Biochar can be used as an excellent platform for supporting various photocatalytic particles due to its unique surface properties,easily tunable functional groups, chemical stability, and electrical conductivity. Compounding photocatalysts with biochar can produce biochar-based photocatalysts and combine the advantages of biochar with catalysts.The resulting composites can significantly improve in functional groups, pore properties, surface active sites, catalytic degradation ability and so on.The electron-conductive nature of biochar can reduce the quick recombination of the e^-/h⁺ pair during photocatalysis and suitable surface functional groups enable immobilization of different pollutants, which is favorable for photocatalysis. The paper aims to review and summarize the various synthetic techniques and physicochemical properties of biochar-based photocatalysts and their effects on the decontamination of wastewater. Various preparation methods including sol-gel, ultrasound, hydrothermal/solvothermal, hydrolysis, calcination, precipitation and thermal polycondensation are summarized and discussed in detail. Furthermore, the synergistic effects of adsorption and photodegradation of pollutants by biochar-based photocatalysts are discussed with in-depth mechanistic evidence. Finally, the application of biochar-based photocatalysts for different contaminants removal is summarized, and some future trends and potentials are outlined.

Flame synthesis refers to the reaction of precursors in burners to obtain nanoparticle products after combustion with a series of complex physical processes and chemical reactions which involve phase changes, particle growth, heat transfer and mass transfer. It has the advantage of one-step production and is an important modern industrial scale approach for preparing high performance materials. Exploring the flame synthesis process is the key to achieve particle product modulation, therefore, this work analyzed the key parts of the process, such as the precursors, burners, particles, etc. In line with these, the growth and transformation of particles, the structure of different burners, and the characteristics of temperature field and flow field were described. The characteristics of particle size and crystal form of TiO₂ nanoparticles synthesized by different burners were analyzed. The basic research on the growth mechanism and morphology regulation of particles from the flame synthesis was of guiding significance for the industrial preparation of TiO₂ particles.

In order to study the influence of the arrangement of special-shaped fibers on its filtration performance, based on the rectangular and staggered arrangement, and keeping the volume fraction of fibers unchanged, the array structure was adjusted by changing the column spacing of fibers. CFD-DEM coupling method was used to simulate the process of dusty air passing through a simplified filter model with different special-shaped fiber array structures. The results showed that when the volume fraction of fiber remained unchanged, the filtration efficiency of staggered fiber array was 35% higher than that of rectangular array, and the adsorption capacity for particles was stronger. On the basis of staggered array, the filtration of the pre-dense array and post-dense array can be maintained at about 80% by adjusting the column spacing, and the particle adsorption capacity was not affected, but the pressure drop generated by the pre-dense array was lower, that is, it has a higher quality factor. In the whole filtration process, the adhesion between fibers and particles was much higher than the interaction between particles, which indicated that particle filtration mainly came from the contribution of fiber particle interaction.

Taking the immersed coil heat exchanger as the research object, the ultrasonic wave was imposed by means of vibration surface, and the influence of the ultrasonic amplitude and the inlet flow rate of the heat exchanger and the pressure outside the tube on the ultrasonic effect and the heat transfer enhancement were compared. The results showed that the increase of ultrasonic amplitude from 20μm to 35μm resulted in the increase of surface heat transfer coefficient from 15.67% to 26.71%, and the increase of external pressure from 0.1MPa to 1.0MPa led to the increase of surface heat transfer coefficient from 20.95% to 48.43%. When the inlet flow rate was reduced from 1.0m/s to 0.05m/s, the surface heat transfer coefficient increased from 1.76% to 39.01%. Increasing the ultrasonic amplitude, environmental pressure and reducing the medium flow rate could all enhance the acoustic streaming and acoustic cavitation effect and effectively improved the ultrasonic heat transfer enhancement effect; the high-pressure environment will cause the sound power to increase exponentially under the same amplitude and frequency ultrasonic vibration, and the high flow rate would reduce the sound energy density of the fluid medium. Both cases needed to match the appropriate ultrasound power to ensure the best effect of enhanced heat transfer.

Microreaction technology has been widely used in the field of chemical process intensification, especially for fast and complicated competitive reaction systems. For liquid-liquid biphase fast competitive reactions, the reaction process is controlled by mass transfer property, which significantly affects the reaction conversion and yield. In this paper, a new type of micropore-jet capillary microreactor (MJCM) was developed to intensify liquid-liquid biphase mass transfer property at the inlet. Liquid-liquid biphase mass transfer property and reaction selectivity were studied under different experimental conditions (flowrate, flux ratio, surfactant concentration, temperature) and structure parameters (pore size, capillary length), adopting respectively the water-benzoic acid-kerosene system and the water-NaOH-toluene-benzoic acid-ethyl chloroacetate system. Meanwhile, the correlation of Sh was obtained. The results indicated that the mass transfer efficiency (E) decreased, and the overall volumetric mass transfer coefficient (k_La) increased, while reaction selectivity index (X_s) first decreased then increased, as the flow rates of two immiscible liquid phases were raised. Both liquid-liquid mass transfer and reaction selectivity weaken under larger pore size. Increasing the capillary length resulted in the increase of E and X_s but decrease of k_La. The volumetric flux ratio of the aqueous phase to the organic phase affected E and k_La in different tendency. Moderate rise of temperature can improve the reaction selectivity. Adding the surfactant can decrease mass transfer property and reaction selectivity. Comparing with other liquid-liquid mass transfer devices, MJCM showed excellent performance on mass transfer property and reaction selectivity, with promising applications in industrial productions to intensify liquid-liquid mass transfer and reaction processes.

In order to explore the ways realizing subcooling in transcritical CO₂ combined cooling and heating system without external assistance, three types of transcritical system with split flow cooling were proposed, and the thermodynamic model of the systems were established. The system performance changes under different working conditions were analyzed by simulation calculation. The results showed that the system scheme of split flow between evaporator and throttle valve could not improve the system performance. The split flow between the gas cooler and the subcooler, and the split flow between the subcooler and the throttle valve had the same effect on improving system performance, and comprehensive COP(coefficient of performance) can be increased by 17.62%. The use of split flow cooling will increase the suction pressure of the compressor. When the temperature of CO₂ at the outlet of the gas cooler was determined, there was an optimal discharge pressure to maximize the comprehensive COP. A reasonable scheme of split flow cooling system could be used as an effective means to realize CO₂ subcooling in transcritical system and improve system performance only by self-circulation.

As a new type of gas-liquid mass transfer element, porous foam material has been proved to have a strengthening effect on the distillation process, but the key mechanism of its strengthening effect is still unclear and needs to be studied urgently. Existing studies have attempted to explain the enhanced mechanism of porous foam material on gas-liquid mass transfer from the perspective of fluid mechanics. Whether porous foam materials has an effect on thermodynamic performance is still lacking in conclusiveness. In this paper, an experiment to study the influence of foamed silicon carbide on the gas-liquid equilibrium of a binary system was designed, which was completed through a gas-liquid dual-cycle phase equilibrium device. The gas-liquid equilibrium data of the binary system of ethyl acetate, ethanol/cyclohexane were aimed at exploring the influence of the pore size of porous foam materials on the gas-liquid equilibrium based on the theory of the structure curvature of the foam silicon carbide with different pore sizes, in which the influence of the porous foamed silicon carbide material on the gas-liquid equilibrium of the ethanol/ethyl acetate and ethanol/cyclohexane system was not obvious on the gas-liquid diagram. Through the analysis of the experimental process and results, the problems of the gas-liquid equilibrium experiment under porous materials were discussed, and the influence of foamed silicon carbide on the gas-liquid composition was explored under the existing experimental technical conditions. Furthermore, suggestions and directions were put forward for the in-depth study of the influence of porous foam materials on the gas-liquid equilibrium of the binary system in the future.

At present, most of the oil fields in China have entered the stage of high water content, and there is often a lot of associated gas in the produced fluid, efficient separation of produced liquid by hydrocyclone separation is of great significance for simplifying surface treatment technology and developing the economy treatment technology of produced fluids for offshore platform. The degassing and oil-removal hydrocyclone system is composed of GLCC type gas liquid separator and oil-droplets size reconstruction hydrocyclone, and the purpose of the design is to ensure efficient degassing while further improving the removal effect of small oil droplets, so as to achieve high-efficiency three-phase separation. Based on the computational fluid dynamics (CFD) analysis, the population balance model (PBM) is used to simulate the coalescence and breakage of oil droplets, and the characteristics and particle size distribution of the internal flow field of the degassing and oil-removal hydrocyclone system were simulated and analyzed, and the effects of gas volume fraction and gas phase exit split ratio on the separation performance of the degassing and oil-removal hydrocyclone system were compared and analyzed by combining numerical simulation with the experiment. The results showed that the interaction between gas volume fraction and gas phase exit split ratio was significant. By considering degassing efficiency and oil removal efficiency, the best gas phase exit split ratios are 25%, 30% and 35% when the gas volume fractions are respectively 10%, 20% and 30%. The numerical simulation results were in agreement with the experimental results, which verified the reliability of the numerical simulation method. In addition, the larger the gas volume fraction, the more obvious the oil droplets reconstruction phenomenon of the oil-droplets size reconstruction hydrocyclone was. The oil-droplets size reconstruction hydrocyclone could improve the phenomenon of poor oil-water separation effect under gas-containing conditions to a certain extent, and the degassing and oil-removal hydrocyclone system had good applicability for the three-phase separation of oil, gas and water.

In order to improve problems of single inlet hydrocyclone such as poor stability and low grading efficiency, a multi-inlet structure of hydrocyclone was proposed. Through numerical simulation, flow field characteristics and separation performance of single, second, third and fourth inlet hydrocyclones were compared and analyzed under constant feeding conditions. The results showed that increasing the number of inlet had a positive effect on flow field and separation performance of the hydrocyclone. Increasing the inlet number of the hydrocyclone was beneficial to increase the radial pressure of the hydrocyclone flow field. When the inlet number was even, the radial static pressure enhancement effect was better. The tangential velocity of the flow field in the column section of the hydrocyclone increases with the increase of the inlet number of the hydrocyclone, which was beneficial to the enhancement of the separation performance of the hydrocyclone. Meanwhile, the separation efficiency of discrete phase CaCO₃ particles were predicted by using the mixture coupled RSM model. The separation efficiency showed that the multi-inlet hydrocyclone can complete the high precision separation of discrete phase under the low velocity inlet condition. At the feeding speed of 3m/s, comparing with single-inlet hydrocyclone, the bottom flow distribution of 50μm and 57.5μm particles separated by multi-inlet hydrocyclone increased by 10.60% and 5.59% respectively, which had positive effects on inhibiting the mismatching rate of the hydrocyclone overflow product and improving the separation performance. Therefore, increasing the number of hydrocyclone inlet can strengthen separation performance clearly.

Galinstan, a room temperature liquid metal, combines both the features of liquid and metal. Utilizing the oscillating motion of the mixed working fluids of liquid metal and surfactant solution, a high thermal conductivity mixed liquid metal self-dispersed micro-nano droplets in the oscillating heat pipe (OHP) was formed with high heat transfer performance. 6-turn flat plate oscillating heat pipe with Galinstan and surfactant as the working fluids was investigated visually and experimentally under different liquid metal filling ratios and heat input in this work. The results demonstrated that liquid metal was driven to oscillate with the pressure difference induced by phase change of working fluids and broke up into spherical droplets. It was hard for the droplets to coalescence because of exited surfactant solutions. There were nano-particles with the diameter of 410—520nm, left in the surfactant solutions after the oscillation of liquid metal. When the filling ratios of liquid metal was 20%—25%, the high viscosity and mass of liquid metal spherical droplets hindered the oscillating motion of the mixed working fluids easily and thus increased the thermal resistance of the oscillating heat pipe. When the filling ratios was 5%—10%, the mixed working fluids coupled the high thermal conductivity of the liquid metal and the heat transfer performance was improved effectively and the thermal resistance was reduced by 11.21% at most when the liquid metal filling ratio was 5%.

Walls filled with phase change materials (PCM) can effectively reduce building energy consumption and improve thermal comfort. The porous brick roof was filled with paraffin with a phase transition temperature of 25—33℃. The equivalent temperature considering radiation and air temperature was introduced. The GPU accelerated multi-relaxation-time lattice Boltzmann method (MRT-LBM) based on enthalpy method was used to analyze the effects of paraffin wax with different phase change temperatures on the thermal response characteristics of roofs in seven cities of China in August 2020. The results of paraffin with phase change temperature of 27℃ were shown that phase change of paraffin did not occur in the building roof of Shanghai, and the entering heat flux was as high as 324.3kJ/m². The liquefaction rate of paraffin in the phase change roof of Chengdu area changed by 30%. The internal surface temperature fluctuates between 25.6℃ and 27.3℃, and the temperature difference was only 1.7℃. The entering heat flux was only 50.9kJ/m². The results indicated that the change of liquid phase rate in Wuhan and Beijing was very close, the phase transition time was 50% of the whole day and the corresponding heat flux entering the room was 0.37 times of that in Shanghai. The temperature fluctuation of the inner surface of the roof wall in Kunming and Harbin reached 4.5℃ and 4.4℃, respectively, but the corresponding temperature was 28℃. The indoor temperature fluctuation of Guangzhou was 2.6 times of that in Chengdu. Beijing, Chengdu, Wuhan and Kunming were suitable for paraffin with phase transition temperature of 27℃, while Guangzhou, Shanghai and Harbin were suitable for paraffin with phase transition temperature of 29℃, 31℃ and 25℃, respectively. This work can provide the guide for the optimization design of phase change building.

The properties of regenerator materials is one of the key factors to the performance of pulse tube cryocoolers. Losses in the regenerator, energy flow along the axial direction and cooling capacity of the pulse tube refrigerator were compared in 10—30K, when the lower temperature part of the regenerator was filled with stainless steel wire mesh (SS) and HoCu₂, respectively. The simulation analysis of regenerator losses showed that there was a large imperfect heat transfer loss when SS was filled, while the influence of flow resistance loss increased significantly when HoCu₂ was filled. With the increase of cooling temperature, the imperfect heat transfer loss of the regenerator was reduced, while the flow resistance loss increased a little bit. The simulation result of energy flow in the 2nd pulse tube refrigerator showed that the enthalpy flow of the regenerator and the PV work transferred to the cold end were smaller when HoCu₂ was filled. Finally, Comparative experimental tests were conducted on a thermally coupled two-stage pulse tube with active phase shifter. The results showed that the no-load temperature of the lower-temperature pulse tube filled with SS and HoCu₂ was 9.56K, and the cooling efficiency was higher than that of pure SS when the refrigeration temperature was 25K or below. When the cooling temperature was above 28K, the cooling efficiency of pure SS was higher. By comparing the refrigeration performance of regenerators filled with conventional material and magnetic material, it provided a reference for the design of higher efficiency regenerator in liquid hydrogen temperature zone.

Selective CO methanation is considered as the most promising deep CO removal technology for the low-temperature fuel cells. Furthermore, the key to its wide applications is the development of high-performance supported catalysts. The research progress of selective CO methanation in recent years is reviewed in this article. Starting with the selection and evaluation criteria of catalysts, this article focuse on the reaction mechanism of CO and CO₂ methanation, the effects of particle size, supports and promoters on the catalytic activity and selectivity. Finally, the research on selective CO methanation is summarized and future research direction is also prospected. It is concluded that selecting appropriate loading of active components, supports and promoters can significantly improve the activity of the catalyst. However, the metal-support interface can be controlled by the chloride ion modification and the preparation of Ru-Ni bimetal, which plays a vital role in the improvement of the selectivity. The research on the methanation reaction mechanism and the development of long-term stable catalysts will be the focus of future researches.

Microwave pyrolysis of biomass has the advantages of fast reaction rate and high energy utilization, but there are problems such as low product selectivity and low quality. Combined with the use of catalysts, it has the application potential for preparing high-value products. In this paper, the research progress of microwave catalyzed pyrolysis of biomass is reviewed, and the mechanism of microwave catalyzed pyrolysis, the reaction system, and the effects of pyrolysis products on the preparation of high value-added products are introduced. The mechanism of microwave catalytic pyrolysis is briefly described. The microwave catalytic pyrolysis system is discussed from three aspects of raw materials, microwave absorbers and catalysts. The difference in product yields of different types of raw materials and the difference in product selectivity of different catalysts are introduced. Different methods for improving product yield and selectivity are analyzed, and it is pointed out that optimizing and improving catalyst characteristics to make it have compound function, developing large-scale microwave reactor, product directional enrichment and conversion are still problems that need to be solved. It provides a reference for the production of hydrocarbon-rich bio-oil, high-performance bio-char and other products, and then promote to industrial applications.

The actual combustion process of aviation kerosene often has high stoichiometric ratio (Φ) oxygen-lean conditions. In this paper, n-decane was used as a one-element alternative fuel of aviation kerosene, and the oxygen-depleted catalytic/non-catalytic combustion characteristics of n-decane in micro tube with Pt/ZSM-5 catalyst or quartz sand packed bed were experimentally studied under oxygen-lean conditions (Φ=2—4). The effects of equivalence ratio (Φ=2—4), temperature (300—450℃) and catalyst on the conversion rate of n-decane, combustion efficiency and gas phase product distribution were analyzed. The results showed that the Pt/ZSM-5 catalyst had an obvious promotion effect on the combustion reaction of n-decane, and there was a phenomenon of temperature surge. When the equivalence ratio Φ increased from 2 to 3.5, the dynamic ignition point rised from 196℃ to 271℃; while without catalysis, there was no obvious point of ignition. The conversion rate of n-decane under the oxygen-lean catalysis condition was always lower than that under the no catalysis condition, but the combustion efficiency was significantly higher than that under the no catalysis condition. The main gas-phase product of catalytic combustion of n-decane was CO₂, and the main gas-phase product without catalysis was CO and olefins.

At present, there are insufficient studies on the application of adsorption to remove high-pressure and low concentration CO₂, and reference data for the design of the decarbonization process are not readily available. In this paper, dynamic adsorption experiments of low concentration (3%) CO₂ on 13X zeolite were performed. The influence of different pressure, temperature, gas flow, filler height and molecular sieve specifications (size, shape) on the dynamic adsorption operation parameters were explored. The result showed, with the increase of adsorption pressure, the CO₂ adsorption capacity of 13X zeolite increased but with decreasing pace. Decreasing the adsorption temperature, reducing gas flow and increasing the height of packing were all conducive to enhance the dynamic adsorption performance of 13X zeolite and improve the adsorption decarburization performance, and temperature and filler height have greater impact. The experiment also found that the dynamic adsorption and decarburization performance of the small strip 13X zeolite was better than the other ones. Based on the CO₂ adsorption capacity when the outlet CO₂ concentration was 50mL/m³ under specific conditions, the coefficient between the amount of adsorbent required and the treatment capacity of liquified natural gas (LNG) decarbonization was given.

In order to understand the role of oxygen (O₂) in hydrothermal pretreatment of corn stover and optimize the ethanol production process of corn stover,corn stover was pretreated under three different hydrothermal pretreatment conditions:Ⅰ(195℃,15min), Ⅱ(195℃, 15min, 12bar O₂), and Ⅲ(195℃, 15min, 12bar O₂, 2g/L Na₂CO₃). Ethanol production from pretreated corn stover by simultaneous saccharification and fermentation (SSF) with baker yeast was studied. The results showed that corn stover was divided into solid cake and hydrolysate after pretreatment. Most of the cellulose remained in the solid cake while the hemicellulose and lignin were partially solubilized and degraded due to instability. Under the three pretreatment conditions, the overall yield of cellulose after pretreatment was 91.2%, 94.6% and 95.9%, the overall yield of hemicellulose was 74.5%, 50.3% and 68.2%, the lignin mass fraction in the solid cake was 25.2%, 17.5% and 13.7%, and the total yield of glucose after enzymatic hydrolysis was 64.8%, 65.8% and 67.6%, respectively. It showed that oxygen had little effect on the yield of cellulose and could promote the dissolution of hemicellulose. Oxygen mainly reacted with lignin and adding sodium carbonate (Na₂CO₃) facilitated the degradation of lignin, thereby effectively obtaining higher yield of cellulose and cellulase hydrolysis efficiency. After 142h of SSF, the highest ethanol concentration of 25.0g/L was obtained by baker yeast with substrate mass fraction of 8% corn stover pretreated under the condition Ⅲ, no obvious inhibition effect occurred during fermentation process.

Isothermal gasification reaction of coal was often conducted by thermogravimetric analyzer in laboratory, while the gas switch effect in this process was rarely considered. In this paper, a coal char was used to evaluate the effect of the gas switch step on the isothermal gasification experiments by comparing the traditional gas switch process with a newly designed all CO₂ process. The on line mass spectrometry was also used to evaluate the reactive gas evolution behavior in these processes. The results showed that for the gasification reaction with the gas switch process, though the CO₂ could reach to the reaction zone quickly, the coal char was still reacted in the mixture atmosphere of the CO₂ and the initial inert gas for the emission of the inert gas was not an ideal plug flow condition. This greatly affected the gasification rate of the char, further affected the selection of kinetic model, and finally caused the decrease of the calculated activation energy for which was affected by the gas diffusion effect. Therefore, it is suggested that in the study of isothermal gas-solid reactions via thermogravimetric analyser with the gas switch process, the gas evolution behavior should be detected first, and the influence of the gas switch process should be evaluated so as to reduce the errors caused.

A series of experiments was conducted at 276.15K and 6.0MPa to evaluate the kinetics of IGCC synthesis gas hydrate formation in the system containing corn cobs and tetrahydrofuran (THF) by measuring induction time, gas consumption, CO₂ recovery and hydrate structure. The results showed that for all experiment cases with or without corn cobs, the induction time was within 180s. Besides, the induction time of the system containing corn cobs was slightly longer than that without corn cobs and this difference almost disappears as the THF concentration increases to mole fraction 4.0% and 5.6%. Further, relative to the system without corn cobs, the time required to complete hydrate formation was longer in the presence of corn cobs. As the THF concentration increases, less time was required for achieving 90% of final gas consumption in the presence of corn cobs. In addition, at a certain THF concentration, the gas consumptions in the presence of corn cobs were larger than that in the system without corn cobs. These indicate that the addition of corn cobs had a positive effect on the kinetics of IGCC syngas hydrates formation and the CO₂ recovery. Interestingly, structure analysis proves that only s?Ⅱ hydrates were observed in the presence of THF with or without corn cobs, while both s??Ⅰ and s?Ⅱ hydrates were found in pure water.

Aiming at the problems of the large consumption of water resources, high moisture content of semi-coke, and severe environmental pollution in the production process of pulverized coal pyrolysis, the process flow of semi-coke dry quenching and waste heat recovery for drying pulverized coal by using inert gas as the cooling medium was proposed. The influence of initial temperature, water content, flow rate of different circulation media (nitrogen, carbon dioxide, flue gas, and coal gas) on the temperature of quenching semi-coke and preheated coal was studied by system simulation. The effect of water-saving and energy-saving was analyzed, and the model test based on 10000-ton pulverized coal pyrolysis was carried out. The results showed that the technology of waste heat recovery from dry quenching of semi-coke was feasible. The temperature of semi-coke after coke quenching and the outlet temperature of preheating coal have no significant relationship with the type of cooling medium but were closely related to the cooling medium's specific heat. Compared with the wet quenching, the dry process had a significant energy-saving effect and zero water consumption, which could reuse 65%—75% of the sensible heat of semi-coke while meeting the process requirements. Theoretical analysis and experimental results showed that dry quenching waste heat recovery had a good application prospect.

NiO-CeO₂/γ-Al₂O₃ oxygen carrier was prepared with the impregnation method and the effects of Ni/Ce mass ratios on the performance of chemical looping reforming hydrogen production were studied. The experiments with fixed bed reactor revealed that the selectivity of hydrogen first increased and then decreased as the ratio decreases. For the ratio of 3∶1, there was a maximal selectivity of hydrogen together with the highest concentration of hydrogen produced. The cycle test showed that the 3∶1 oxygen carrier still maintained good reaction activity and the lowest carbon deposited after 20 cycles. Meanwhile, the XRD results showed that addition of CeO₂ was leads to formation of Ce-O-Ni solid solution, which weakened the interaction between NiO and γ-Al₂O₃ to a certain extent, and subsequently increased oxygen vacancies and improved the dispersion of active materials. Further analyses on the XRD results indicated that the 3∶1 oxygen carrier had the smallest particle size, which was more conducive to hydrogen production by reaction. In fact, the microscopic morphology of the 3∶1 oxygen carrier particles only changes slightly after 20 cycles of testing according to SEM analyses. The further fixed bed experiments indicated that higher temperature was conducived to the hydrogen production reactions and the 3∶1 oxygen carrier performed significantly better than the others. Meanwhile, it was found the 3∶1 oxygen carrier could still maintain high product selectivity under higher water-to-carbon ratio.

Hydrogen is a clean and green fuel and energy source. Its production through reforming reaction is currently one of the mature processing technologies in chemical industries. Ni-based catalysts have attracted extensive attentions of researchers because of their high availability, high activity and low cost. However, the deactivation of catalysts often occurs due to sintering, carbon deposition and poisoning during the reaction. How to improve the stability of the Ni-based reforming catalysts is still a problem to be solved. In this paper, three main reasons for the deactivation of Ni-based reforming catalysts are summarized. In addition, the research progress in improving the reaction performance and the stability of Ni-based reforming catalysts in recent years is reviewed from the aspects of the regulation of size and nanostructure of Ni particle, enhancement of the metal-support interaction as well as the formation of lattice oxygen or surface oxygen species. Finally, it also shows that the optimization of reaction conditions, adjusting the chemical composition and tailoring the nanostructure of Ni particle can be used to improve the stabilities of Ni-based catalysts in the reforming reaction.

Fluid catalytic cracking (FCC) is the most important secondary processing process in refineries, and also the second largest source of propylene in petrochemical applications. Adding propylene production-increasing additives, mainly composed of active component ZSM-5 zeolite and matrix, to FCC catalyst is a flexible and efficient method to increase propylene yield. In this paper, the research status of additives for increasing propylene production is introduced from two aspects of active component ZSM-5 zeolite and matrix. The modification of ZSM-5 zeolite is used to improve the performance of active component, which is by adjusting the acidity, improving pore structure and particle size, and improving hydrothermal stability of zeolite. The important effects of structure and acid gradient distribution of matrix in improving feedstock conversion, reducing coke formation and increasing propylene production in FCC process is analyzed. Finally, it is pointed out that introducing modification elements in the synthesis of zeolite can reduce the loss of elements, improve the utilization rate of modified elements. At the same time, there are still some deficiencies in the research of additive matrix. The development of high-performance matrix with low cost, large pore size and suitable acidity is also the future research direction of additives for increasing propylene production.

The SAPO-34 zeolite catalyzed methanol to olefins (MTO) process has been shown of practical significance. Recent study has demonstrated that steam regeneration is superior to air combustion in terms of CO₂ emission reduction and light olefins selectivity enhancement. In this work we investigated the effect of regeneration time on the steam regeneration of spent catalyst used in MTO process. The crystal structure, acidity, residual coke properties and structural parameters of the catalyst samples regenerated under different regeneration time were characterized by XRD, NH₃-TPD, FTIR, TGA, GC-MS and N₂ physical adsorption-desorption. The results showed that the increase of regeneration time would reduce the amount of residual coke on the regenerated catalyst, and yield better recovery of the acidity, BET surface area and pore structure of the catalyst samples, which could prolong catalyst's lifetime. Furthermore, it is shown that the residual coke species on the catalyst changed from pyrene and phenanthrene to naphthalene during the steam regeneration. However, the soluble residual coke species decreased with the extension of regeneration time, which would reduce the selectivity of light olefins at the beginning of MTO reaction.

The Pd or Cu-Pd modified S-1 catalyst was prepared by an equivalent volume impregnation method. A dielectric barrier discharge (DBD) plasma reactor was used to study the nonoxidative conversion of methane to light olefins (C₂—C₄⁼), focusing on the production of ethylene. The effects of the Ar addition and specific input energy (SIE) on methane conversion and product distribution were investigated. The experimental results showed that the catalytic performance of plasma-catalyst cooperation was better than that of plasma-only mode. The selectivity of ethylene was increased by a factor of 3.1 and the selectivity of C₂—C₄⁼ was increased by a factor of 2.7. Compared with S-1, Pd/S-1 provided higher ethylene selectivity. This is because the metal Pd supported on S-1 promoted the in-situ hydrogenation of acetylene to ethylene. The suitable Pd loading was beneficial towards achieving higher olefins selectivity, while excessive Pd loading caused continuous hydrogenation of unsaturated hydrocarbons so that the production was alkanes. Compared with single metal Pd modification, Cu-Pd bimetal modification inhibited further hydrogenation of ethylene and improved the selectivity of ethylene. The catalysts were characterized by using SEM, TEM, HRTEM, XRD, XPS. The results showed that the addition of Cu transferred its own electrons to Pd, which increased the electron density of Pd. In addition, the presence of Cu improved the dispersibility of Pd. Better reaction performance were obtained with the 2Cu-0.1Pd/S-1 catalyst.

A series of citric acid (HCA) modified H-beta zeolites were prepared and characterized by XRD, SEM, TEM, FTIR, N₂ physical adsorption and desorption, NH₃-TPD, and Py-IR. The experimental results showed citric acid treatment did not damage the skeleton structure of H-beta, but had the function of both dealuminization and realuminization. The channel was more open due to removal of non-framework aluminum. Though the total acid decreased, the content of medium strong acid and Bronsted acid were increased, therefore the catalytic activity was enhanced. However, high concentration of citric acid removed the skeleton aluminum, damaging the lattice structure and reducing the catalytic activity. The performance assessment of catalysts in butylation of toluene showed that the suitable citric acid concentration for the modification was 0.25mol/L. The highest conversion of toluene could reach 67.0% and the selectivity of PTBT was 80.4% under 0.25HCA/H-beta.

MoS₂ catalysts supported on reduced graphene oxide (MoS₂/rGO) were synthesized through hydrothermal process. The nanostructure parameters including stacking layers, slab length, and dispersion were characterized by scanning electron microscopy with energy dispersive X-ray spectroscopy, X-ray diffraction, Raman spectroscopy and high-resolution transmission electron microscopy. The results indicated that the hydrothermal synthesis method could successfully load MoS₂ over the surface of rGO support, and adjust the catalytic active sites of MoS₂ by tuning the Mo precursors. Polycyclic aromatic hydrocarbon anthracene was used as the model compound of heavy oils to evaluate the catalytic hydrogenation performance of the MoS₂/rGO catalysts. The MoS₂/rGO-ATTM catalyst, synthesized with ammonium tetrathiomolybdate as Mo precursor by the hydrothermal method, demonstrated an extremely high anthracene hydrogenation conversion of 55.1% and a high selectivity to octahydroanthracene of 86.6%, which were respectively 2.0 times and 4.2 times as high as those of the IM-MoS₂/rGO catalyst synthesized by impregnation method. The catalytic hydrogenation activities of MoS₂/rGO catalysts were not related to their surface area, but depended on their stacking layers and slab lengths. The excellent catalytic activity of the MoS₂/rGO-ATTM catalyst may be ascribed to the high exposure of hydrogenation active sites, the enhanced dispersion of MoS₂ nanosheets in the catalyst, and the good suspension of the catalyst in the reaction mixture.

Microwave heating technology has been widely used in many fields, such as chemical strengthening, metal smelting, ceramic sintering, food processing and so on, because of its advantages of green environmental protection, volume heating and selective heating. However, there are many problems in microwave reactor, such as poor transmission effect and low utilization rate of microwave. With the continuous development of microwave heating technology, more and more attention has been paid to the selection of wave-transmitting materials in microwave heating equipment. This research mainly reviewes the application status of wave-transmitting materials in the field of microwave heating. The types of wave-transmitting materials are briefly introduced, and the microwave heating containers and thermal insulation materials are discussed. The research progress of high-temperature wave-transmitting materials such as oxides, nitrides, silicates and phosphates, and medium and low-temperature wave-transmitting materials such as polytetrafluoroethylene, glass fiber reinforced resin base and epoxy resin are introduced in detail. It also specifically discusses the dielectric properties and wave-transmitting properties of various ceramic fiber products such as fiber cotton, fiber blankets and fiberboards commonly used in microwave heating. Finally, this article points out the current common problems of wave-transmitting materials for microwave heating, and prospected the application and development of wave-transmitting materials.

Pressure-driven ultrafiltration membranes suffer from the trade-off between permeability and selectivity, as well as membrane fouling during filtration. Porous nanomaterials are an important category of additives in ultrafiltration membranes modification and also a research hotspot of novel functional membranes for water treatment. It has been reported that the introduction of porous nanomaterials into the ultrafiltration membrane has the potential to overcome the permeability-selectivity trade-off effect by simultaneously enhancing the membrane permeability and contaminants rejection efficiency thanks to the provision of extra water channels as well as the creation of highly selective nanochannels by the adjustable pore size. Meanwhile, the incorporation of hydrophilic porous nanomaterials is beneficial to improve the antifouling properties of ultrafiltration membranes. In this paper, the modification methods and the research progress of ultrafiltration membranes modified by porous nanomaterials including microporous zeolites, mesoporous carbon, mesoporous silica, metal organic frameworks (MOFs) and covalent organic frameworks (COFs) for water treatment are reviewed. The modification effects of different porous nanomaterials are evaluated based on the membrane hydrophilicity, permeability and antifouling property. Finally, perspectives of research and application on ultrafiltration membranes modified by porous nanomaterials for water treatment are proposed.

Graphene has a variety of excellent properties, however, it is easy to aggregate to restack into graphite by π-π stacking and van der Waals force. In order to solve the stacking problem and improve the applicability of graphene materials, graphene and its derivatives have been combined with magnetic nanoparticles to obtain new functional materials with high performance. Based on the recent internal and international research works, the preparation methods of magnetic graphene nanocomposites such as hydrothermal, solvothermal, chemical grafting and microwave-assisted methods are summarized. The application of magnetic graphene composite materials in the separation and enrichment of environmental samples, catalysis, corrosion resistance of coatings, wave-adsorbing material and energy area are introduced. Some problems of magnetic graphene composite materials, such as the tendency to agglomeration of magnetic particles, the verification of its biological safety and the reduction of adsorption sites led by graphene oxide reduction are pointed out. At present, the preparation technology of graphene (oxide) is improving and the most important research in the future is the surface modification of magnetic graphene, which can make the surface of graphene have more adsorption sites, and also lead to the more uniform morphology and distribution of magnetic nanoparticles on graphene surface, being conducive to the stable play of the functional properties of magnetic graphene.

Phase change materials (PCM) show high energy storage density, which is conducive to the storage and efficient utilization of energy. For low temperature phase change materials, their applications range can be from air-conditioning and construction industrial to industrial refrigeration, transportation and storage of food and medicine. This paper provides a systematic introduction to phase change materials for subzero applications, and reviews recent research on phase change materials for subzero applications from the perspectives of supercooling, chronic stability and thermal conductivity. In view of the severe supercooling of the aqueous PCM systems and metal corrosion of salt solution, the relevant research in recent years show that these problems can be solved by using suitable nucleating agents and improving the compatibility between the PCM and the nucleating agent, avoiding nanoparticles agglomeration and encapsulating PCM with stainless steel or polymer materials. The problem of low thermal conductivity of non-aqueous PCM systems can be solved by introducing nanoparticles and supporting materials with high thermal conductivity or encapsulating PCM. Finally, as for the aggregation of nanoparticles and the latent heat loss caused by the introduction of support materials and microencapsulated PCM, it is worth trying to improve the compatibility of nanoparticles and support materials with PCM.

The porous g-C₃N₄-based photocatalysts have broad application prospects due to their unique properties such as large specific surface area, abundant surface reaction active sites and short electron transfer pathway, which can well overcome the disadvantages as compared with the bulk g-C₃N₄ including low specific surface area, fast recombination possibility of photogenerated electron-hole pairs and low utilization of visible light. In the review, the general synthetic strategies applied to prepare porous g-C₃N₄-based photocatalyst, such as hard template method, soft template method, hydrothermal methods, thermal polymerization and supramolecular self-assembly, are briefly introduced. Besides, the potential applications of porous g-C₃N₄-based photocatalyst in photocatalytic water splitting, photocatalytic degradation of organic pollutants, photocatalytic CO₂ reduction and photocatalytic NO_x abatement are discussed in detail. Finally, several comments to the challenges and the development trends of porous g-C₃N₄-based photocatalyst are also prospected.

Heavy metal pollution is still a major challenge around the world. Traditional treatment methods have unqualified to the sustainable development strategy due to high cost, environment pollution, low efficiency, etc. Cellulose nanofibers (CNF) have a bright application prospect due to rich sources, renewable, high activity, large specific surface area and low density, which has been widely applied in environment, food, agriculture fields for the adsorption of heavy metal in recent years. In this paper, the chemical modification methods of CNF and the application progress of the modified products in the adsorption of heavy metal ions in water system are reviewed. Firstly, the modification of CNF is summarized systematically, including chemical graft modification (carboxylation, amination, hydrophobicity, phosphorylation, sulfonic acid group, aldehyde group, silanization, etc.) and graft copolymerization modification. Secondly, from the aspect of structural design, the application of modified CNF in adsorption of heavy metal ions in water system by different forms such as aerogel, hydrogel and composite membrane is emphatically expounded. Finally, the advantages and disadvantages of CNF-based heavy metal adsorbents are discussed, the limitations and applicability of CNF-based heavy metal adsorbents are pointed out, and the development direction of CNF in the field of heavy metal ion removal in water system is prospected.

The effect of the solvent systems which composed of different ratios of acetone (AC)/dichloromethane (DCM) on the foam-transfer process and properties of PS microspheres were investigated, and the corresponding mechanisms were interpreted. It was found that by increasing the concentration of AC, the foaming temperature increased; while the average particle size of the polystyrene microspheres decreased with narrower particle size distribution and the structure of the PS microspheres evolved from the porous to the hollow. The change on the properties of polymer microspheres was mainly due to the migration of AC from the dispersed phase to the continuous phase, which not only decreased the surface tension but also altered the evaporation process.

Hollow mesoporous silica nanoparticles (HMSNs) with high specific area were prepared by aerosol assisted self-assembly technology using tetraethyl orthosilicate (TEOS) and methyltrimethoxysilane (MTES) in different molar ratio as mixed silicon sources, and applied to proanthocyanidin (PC) loading in order to improve their bioavailability. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), infrared spectroscopy (FTIR) and particle size analysis (DLS) were used to investigate the formation process, structural characteristics and loading performance of the carrier particles. The surface area of HMSNs was calculated based on the (BET) analysis and the pore size distribution was also analyzed. The results showed that the active intermediate hydrolyzed by the precursor solution condensed into a silica network structure, and the atomized aerosol droplets self-assembled into a spherical structure at the radial concentration gradient. The synergistic action of the hydrolyzation-condensation process and the self-assembly process led to formation of the mesoporous silica (MSNs) with good dispersive properties. After annealing and purification, the template NaCl and the surfactant hexadecyl trimethyl ammonium bromide (CTAB) were removed, and the HMSNS with hollow structure were finally obtained. When the molar ratio of TEOS/MTES was 60/40, the generated HMSNs had a maximum specific area of 1083m²/g with a large pore volume of 0.37cm³/g, the pore size was distributed between 2—4nm and the loading capacity of PC in HMSNs was as high as 30.7mg/g.

With advanced properties of high-temperature resistant and high strength, semi-aromatic nylon has been widely used in electronic appliances, automobiles, rail transit and special equipments. However, conventional synthesis methods have long-standing technical problems of semi-aromatic nylon with a long preparation cycle and wide molecular weight distribution. In this paper, the rapid and uniform heating under microwave conditions was used for the first time to provide a new solution to these problems though preparing high-temperature resistant semi-aromatic nylon PA12T. The influence of polymerization conditions such as the amount of water used as the wave-absorbing medium, reaction temperature and reaction time on the molecular weight of the polymerized product under a closed system were investigated. The results showed that microwave-assisted polymerization took one third of the time comparing with the traditional method and the product had the narrower molecular weight distribution than conventional polymerization. This method provided a valuable reference for the further study of high efficiency polymerization of semi-aromatic nylon and the design and improvement of microwave reactor.

Three-dimensional interconnected CuGeO₃ nanosheets were directly grown on nickel foam (NF) substrates by in-situ generation method, and the CuGeO₃/NF was directly used as binder-free anodes for lithium ion batteries (LIBs). The microstructure and morphology of the materials were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscope. Electrochemical performance of CuGeO₃/NF and CuGeO₃ electrode was investigated. The results indicated that CuGeO₃/NF electrode exhibited better electrochemical performance in comparison with CuGeO₃ electrode. The CuGeO₃/NF electrode showed reversible capacity of 972mA·h/g at a current density of 0.2A/g after 500 cycles with capacity retention of 94.1% when the current density returned to 0.1A/g from 1A/g (578mA·h/g). CuGeO₃/NF electrode delivered a high capacity of 936mA·h/g. The superior electrochemical performance of the CuGeO₃/NF electrode can be attributed to three-dimensional conductive network of the Ni foam. Additionally, the Ni foam supported CuGeO₃ nanoflakes promoted fast electron and ion transport, and alleviated the volume change during the Li⁺ insertion/extraction process.

It is urgent to develop transparent electrochemical energy storage devices such as transparent supercapacitors for wearable and portable electronic devices. The carbonized leaf vein is composed of a continuous carbon fiber network, which has the advantages of very good transparency, good conductivity and light weight. In this paper, we used carbonized leaf vein network as current collector to directly grow Ni/Co-based metal organic frameworks (MOFs) by using a solvothermal method. The continuous carbon fiber network of carbonized leaf vein can provide pathways for continuous electron and ion transportation. The mixed metal centers in Ni/Co-MOF are beneficial to provide more electrochemical sites for charge storage. The prepared transparent carbonized leaf vein network@Ni/Co-MOF electrode exhibited a high areal capacity of 1.15F/cm² at a current density of 1mA/cm². In addition, its capacity retention rate after 1000 cycles was 105.4%, indicating a good cycle stability. The transparent asymmetric transparent supercapacitor was assembled by carbonized leaf vein@Ni/Co MOFs and carbonized leaf vein@activated carbon, which achieved an areal capacitance of 0.47F/cm² and an areal energy density of 0.61W·h/cm² in a wide potential range of 0—1.6V and at a current density of 1mA/cm². Moreover, the supercapacitor exhibited a good cycling stability with an areal capacitance retention rate of 93.6% after 300 cycles. The method presented here provides a new way for the preparation of transparent functional devices such as sensors, optoelectronic devices, solar cells and lithium-ion batteries.

Adding traditional styrene butadiene latex can greatly improve mechanical properties of the cement. However, the modified cement material has poor fluidity and loss of compressive performance. In order to improve the fluidity of the cement after adding styrene butadiene latex and reduce the loss of compressive performance, the styrene-butadiene latex was modified, styrene and polybutadiene were used as the core layer, and sodium p-styrene sulfonate with benzene ring as the shell layer to prepare the SSBR latex. After adding newly synthesized SSBR latex to the cement , the mechanical properties of the cement were characterized. Since the benzene ring rigid chain is connected to the sulfonate in the SSBR latex, the steric hindrance effect is obvious, and the fluidity index of the cement slurry with 8% SSBR latex increased to 0.898. The molecular chain strength was large, the 7-day compressive strength loss of cement stone was 2.31%, at the same time, the flexural strength was increased by 17%. The mechanism of the mechanical properties of SSBR latex modified cement-based materials was explored. The results showed that SSBR latex has obvious filling effect, strong adsorption effect, and increases the fluidity of cement slurry, and it can complex with Ca²⁺ to form a three-dimensional network structure, increase the strength of the mechanical properties of the cement stone, improve the toughness, so as to achieve the purpose of enhancing the mechanical properties of the cement stone.

Studying on the adsorption and controlled release behavior for the molecularly imprinted polymers is of great theoretical and applied value. In present work, a thermosensitive diosgenin imprinted silica microsphere (TMIP) was prepared by a surface imprint technology using silylated silica as the carrier, diosgenin as the template, methacrylic acid(MAA) and N-isopropylacrylamide(NIPAm) as common functional monomers, ethylene glycol dimethacrylate as the cross-linker and azodiisobutyronitrile(AIBN) as the initiator. Superficial chemical groups and particle morphology for this TMIP were characterized by using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). Loaded capacity and controlled release behavior for this TMIP toward diosgenin under different environmental conditions were tested. Results showed that the imprinted microspheres had higher adsorption capacity toward diosgenin, with a saturated adsorption capacity of 21.6mg/g. It was indicated from drug release dynamics that while the imprinted microspheres emerged a high controlled drug release capability, with a diosgenin-releasing percentage of 81.9% within 12h, the non imprinted silica gel microspheres had no sustained-release property. Environmental conditions also had great influence on the controlled release of thermosensitive imprinted silica microspheres, with the maximum release rate of 99.28% when release was performed at 303K in methanol solution with a NaCl-controlled ionic strength of 1.5×10^-4mol/L.

The keratin/polylactic acid nanofiber membrane was surface modified by ultraviolet-induced dopamine oxidation and self-polymerization to improve the problems of poor hydrophilicity, insufficient mechanical properties and low cell activity. Through scanning electron microscope, Fourier transform infrared spectroscopy, thermogravimetric analysis, contact angle experiment, electronic universal testing machine, cell activity toxicity experiment and cell adhesion experiment, the morphology, structure, and thermal stability of the nanofiber membrane before and after surface modification Properties and thermal degradation rate, hydrophilicity, mechanical properties, cell activity toxicity and adhesion were tested and characterized. The results showed that: polydopamine successfully adhered to the surface of the fiber, the average diameter of the modified fiber increased from (356±78)nm to (507±98)nm, the contact angle decreased from 103.34? to 82.46?, the modulus of elasticity and fracture the elongation increased by 2.75—5.33MPa and 31.75%—51.50% respectively, and the cell viability increased from 72% to 221% after 24h inoculation, an increase of 149%.

A series of novel YM demulsifiers, synthesized by polyether（YM）, maleic anhydride（MA）, sodium styrene sulfonate（SSS）, and acryloxyethyltrimethylammonium chloride（DAC）, were applied for SAGD produced liquid separation of Xinjiang heavy oil. The structures of the products were characterized by FTIR、¹H NMR, and GPC. The effect of products on the separation of SAGD produced liquid was investigated by interfacial tension, zeta potential, and backscattered light intensity analysis. The results showed that ester groups and sodium benzenesulfonate anionic groups in YMA and YMB weakened the binding strength between dispersion asphaltenes and reduced interfacial film strength and interfacial tension, which lead to a reduction of oil-water interfacial tension. The cationic group of acyloxyethyltrimethylammonium chloride in YMB dropped the absolute value of zeta potential of SAGD produced water. The backscattered light intensity of SAGD produced liquid decreased by 1.36%, 4.52% and 5.63%, respectively when adding YM, YMA and YMB, which meant YMB demulsifier had the best effect on reducing the stability of SAGD produced liquid. The YMC obtained by the combination of YMB and acetic acid had a better dehydration effect. Under the optimized separation conditions of SAGD produced liquid, a satisfactory separation result could be achieved with the addition of YMC.

Anaerobic ammonium oxidation coupled to iron reduction, termed as Feammox, is a novel autotrophic nitrogen removal technology with cheap and available iron as the electron donor. The technology is a potential denitrification approach in fields such as natural systems and sewage treatment systems due to its significant advantages such as no need for organic carbon sources, low cost, low sludge output, and no greenhouse gas emission. The production and development of Feammox are focused, and the reaction mechanism and the microorganisms are introduced in detail. The microorganisms playing a major role in the Feammox process are a type of iron-reducing bacteria that can drive ammonia oxidation; the influencing factors such as pH, temperature, DO, organic matter, iron content are analyzed. The relationship between nitrogen loss pathways such as FeNiR, Anammox and denitrification are discussed. Finally, the challenges that Feammox still faces and future development trends are pointed out. The future research direction of Feammox shall be rapid enrichment and separation and purification of bacteria, control parameters, and interaction with other denitrification pathways.

Vehicle exhaust is one of the most important sources of NO_x emission. However, the common NO_x reduction techniques of diesel vehicle exhaust have poor performance during the cold start, so passive NO_x adsorbent (PNA) has been proposed. PNA can adsorb NO_x at low temperature and desorb NO_x at high temperature, then the released NO_x is thoroughly purified by downstream NO_x treatment unit, such as selective catalytic reduction (SCR) or storage reduction (NSR). This review summarizes the recent progress of PNA materials for NO_x purification during cold start at low temperature, and compares the structure and properties of different types of PNA materials. Among them, Pd/zeolites show good NO_x adsorption-desorption performance at low temperature, high sulfur resistance and hydrothermal stability. Further, Pd/zeolites are discussed in depth, including the NO_x storage mechanism and the influence factors. Finally, the problems of PNA in the low-temperature adsorption-desorption of NO_x are analyzed and the prospects are also outlooked. It is pointed out that increasing the number of NO_x adsorption sites with excellent water resistance and the Pd species dispersion are the important prerequisites for the development of high-performance PNA.

As a by-product of desulfurization, sulfite has the advantages of low price, low toxicity and simple preparation. It can be activated to produce sulfate radicals (SO{}_{\mathrm{4}}^{·-}), sulfite free radicals (SO{}_{\mathrm{3}}^{·-}), peroxysulfate radicals (SO{}_{\mathrm{5}}^{·-}), hydroxyl radicals (OH^?) and many other active substances with high oxidation potential to oxidize and degrade various organic pollutants quickly and efficiently. Therefore, sulfite is regarded as a more economical and environmentally friendly alternative to persulfate. This article reviews the research progress of sulfite activation technology, including transition metal ion activation, ultraviolet light radiation activation and oxygen-containing metal acid salt activation, etc.. The mechanism of sulfite activation such as the radical chain reaction of transition metal activated sulfite and the formation of free radicals by ultraviolet radiation sulfite photolysis is introduced in detail. The research status of sulfite advanced oxidation process for the treatment of various organic wastewater is summarized. At present, this technology has significant effects in the treatment of a variety of refractory wastewater, but most of the research is still at the experimental stage and the treatment object is single. There is little research on actual wastewater treatment.

A low-cost, easy-to-recycle, green and pollution-free biochar/geopolymer composite film (BC/GM) was prepared by in-situ synchronous carbonization and self-activation with alkali lignin, metakaolin and slag for the catalytic degradation of tetracycline antibiotics in water. The morphology and physical and chemical properties of BC/GM were analyzed by SEM, XRD, FTIR and XPS. The effects of water glass modulus, alkali lignin content and calcination temperature on the degradation efficiency of tetracycline hydrochloride by H₂O₂ were investigated. The results showed that the geopolymer inorganic film (GM) not only acted as a porous carrier to facilitate the recycling of biochar and prevent the biomass precursors from direct carbonization and coking , but also helped to realize synchronous self-activation of alkali lignin precursor in the process of in-situ carbonization. When the water glass modulus was 1.2, the removal rate of alkali lignin was 0.2mL and the calcination temperature was 600℃, the removal rate of H₂O₂ catalyzed degradation of tetracycline hydrochloride by BC/GM reaches 92.55%, which was 40% higher than that of biochar. The graphitized carbon in BC/GM had a porous structure, which contributes to the generation of ?OH, and eventually realized the efficient degradation of tetracycline hydrochloride.

Lead acid batteries are widely used in China, and there are some problems in the traditional recovery process, such as environmental pollution, high energy consumption and long recycling process. Therefore, solution synthesis of PbO has attracted people's attention. Based on the solution synthesis of PbO from lead acetate solution and NaOH, two crystal forms of PbO, α?-PbO(litharge) and β?-PbO(massicot), were synthesized by changing the way NaOH was added. The synthetic conditions, intermediate process and mechanism were preliminarily discussed. Lead acetate solution prepared by simulated desulfurization lead paste was used as raw material and the effects of NaOH dosing mode, reaction temperature, reaction time and mole ratio of NaOH to Pb were explored, respectively. The results showed that the intermediate products Pb₃O₂(OH)₂ was synthesized firstly and then decomposed into PbO quickly. A more stable product α?-PbO was synthesized with the participation of exothermic process of NaOH dissolution. Therefore, two crystal forms of PbO, α?-PbO and β?-PbO, could be synthesized by changing the dosing mode of NaOH. The optimized conditions to obtain α?-PbO were as follows: the temperature was 95℃, the NaOH particles quickly mixed with equal mass of deionized water and then added, the molar ratio of NaOH/Pb_{was 2.50, and the mixture was stirred under the given temperature for 20min; The optimized conditions to obtain β-PbO were as follows: temperature of 95℃, adding 50% NaOH solution prepared one day in advance, the molar ratio of NaOH/Pbwas 2.50, and stirring for 20min under the given temperature. This study can provide theoretical reference for the synthesis of α-PBO and β-PBO in liquid phase by wet recovery of waste lead-acid battery.}

Burning Shenhua coal with three typical industrial organic solid wastes in a laboratory atmosphere furnace to get the mixed ash sample as the research object, through the appearance analysis, melting temperature analysis, X-ray diffraction pattern analysis (XRD) and scanning electron microscope coupled X-ray energy spectrum analysis (SEM+EDS), the slagging characteristics and slagging mechanism of solid waste and coal coupled fuel in air atmosphere were studied. The results showed that compared with raw coal ash, activated carbon and medicine slag significantly reduced the melting point of mixed ash and promote slagging; resin increases the melting point of mixed ash and was not easy to slag and melt. After adding activated carbon and medicine slag, more low-melting substances such as nepheline and sodium/potassium feldspar were produced in the mixed ash, which are easily combined into a low-temperature eutectic containing sodium potassium silicate and inhibit the mullite generation. The medicine slag contained a large amount of phosphorus-containing minerals such as aluminum phosphate and calcium iron phosphate, which are easy to form a low-temperature eutectic of amorphous glass phase with calcium-containing minerals and hematite. Under the same conditions, the slagging phenomenon of the added medicine slag was more serious than activated carbon. A large amount of high melting point substances such as mullite were generated in the mixed ash after the resin was added, which together with alumina and quartz construct the "skeleton" of the ash, and maintain good slag resistance characteristics. In general, it was feasible to blend 20% of the resin in Shenhua coal. For activated carbon, the blending ratio should not be higher than 10%, and the dregs of a decoction should be less than 5%.

Metal contamination is an important factor leading to the deactivation of fluidized bed catalytic cracking (FCC) catalyst, and making full use of the deposited heavy metals is the key to utilization the spent FCC catalyst. In this paper, the waste FCC catalyst was proposed for the adsorption desulfurization of light oil. The removal of dimethyl disulfide in LPG was taken as the target to test the feasibility of using the spent FCC catalyst as desulfurizer. After removing the deposited carbon on the spent FCC catalyst surface, the desulfurization performance was improved obviously. Under the conditions of normal temperature and mass space velocity of 4.0h^-1, the sulfide mass fraction in LPG was reduced from 382mg/m³ to 40mg/m³. The total mass fraction of lanthanum, iron, nickel, vanadium, calcium and antimony was increased from 10.2% in fresh catalyst to 46.6% in the calcined spent catalyst. The desulfurization ability was significantly improved after immobilizing the six metals on fresh catalyst separately. Results showed that the metals which lead to the deactivation of FCC catalyst had high desulfurization activity, and the utilization of spent FCC catalyst in LPG adsorption desulfurization has a good industrial application prospect.

Boron removal is important for the sustainable development of unconventional oil/gas resources. Electrocoagulation as an environmentally friendly technology has attracted more and more attention in recent years. From the perspective of electrochemistry, the electrochemical performance of different electrodes is different, which affects the coagulation performance. However, as an economical and effective electrode material, the effect of different iron-based electrodes on boron removal has not been systematically studied until now. In this work, different iron-based electrodes were used to investigate their boron removal performance in electrocoagulation. The flocs were characterized by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) to explain the reasons for the performance discrepancy of boron removal. The results showed that under the same conditions, boron removal efficiency of stainless steel was about 17%, which was about 10% higher than that of carbon steel. When stainless steel electrode was used, the content of Fe³⁺ in the medium was 43%, while it was only 30% when carbon steel was used. The flocs had more dispersed and loose shape, and the particle size distribution was more uniform by using stainless steel. They were both conducive to obtain better coagulation effect.

In order to solve a large amount of refining sludge produced in the process of oily wastewater treatment in refinery, the refining sludge was treated by thermochemical-washing, the effects of different types of alkaline inorganic salts and surfactants on the oil removal efficiency of refining sludge were investigated, and the hot washing process conditions were optimized. The results showed that sodium silicate (Na₂SiO₃) has the best degreasing effect in single hot washing agent, and the degreasing rate was up to 40.3%. Sodium silicate sodium fatty alcohol polyoxyethylene ether sulfate (AES)?-octylphenol polyoxyethylene ether (OP-10) had the best oil removal rate of 58.2%. The results of orthogonal experiment showed that the influence of chemical hot washing process conditions on oil removal rate was as follows: reagent concentration>hot washing temperature>hot washing time>sludge-water ratio>stirring rate. The optimum operating condition was agent concentration 3g/L, washing temperature 80℃, thermal washing time 60min, stirring speed 300r/min and sludge-water ratio 1∶6, the oil removal rate was 75.1%. Gas chromatography analysis showed that the composition of crude oil decreased significantly before and after hot washing, shorter component(C₁₂—C₂₀), medium length component(C₂₁—C₃₀), and longer components(C₃₁—C₃₆)removal rates were 57.8%, 86.2% and 98.0%, respectively. The removal efficiency of long chain alkanes(C₃₁—C₃₆)was the best. After the hot washing agent was reused for 3 times, the oil removal rate was still more than 40.8%.

Daqing tank bottom sludge is a kind of sludge with high oil content and great resource recovery potential. It also has the characteristics of high viscosity, strong adhesion, complex composition and slow natural settlement. In this study, the pyrolysis characteristics and pollutant release characteristics of high oil sludge in Daqing were investigated. The quality and composition of gas/liquid/slag three-phase products under different final pyrolysis temperature and heating rate were tested. The results showed that the amount of C₂H₄ released from pyrolysis gas was significantly higher than that from other gases. CO₂ gas only had a peak value at 700℃, and H₂ was released before 700℃, and a large amount of H₂ was released between 700℃ and 800℃; the increase of final pyrolysis temperature and heating rate will lead to a large number of low chain hydrocarbons, and medium chain hydrocarbons showed a trend of first increase and then decrease; final pyrolysis temperature would have a certain effect on SiO₂ and CaCO₃ in solid products, while heating rate has little effect on solid products influence. The release characteristics of N, S and Cl small molecule pollutants in gaseous products were measured by on-line flue gas analyzer. HCN and NH₃ were the precursors of NO_x and convert to NO_x at 600℃; most of the chlorinated compounds would be released below 600℃; sulfur pollutants were released in two peaks, and the peaks above 600℃ were mainly due to the decomposition of sulfate.

In view of the environmental toxicity and potential value of engineered nanoparticle (ENP) in water, the efficient enrichment and recovery of ENP is an important subject for its resourceful treatment. This paper developed a flotation method based on the intensified foam drainage for ENP enrichment and recovery to break the technical bottlenecks of its low enrichment and difficult subsequent separation. Using titanium dioxide nanoparticle (TNP) as the research target and cetyltrimethylammonium bromide (CTAB) as collector and foaming agent the regular-hexagon hollow prismoid (RHP) internal was constructed. Its effect of intensified drainage was discussed in terms of liquid holdup, bubble diameter and enrichment ratio and the mechanism was analyzed. The results of experiments showed that the enrichment ratio and recovery percentage of TNP reached 48.3±2.4 and 98.2%±4.9%, respectively, under the conditions of RHP internal installed in the middle of the foam phase with pH value 9.0, CTAB concentration 100mg/L and airflow rate 250mL/min. The liquid holdup of flotation process was reduced by 72.1%, while the enrichment ration of TNP was increased by 68.9% compared with those without RHP. In conclusion, this flotation method developed in this paper provided important theoretical guidance and technical support for effective treatment of ENP water pollution.

The mechanism of catalytic oxidation degradation of organics in high salt wastewater of coal chemical industry by ozone was studied. Firstly, the high-salt wastewater of a typical coal chemical enterprises in China was collected, and the composition and content of various salt ions in the water were determined. Secondly, the effects of different active components on the efficiency of ozone catalytic oxidation were studied to screen the best ozone catalyst. Characterization analysis was carried out on the ozone catalyst to determine the apparent morphology, element composition and active component loading of the catalyst. Finally, the simulated water sample with formic acid was used to study the action mode of ozone catalytic oxidation, the change of ozone attenuation rate, the change of hydroxyl radical(·OH), H₂O₂ and superoxide radical (·O₂^-) to reveal the action mechanism and reaction process of ozone catalytic oxidation. The results showed that the cations of the high-salt wastewater from coal chemical industry were mainly sodium ions, followed by potassium ion, calcium ion, and magnesium ion. The anions were mainly chloride ions and sulfate ions, followed by nitrate ions. By studying the effect of different active components on the ozone catalytic oxidation efficiency, we found the best catalyst was SiO₂/Al₂O₃-Fe₂O₃. The characterization analysis of the catalyst showed that the catalyst's support was SiO₂/Al₂O₃, and iron was loaded on the support as the active component. Through the degradation mechanism study, it was found that the process of ozone catalytic oxidation followed the action mechanism of hydroxyl radical. i.e. O₃ produced hydroxyl radical through attenuation, and the addition of the catalyst promoted the formation of ·OH. The amount of H₂O₂ produced during the reaction was related to·OH. The more·OH, the more H₂O₂ was produced, but the production of·O₂^- was not related to·OH.

Emergency rescue (ER) and emergency evacuation (EE) are two key decisions in the emergency response of chemical industrial parks. In the actual emergency response, due to the simple road network and weak traffic capacity in chemical industrial park (CIP), a road conflict or congestion is likely to occur, leading to evacuation failure or inability of rescue vehicles to leave. To solve the above problems, a two-way route planning method was developed for emergency rescue and evacuation in CIP considering intelligent obstacle avoidance was proposed. A dynamic grid-based environment model was constructed. Aiming at the two stages of emergency response within CIP and the collaborative emergency response inside and outside CIP, the structures and movement rules of the ER agent belonging to CIP (ERB), the EE agent, the ER agent outside entering CIP (EROE) and the ERB agent leaving CIP (ERBL) under different emergency response stage were defined. According to the characteristics of the two stages of emergency response in CIP, two intelligent obstacle avoidance models were proposed to prevent potential road conflicts and congestions. On this basis, the two-way route planning for emergency rescue and evacuation models in two emergency response stages were established. The grid environment of CIP was updated in real time by dynamic grid method. Dijkstra's algorithm was used to simulate and verify the two-way route planning for emergency rescue and evacuation models in emergency response of CIP. The results illustrated that the proposed method was able to generate a set of optimum routes in the two stages of emergency response and overcomes possible road conflicts and congestions successfully.

The application and funding of projects in Chemical Engineering & Industrial Chemistry at National Natural Science Foundation of China (NSFC) in 2021 are summarized. The evolution of projects in Chemical Engineering & Industrial Chemistry are analyzed after the implementation of new discipline codes, which provides a reference for projects applications in the future.