and high conversion efficiency. In recent years, supercritical water gasification of microalgae has received extensive attention from domestic and foreign researchers. This study aims to provide a comprehensive review of the recent advances in hydrogen production from microalgae supercritical water gasification. The main influence factors during microalgae supercritical water gasification process are discussed in detail, including reaction temperature, pressure, residence time, microalgae/water blending ratio and reactors. The influence mechanism of different catalysts on the supercritical water gasification process of microalgae is elucidated, and the reaction mechanism of the main model compounds of microalgae in the supercritical water gasification process is also discussed. The kinetic and thermodynamic characteristics of the microalgae supercritical water gasification process are summarized. Finally, the future research direction of microalgae supercritical water gasification for hydrogen-rich syngas production is proposed, which is expected to provide theoretical guidance for the fundamental research and practical application of microalgae supercritical water gasification technology.

Industrial by-product gas is an important resource for hydrogen production with a huge annual output in China. Due to the high impurity content, the recovery of hydrogen from by-product gas by conventional approach suffers from high energy penalty, high cost and low efficiency. Compared with the traditional method, the chemical looping hydrogen generation technology provides a promising way to convert industrial by-product gas into high-purity H₂ with shorter process. In this review, the technical advantages of chemical looping hydrogen generation technology from industrial by-product gas were discussed and the effects of different reducing gases were summarized systematically. During chemical looping hydrogen generation process, the reaction activity of H₂ was better than CO, while the reaction process of CH₄ was more complicated. Temperature had a more significant effect on the reaction characteristics of different gases, and the impurity gases, i.e., N₂ and CO₂, had a negative effect on the reduction process. For oxygen carriers, high activity and stability carriers were the focus of research, and the methods such as designing composite materials, doping heterovalent elements and loading ionic conductors were important ways to improve the performance. In general, the chemical looping hydrogen generation technology had achieved rapid progress, which can also provide a reference for other chemical looping technology.

In order to study thermochemical reaction kinetics with XAFS (X-ray absorption fine structure) technology, a time-resolved in-situ XAFS methodology was developed at the BL14W1 beamline at Shanghai Radiation Facility. A dedicated data acquisition device was made to solve the problem of synchronous triggering and acquisition of different types of signals in time-resolved XAFS technology, achieving accurate matching between data. A 9.6-second Cu standard sample data spectrum was obtained under the conditions of the monochromator speed of 720"/s, the data acquisition device sampling rate of 2MS/s, and the data length of 1200eV. By comparing it with conventional XAFS data and standard XAFS data, the results showed that the time-resolved XAFS experimental system developed in this paper had good accuracy, resolution, and signal-to-noise ratio. On this basis, the time-resolved thermochemical in-situ XAFS method was further developed in combination with in-situ cells independently developed at the BL14W1 beamline. It was observed that the absorption edge energy of Cu gradually shifted to the low energy, while the main peak intensity at 8998eV gradually weakened and split into a bimodal structure showing obvious characteristics of metallic Cu within 30 minutes under a constant temperature hydrogen atmosphere at 230℃. This indicates the methodology has achieved the expected goal of capturing the dynamic evolution process of substances. On one hand, it has expanded the XAFS spectroscopy experimental platform. On the other hand, it provides a powerful experimental tool for studying the kinetic processes of thermochemical reactions.

With the continuous development of industry, the consumption of mineral resources such as coal, oil shale, magnesite and iron ore has been increasing, resulting in a large amount of inorganic industrial solid waste. Inefficient solid waste disposal methods to date have led to significant environmental pollution and resource waste. In this work, a high-temperature thermochemical conversion method for industrial solid waste was proposed, directly converting the solid waste into high-value-added materials. This conversion method determined the target products and reaction temperatures through thermodynamic analysis and utilizing fluidized beds to take their advantages, such as high heat and mass transfer efficiency, which were easy to scale up and to promote solid-solid high-temperature thermochemical reactions among various chemical components in solid wastes. This process produced composite powders for direct use or other higher-value end products through further processing. Experiments conducted with various solid waste materials, such as magnesite flotation tailings, boron mud, oil shale residue, iron tailings, alumina ash and coal gangue, had validated the feasibility of this method. Experimental results demonstrated that utilizing high-temperature fluidized bed thermochemical reaction technology can successfully convert inorganic industrial solid waste into high-value-added products. This research provided a new approach to effectively utilize inorganic industrial solid waste, reduce resource load, protect the ecological environment and promote green, low-carbon, and sustainable development.It also offered specific data support for the comprehensive utilization of related solid waste materials.

In order to analyze the flow field and performance change regulations of hydrocyclone caused by the blocked problem in downhole, the downhole inverted cone hydrocyclone was used as the study object, and the flow field characteristics and separation performance of the hydrocyclone were analyzed in six different blocked conditions by combining numerical simulation and experiment, and a quantitative characterization method of flow field asymmetry was proposed to clarify the change of the flow field and the average offset unsymmetry of the hydrocyclone under different blocked conditions. The results showed that in condition of three closely neighboring flow channels blocked, the average offset unsymmetry rates of both tangential and axial velocities produced maximum values of 67.82% and 34.99%. Compared with the non-blocked condition, the average pressure drop increases and the separation efficiency decreased in all six different blocked conditions, and working condition six in condition of four closely neighboring flow channels blocked, the average pressure drop was the largest and the separation efficiency was the smallest. The separation performance analysis under different blocked conditions was carried out, and the average error between the simulation results and the experimental results was 1.22%, which reflected a good consistency and proves the accuracy of the numerical simulation results.

The stable and clear interface in the microchannel is an important basis for further particle screening. Using the ferrofluid as the core flow and the non-magnetic fluid on both sides as the sheath flow is conducive to microfluidic focusing of particles under magnetic field. This paper is based on the experimental analysis of the ferrofluid-water interface in three-phase laminar microfluidic chip and the solution of the mechanical model. The dimensionless numbers Pe, Bo_m, Ca, We, Re, and the time t_T, t_d, t_i to represent the movement state of the particles at the interface were introduced, and it obtained d/h∝(X/Pe)^0.633~0.852. The effect of each force on the interface was in the order of magnetic force greater than interfacial tension, inertial force, and viscous force. When Q_f/Q_w=2, Q_f=15μL/min, the convective effect was obviously greater than the diffusion effect. In this case, the viscous dissipation effect of particles was small, and the interface was stable at the center of the channel. The diffusion time t_d∝(X/Pe)^0.523~0.872 oscillated violently at the entrance stage, accelerating fluid mixing. Meanwhile, the increase of magnetic field gradient and fluid diffusion velocity will lead to a drastic change in interfacial time t_i∝(X/Pe)^0.778~1.172. When X=225—250 in the middle of the magnetic field, t_T>t_i>t_d, and the screening efficiency of magnetic swimming was the highest.

Xylose is the most abundant pentose in hemicellulose of lignocellulosic biomass, and its derivatives have a huge application market. Under the national“carbon peaking and carbon neutrality”strategic goal, the more green and efficient xylose refining process conforms to the national requirements of energy conservation, emission reduction and green cycle development, and can also effectively reduce the cost of xylose preparation and promote the high-value utilization of xylose. In this paper, the biological refining process of xylose is reviewed, and the development status and existing problems of different processes are analyzed. At the same time, the development of xylose hydrolysis and separation technology in recent years and the high-value applications of xylose in bio-based chemicals and bio-based materials are reviewed. Finally, suggestions for promoting the development of xylose biorefinery and prospects for high-value applications of xylose are proposed.

Among many factors determining the performance and cost of direct methanol fuel cells(DMFC), methanol oxidation electrocatalyst is the most crucial one. At present, platinum-based catalysts are considered to be the most promising and efficient for methanol oxidation reaction. However, during the reaction process, there are deactivation problems caused by the agglomeration and leaching of active sites, poor anti-CO toxicity, and the corrosion and collapse of the support, which hinder the commercialization of DMFC. How to improve the stability of anode catalyst for DMFC is an urgent problem to be solved. Firstly, the principle and catalytic mechanism of methanol electrooxidation are summarized in this review. Then, the deactivation mechanisms of anode catalysts were reviewed in detail, and the effective methods to solve the deactivation issues were discussed. Finally, it was pointed out that using the confinement to restrict metal migration and aggregation, the construction of multi-alloy, the design of composite support, and combining the theoretical research with the insitu characterization technique, which were the main research directions of the development of higher and more stable anode catalysts in the future.

Ni based catalysts are relatively cheap and active for hydrodeoxygenation (HDO) of lignin biomass derived phenolic compounds to produce aromatics, but they suffer from the C—C hydrogenolysis under mild conditions. Herein, highly dispersed Ni/SiO₂, Cu/SiO₂ and bimetallic Ni-Cu catalysts with different Cu content were prepared by sol-gel method, and tested for HDO of m-cresol at 350℃ and atmospheric pressure. Although bare Ni/SiO₂ with Ni size of 2nm showed high activity and toluene selectivity, significant C—C hydrogenolysis activity toward CH₄ and benzene were observed. Ni and Cu in bimetallic Ni-Cu catalysts could interact each other and form Ni-Cu alloy after reduced. Toluene were the dominant product over optimal bimetallic catalyst (Cu/Ni molar ratio of 3) at all conversion levels. At m-cresol conversion of 97.2%, the yields of toluene and aromatics reached 85.0% and 91.6%, respectively. Analysis of intrinsic reaction rate and activation energy indicates that the addition of Cu enhances the direct deoxygenation toward toluene by inhibiting the competitive C—C hydrogenolysis reaction.

Covalent organic frameworks (COFs) are organic porous materials with periodic network structure formed by the orderly connection of C, B, N, O, etc. light elements through strong covalent bonds. They have the advantages of large specific surface area, low density, ordered pore structure and easy to modify, diverse structure and good stability, which have been widely used in many fields. This review introduced the structure of COFs, mainly summarized the progress of boric acid polycondensation, C-C coupling, Schiff base, cyano self-polymerization and aryl ether polymerization for the synthesis of COFs, and introduced the main preparation methods of COFs, such as solvothermal, microwave, ion-thermal, mechanical grinding, interfacial synthesis, microfluidics and post-synthetic modification methods. At the same time, it also discussed the characterization of the structure of COFs. In addition, the application of COFs in gas adsorption and separation, photocatalysis, electrocatalysis, asymmetric catalytic synthesis and chiral separation and electrochemical energy storage was also summarized and discussed. Finally, the opportunities and challenges of the synthesis and application of COFs were prospected. It was hoped to provide useful reference and inspiration for the further in-depth study of COFs.

As a promising electrode material, vanadium pentoxide (V₂O₅) has the advantages of abundant reserves, non-toxicity and high capacitance potential. The material properties can be optimized through the strategies of V₂O₅ nanosizing and compounding. This paper reviewed the recent applications of V₂O₅/C nanocomposites in the fields of supercapacitor energy storage. The preparation methods of V₂O₅/C nanocomposites with different dimensions, the influence on morphology and electrochemical performance were summarized. Strategies for enhancing the electrochemical properties were discussed via the component optimization, increasing effective specific surface area, heteroatom doping and constructing ternary nanocomposites. V₂O₅/C nanocomposites overcame the limitations of single electrode materials with their unique structure and excellent efficiency, which had strong practical application potential. Finally, the problems faced by V₂O₅/C electrode materials in terms of performance improvement, mechanism exploration and large-scale production were proposed, and the future development trend of electrochemical energy storage technology were presented, that is, the development of high-performance and intelligent new composite materials or energy storage devices, which provided theoretical and practical support for the construction of efficient and safe electrochemical energy storage systems.

Compared with present commercial batteries, aqueous organic batteries (AOBs), with improved safety, environmental benignity, and affordability, are very appealing for portable electronics and grid-scale applications. The electrode material is an important component of AOBs, which plays a critical role in achieving high energy and long cycle life of aqueous batteries. In the context of green development, organic electrode materials show advantages of environment friendliness, resource renewability and design flexibility. This paper reviewed the latest research progress of organic electrode materials with different storage mechanisms, including conducting polymers, carbonyl compounds, imine compounds, COFs/MOFs materials and compound materials, and summarizd their conductivity and dissolution issues. At the same time, their conductivity and dissolution issues, and strategies to enhance the electrochemical performance of organic electrode materials were also introduced. Finally, the critical challenges and future efforts of aqueous organic batteries were discussed. More organic electrode materials with better electronic conductivity and fast reaction kinetics were still needed to build AOBs.

Photocatalytic conversion of carbon dioxide (CO₂) into solar fuel or chemicals is considered to be one of the effective ways to alleviate the energy crisis and greenhouse effect. In order to improve the activity and selectivity of CO₂ photoreduction, the structure design and performance regulation of photocatalysts is critical. Among various photocatalysts, two-dimensional layered double hydroxides (LDHs) exhibit fascinating properties in the field of photocatalysis due to their adjustable composition and ratio of cations on the host layer, and exchangeable capability of interlayer guest anions. Considering the rapid development of LDHs photocatalysts, this review presents the research progress of structural regulation of LDHs for enhancing photocatalytic CO₂ reduction. Firstly, the mechanism of photocatalytic CO₂ reduction and the structural characteristics of LDHs photocatalysts are briefly introduced. Secondly, the electronic structure and geometric structure of LDHs photocatalysts are reviewed in terms of defect engineering, morphology and size regulation and heterojunction structure construction. The performance of the optimized LDHs is improved by enhancing light absorption, electron hole separation and migration, and surface reduction, especially by adjusting the structure of the active site to reduce the reaction energy barrier. Facing the challenges of LDHs applications for photocatalytic CO₂ reduction, we finally proposed related insights and strategies for design and fabrication of LDHs, the investigation of reaction mechanism and the modification of multi-carbon products.

With the rapid development of China’s economy and people’s higher and higher requirements for living standards, energy conservation and emission reduction are becoming more and more important to achieve the goal of “carbon peak” and “carbon neutrality”. Vacuum Insolation Panels (VIPs) are a new type of high-efficiency thermal insulation material. The core material of VIPs serves as the backbone structure and plays a crucial role in both supporting and facilitating heat transfer within the panel, thus ensuring its thermal insulation performance. Based on this, this article first focused on the significance of the application of VIPs in green buildings and cold chain logistics, and identified the key issues currently hindering the development of VIPs. It then reviewed the research status and progress of VIP core materials, compared different types of core materials (particle-based, foam-based, fiber-based, biomass-based and composite-based) in terms of raw material sources, thermal insulation performance, production processes and environmental protection with particular emphasis on the comparison of green and renewable biomass-based materials as core materials for VIPs. Finally, the future research directions and development prospects of VIP core materials were summarized and discussed. This paper pointed out that traditional VIPs, which used glass fiber, organic foam or aerogel as core materials, faced issues such as high production costs, non-renewability, difficult degradation and environmental pollution. Therefore, obtaining novel, green, low-cost core materials with excellent micro-porous structures and high thermal resistance through functionalization was the key to the development of VIPs. Biomass material had the advantages of wide source, low cost, green environmental protection and rich pore structure, etc. It was a kind of VIP core material with great potential, and would also be an important research direction of vacuum insulation panel core material. Therefore, the future development of biomass-based core material VIPs required further diversification of material sources, improvement of preparation methods and processes, clarification of aging and performance under service conditions, and attention to the development of composite core materials in order to continuously improve VIP performance and expand its application domains.

As an emerging technology, membrane-based gas separation has received widespread attention. Aromatic polyimide is one of the most promising materials for gas separation membranes. Currently, polyimide with various structures has been developed and researched on laboratory scales. However, in situations of industrial application, the physical aging phenomenon of membrane materials during long-term operation significantly affects the accurate evaluation of gas separation performance and the reasonable design of process parameters. The current research status of the physical aging behavior of polyimide thin films and asymmetric membranes was reviewed, the aging mechanism and models proposed by predecessors were summarized, the main factors affecting the aging process were analyzed and the prevention methods of physical aging were proposed. The characteristics of polyimide used for gas separation membranes that were not prone to aging included high molecular chain rigidity, limited chain space configuration, and appropriate inter-chain interactions. Future research was expected to focus on not only developing new structures of polyimides as well as crosslinking agents, but also preparation process optimization.

Phase change material (PCM) can store or release heat through their own phase change, thus reducing the energy supply-demand imbalance and improving the effective use of energy, but their drawbacks such as leakage during solid-liquid phase change and poor thermal conductivity limit their further development. Waste biomass materials are a class of renewable energy, inexpensive, widely available, and mostly belong to porous media, which are good carriers of PCM. Waste biomass composites utilize the rich pore structure of biomass to efficiently encapsulate PCM, which not only improves the drawbacks mentioned above, but also achieves carbon sequestration. This paper reviews the basic properties, phase change characteristics and binding methods of several PCMs (polyethylene glycol, paraffin wax and fatty acids) that are often composited with waste biomass, summarizes the construction methods of waste biomass composites as well as their applications in the fields of solar energy utilization, architectural energy saving, thermochromic textiles, cold chain temperature control, agricultural technology, etc., and discusses the development limitations and future prospects of biomass composites. This review provides a reference for advancing the research of biomass composites, which is crucial for resource recycling as well as green and low-carbon development.

The f-Ti₃C₂T _x /ZIF-8 composite material with heterostructures was synthesized by electrostatic self-assembly technology. The phase structure and microstructure of synthesized samples were characterized by FESEM, XRD, N₂ isothermal adsorption-desorption tests and their gas sensing properties estimated via a self-designed equipment with four test channels. The material analysis and testing showed that ZIF-8 material with regular shape was well-distributed on the surface and between layers of two-dimensional few-layered Ti₃C₂T _x, and there existed a typical heterostructure at the interfaces. The gas sensing performance tests indicated that the gas sensing response of the composite material toward 100μL/L NO₂ was as high as 98.35%, which was 2.1 times that of the ZIF-8 material. The heterostructures formed by the recombination of strongly conductive two-dimensional f-Ti₃C₂T _x and ZIF-8 not only provided conductive channels for the free electrons generated by the surface reaction of ZIF-8 and gas, but also strengthened the separation efficiency of electrons and holes during the gas-solid reaction on the surface of the composite material through the interface effect. Therefore, the gas sensing performances of the composite material toward NO₂ gas were significantly improved. Meanwhile, the layered structure of few-layered f-Ti₃C₂T _x /ZIF-8 composite material provided convenient diffusion paths for gas molecules to the surface of ZIF-8.

In order to improve the shielding performance of carbon fiber (CF) and realize wide-band application, carbon fiber hybrid materials (CF@Ni, CF@FeNi) were prepared by electroless plating on CF surface. Secondly, waterborne polyurethane (WPU) was used as matrix, and CF, CF@Ni and CF@FeNi were used as fillers in turn to prepare lightweight and flexible composites. At the same time, the electromagnetic shielding properties of the composites at 30—3000MHz and 10—100kHz were tested. The results showed that a dense and uniform metal layer was successfully deposited on the surface of carbon fiber, in which the saturation magnetization (Ms), remanent magnetization (Br) and coercivity (Hc) of CF@FeNi reached 10.02emu/g, 0.76emu/g and 26.06Oe, respectively. Metal coating improved the electromagnetic shielding performance of carbon fiber and effectively improved its magnetic shielding performance in low frequency band. The peak shielding effectiveness of WPU@CF@FeNi at 30—3000MHz and 10—100kHz reached 26.9dB and 18.0dB, respectively when the addition of WPU@CF@FeNi was 9%.

The biochar of silkworm excrement(BCSE) was obtained by activation at 900℃, using silkworm excrement as raw material and zinc chloride as activator. The physicochemical property of BCSE were analyzed by nitrogen adsorption and desorption, SEM, XRD and FTIR, and its synergistic adsorption and desorption performance on pesticide monosultap and dinotefuran, as well as the storage stability after adsorption were tested. The results showed that BCSE had a rich pore structure, the BET specific surface area of BCSE-3 reached 833.0m²/g, and the individual adsorption of monosultap and dinotefuran was 0.83mmol/g and 1.43mmol/g respectively. Compared with the individual component, the adsorption capacity and adsorption rate of the two pesticides were significantly improved when the components were adsorbed synergistically. The results also proved that the two pesticides had a stability of more than 35 days in BCSE-3 at 54℃ (pesticide degradation rate<2%), far exceeding the requirements in relevant regulations of the Ministry of Agriculture. Finally, molecular simulation calculations showed that the π-π interaction between the oxygen-containing five-membered heterocyclic ring with high electron density on dinotefuran and the benzene ring on BCSE was the main reason for the higher adsorption capacity and faster adsorption rate of dinotefuran. The hydrogen bond between monosultap and dinotefuran was the main reason why the adsorption capacity of the mixture of the two was greater than that of the individual component.

Using coal as a precursor to prepare carbon nanomaterials is of high significance for the clean and resource utilization of coal. Carbon dots show great potential in many application fields owing to their excellent performance. However, current chemical and physical methods for preparation of coal-based carbon dots have some shortcomings, such as the use of chemicals, expensive equipment, and difficult to scale production. Therefore, it is urgent to develop a green and scalable preparation method. Herein, using anthracite as a precursor, hydrodynamic cavitation was first applied for the exfoliation of coal-based carbon dots. The morphological results showed that the carbon dots were quasi-spherical with an average size of 2.1nm and graphitic lattice structure. XPS and FTIR spectra demonstrated the carbon dots mainly compose of C and O elements and had abundant oxygen-containing groups on the surface, which caused good dispersion in aqueous solution. Due to its special core-shell structure, the carbon dots exhibited unique fluorescence properties. It showed two fluorescent peaks of blue and yellow emission under excitation wavelength of 360nm. When the wavelength was less than 360nm, the blue emission was dominant in fluorescence spectrum. Otherwise, the yellow fluorescence was dominant. In addition, as the excitation wavelength increased, the blue peak showed dependent behaviors, while the yellow emission was basically unchanged. The successful preparation of the carbon dots provided a new physical basis for the investigation of the fluorescence mechanism with double emission and the transition and conversion between the two emission peaks. More importantly, the research results would provide new ideas and methods for green, efficient, low-cost, continuous and large-scale preparation of carbon dots, as well as the high-value utilization of coal resources.

The residual metal catalysts in carbon nanomaterials will affect the performance of their intrinsic properties and usually need to be removed by strong acid pickling. However, the cost of acid pickling is high and the surface structure of carbon nanomaterials is destroyed, even causing environmental problems. Carbon nanofibers (CNFs) were prepared by chemical vapor deposition using acetylene as carbon source and sodium carbonate as catalyst. The effect of preparation temperature on the morphology of CNFs was investigated. The microstructure and elemental composition of CNFs were characterized by field emission scanning electron microscopy, transmission electron microscopy and energy dispersive spectroscopy. The crystal structure and surface functional groups of CNFs were characterized by X-ray diffraction, Raman spectroscopy and Fourier transform infrared spectroscopy. The results showed that the diameter of CNFs prepared at 500℃ was about 50nm and the diameter of the product was uniform. The sodium carbonate catalyst on the surface of CNFs can be removed by simple water washing. The acetylene conversion rate was 31.0% and the yield of CNFs was 1396.7%. The carbon atoms on the surface of CNFs were disorderly arranged and the degree of graphitization was low, which was mainly composed of C—H and C\stackrel{}{̿}C functional groups.

Barium titanate has excellent properties such as high dielectric constant and low dielectric loss, and is the main raw material for preparing multilayer ceramic capacitors and other components. The thermal decomposition and gas precipitation characteristics of nano barium titanate precursor prepared by oxalate co-precipitation method were studied using a thermogravimetric-mass spectrometry analyzer, and the mechanism of thermal decomposition reaction of nano barium titanate precursor was revealed. The kinetic calculations were carried out using kissinger-akahira-sunose (KAS) method and flynn-wall-ozawa (FWO) method. The microstructure of the thermal decomposition products was observed using scanning electron microscopy (SEM), and the evolution mechanism of particles was analyzed. The results showed that the thermal decomposition process of nano barium titanate precursor could be divided into four weight-loss stages. The first stage was the release of water, the second stage produced CO and CO₂, and the third and fourth stages produced CO₂. Based on these results, the reactions involved in each stage were derived. As the heating rate increased, the maximum weight loss rate temperature corresponding to each weight loss stage moved towards the high-temperature zone. The fourth stage had the largest displacement towards the high-temperature zone, reaching 113℃. However, this stage had the fastest weight-loss rate and the reactions had been strengthened under the condition of 30℃/min. The FWO model was more suitable for describing the thermal decomposition process of nano barium titanate precursors. The average activation energies of the four stages were 67.89 kJ/mol, 208.92 kJ/mol, 494.04 kJ/mol and 195.11 kJ/mol, respectively. The activation energy of the third stage was the highest and the reaction was difficult to occur. During the thermal decomposition process of nano barium titanate, macroscopic large particles would evolve into aggregates of microscopic small particles. A higher constant temperature would lead to an increase in particle size. Therefore, the recommended constant temperature should not exceed 900℃. This research provided a theoretical basis for the selection of thermal decomposition process parameters for nano barium titanate precursors.

Chemical-enzymatic epoxidation is an economical and environmentally friendly process to produce olefin epoxides, but the enzyme inactivation phenomenon caused by high concentrations of hydrogen peroxide is still a challenge that hinders its development. In this paper, rape pollen, a natural biological resource, was selected as the raw material for biochar preparation, porous biochar materials of uniform size and pore size were obtained after organic solvent washing and etching in 12mol/L sulfuric acid, and immobilized Candida antarctica lipase B (CRP@GA@CALB) was prepared by cross-linking with glutaraldehyde. The immobilized enzyme was characterized using scanning electron microscopy (SEM) and contact angle. The organic-water biphasic epoxidation reaction system was constructed by using rape pollen biochar with hydrophobic and low-density characteristics. The optimal reaction efficiency was obtained by optimizing the conditions of acyl donor, hydrogen peroxide, immobilized enzyme dosage and reaction temperature. Under the optimal reaction conditions: 1.5mol/L n-octanoic acid, 30% hydrogen peroxide, 30mg/mL (organic phase volume) enzyme addition, and reaction temperature of 30℃, 1mol/L α-pinene reached 100% conversion in 60min and obtained 99.1% epoxidation yield, which was maintained at 51.8% epoxidation yield after nine reapplications.

Microaerobic anaerobic digestion is a type of anaerobic digestion between anaerobic and aerobic environments with low concentration of dissolved oxygen. It has advantages over traditional anaerobic digestion because it doesn’t require for additional treatment facilities and the aeration rate can be precisely controlled, which can achieve higher bioconversion and methane production. It is a reliable and effective method for the energy conversion of organic waste. Presently, microaerobic anaerobic digestion, a new research direction of anaerobic digestion in recent years, has been proved to have unique advantages in improving microbial diversity, accelerating hydrolysis, reducing hydrogen sulfide generation, improving methane production, etc. This paper combed the researches on microaerobic anaerobic digestion in recent 20 years, expounded its concept and mechanism, summarized the impact of microaerobic on anaerobic digestion and its application, analyzed its influencing factors, and pointed out its existing problems and the future development direction. It is expected that this paper can provide scientific basis and support for the improvement and application of microaerobic anaerobic digestion system.

The identification of low-grade refractory zinc oxide ore as a substantial zinc reservoir has emerged as a consequence of the advancement and exploitation of zinc resources. Smithsonite, as the most prevalent form of zinc oxide ore, holds considerable significance as a valuable mineral resource for zinc extraction. As a comprehensive analysis of surface sulfidation flotation, a significant flotation technique for smithsonite was presented. The mechanism of sulfidation flotation was thoroughly elucidated, including the chemisorption and chemical reaction that occured during the sulfidation process. Furthermore, the mechanism of the precipitation-dissolution reaction during sulfidation was explained in detail. It was emphasized that the sulfidation process represented a dynamic equilibrium between the precipitation of the sulfide layer and the shedding of the oxide layer. The nucleation process in this study was characterized by heterogeneous nucleation, where the solubility product serves as the primary driving force. It was observed that the rate of sulfidation exhibited temporal variations at different stages of the process. The present study provided a comprehensive analysis of the effects of pH, sulfidation time and sulfidation temperature on the process of precipitation-dissolution sulfidation in flotation. At the same time, it was emphasized that future research on zinc ore sulfidation flotation should prioritize high-efficiency enhanced sulfidation and green sulfidation. The incorporation of chemicals in the sulfidation process can significantly enhance its efficiency, leading to a reduction in the consumption of sodium sulfide. Furthermore, the development of environmentally friendly organic sulfidation agents can help to minimize the reliance on inorganic sulfidation agents like sodium sulfide. This approach aimed to mitigate the pollution and treatment challenges associated with mineral processing wastewater. It was worth noting that sulphide flotation currently played a significant role in the efficient separation of zinc ore both presently and in the foreseeable future. It was pointed out that sulfide flotation was an important method for effective separation of smithsonite at present and in the future.

Under the background of carbon peak and carbon neutrality, the standard method of manual determination of flue gas velocity and volume flow rate, as a reference method, urgently needs to be improved, while the requirements of carbon emission monitoring and measurement accuracy are raised in China. In this case, the current situation of manual monitoring methods were reviewed, including the requirements of measurement sites, layout of measurement points and determination methods, on the basis of which the current problems and improvement direction of monitoring methods in China were proposed. In terms of measurement sites, standards from various countries have specific requirements for the distance between the measurement site and the flow disturbance, but there are certain differences in details. Compared with American, European, and ISO standards, Chinese standards lack specific rules of verification of airflow direction and flow field homogeneity. In terms of measurement points, the method for determining the number of measurement points in standards of the United States differs greatly from standards of other countries, while Chinese standards are similar to European and ISO standards. The layout methods of measurement points in standards of various countries are all grid method. In terms of determination methods of velocity and volume flow rate, there is a significant gap between China and other country in the development of standards in China, especially lacking three-dimensional or two-dimensional pitot tube methods to improve the accuracy of measurement results, the measurement methods of wall effects adjustment fact to reduce measurement errors, measurement uncertainty evaluation methods aimed at evaluating the accuracy of results, and so on. On this account, it is necessary for China to accelerate the development of manual monitoring standard methods for flue gas flow velocity and flow rate from multi-aspects.

Fly ash is the main solid waste of coal combustion, and its large accumulation poses a serious threat to human health and the environment. Due to the porous structure and adsorption performance of fly ash, it can play a role in dispersing and stabilizing photocatalyst, and thus significantly improve the photocatalytic activity, achieving a synergistic effect between adsorption and photocatalysis. This article provides a brief overview of the preparation methods and applications of fly ash loaded photocatalytic materials both domestically and internationally in recent years, focusing on the aggregation issue of semiconductor photocatalytic materials. Firstly, the properties and modification methods of fly ash are introduced, and the advantages and disadvantages of the preparation of fly ash photocatalytic composites by sol-gel method, hydrothermal method and liquid phase precipitation method are compared. In addition, fly ash composite photocatalyst are analyzed from the performance and the positive influence in degradation of water pollutants, NO _x and VOCs gas pollutants, self-cleaning ability, and CO₂ reduction, which show that fly ash mainly participates as adsorbent and carrier. However, as a carrier, fly ash has insufficient active sites, the modification technology was not mature enough, and the research was still at the laboratory scale, making it difficult to achieve large scale industrial applications. Therefore, it is necessary to improve the modification technology of fly ash, and the functional building materials with fly-ash supported photocatalytic materials will be further studied to improve their practicability.

As an emerging pollutant, microplastics are ubiquitous in various environments, including water, soil and atmosphere, and pose a potential threat to ecological safety and human health. In this paper, the pollution characteristics of typical microplastics, including polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC) and polyethylene terephthalate (PET) are summarized. The microbial degradation pathways of microplastics are reviewed, and the degradation mechanisms are analyzed along with the influencing factors. Microplastics in environmental media can be degraded by bacteria, fungi and actinomycetes through microbial colonization, biofilm interception and enzyme degradation. The degradation efficiency of microplastics is closely related to microbial models and microplastic physicochemical properties, and is affected by various environmental factors, such as illumination, temperature and pH. This paper systematically summarizes the research progress of microbiome-mediated degradation of microplastics, which provides theoretical guidance and technical support for the effective control of microplastics.

The groundwater contamination by halogenated hydrocarbons has gained increasing attention in recent years. Among various available remediation technologies, persulfate (PS)-based advanced oxidation processes have become a promising option in the water treatment community due to their high oxidation capacity, wide range of applicable pH, and long half-life with a wide range of oxidation. In this review, the types of halogenated hydrocarbons commonly detected in groundwater were classified, and dense non-aqueous phase liquids (DNAPLs) were the most frequently detected type of halogenated hydrocarbons in domestically contaminated sites. Next, statistics were presented regarding the types and frequencies of halogenated hydrocarbons identified in a total of 155 sampled contaminated areas. Additionally, this review included a detailed analysis of the degradation mechanism of PS-based advanced oxidation processes, which was categorized into two pathways: free radical and non-free radical. Given the low activity of single PS, activation was required to achieve optimal oxidation performance, and this review summarized the properties and characteristics of metal-based and carbon-based catalysts. Lastly, the effects of various factors on the reaction in specific applications were discussed, including PS concentration, inorganic anions, initial pH of the reaction, and the presence of natural organic matter in groundwater. PS-based advanced oxidation processes had the potential to be an efficient and environmentally friendly alternative to conventional groundwater halogenated hydrocarbon remediation technologies.

Under the rapid development of new energy and the prospect of carbon peaking and carbon neutrality goals, it is expected that China's fossil energy air pollutant emissions will be greatly reduced in the long term. But before 2030, the amount of traditional fossil energy air pollutant emissions that need to be addressed in China is still projected to increase. To address this issue, it is strongly advised to revise the existing air quality standards and pollutant emission standards policies, specifically the ones concerning the release of pollutants from petrochemical flue gas and volatile organic compounds (VOCs). This proactive approach is essential to ensure effective control and mitigation of air pollution as part of China’s broader sustainability agenda. The environmental standards and policies of the United States serve as valuable references for China’s future revision on relevant standards. It is advisable for China to establish new criteria and improve the existing ones for pollutant emissions based on the sources of VOCs, emphasizing the reduction of large emissions while relaxing control over smaller ones. Also, it is important to rely on mature technologies, prioritizing the timeliness, relative stability, and regional applicability of standard policies, while formulating stringent emission standards. Meanwhile, it is suggested that a feasibility analysis should be included in the "Guide of Emergency Emission Reduction Technology" regarding the condensable particulate emissions from coal-fired power plants. To further reinforce stringent standards regarding the emission of VOCs from industrial petrochemical production process, we need to give precedence to the regulation of organic liquid storage tanks. Additionally, it is imperative to prioritizing the management of methane emissions in oil and gas fields within the petrochemical industry. Also, academic investigation ought to be conducted to explore potential interventions targeting the manipulation of positive and negative ions during heavy pollution weather, with the objective of mitigating adverse weather conditions. When revising the pollutant emission standards of GB 31570—2015 (emission standard of pollutants for petroleum refining industry), GB 31571—2015 (emission standard of pollutants for petrochemical industry), and GB 31572—2015 (emission standard of pollutants for synthetic resin industry), several bullet points are suggested as below: ①The total emission volume of pollutants should be reduced in the revised version of pollutant emission standards. ②As referred to the terminology definition and analysis method in the U.S. standards, we should modify the term “non-methane total hydrocarbons” in Chinese standards to “total organic compounds” (TOC) without taking methane and ethane into accounts. ③In order to conform to the provisions outlined in Table 4 of GB 31570—2015 and Table 5 of GB 31571—2015 for organic waste gas treatment devices in wastewater treatment facilities, it is recommended to replace the term “non-methane total hydrocarbons” with “TOC” and establish a maximum threshold of 60mg/m³. ④Modifying the removal efficiency of “non-methane total hydrocarbons”“emitted by the organic waste gas in Table 4 of GB 31570—2015 and Table 5 of GB 31571—2015 to ”TOC removal efficiency of ≥99%“or alternatively, stipulating a maximum permissible”TOC concentration of ≤60mg/m³). Also, it has taken the control indicators for benzene (≤4mg/m³), toluene (≤15mg/m³), and xylene (≤20mg/m³) into accounts as listed in Table 4 of GB 31570—2015. ⑤Eliminating the oxygen conversion factor of atmospheric pollutant emission concentrations from organic waste gas emission outlets.

Incineration is the primary method of municipal solid waste disposal in China, and the resulting fly ash contains dioxins and heavy metals, classifying it as hazardous waste. The treatment methods are relatively limited, but the demand for effective disposal is substantial. Promoting the development of technologies for the harmless disposal and resource utilization of municipal solid waste incineration fly ash, actively addressing the shortcomings in municipal solid waste treatment facilities, all align with the national requirements for energy conservation, emission reduction, and green development. This study systematically analyzed the basic characteristics of municipal solid waste incineration fly ash in typical regions of China, focusing on the generation of dioxins and heavy metals. It provided an overview of the main technologies for treating dioxins in fly ash, including sintering, melting/vitrification, cement kiln co-treatment, low-temperature pyrolysis, and mechanochemical techniques. The major methods for treating heavy metals in fly ash were compared, encompassing solidification/stabilization, thermal treatment, and heavy metal extraction technologies. The study gave a summary and outlook on the application of fly ash treatment technologies, aiming to guide the development of reduction, harmlessness, and resource utilization technologies for municipal solid waste incineration fly ash in China.

To investigate the effects of different oxidation systems and operating parameters on the degradation performance of soil PAHs, synthetic siderite (SFC) was artificially simulated and modified siderite (FFC) was obtained by introducing nZVI with excellent performance to catalyze the oxidative degradation of PAHs in actual contaminated site soil. The results showed that both SFC and FFC-catalyzed PDS systems were effective in degrading PAHs, and the soil PAHs degradation rate was further improved by optimizing the operating parameters, including lowering the initial pH, increasing the soil-to-water ratio and extending the reaction time. In addition, the use of H₂O₂ equivalent instead of PDS could reduce the treatment cost, but the degradation rate was slightly decreased. The results of soil toxicity assessment showed that the germination rate of ryegrass seeds was significantly increased after SFC/PDS and FFC/PDS treatments. The study indicated that SFC and FFC catalytic systems could effectively remediate PAHs-contaminated soil and reduce soil ecotoxicity.

Ventilation rate is an important limiting factor that affects the quality of aerobic fermentation products of food waste and is vital to the success of aerobic fermentation. By adjusting the ventilation rate during the fermentation process, the oil degradation and the generation and accumulation of organic acids in food waste were controlled, and the limited acidification of the fermentation process could be achieved. It not only reduced the volatilization and loss of NH₃, but also improved the quality of fermentation products. The results of this study showed when the ventilation rate of aerobic fermentation piles increased, the peak temperature of the fermentation piles increased, but the high-temperature period was shortened, with the organic matter degradation rate and pile maturity firstly increasing and then decreasing. As the ventilation rate was 0.2L/(L·min), the aerobic fermentation efficiency of food waste pile was better. The greater the ventilation rate during the aerobic fermentation of food waste, the lower the accumulated volatilization of NH₃. When the ventilation rate was 0.1L/(L·min), the high temperature period was longer, which was not conducive to the growth and reproduction of nitrifying microorganisms for the conversion of NH₃ to NO _x^-, and NH₃ emissions were the highest. When the ventilation rate was 0.3L/(L·min), the high-temperature period was the shortest, and water loss of piles was severe, while organic matter degradation was not complete, and NH₃ volatilization was also the lowest. Compared with the absence of self-made oil removal microbial inoculants (ORMI), the addition of ORMI effectively enhanced the aerobic fermentation of food waste. At the end of aerobic fermentation, the oil degradation rate, seed germination index and total nutrient content were increased by 23.08%, 29.48% and 7.36%, respectively. The ventilation rate affected the activities of relevant microorganisms and lipase enzyme, further influenced the degradation of oil and accumulated volatilization of ammonia, and ultimately promoted the maturity and total nutrient content of the aerobic fermentation products.

Nanofluids have been widely used in various fields due to their unique enhanced heat transfer properties. The thermal conductivity and viscosity directly affect the applicability of nanofluids in practical engineering, so before examining the enhanced heat transfer characteristics of nanofluids, it is first necessary to analyze and study their thermal conductivity and viscosity. In this study, water-based carbon black collagen nanofluids were prepared by a two-step method using carbon black and collagen. The effects of carbon black and collagen concentration and temperature on the thermal conductivity and viscosity of nanofluids were analyzed. The weights of these parameters were mathematically calculated by the gray correlation method, and a BP neural network prediction model with three inputs and two outputs was established based on the experimental data, and the BP model was optimized by genetic algorithm (GA). The results showed that the BP neural network model optimized by the genetic algorithm had higher accuracy and better stability for the predicted output, and the regression coefficient and maximum deviation were 0.99918 and 0.002, respectively. This study was not only of great significance for understanding and controlling the thermophysical properties of water-based carbon black-collagen nanofluids, but also provided new ideas for the application of engineering design and materials science.

Photocatalytic production of hydrogen peroxide (H₂O₂), as a green and sustainable technology, has the advantages of clean and pollution-free, safety, low energy consumption and low cost compared with the anthraquinone method commonly used in industry. Graphitic phase carbon nitride (g-C₃N₄), as an inorganic nonmetallic material, is a promising H₂O₂ producing photocatalyst. However, bulk g-C₃N₄ suffers from severe photogenerated electrons-holes complexation and weak photogenerated charge transfer ability, resulting in its low photocatalytic H₂O₂ production efficiency. In order to improve the photocatalytic H₂O₂ production activity of g-C₃N₄, ultrathin g-C₃N₄ nanosheets containing carbon vacancies (CNS₅₈₀) were prepared by simple sequential two-step high-temperature calcination in this paper, and the structure and morphology, light absorption properties and electrochemical properties of photocatalysts were characterized by XRD, SEM, AFM, ESR, UV-Vis, TPC and EIS. The results showed that the photocatalyst had an ultrathin nanosheet structure with a thickness of about 2.15nm, which could improve the transmission efficiency of photogenerated charge. Meanwhile, the introduced carbon vacancies could capture photogenerated electrons, which would improve its photogenerated electrons-holes separation ability. In the experiment of photocatalytic H₂O₂ production, the H₂O₂ production concentration by CNS₅₈₀via photocatalytic reaction for 6h could reach 0.091mmol/L, which was 4.13 times higher than that of the bulk g-C₃N₄. In addition, the possible mechanism of photocatalytic H₂O₂ production for CNS₅₈₀ was discussed and proposed.

The types of pollutants extracted from refinery pollution site are complex and highly toxic, with strong uncertainty in water quality and quantity. Rapid and standardized treatment and on-site reuse are one of the ideal treatment and disposal methods, and efficient treatment technologies and operating parameters need to be optimized to shorten the treatment process. The optimal conditions for Fenton and optoelectronic coupling treatment through orthogonal experiments to form a short-range treatment process for extracted water were investigated. The results showed that the key influencing factor of chemical Fenton was the mass ratio of H₂O₂ to organic pollutants (characterized by COD). Coupled with ultraviolet light irradiation, the efficiency of the agent could be improved and the amount of sludge could be reduced. The key electrochemical influencing factor was the distance between the electrode plates, followed by the type of electrode plates. Under the optimal treatment conditions determined by orthogonal experiments, the coupled process could achieve a total removal efficiencies of 88.33% for TOC and 98.09% for TN in the extracted water, which could meet the requirements of on-site reuse water index (≤40mg/L) for TN in the effluent. The Fenton and photoelectric coupling treatment formed could significantly shorten the existing treatment process, reduce the dosage of chemicals, thereby reducing the amount of sludge, and ensure the stability and compliance of the effluent. This study indicated that Fenton and photoelectric coupling technology can quickly and efficiently remove high concentration of pollutants from the extracted water of refinery pollution sites, supporting the rapid implementation of contaminated site remediation projects. At the same time, it can avoid environmental risks of sewage transportation and impact on the advanced processes of sewage treatment plants, providing important references for the selection of efficient and rapid treatment processes on site and the adjustment of operating parameters.

This study established a heat transfer model for a multi-layer composite insulation structure applied to steam pipelines, conducting experiments on DN200mm pipelines to investigate the impact of various insulation structures and materials on insulation performance. The model's accuracy was validated against experimental data, facilitating the determination of the optimal insulation plan under diverse operating conditions. Experimental findings indicated that the pipe surface heat flow density decreased with the addition of convective layers and airbag layers, while it gradually diminished with increased shawl thickness and overall insulation thickness. However, an increase in reflective layers initially decreased and then increased the heat flow density. The heat transfer model predictions closely aligned with experimental data, showing a deviation of less than 6%. Economic analysis advised against using convective layer as insulation material. The recommended optimal insulation solution substantially reduced the system's total heating cost. The optimal insulation thickness value increased with the increase of the medium temperature and pipe diameter. Particularly for high-temperature pipelines exceeding 400℃, adopting composite insulation structures can yield over 30% savings compared to single aluminum silicate insulation.