The USA is the second largest greenhouse gas emission country in the world. In recent years, its greenhouse gas emissions have shown an overall downward trend. 6.558 billion tons of greenhouse gas were emissioned in 2019, accounting for about 12.5% ??all over the world. CO₂ is the most important greenhouse gas. The development of the USA petrochemical industry has reached the world advanced level. Although the number of refineries has been reduced to 135 in 2019, but its refining capacity and ethylene capacity reached 940Mt/a and 36.28Mt/a. Meanwhile, refining output and ethylene output reached 850Mt/a and 32.27Mt/a. Affected by factors such as plant scale and energy consumption, the total carbon emissions of the USA petrochemical industry in 2019 reached 296 million tons, accounting for about 4.5% of USA greenhouse gas emissions. However, its carbon emissions have not been increased with petrochemical capacity in the past 30 years. The main reason is that USA petrochemical industry have adopted low-carbon strategies, such as strengthening energy conservation and efficiency, adjusting refinery energy structure, expanding the scale of biofuels production and promoting the recycling of waste plastics, gradually optimizing the industrial structure and vigorously developing the CCUS. Petrochemical industry as the fourth largest source of carbon emissions in China, should seize the wave of green and low-carbon development of the times. To begin with, adopting to the principle of giving priority to energy conservation, and promote the low-carbon transformation of the industry. Moreover, it should be increased the proportion of clean energy and achieve diversified development of raw materials. Thirdly, strengthening the leadership of scientific and technological innovation, and solve the problems of low-carbon technology. Last but not the least, find out the carbon data as soon as possible and include it in the carbon market timely.

Fluid-driven rotating equipment is widely used in energy conversion and recovery. In recent years, new structures of fluid-driven rotating equipment have emerged constantly, and their applications have been expanded, which combined with seawater desalination, refrigeration, mixing, velocity measurement and other processes gradually. In the course of this development, computational fluid dynamics technology provides a new approach for the design optimization of fluid-driven rotating equipment. In this review, the different applications of fluid-driven rotating equipment in energy engineering, chemical engineering and other fields are reviewed, and the research progress in computational fluid dynamics methods of fluid-driven rotating equipment is summarized. The active and passive rotation simulation methods are compared, and the significance of passive rotation simulation in the study of fluid-driven rotating equipment is pointed out. Finally, the new application of fluid-driven rotating technique in high-gravity equipment is outlined.

Reaction network is a micromolecular-scale expression of the chemical process mechanism, but the complexity of the network poses a challenge for in-depth understanding of the production process. This paper propose the idea of exploring the integration of intelligent algorithm and reaction network, of which the structural statistical indicators, structural topological characteristics, node properties, mechanism dynamic evolution, modeling application performance are analyzed based on the conception of “transparency engineering”. Subsequently, a three-step mechanism-digital reaction network research method combining data structuring, intelligent optimization and analysis, and intelligent surrogate modeling is used, which provide a partial enlargement in micro scale and an accurate prediction in industrial application. The integration of the intelligent algorithms and reaction network implement a visible, explainable modeling, analysis and optimization of the industrial practice, which further provide decision-making recommendations for quality and efficiency enhancement. Additionally, these attempts could help humans to break through the limit of cognition and go deeper into the understanding of the reaction mechanisms, extraction of the key reactions, and intellectualization of the chemical industry.

Whey wastewater has a high organic load. If discharged directly, it will cause serious environmental pollution and waste of protein resources. Therefore, the resource utilization of whey wastewater has attracted increasing attention. This paper briefly introduces the composition, characteristics and application of whey protein, and summarizes the application of membrane technology in whey resource utilization in recent years. First, the application of ultrafiltration and charged ultrafiltration in the separation and concentration of whey protein in the pressure-driven membrane technology is introduced. Then, the latest progress of the application of electro-ultrafiltration(EUF) and electrodialysis with ultrafiltration membrane(EDUF) in the separation and recovery of whey protein and active peptide in the process of electro-driven membrane is emphasized. In addition, the membrane fouling phenomenon in the process of whey protein separation is analyzed, and the influencing factors as well as control measures of the membrane fouling process are put forward, in order to provide a useful reference for the resource utilization of whey. Finally, it pointed out that membrane technology still has certain limitations in the separation and recovery of single whey protein and industrial scale-up, and proposed solutions and future development directions.

The research progress of magnetic field-based enhancement of heterogeneous media separation is reviewed, and the related enhancement methods are analyzed and compared. According to the types of heterogeneous media affected by magnetic field, the technology, equipment and working principle of magnetic field-assisted multiphase media separation in different fields are introduced, namely, magnetic separator, eddy-current separator, heavy medium magnetic cyclone, disk separator, magnetic field-assisted separation gas-solid cyclone, magnetic fluidized bed and so on. It can be summarized as magnetic field-assisted solid separation (solids with different magnetic conductivity), gas-solid separation, solid-liquid separation, liquid-liquid separation, etc. The simulation methods of magnetic field distribution, interaction between magnetic field and particles, coupling of magnetic field and fluid field are summarized, which provides a basis for magnetic field enhancing multiphase media separation. Aiming at the bottleneck problem of common equipment separation ability, it is proposed that magnetic field and equipment operation parameters should be considered to maximize separation efficiency, the coupling between magnetic field and fluid field test should be strengthened and the field of magnetic field separation should be extended to non-magnetic fluid.

Hexane oil distillation is an important process in solvent oil production accompanied by high energy consumption and high emission. Therefore, the energetic, economic and environmental(3E) multi-objective optimization of hexane oil distillation process is of great significance for the sustainable development of solvent oil industry. Regarding slow convergence and easiness of trapping in local optimum for the conventional non-dominated sorting genetic algorithm (NSGA-Ⅱ), a novel multi-strategy ensemble non-dominated sorting genetic algorithm (MENSGA-Ⅱ) was proposed. In this algorithm, a guidance strategy based on the global and local optimal of individual neighborhood, was developed to accelerate the convergence speed of the algorithm. At the same time, the random limit walk strategy was introduced to improve the convergence and distribution of the solution set obtained. The MENSGA-Ⅱ was applied to the typical test functions and the actual hexane oil distillation process. The results showed that the algorithm has advantages in stability, convergence speed and uniformity of the Pareto front. Compared with the actual operating condition, the annual gross profit of the distillation system under typical optimized conditions could be increased by 4.99×10⁵USD/a, with energy consumption and CO₂ emissions reduced by 5.09×10²kW/a and 4.82×10²kg/a, respectively.

The preparation of thin films by electrostatic spraying is one of the emerging nanomaterial preparation processes in recent years. It has attracted wide attention because of its simple process, high material utilization and strong surface adaptability. As an important index for evaluating spraying quality and production efficiency, spraying area is easily affected by parameters such as applied voltage, solution properties, spraying distance, etc., and is difficult to accurately control in the relevant production process. In order to solve this problem, a mathematical model for predicting the radius of electrostatic spray deposition was proposed. The electrostatic spray plume was equivalent to a space charge field by Gauss’s law, and then the force analysis of the droplets outside the plume was carried out, and the expansion radius of the spray plume at different positions was obtained, which was the deposition radius of the electrostatic spray. The comparison showed that the model was in good agreement with the related results. Compared with the traditional Lagrangian method and experimental method, the model can quickly predict the spray area under various working conditions to provide guidance for industrial production operations and atomizer design.

Based on the traditional four-baffled stirred tank, the discontinuous spoiler was added and arranged asymmetrically. The flow field characteristics and chaotic effect in four-baffled stirred tank with no discontinuous spoiler, symmetrical arrangement of discontinuous spoiler and two kinds of asymmetric arrangement of discontinuous spoiler were studied by numerical simulation. The results showed that under the condition of constant power number, the discontinuous spoiler could suppress the periodic radial and tangential flow by 42.19% and 19.55%, respectively, and the axial flow with stronger mass transfer was increased by 20.27%. The tracer fluid diffused to the surrounding area, the area near the discontinuous spoiler presented chaotic characteristics, and the mixing effect was improved. The maximum speed difference of one pair and two pairs of discontinuous spoilers arranged up and down in relative positions was increased by 472.72% and 218.18%, respectively, as compared with that in symmetrical arrangement. The uneven distribution of velocity field greatly increased the collision probability of fluid clusters, and the whole stirring region tended to be chaotic, and the stirring process is strengthened. The asymmetric arrangement of spoilers broke the periodic coherent structure in the tank and caused multi-scale vortices, which dissipated energy in the collision between impurity ions and zinc powder particles and improved the displacement reaction rate. The energy consumption of the whole process was about 14.3%.

The flow boiling of interconnected microchannels, in which main channels are connected by branch channels, has superior heat transfer characteristics. However, the mechanism of heat and mass transfer enhancement is not clear enough, which limits its practical application. Hence, based on the volume of fluid (VOF) method, a two-dimensional unsteady numerical simulation of subcooled flow boiling in the interconnected microchannels was carried out. The influences of local flow field disturbance and thin liquid film distribution between shedding bubbles and heating wall on the heat transfer characteristics of microchannels were discussed. It was found that the mechanisms of heat transfer enhancement contain two types. The first one is that the shedding bubbles of branch channel can enhance the flow field disturbance of main channel, thus promoting the redevelopment of thermal boundary layer of main channel. The second one is that thin liquid film can be formed between shedding bubbles and heating wall, which reduces the heat transfer resistance. The effect of dip angles (θ) of branch channel on the heat transfer characteristics of interconnected microchannels was further studied. It was found that the overall average heat transfer coefficient of interconnected microchannels was improved by 10.51% to 17.66% compared to unconnected microchannels, and the average heat transfer coefficient of single main channel was improved by up to 27.94%. When θ=45°, the interconnected microchannels showed the best heat transfer characteristics. The research could provide guidance for the design of efficient chip cooling structures.

A periodic fluid disturbance microstructure was designed, which consisted of cavities arranged on the sidewall of the microchannel and pin fins in the center of the microchannel. The flow and heat transfer characteristics in the heat sink were studied, and the effects of geometric parameters of the fluid disturbance structure on the irreversible loss and heat dissipation efficiency of the heat sink were analyzed. The overall performance of the heat sink was evaluated by the thermal resistance and heat transfer enhancement factor. Results showed that relative length of the bottom of the isosceles trapezoidal cavities (RL) had a significant effect on the heat sink performance. When Reynolds number (Re) was large, decreasing RL could reduce the vortex in the cavities significantly, thus the flow friction loss, pressure drop and flow irreversibility of the microchannel were decreased. At the same time, reducing RL was beneficial to enhance the scours effect on the cavity contraction section, reduce the laminar flow stagnation zone in the cavity, take away the heat at the cavity timely, thereby the heat dissipation efficiency of the heat sink was improved. Compared with the traditional smooth microchannel (SM), the periodic fluid disturbance structure was able to reduce total entropy generation and thermal resistance of the heat sink, increase heat transfer enhancement factor, and improve overall performance of the heat sink markedly. Considering heat transfer and flow resistance synthetically, the heat sink with RL=0.3 had the best overall performance under the condition of low pump power. For the high pump power, the overall performance of the heat sink with RL=0 was the best. The periodic fluid disturbance structure can make the micro cooling system more efficient and economical, hence it has a broad application prospect in the field of micro device cooling.

Vinylation reaction of 2-pyrrolidone with acetylene to synthesize N-vinyl pyrrolidone was successfully implemented in a microreactor, which had the advantages of the intrinsic safety of acetylene and intensified gas-liquid mass transfer. To realize the efficient transformation of the reactants, the liquid phase was recycled to obtain the sufficient gas-liquid contact time. The effects of reaction temperature, KOH content, internals in the microreactor and acetylene purifier on vinylation reaction with the recycled liquid phase were investigated in detail. The results showed that both reaction temperature and KOH content had significant effects on the selectivity to N-vinyl pyrrolidone. The higher reaction temperature and higher catalyst content caused the reduction of the selectivity seriously, among which a better result of >95% selectivity to NVP can be achieved by comprehensive control of these two operation conditions. The application of internals improved the mixing efficiency and promoted the gas-liquid mass transfer rate evidently. As a comparison, the yield of NVP was increased by 28.7% (without promoters) against the semi-continuous process in autoclaves, and the reaction time was shortened as well.

To reduce by-products such as polynitrophenols and organic content of spent acid in toluene kettle nitrification, the effects of flow rate, molar ratio of toluene to nitric acid and mass ratio of sulfuric acid to nitric acid on nitrification were studied under the premise of excess toluene in a micro chemical system. Results show the optimal process conditions are as follows: 73% sulfuric acid, initial temperature is 35℃, molar ratio of nitric acid to toluene is 0.6, mass ratio of sulfuric acid to nitric acid is 10, and residence time of reaction system is 240 seconds. Under above conditions, the utilization rate of nitric acid is more than 97%, DNT content is 0.84%, and polynitrophenol content is 0.12%. Compared with conventional kettle process, the continuous adiabatic nitrification can significantly shorten the reaction time and reduce polynitrophenol content by more than 50%. If toluene is excessive, toluene takes the function of extraction, and the organic content in acid phase is reduced to 0.18%, which facilitates the subsequent treatment of spent acid.

The emission control of the combustion process in petrochemical and heating furnaces is of a great significance. Swirl combustion has the potential of low NO _x emission, attracting wide attention from both academia and industry. Combining the advantages of bluff body combustion and swirl combustion, a swirl premixed burner integrated with a displacing bluff body is proposed in this study. The structure of the displacing bluff body was first optimized based on the investigation into the emission under different bluff body structures. Subsequently, the studies on emission, flame morphology, and temperature distribution were conducted. The results showed that the smaller inverted cone-shaped bluff body with the half-cone angle of 30° provided relatively lower NO _x and CO emissions. The NO _x emission first decreased and then increased as the swirl number increased from 0 to 0.83, with the NO _x emission being the lowest when the swirl number was 0.25. At the same thermal power of the combustion, the flame height decreased as the swirl number increased. At the same swirl number, the flame width increased as the thermal power increased. The trend of NO _x emission variation was consistent with that of temperature. The lower NO _x emission was, the lower temperature of the corresponding flame would be. Thereby, it is expected that the temperature change caused by the swirl number variation is one of the main reason for the NO _x emission variation. The conclusion of present study provides a theoretical basis for the design of swirl premixed burner.

The hydrogen products pressure of conventional hydrogen recovery methods is low and can only be used by the high-pressure hydrogenation units after multistage pressurization, which has high hydrogen pressurization cost. The hydrate method for recovery of hydrogenation tail gas has the advantages of slight pressure drop loss and high product hydrogen pressures, which can effectively reduce the hydrogen pressurization cost for high-pressure hydrogenation units. To reduce the utilized cost of hydrogen for high-pressure hydrogenation units, we developed the hydrate hydrogen recovery technology. We established a hydrate industrial side-stream trial unit in a Maoming refinery factory to recover hydrogen from a diesel hydrogenation unit tail gas. The separation effect of hydrogen recovered from diesel hydrogenation tail gas using the continuous stirred tank method under different conditions was investigated. The trial results show that most CH₄ and almost 100% H₂S can be effectively removed by the hydrate method. In the continuous trials, the hydrogen volume fraction increases from 83.76% to 91.65%, and H₂S volume fraction from 0.73% to 0.07%.

In multiphase reaction systems, applied electric field have been widely noted for the advantages in promoting the dispersion of discrete phases in continuous phases and enhancing mass transfer. In this study, an electrostatic liquid-gas dispersion experimental measurement system was designed and constructed to create a non-uniform electric field by applying a high-voltage direct current between needle-ring electrodes, with ethanol as the continuous phase and air as the discrete phase. The bubble dispersion process under the electric field was visualized and measured by high-speed photography, taking into account the impact factors of gas flow and applied voltage. The results showed that the bubble dispersion was associated with three typical patterns in the manipulated parameter regions, including the dripping, mixed, and spraying modes. The bubble size, characterized by the dimensionless bubble diameter (ζ), decreased significantly with increasing electric Bond number (Bo_E) and increased with rising gas Weber number (We_g), where the microbubble size was basically below 20μm in the mixed and spraying modes. Increasing Bo_E and We_g both promoted the production of bubbles, but the effect of Bo_E was more obvious. Meanwhile, it was found that the transition of bubble dispersion patterns depended strongly on the Bo_E, and the rise in We_g tended to slow down the transition process. In addition, a predication model of ζ as a function of Bo_E and We_g was established for the dripping mode of bubbles based on the present experiment data, and the results of this model were in high agreement with the experimental results at ζ ≤ 5. The production of small bubbles through low energy consumption had been a technical challenge, and the use of electric field to enhance bubble dispersion provided new ideas for the development of corresponding technologies to achieve enhanced interphase mixing and mass transfer in multiphase systems.

Based on the reaction kinetics model for modified ZSM-5 catalyst with high Si/Al ratio, the factors influencing the para-xylene (PX) selectivity for methylation of toluene and methanol were discussed, and a short process for PX production was proposed based on the idea of PX selectivity intensification. The proposed short process was compared with the existing processes from the aspects of raw material utilization, energy consumption and economic indicators. The results showed that the PX selectivity for xylene can reach more than 99.7% under the conditions of short contact time, high toluene/methanol feed ratio, high diluent/methanol ratio, low reaction temperature and pressure. Compared with the existing processes, the short process was of high raw materials utilization rate, low energy consumption, process simplicity and good economy, and avoids the separation of xylene isomers. Hence, the short process had strong technical competitiveness for PX production by toluene methanol methylation.Meanwhile, by using non-petroleum-based methanol, it was helpful to form a complementary and coordinated development mode for coal chemical industry and petrochemical industry.

To study the reaction mechanism and combustion characteristics of diesel fuel under CO₂/O₂ atmosphere, quantum chemical calculations and optical experiments were performed. The reactive sites on molecules were analyzed by the average local ionization energy and surface electrostatic potential, and new chemical reactions were proposed by computational chemistry calculations, which were simplified after sensitivity analysis to compute the flame natural luminosity and the flame lift-off length. Finally, a constant volume combustion chamber experimental platform with optical channels was built and fluid mechanics simulation of diesel combustion was performed. Compared with the experimental results, the calculated maximum, minimum and average errors of the flame lift-off length under 35% CO₂+65% O₂ atmosphere were 13.9%, 0.5% and 1.4%, respectively, which were all acceptable and indicate the suitability of the new mechanism. It was found that high concentration carbon dioxide causes flame bifurcation and turbulence, which was pyrolyzed into carbon monoxide and oxygen radicals at high temperatures, and the chemical reactivity of carbon atom was greater than that of oxygen atom, with an average local ionization energy of 12.62eV and a very small electrostatic potential of -0.51eV.

The phase change material with erythritol/mannitol as the base liquid was prepared. During the process, the addition of nano-titanium dioxide provided crystal adhesion for the solidification of the phase change material and promoted the formation of crystal growth crystals. Through ultrasonic treatment, the phase change material locally produced high temperature and high pressure to promote the generation and growth of crystal nuclei. The effects of nanoparticle content, ultrasonic time and ultrasonic power in the preparation process of the material on the supercooling degree and solidification process of erythritol/mannitol were analyzed. The experimental results showed that the increase in the content of nanoparticles and the extension of the ultrasound time would reduce the subcooling of the material, while with the increase of the ultrasound power, the subcooling first decreased and then increased. When the mass fraction of nanoparticles, ultrasonic time and ultrasonic power were used as single variables, the subcooling was the lowest at 11.3℃, 16.2℃ and 10.8℃, respectively, and the corresponding shortening of solidification time was 38.0%, 18.4%, and 16.4%.

With the increasing strictness of environmental regulation and fuel quality requirements, the hydroisomerization of n-paraffins for producing high-octane gasoline, low-freezing point diesel and high-viscosity index lubricating oil, becomes more and more important. This review summarizes the bifunctional catalysts for the hydroisomerization reaction, which were mainly composed of a metal center to provide hydrogenation/dehydrogenation activity and an acidic support for skeletal isomerization. The contributions of different metal centers and acidic supports in dual-functional catalysts are introduced. Compared with bifunctional catalysts loaded with precious metals, catalysts doped by bimetallic, transition metal phosphides and rare earth have similar activity, higher sulfur resistance and lower cost. Moreover, mesoporous molecular sieve with large pore size is beneficial to the diffusion of reactants and products, and has high acidity, which promotes the skeleton isomerization. Therefore, it attracts extensive attentions from researchers. Finally, the main factor affecting the isomerization performance of dual-functional catalyst is the balance between the metal and the acidic support, that means, the ratio and distance between the metal center and the acid center. The catalysts with a suitable metal center/acid center ratio and a nano scale metal-acid center distance should have high catalytic activity and isomerization product selectivity.

Amines, especially primary amines, have been extensively employed in pesticide, medicine, dye and high molecular polymer as raw materials or intermediates. Recently, direct reductive amination of carbonyl compounds (aldehydes or ketones) has been a research focus for synthesizing primary amines. Heterogeneous and homogeneous catalysts based on noble and non-noble metals have been proven to be efficient for direct reductive amination of carbonyl compounds. In this paper, we carefully review the state of art of direct reductive amination of carbonyl compounds (one-pot method) to synthesize primary amines, including reaction profile, recent progress in catalysts, reaction conditions, the substrate scope and catalytic mechanism, especially the catalysts. Generally, heterogeneous catalysts are highly active and could be reused, while homogeneous catalysts have the advantages of high efficiency and high primary amines selectivity. On the other hand, noble catalysts like Pd, Rh and Ru are more active and expensive, so non-noble metal based catalysts like Co and Ni catalysts could be alternative for the sake of economic. Thus, the catalysts for direct reductive amination to synthesize primary amines with high efficiency, mild reaction condition and high universality should be developed.

Nitrogen-rich covalent organic framework material COF-MC (mass fraction of nitrogen was 55%) was synthesized using melamine and cyanuric chloride as precursors by solvothermal method. COF-MC was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), N₂ adsorption-desorption, scanning electron microscopy (SEM), thermogravimetry (TGA) and X-ray photoelectron spectroscopy (XPS). Through the evaluation of the catalytic performance of COF-MC in the Knoevenagel condensation reaction of benzaldehyde and malononitrile, the relationship between reaction conditions and catalytic performance was investigated, and the basic catalytic mechanism of Knoevenagel condensation reaction was preliminarily discussed. The experimental results showed that: with COF-MC as the catalyst in the nitrogen environment without the help of other solvents, the conversion of benzaldehyde was 98% and the selectivity of benzalmalononitrile was over 99.9% after stirring at 80℃ for 2h. The reacted catalyst could be separated by simple thermal filtration, and the conversion of benzaldehyde could still reach 89% even after being utilized repeatedly four times. In addition, due to no metal ion in the catalyst, metal pollution to the environment was avoided.

Using tert-butanol as the reaction solvent, aqueous hydrogen peroxide was fused with other hydrophobic reaction substrates to construct a single-phase reaction system for epoxidation of α-pinene to replace the traditional organic-water “two-phase” system. Firstly, the single-phase system was optimized in shaking flask. When the concentration of α-pinene was 0.3mol/L, the optimum concentration of ethyl acetate and hydrogen peroxide was 3.5mol/L and 0.5mol/L, respectively, trisodium citrate was selected as the acid-trapping reagent, and the epoxidation conversion and yield at 40℃ for 90min were 92% and 88%, respectively. Under this process conditions, Novozym435 could still maintain 64% relative activity after being reused 6 times. Then, based on the shaking flask experiment, a continuous stirred tank reactor (CSTR) was constructed, the optimal operating conditions of the reactor were studied, and its long-term operating performance was tested. The results showed that: when the amount of Novozym435 enzyme was 2.0g, the concentration of hydrogen peroxide was 0.5mol/L and the residence time was 3h, the tank reactor had the best operating effect with a conversion of 83% and a yield of 79%. Under these conditions, the reactor could still maintain more than 70% conversion and more than 55% yield after 10 days of continuous operation.

In this study, molecular dynamics simulation method was used to study the mechanism of hydrogen production by catalytic fast pyrolysis of tire rubber over Ni, ZSM-5 and Ni/ZSM-5. At the same time, it was compared with the previous experimental studies to verify the simulation calculation. The model was established by Material Studio, the transition state of the hydrogen generation path was searched by DMol3 module, and the catalytic pyrolysis process of adding Ni was simulated by CULP module. The simulation results indicated that the energy barrier of hydrogen generation path decreased with the addition of three catalysts, and the order of catalytic effect was Ni>Ni/ZSM-5>ZSM-5. The catalytic fast processing was divided into two stages:①the low temperature stage was the long chains released monomer compounds, which was mainly isoprene, styrene and 1,3-butadiene; and ②the high temperature stage was that free radical attacked monomer compounds to form small molecular structure. The addition of the catalyst in the low temperature stage was mainly manifested in speeding up the pyrolysis process and increasing the number of monomers in the low temperature stage. The pyrolysis temperature was reduced and the proportion of H₂ increased with the addition of Ni catalyst.

Cellulose is the most abundant natural, renewable and biodegradable polymer in the world, and has a wide range of applications in chemical, material and other fields. This paper mainly summarizes the research progress of cellulose-based hydrogels in recent years. First, the research background of cellulose-based hydrogels is introduced. Secondly, the cross-linking methods of cellulose water-based gels are listed, which are mainly composed of physical cross-linking and chemical cross-linking. Among them, physical crosslinking includes hydrogen bond crosslinking, hydrophobic crosslinking, ionic crosslinking, etc., while chemical crosslinking includes esterification crosslinking, Michael addition, free radical copolymerization, dynamic covalent bond crosslinking, etc. Finally, the applications of cellulose-based hydrogels in the fields of degradability, biomedical properties, hydrophilicity, adsorption, and electrical conductivity are highlighted. In addition, the development of cellulose-based hydrogel materials in terms of high mechanical properties and industrialized preparation is prospected.

Crude oil spill accidents and industrial oily wastewater discharge have severely damaged the eco-logical environment that humans rely on. How to effectively separate oil-water mixtures has become a current research hotspot. The non-recyclability of traditional oil-water separation materials causes secondary pollution of the materials, which greatly limits their wide application. Cellulose is the most abundant natural polymer on earth. It has the characteristics of biocompatibility, biodegradability, chemical stability and low cost, which makes cellulose-based oil-water separation materials have received extensive attention. This article systematically summarized the research progress of filtration and adsorption cellulose-based oil-water separation materials in recent years, focusing on detailed analysis of cellulosic materials as the substrates (filter paper, cotton cloth, etc.) and the coatings (cellulose nanocrystals, cellulose derivatives, etc.), and all-cellulose-based oil-water separation materials. Finally, the existing problems of cellulose-based oil-water separation materials are discussed with looking forward to their future development.

Fluoride poisoning caused by fluorine wastewater discharged from semiconductor, rare earth mining and other industries has attracted much attention. Adsorption is a kind of effective methods to remove fluoride from wastewater. However, traditional adsorbents have the disadvantages of low adsorption capacity and poor selectivity. It is urgent to develop adsorbents with high adsorption capacity, regeneration and no secondary pollution. Some new adsorption materials, involving polymer adsorbents, biochar, layered double hydroxides, industrial wastes and modified nano-materials in the treatment of fluoride-containing wastewater are induced. The preparation process, the adsorption and fluorine removal ability of these modified materials are summarized. The adsorption and fluorine removal mechanism of new adsorption materials and the influencing factors such as coexisting ion interference and pH application range are analyzed, and the existing problems in the preparation of materials are pointed out, so as to develop effective adsorbents in the field of fluorine removal in the future. The development direction of how to prepare modified adsorption materials with high selectivity for fluorine ions in the future and the important problems to be solved in material recycling are put forward.

The application field of polyvinyl alcohol fiber (PVAF) is limited although it has many advantages such as acid and alkali resistance, wear resistance, degradability, water solubility, corrosion resistance, weather resistance, mildew and insect resistance etc. In recent 30 years, the development of PVAF has experienced a profound change from clothing fiber to industrial fiber. Functional modification of PVAF is an effective method to improve its performance and broaden its applications. Focusing on the two stages of polyvinyl alcohol spinning before and after spinning, two typical methods of blending modification and fiber surface modification are reviewed. Among them, blending modification is divided into polymer and small molecule blending. According to its different mechanism, surface modification is divided into surface chemical reaction, surface grafting and surface physical modification. Furthermore, according to the advantages and disadvantages of various modification methods, the relationship between blending modification and surface modification with the corresponding functionality is compared, which will be benefit for the researchers in this field. Based on the present modification method and application of PVAF, the trend is also proposed in depth and breadth to obtain new properties and meet higher requirements in future.

Graphene and its composites have been widely studied and applied in electrode materials, sensors, hydrogen storage materials and other fields due to their advantages of large specific surface area, high electrical conductivity, good thermal conductivity and mechanical properties. However, there are limited reports on the preparation of coal-based graphene and composite materials with high carbon content of natural resources as precursors to achieve clean and efficient utilization of coal, especially the research on its application as electrode materials in the field of energy storage. In this paper, the methods and problems of coal-based graphene and its composites with different morphologies and structures based on coals of different ranks and their derivatives as raw materials were summarized, and the applications of coal-based graphene and its composites in energy storage, especially in supercapacitors, lithium ion battery and sodium ion battery were introduced in detail. Finally, the main research direction of coal-based graphene and composite materials was proposed. The purpose of this review was to provide some insights and ideas for the preparation and development of coal-based new carbon materials—coal-based graphene and its composites as well as its application in the field of energy storage.

Starch is a potential substitute for petroleum-based plastics, but its poor water resistance severely limits the wide application of starch-based packaging materials. In this paper, the characteristics of single modification and composite modification of starch are analyzed in detail, and the research on the preparation of starch-based hydrophobic packaging materials by the combination of starch and hydrophobic materials is introduced. The analysis shows that the research focus of starch hydrophobic modification is to increase the degree of substitution, reduce the production costs and use non-toxic and harmless green solvents. Synergistic modification has become a research hotspot. The key to improve the blending effect is to solve the interface problem of incompatibility between hydrophilic starch and hydrophobic materials. The common methods include modifying starch and hydrophobic materials or adding compatibilizer. However, the cost of synthesizing degradable polyester is relatively high. Looking for low-cost biomass materials to improve the hydrophobicity of starch-based packaging materials has great potential. In a word, this paper proposes that low cost, excellent performance, safety and environmental protection are the main research directions for the development of starch-based hydrophobic packaging materials in the future, which has a certain reference value for the preparation of starch-based hydrophobic packaging materials.

Microcapsule technology is a new technology with rapid development, and has been successfully applied in biomedicine, food, chemistry, and other fields for its several advantages, including accurate drug administration and controlled content release. Sodium alginate is a unique plant polysaccharide extracted from marine algae, and has been widely used as microcapsule coating materials owing to its good solubility, good film-forming and gelation performance. However, there are still some problems in the manufacture of sodium alginate microcapsules, such as imperfect formula and unstable preparation process, due to the properties of sodium alginate microcapsules being difficult to control and easily affected by base material, cross-linking agent, and process parameters. In order to solve the above problems, the properties of sodium alginate, such as ion exchangeability, pH susceptibility, gelling characteristics, and influencing factors in the preparation process of microcapsules were summarized in this review, and the application of sodium alginate microcapsules in encapsulating cells, drugs, and essential oil were discussed as well. It is pointed out that the future research direction should focus on improving the preparation process of microcapsules, clarifying the relationship between film-forming mechanism and mechanical properties of sodium alginate gel, enhancing the strength and toughness of sodium alginate microcapsules, and promoting the formulation research of sodium alginate with other polymer materials,thereby expanding the application range of sodium alginate microcapsules and accelerating the industrialization process of sodium alginate microcapsules.

Zinc stannate has gradually attracted the attention of scientific researchers in recent years due to its high electron mobility, stability, high electrical conductivity, excellent adsorption properties, optical properties, and flame and smoke suppression properties. This paper presentes the research progress on the preparation methods of zinc stannate nanoparticles (hydrothermal, chemical precipitation, solid-phase chemical synthesis, microwave synthesis, sol-gel method, template method, etc.), morphology and structure (granular, cubic, spherical, octahedral, nano-rod, flake, nano-flower, etc.), particle sizes and their applications in different fields (lithium battery anode materials, gas-sensitive materials, electrical contact materials, DSSC anodes, photocatalysis, flame retardant, etc.). The principles, preparation conditions and product properties of Zn₂SnO₄ nanoparticles using different tin compounds and different methods are analyzed, and the advantages and disadvantages of each preparation method and the formation mechanism of different structures in each preparation method are pointed out, as well as how the different structures affected the relevant properties of Zn₂SnO₄. The article indicates that how efficient and controllable preparation of zinc stannate with specific morphology and grain size is a future direction for zinc stannate nanomaterials.

In this work, the effects of microwave radiation power and radiation time on the synergistic demulsification of magnetic nanoparticles were analyzed. The oil droplet distributions with/without microwave radiation, the wettability and electrification of magnetic nanoparticles were measured by biomicroscopes, contact angle analyzers and zeta potential analyzers to reveal the mechanism of synergistic demulsification of microwave-magnetic nanoparticle. The experimental results showed that too high or too low microwave radiation parameters can inhibit the demulsification of magnetic nanoparticles. Only within the range of optimal radiation parameters, microwave can promote the demulsification of magnetic nanoparticles. By use of 150mg/L Ni, the water separation of 400W and 30s can reach the maximum value of 102.56%, while 125mg/L Co₃O₄ at 400W and 30s can reach 106.06%. This work provided experimental and theoretical basis for the development of magnetic nanoparticles-microwave radiation synergistic demulsification technology.

The binder has an important influence on the performance of the electrode. This paper designed and prepared a new type of water-based poly(ethylene-vinyl alcohol)-lithium sulfonate (EVOH-SO₃Li, ES-Li) electrode binder. Its bonding structure and composition, solubility, electrolyte stability and thermal stability were analyzed. The flexibility, microscopic morphology and electrochemical performance of the prepared electrode were studied. It was compared with poly(ethylene vinyl alcohol) (EVOH) and commercial polyvinylidene fluoride (PVDF) binders. The results showed that ES-Li water-based binder had the advantages of insoluble in electrolyte and good thermal stability. The negative electrode prepared by ES-Li binder had excellent flexibility and microscopic morphology. The battery using ES-Li as the negative electrode binder had excellent performance in electrochemical stability window, interface impedance, first cycle efficiency, cycle and rate, etc. The first coulombic efficiency of the anode with ES-Li was 89.93%, the capacity retention rate after 100 cycles of 1C was 96.93%, and the cycle performance at 2C and 5C rates was better than that of the anode prepared by EVOH and PVDF, which had application potential and commercialization prospects.

To deal with the problem of water pollution effectively, the preparation of β-NaYF₄: Yb³⁺, Tm³⁺/g-C₃N₄ composites and the optimum conditions for photocatalytic degrading methylene blue wastewater under visible light were studied. β-NaYF₄: Yb³⁺, Tm³⁺ and g-C₃N₄ were synthesized by solvothermal method and calcinations method, respectively. Then, β-NaYF₄: Yb³⁺, Tm³⁺ and g-C₃N₄ were mixed and added into the solution of polyacrylic acid-polyvinyl alcohol. The β-NaYF₄: Yb³⁺, Tm³⁺/g-C₃N₄/PAA/PVA composite hydrogel was formed by adding the above mixed solution to the saturated borate aqueous solution dropwise with hard stirring. The products were characterized by X-ray diffractometer, field emission scanning electron microscope, UV-visible spectrophotometer, thermal gravimetric analyzer and specific surface area microporous pore analyzer and so on. The orthogonal experiment L₁₆ (4⁵) was used to explore the optimal conditions for degrading methylene blue. The results showed that the degradation rate of methylene blue in 30mg/L was 94.84% under the optimal conditions of the illumination time 20.0 h, the pH value 7.00, the dosage of composite materials 0.25 g, the temperature 20.0℃ and the ratio of active material β-NaYF₄: Yb³⁺, Tm³⁺ to g-C₃N₄ 1∶4. Moreover, the degradation rate of methylene blue in simulated wastewater was still up to 86.22% after 4 recycles. This study revealed that the prepared composite had a good practical value for the application in wastewater treatment.

In this study, poly(acrylic acid-co-benzo-18-crown-6-acrylamide) (PAB) linear copolymers were prepared, and the Cs⁺-responsive characteristics and Cs⁺-detection performances of PAB linear copolymers with different contents of acrylic acid groups were systematically investigated. The experimental results showed that the lower critical solution temperature (LCST) of PAB copolymers in aqueous solutions shifted to lower temperatures in aqueous Cs⁺ solutions with increasing Cs⁺ concentration. When the content of acrylic acid in PAB linear copolymers was 30% in the experimental range, the detection of Cs⁺ with PAB copolymers in aqueous solutions had the best performance. A relationship function between the LCST of PAB copolymers and Cs⁺ concentrations in aqueous solutions was established based on experimental results, with which the Cs⁺ concentration can be simply detected by observing the LCST of PAB copolymers in aqueous solutions. This study provided a new method for facile detection of Cs⁺.

Lead halide perovskite has attracted enormous attention with its excellent photoelectric properties, while the practical applications are limited by the inherent instability and toxicity of the lead halide perovskites. Therefore, this paper proposed a lead-free copper-based perovskite Cs₂CuBr₄ with relatively stable performance and used its humidity-sensitive characteristics to fabricate a quartz crystal microbalance (QCM) humidity sensor based on the Cs₂CuBr₄ sensitive film. The results showed that when the concentration of perovskite solution was less than 0.4μg/μL, the sensitive film sensitive film had good humidity sensing performance at 11%—84% RH. Among them, the optimal concentration was 0.3μg/μL (QCM-3). When the film mass was 398.95ng, the sensor had high sensitivity (37.65Hz/% RH), excellent logarithmic linear relationship (R²=0.9948) and fast response/recovery time (5s/1s). Therefore, lead-free copper-perovskite Cs₂CuBr₄ had a good application prospect in humidity sensing field.

Based on green deep eutectic solvent (DES), wheat straw biomass fractionations were efficiently isolated to prepare lignin nanoparticles (LNP). LNP-based carbon (LNPC) with hierarchical porous microstructure was prepared by chemical activation and further pyrolysis and carbonization. The influences of Zn-activators and pyrolysis temperatures (600℃, 700℃, 800℃) on the structural properties and electrochemical performances of LNPC were studied by means of SEM, Raman, BET analyzers, etc. The results proved that the activated LNPC with Zn-activators exhibited better dispersibility and more hierarchical porous morphology compared with LNPC from direct pyrolysis consisted of massive carbon nanoparticles aggregation. In particular, LNPC-ZnCO₃-800 possessed outstanding performances on better graphitization (I_D/I_G=0.68), higher BET specific surface area (679m²/g), more mesoporous pores (86.7%) and uniform carbon nanoparticles. Moreover, LNPC-ZnCO₃-800 had a high specific capacitance of 179F/g at a current density of 0.5A/g, which was 180% higher than that of LNPC-800 (64F/g).

Iron-manganese black nanoparticles dispersed in non-aqueous medium were obtained by surface modification technique. In iso-dodecane dispersion (Isopar L), cetyltrimethylammonium bromide (CTAB), sodium lauryl sulfate (SDS), (N-tetrafluoroethylene tetramine) polyisobutylene monosuccinimide (T151) and sorbitan trioleate (Span 85) were used to modify the surface of iron-manganese black particles through a mixing ball milling process. The particle size distribution and surface charging properties of the modified iron-manganese black particles were studied in Isopar L. T151 had the best effect on the modification of iron-manganese black particles. The average particle size of the original iron-manganese black particles was 1μm with the zeta potential of -18.58mV. After modification, the particle size distribution was 117.6nm ± 20.5nm with the average particle size of 110nm, and the zeta potential was -96.71mV. The modified iron-manganese black particles were used as electrophoretic display black particles. The prototype device prepared had an electrophoretic response under an external electric field with the device contrast of 5.6. The modified iron-manganese black particles had not only high dispersion stability and high charge, but also the characteristics of high temperature resistance and environmental protection. This provided a reliable experimental basis for the application of iron-manganese black particles in electrophoresis display and more possibilities for the selection of black particles in electrophoresis.

Use hydroxy-terminated silicone oil (HS) and pentaerythritol tetra-3-mercaptopropionate (PETMP) to modify UV-curable waterborne polyurethane acrylate (WPUA) successively, and explored the addition amount of HS and PETMP influence on the properties of the coating film. The structures of the products before and after modification were characterized by FTIR, the particle size of emulsion was tested, and the morphology and coating cross section of emulsion were analyzed by TEM and SEM. The mechanical properties, hydrophobicity, heat resistance and corrosion resistance of the coating were evaluated by adhesion, hardness, flexibility, impact resistance, contact angle, comprehensive thermal analysis, electrochemical impedance spectroscopy and polarization curve. The results showed that when the addition of HS and PETMP were 3% and 5%, respectively, the hardness of UV cured WPUA coating modified by silicon/sulfhydryl composite increased from HB to 3H, the adhesion increased from level 3 to level 1, the flexibility was 0.5mm, the impact resistance was 50cm, the contact angle increased from 68.5° to 90.5°, the water absorption rate decreased from 18.78% to 6.94%, and the thermal stability of the coating was significantly enhanced. The coating impedance increased from 1.86×10⁶Ω·cm² to 6.45×10⁷Ω·cm², E_coor positively moved from -1.069V to -0.4215V, I_coor reduced from 2.12×10^-8A/cm² to 8.11×10^-10A/cm² with an annual corrosion rate of 0.0242mm. The introduction of appropriate amounts of HS and PETMP significantly improved the overall performance of the coating.

In this paper, hydroxylated hexagonal boron nitride (BNNSs) was prepared by hydrothermal method. The functionalized hexagonal boron nitride (Fh-BN) was obtained by grafting isophorone diisocyanate (IPDI) and hydroxyethyl acrylate (HEA) on the surface of BNNSs. The resulting Fh-BN was adding into the PUA coating and the modified Fh-BN/polyurethane acrylic coating was successfully prepared. The effect of time and temperature on BNNSs B—OH content was studied respectively, and the B-OH content was 5.97% in the optimal hydrothermal reaction of 180℃ for 12h. The modified Fh-BN/polyurethane acrylic coating was evaluated by mechanical performance test, water resistance, coating impedance and Tafel polarization curve test. When 0.75% Fh-BN was added to the coating, the hardness reached 3H with the flexibility of 0.5mm and the impact resistance of 50cm. The water absorption of coating reduced by 4.96%, Fh-BN improved heat resistance with T_50% arising 6℃ and Immersion without change in water 168h, while E_corr shifted positively from -0.4886V to -0.32124V and I_corr decreased from 2.5552×10^-7A/cm² to 1.5555×10^-8A/cm². The mechanical properties, water resistance and corrosion resistance of the coating were significantly improved by Fh-BN.

Using paraffin wax and copper metal foam, copper metal foam composite phase change materials were prepared in this study. The effect of the copper metal foam proportion on heat transfer enhancement in the melting process of PCMs was analyzed using visualization heat storage experimental equipment. The integrated heat transfer coefficient of the copper metal foam composite PCMs was obtained. The experimental results showed that when the copper metal foam proportion was 0, 0.43%, 1.29% and 2.15%, the integrated heat transfer coefficient of the composite phase change material first decreased and then increased, which was 1.26W/(m·K), 1.18W/(m·K), 1.44W/(m·K) and 1.88W/(m·K), respectively. Thus, with the increase of copper metal foam proportion, the melting time of composite phase change materials increased first and then decreased. In addition, as the proportion of copper metal foam increased from 0.43% to 2.15%, the proportion of heat conduction in the heat transfer mechanism rose from 17.26% to 86.01% and the proportion of natural convection dropped from 82.74% to 13.99%.

Using cetyltrimethylammonium bromide (CTAB) as the template, Vienna Ab Initio simulation package was used to study the interaction of CTAB and Ce³⁺ in three different cerium salt systems(nitrate, sulfate, chloride) and the stability of the bond formation. In the water environment under different cerium salt systems, only Br^－ in CTAB interacted with Ce³⁺ and formed a Ce—Br bond. From the perspectives of COHP (crystal orbital hamiltonian population), ICOHP (integral of COHP) and radial distribution function(RDF), the bonding stability of Ce—O bond and Ce—Br bond in different systems was analyzed. The results showed that the ICOHP value of the Ce—O bond formed by Ce³⁺ and H₂O under different cerium salt systems was not much different, and the bond formation was relatively stable, while the Ce—Br bond formed by Ce³⁺ and Br^－ in CTAB had a big gap in stability. The order of ICOHP was: ICOHP_{nitric acid system}<ICOHP_{sulfuric acid system}<ICOHP_{chlorination system}, which indicated that CTAB had the strongest control effect on Ce³⁺ under the nitric acid system. This proved that the templating agent CTAB had a better ability to control the nucleation stage of the preparation of ceria crystals under the nitric acid system.

Wet torrefaction (WT), as a biomass pretreatment technology in superheated water at temperatures within 180—260℃, has received extensive attention because of its high adaptation, low energy consumption, superior pretreatment effect and other advantages. But it remains some disadvantages because WT is still in its infancy. In this paper, the definition, reaction mechanism and advantages of WT are reviewed, and the improvement in physical and chemical properties of WT solid products is highlighted (under the optimal conditions, the product mass density, energy density, pellet durability, calorific value and ignition temperature increased by 33.2%, 48.2%, 33.0%, 45.1% and 67℃, respectively, while the grinding energy consumption and equilibrium moisture content decreased by 25.6 times and 2.9 times, respectively). The impacts of WT conditions on the treatment performance are discussed, and the internal relationship between WT conditions and fuel property is determined. Particularly, the research progress of WT and its subsequent applications are comprehensively overviewed, and the economic feasibility of WT is generally analyzed. Finally, the shortcomings of WT and the remediation are clarified. At the same time, it is hoped to provide some analyses and outlooks for future application scenarios of WT, so that WT will have better environmental friendliness and economic feasibility.

In recent years, the application of activated sodium percarbonate (SPC) and peroxymonocarbonate (PMC) in water treatment has received extensive attention from scholars. By investigating a large number of domestic and foreign documents, this article systematically summarizes the current application of activated SPC system and activated PMC system in water treatment, and sorts out the common activators in SPC system, such as iron-based materials, biochar and metal composite systems, etc. , and the common transition metal ions and metal complex activators of PMC system. The main influencing factors and reaction mechanism of activating SPC and activating PMC system to degrade pollutants are explained. The influencing factors include the initial pH of the solution, the oxidant, the activator, the concentration of pollutants, and the coexisting ions. The addition of activators in the SPC and PMC systems will promote the generation of HO· and play a role in the degradation of pollutants. Finally, suggestions are made for the development trend of related research in the future. It is possible to further explore the repair performance of activated SPC and PMC systems on water, as well as their stability and safety in actual water treatment, and clarify the mechanism for free radicals generated in the system to remove pollutants in water.

The pollution of polycyclic aromatic hydrocarbons (PAHs) in soil has become a serious environmental problem. Therefore, it is necessary to develop low cost and efficient technology of microbial remediation. Based on the environmental pollution characteristics of PAHs in soil, and combined with the research progress of removing PAHs from soil by microbial remediation technology in recent years, this paper analyzes the existing challenges and solutions of the engineering application. Then the mechanism of interaction between microorganisms and PAHs is introduced. It is pointed out that bacteria degrade PAHs mainly by dioxygenase, fungi degrade PAHs by monooxygenase, while algae degrade low-cyclic PAHs mainly by monooxygenase system, and high-cyclic PAHs mainly by dioxygenase system. Finally, the main research directions of remediation technology for PAHs contaminated soil in the future are proposed, including the establishment of screening system for efficient degrading bacteria, the construction of mixed microorganisms and genetically engineering bacteria, and the strengthening of the reaction process and metabonomics research, in order to provide guidance for the industrialization development and large-scale application of soil remediation technology in China.

Compared with traditional adsorbents, mesoporous metal organic frameworks (MOFs) have many advantages, such as large pore size, adjustable porosity, large specific surface area, rich functional groups, convenient for functional modification and so on, which can efficiently adsorb heavy metal pollutants in water. The characteristics, synthesis strategies and four synthesis methods of mesoporous MOFs are introduced in this paper. The formation mechanism of mesoporous MOFs and the problems that those four methods faced are analyzed, the advantages and disadvantages of four synthesis methods are compared. The research progress of adsorption and removal of heavy metal ions, heavy metal like anions and radioactive metal ions by mesoporous MOFs and the reusability of mesoporous MOFs in adsorption and removal of heavy metal ions is reviewed. The adsorption mechanism of mesoporous MOFs for the removal of heavy metal pollutants in water is described. The optimization direction is put forward for those problems such as high cost, harsh synthesis conditions and difficult recycling. It is pointed out that improving the water stability of mesoporous MOFs, easy recycling, simple green synthesis technology and trace removal will be the research direction in the future.

With the substantial increase of polyethylene terephthalate (PET) material consumption, the environmental pollution caused by the accumulation of a large number of waste PET products has become increasingly prominent, and its recycling technology has also received widespread attention. Among different PET recovery methods, the chemical recycling of degrading PET into monomers or oligomers is the most efficient and most valuable method for product utilization. However, there are also problems such as harsh reaction conditions and low product yields. This review combs the main characteristics of the chemical recycling methods such as hydrolysis, methanolysis, glycolysis, aminolysis and ammonolysis. Meanwhile, the applications of emerging technologies such as microwave heating, ionic liquids and nanotechnology in the chemical recycling of PET are also introduced. Through the comparison of various chemical recycling processes, it is concluded that glycolysis is the most valuable method for commercial application. On this basis, the focus is on the chemical processes, development status, restricting factors and improvement measures of the glycolysis of PET and the further preparation of unsaturated polyester resins. The analysis shows that the preparation of unsaturated polyester resins from PET glycolysis products is an important way to improve the resource efficiency of waste PET, enrich the supply of raw materials and promote product upgrades. The development of high-efficiency, low-cost and environmentally friendly new catalysts or enzyme catalysis is the main development direction in the field of waste PET recycling in the future.

With the development of large-scale energy storage and electric vehicle market, the demand for lithium-ion batteries is increasing, resulting in an explosive growth in the number of spent lithium-ion batteries. The cathode materials of spent lithium-ion batteries contain abundant valuable metal elements such as lithium, cobalt, nickel and manganese. The recovery of those metals has high economic value and significant environment benefits. As a green solvent, deep eutectic solvents (DESs) show great potential in the recovery of valuable metal elements from spent lithium-ion batteries. Based on a brief introduction of the properties and applications of DESs, this paper systematically reviews the research status of DESs in the recycling chain of cathode materials from spent lithium-ion batteries, mainly including the separation of cathode material, leaching of active substances and recovery of valuable metal. The current recycling methods and process flow are discussed, and the advantages and disadvantages of different kinds of DESs for leaching cathode active materials are compared as well. Finally, the common problems of the current DESs in the recycling spent lithium-ion batteries are analyzed, and the development direction of DESs recycling of lithium-ion batteries is proposed.

The biochemical treatment process of azo-dye saline wastewater was complicated, and had the problems of the electricity consumption and unclear degradation mechanism. In this research, being based on the acidic-potassium-dichromate-method hydrothermal treatment, the modified anode was obtained and then was applied to construct microbial fuel cell to treat azo-dye saline wastewater. The effects of different divalent anions on the electricity generation performance and the organics degradation of MFC were investigated, and the degradation mechanism of Direct Red 13 by MFC was also explored. The results showed that when the inorganic salt in the azo-dye saline wastewater was sodium sulfate, the maximum power density of MFC could reach 265.38mW/m², and the maximum current density was 1.10A/m², which was higher than that of the wastewater containing sodium carbonate. As the wastewater with additional salt, the removal rate of Direct Red 13 by MFC was much lower than that without additional (71.13%). The order of the removal efficiency of glucose was sodium sulfate > sodium carbonate > no additional. Analysis of microbial communities and degradation products showed that, the anode biofilm realized the bio-electrochemical degradation of Direct Red 13 through the synergistic effect of microorganisms like Proteobacteria and Bacteroides, and the degradation products were mainly reduced products (aromatic amines) under electricity generation.

Coke powder is a low-value by-product of coking/coal industries, and the use of coke powder as a pollution control material is an important field for its high-value application. The morphology and elemental composition of coke powder were characterized. The performance of persulfate activated by coke powder was evaluated by the removal efficiency of aniline. The characterization results showed that the coke powder had a rough surface with a pore structure. The activity test results presented that 5mmol/L persulfate could be efficiently activated by 1g/L coke powder, and more than 99% aniline (20mg/L) was degraded after 120min. The ash in CP did not contribute to aniline degradation. The degradation efficiency of aniline could be improved by increasing coke powder dosage and persulfate concentration. Moreover, coke powder could efficiently activate persulfate to degrade aniline in the range of pH 3—11, and the aniline degradation efficiency could be maintained above 83%. Meanwhile, aniline degradation in the system was maintained above 90% in the presence of Cl^-, HCO{}_{\mathrm{3}}^{-} or SO{}_{\mathrm{4}}^{\mathrm{2}-}, indicating that coke powder had the potential to be used to repair organic pollutants in complex wastewater. Response surface analysis showed that coke powder could efficiently activate persulfate to degrade aniline, and the interaction between coke powder dosage and persulfate concentration was strong, both of which contributed to the degradation efficiency of aniline. Furthermore, free radical quenching tests proved that O{}_{\mathrm{2}}^{·-} and ·OH were the dominant radicals generated in the system of coke powder with persulfate. The findings can provide guidance for the high-value application of low-value coal-based by-products, and provide new opportunities for the further development of environmentally friendly wastewater pollution control and resource utilization technologies.

The composite materials (BGO) prepared by graphene oxide (GO) and bentonite (Bent) through ultrasound method were tested for their ability to absorb Basic Violet 3. The materials structure were characterized by X-ray Diffraction, Fourier Transform Infra-Red Spectrophotometer, BET equation, Scanning Electron Microscope and X-ray Photoelectron Spectroscopy. The biosorption data were analyzed using Langmuir, Freundlich, pseudo-first-order kinetic model and pseudo-second-order kinetic model, and the thermodynamic parameters of the biosorption were determined by Van’t Hoff equation. XRD analysis indicated that the interlayer spacing of Bent increased from 1.35nm to 1.6nm after GO were inserted successfully, and the specific surface area of BGO were improved significantly. Langmuir model and pseudo-second-order kinetic model proved to be the best fit to the experimental data. BGO performed more significant adsorption capacity and adsorption speed. Compared with Bent, the maximum adsorption capacity of BGO was 420.17mg/g at an initial dye concentration of 250mg/L and 30℃. Thermodynamic analysis verified that BGO biosorption was spontaneous and endothermic. Mechanism analysis revealed that the synergy between GO with high specific surface area and oxygen-containing groups and Bent played a prominent role in adsorption ability of BGO.

Thermochemical cleaning is a cost-effective method for treating oily sludge. The thermochemical cleaning effect was analyzed systematically, and the mechanism of crude oil desorption was also discussed preliminarily in this study to realize harmless treatment of oily sludge. This study showed that the compound cleaning agent NAS can reduce residual oil rate in solids to 0.94% with cleaning conditions of 4% (concentration), 60℃ (temperature), 8∶1 (liquid-to-solid ratio), and 60min (time), which is far lower than the requirement of oil content ≤2.0% in the "Pollution control requirements for comprehensive utilization of oil and gas field oily sludge" (DB 65/T 3998—2017) and other standards. The results of desorption isotherm model fitting and thermodynamic parameter calculation showed that the desorption of oil from solids surface conforms to the Langmuir model and was a spontaneous endothermic process. Combined with the analysis results of FTIR and XRD, it can be seen that the thermochemical cleaning method mainly removed the light components of crude oil in the oily sludge, and chemical adsorption occurred between solids surface and heavy components, which was the dominant factor affecting the desorption of crude oil.

The thermally regenerative ammonia-based battery (TRAB) exhibits unique advantages and good application prospects in copper-containing electroplating wastewater treatment and recycling. It can remove copper ions while generating electricity from low-temperature waste heat. As one of the critical operating parameters, the load affects the electrochemical reaction rate, the performance of electricity generation and the removal effect of Cu²⁺. In addition, the presence of ammonia permeation significantly affects the removal effect of copper ions. In this paper the TRAB battery was discharged in batches under different loads to investigate the effect of loading on the electrical production and removal rate of Cu²⁺. The reactions of the cathode under different ammonia concentrations were explored using cyclic voltammetry. After discharge, thermal regeneration was carried out to investigate the effects of different regeneration temperatures on the thermal regeneration process, battery power and Cu²⁺ removal rate. The results indicated that a lower load could result in a higher total charge and shorter processing time. In addition, it can improve the coulomb efficiency of the cathode by slowing down the ammonia crossover and reducing the occurrence of side reactions. Therefore, higher removal rates of copper ions were obtained under low load. When the load was 1Ω, a higher power yield (350C) was obtained, the treatment time was shortened to 2.1h and the removal rate of Cu²⁺ reached 80.5%. During the next batch, the thermally regenerative process was important for the battery performance and copper removal rate, which could be enhanced by increasing the regenerative temperature in a certain range.

At present, bagasse boiler has many problems, such as long service life, insufficient combustion, low efficiency, serious fuel waste and high pollutant emission. There is a lack of large amount of field test data to analyze the reasons. In order to solve this problem, the energy efficiency of 121 bagasse boilers was tested. The results show that the number of boiler thermal efficiency reaching the standard limit value and target value accounts for only 51.24% and 0.83%, respectively. The heat loss of flue gas is up to 10%, among which the heat loss of moisture accounts for nearly 1/4. The average carbon dioxide emission reaches 131.54kg/GJ. The main influencing factors are flue gas temperature, excess air coefficient and carbon content of fly ash. In view of these factors, measures to improve energy efficiency are proposed. If the energy efficiency can reach the limit value or the target value, the annual bagasse consumption will be reduced by 157kt or 568kt, the carbon dioxide emission will be reduced by 160kt or 522kt, and the emission of other pollutants will also be reduced. When applied to the bagasse boilers nationwide, the energy saving and emission reduction potential will be greater.

In order to solve the problems of complex composition, high toxicity and low resource utilization rate of phenolic distillation residue, a multi effect resource utilization scheme of vacuum deep drawing and thermochemical conversion was proposed according to the component characteristics of phenolic residue. And the preparation process of different products in this scheme was verified by experiments. The results showed that the main light components of phenolic residue were hydroquinones, and the proportion of phenols from the phenolic residue was 70.38%. The special resin for magnesia carbon brick refractories was prepared by condensation reaction of formaldehyde and phenol with its additive which from the deep drawing light components of phenolic residue. The performance index of the stillage residual resin can meet the enterprise standard and basically reach the industry level. The properties of MgO-C brick prepared by the residual resin of the autoclave were not significantly different from those prepared by commercial resin Nv. After chemical modification and increasing the degree of crosslinking, the residual heavy components of phenolic residue could basically meet the requirements of granular activated carbon adhesive. At the same time, from the cost-benefit point of view, a comparative evaluation was made on the utilization schemes of phenolic distillation residue. This study provides an alternative way of resource utilization for the treatment of phenolic distillation residue.

The prevention and control of volatile organic compounds (VOCs) pollution is considered a core task of air pollution control. Taking scientific and reasonable evaluation and screening optimal treatment technologies are the key points of VOCs emission reduction. The comprehensive evaluation model of VOCs end treatment technology still lacks scientific and universal technical evaluation model. Fuzzy analytic hierarchy process (FAHP) has the advantages of objectivity and accuracy in constructing quantitative and qualitative index evaluation models, which can solve this problem. The evaluation model of VOCs terminal treatment technology based on FAHP is studied introduced, which included three first-level indicators of economy, environment and technology and eleven second-level indicators. By analyzing the typical production process and the emission of VOCs from the pesticide production in Jingzhou Economic and Technological Development Zone, nine typical terminal treatment technologies of VOCs are evaluated quantitatively. The results show that catalytic combustion, thermal incineration and membrane separation technology has obvious environmental and economic advantages, besides, adsorption technology has obvious economic and technical advantages. Comprehensive evaluation results indicate that the comprehensive evaluation of catalytic combustion (0.143) is a potential strategy, thus is worthy to extend in the terminal treatment of VOCs. This study provides reference for screening VOCs terminal treatment technologies, which is beneficial in VOCs emission reduction strategy in chemical enterprises.

To guide the development of CCUS by government policies, it is necessary to redefine the attributes and value of carbon dioxide, and to deeply explore its resource attributes. In the energy revolution, all social activities and industries will be affected and reconstructed in order to enable the transformation from carbon-based energy to carbon-free energy. Thinking of CCUS green technology in the low carbon scenarios of the future with innovative development and application of the three technologies forcarbon dioxide hydrogenation, carbon dioxide could be converted into syngas (CO+H₂), so as to realize high value, resource utilization and carbon solidification and archive. In sddition, Fischer-Tropsch synthesis of high-carbon hydrocarbon fuels and carbon dioxide hydrogenation in the coal power, coal chemical and cement industries is not only a way of realizing the value from carbon dioxide, but also of peak regulation of the power grid. Similarly, the dry reforming of CO₂ and CH₄ into biogas and unconventional natural gas can produce green hydrogen, renewable fuels and methanol with high value, which is of special significance for China’s rural revitalization, and can open up rural waste treatment to energy transformation and enable national industry to generate supplementary value for agriculture. The funding related to this will also enable China’s rural revitalization projects to obtain new opportunities for capital. Through low-carbon transformation of the steel and chemical industries, the high-value utilization of carbon dioxide in dry reforming of coal gas and dry gas, especially the production of methanol by dry weight integration into gas, and carbon solidification via the production of ethylene, propylene and polymers by MTO, will enable CCUS to creat new opportunities along the industrial chain. In a sense,CCUS will become a subsidiary industry of all social activities and industries and, could be regarded as a new public service industry chain.