The aqueous wet oxidation desulfurization process has been widely used in the screening of industrial process gas containing H₂S, but there are common problems such as easy degradation of desulfurizer, poor sulfur quality, high output of by-salts and serious secondary pollution. The non-aqueous wet oxidation process constructed with dissolution of inorganic iron salt in organic solvents can not only realize oxidative desulfurization performance, but also has the advantages of eliminating the interference of CO₂ and avoiding the overoxidation of desulfurizer by reactive oxygen species. However, due to the low solubility of iron salts in organic solvents, the development of non-aqueous wet oxidative desulfurization of iron salts is restricted. In recent years, the non-aqueous ionic liquid wet oxidative desulfurization process (Nasil) based on metal-based ionic liquids with good oxidation ability, redox reversibility, chemical thermal stability and super solubility in organic solvents has achieved rapid development. This paper states the necessity and development opportunities of wet oxidation desulfurization aiming at the causes of the problems of aqueous wet oxidation desulfurization process and the current development trend of energy environment. The principle of non-aqueous wet oxidative desulfurization reaction and process intensification with application of iron-based ionic liquids is introduced, and its theoretical developments and application exploration process in the past ten years are summarized from the point of the structural design and composition optimization of metal based ionic liquid desulfurizer. In view of the challenges faced by the current wet oxidative desulfurization technology, it should focus on the urgency of developing new desulfurization ideas. Finally, the prospects for the integration and development of hydrocarbon resources in the desulfurization purification process are put forward.

Currently, with the scarcity of primary energy, the significance of energy utilization efficiency has been gained much attention. Phase change thermal storage can effectively enhance energy utilization efficiency, people have started to combine phase change materials with other substances to further increase their application scope. Nano-titanium dioxide has been widely studied for phase change thermal storage thanks to its low cost, non-toxic, high electrical conductivity, high chemical stability, and high thermal stability, etc. The research progress of nano-titanium dioxide in phase change energy storage field is reviewed, which is mainly divided into the following two parts in terms of function of nano-titanium dioxide in composite phase change materials: (1) the current situation of research on the application of nano-titanium dioxide in shape-stabilized phase change materials; (2) the research progress of nano-titanium dioxide in other functional phase change materials. The aim of this paper is to provide a theoretical basis and reference for further applications of nano-titanium dioxide in phase change energy storage filed.

Ionic liquids (ILs) have excellent electrical conductivity, and their conductivity properties are not only a key property for its electrochemical applications, but also widely used to investigate the thermodynamic properties and microstructure of the mixture containing ILs. Firstly, the recent experimental research progress on the conductivity (κ) or molar conductivity (Λ) of pure ILs, ILs+solvents and ILs+ILs systems are summarized, and the effects of the structure of ILs, temperature, and concentration on κ or Λ are discussed. Combined with the solution thermodynamic model, the changing laws of κ or Λ of ILs are analyzed. On this basis, the application and progress of electrical conductivity properties in studying the ionic rate of pure ILs and the microstructure and interaction of ILs+solvent systems are highlighted. Finally, some suggestions are made on the research and application of the conductivity properties of ILs.

As a complicated natural phenolic polymer, lignin contains abundant functional groups, including hydroxyl groups, carboxyl groups, double bonds, etc., which has drawn significant research and industrial attention for decades. Technical lignins, especially the alkali lignins, are mainly separated from black liquors after alkali or kraft pulping. As the primary lignin resource, technical lignin plays an essential role in current lignin utilization. On account of the variety of functional groups and interunit linkage types between the structural units, the structures of technical lignins from different sources are quite different. In addition, due to the depolymerization and condensation of lignin during the pulping process, technical lignins show a much higher polydispersity and heterogeneity, which have a profound impact on the stability and uniformity of lignin-based products. To reduce the polydispersity and heterogeneity of lignin, various methods to fractionate lignin into different fractions with specific chemical characteristics and properties by molecular weights are developed. This article summarized the advances of prevailing lignin fractionation methods as well as their influence on the corresponding applications. Furthermore, the current problems and new insights on the development of lignin fractionations were highlighted and discussed.

Coal to calcium carbide (CaC₂) acetylene process occupies an important position in the coal chemical industry in China. However, it has been restricted by high power consumption and heavy carbon dioxide emission in the industrial production of its key intermediate calcium carbide. Therefore, it is of great significance to develop a green and environment-friendly alternative process to replace calcium carbide production in coal to acetylene. In this paper, barium carbide was utilized to produce acetylene synthesized from the mixture of barium carbonate with carbon. The characteristics of the BaC₂ synthesis reaction system were analyzed from the perspective of thermodynamics, and the experimental verification of the synthesis of BaC₂ was carried out at 1550℃. The results showed that a new route for converting carbon and carbon dioxide into acetylene and carbon monoxide via BaCO₃-BaC₂-Ba(OH)₂-BaCO₃ barium cycle by replacing CaC₂ with BaC₂ as the key intermediate of coal-to-acetylene has the advantages of low reaction temperature and zero reaction temperature. The easy regeneration and reuse of barium carbide would highlight barium-based sustainable chemical technologies as promising instruments for total carbon recycling, which provide new methods for the development of the modern coal chemical industry.

Biodiesel is a clean and renewable liquid fuel that is readily made from vegetable oils. Transesterification of the refined vegetable oils with methanol is an important reaction for the production of biodiesel. In order to accurately calculate the multicomponent-phase equilibrium compositions in the transesterification reactions, the multicomponent-phase equilibria of the transesterification reaction between soybean oil and methanol at atmospheric pressure and 60℃ were studied. The transesterification of triolein with methanol was particularly taken as a model reaction, and the UNIFAC and modified UNIFAC activity coefficient models were used to predict the ternary and quaternary phase equilibrium compositions. The results showed that in the region that the overall composition deviates from the binary composition of methanol-methyl esters, the UNIFAC and modified UNIFAC models accurately provided the ternary and quaternary phase equilibrium compositions in the transesterification reaction system. At the glycerol contents greater than 2.2%(mass) or the conversions lower than 90%(mass), using the UNIFAC model, the phase equilibrium compositions for the reaction process were accurately calculated with a deviation of about 2% compared to the experimental values. Both the experimental and modeled values showed that the continuous countercurrent separation of glycerol can improve the methanol to oil ratios and facilitate the mass transfer and transesterification rates. These results provide a theoretical reference for biodiesel process simulation, equipment optimization and new technology development.

The absorption performance of CO₂ by blends of alkanolamines [monoethanolamine (MEA) and methyldiethanolamine (MDEA)] and ionic liquids [1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF₄]) and 1-hydroxyethyl-3-methylimidazolium glycine ([C₂OHmim][GLY])] was investigated in the microchannel. The influence of the concentration ratio of alkanolamine/ionic liquid (c_AA∶c_IL) on the liquid-phase volumetric mass transfer coefficient (k_La) was highlighted. The results show that k_La increases with the increase of reaction rate for all solutions. In order to further elucidate the mass transfer mechanism of CO₂ absorption by the compound aqueous solution, the effects of specific surface area, diffusion rate, enhancement factor and liquid-elastic circulation on the mass transfer rate were analyzed. The results show that the overall mass transfer rate is significantly controlled by chemical reaction rate at low flow rates, and by circulation frequency (f_cir) at high flow rates. Nevertheless, k_La can still be expressed as a mathematical function of f_cir. k_La is linearly related with f_cir at low gas flow rates, and the slope is positively related with the reaction rate. At high gas flow rates, the effect of circulation on mass transfer rate becomes weak due to the difficulty of film-slug exchange. In this case, k_La follows a power-law relation with f_cir whose exponent is less than 1.

Conventional dust removal device has a penetration window for the particles from coal combustion. The dust removing efficiency of wet electro-static precipitator could be improved by increasing the relative humidity (RH). The efficiency is different in coal and RH. The experimental facility and kinetic model for different fly ash particles against a flat surface under humid conditions were built to explore the variation of restitution coefficient. The results show that the coefficient of restitution of anthracite is the smallest under 65% RH, and it is easy to capture. With the increase of RH, the capillary force is dominant, and the damping coefficient, critical impact velocity and contact time increase.

Based on the pimpleFoam solver in OpenFOAM, the flow-reaction coupling process of the dual parallel plane jets with a second order non-equilibrium elementary reaction (A+B\stackrel{}{\to }R) is numerically investigated. More specifically, the production, consumption and transportation behaviors of reactive dual jets along the centerline with different jet separation distances are considered. The simulation results of a single reactive jet are compared with the corresponding previous experimental and numerical results to verify the accuracy of the numerical algorithm adopted. The main conclusions are as follows: (1) The behavior of the two jets at the quasi-stagnation point and the mixing point directly affects the chemical reaction. (2) Jet interaction length scales can effectively predict the statistics of the reactant and product terms of jet interactions under different jet separation distances. (3) When Da=0.1 and Sc=0.71, the transport of reactants and products is dominated by the convective process. (4) The joint probability distribution function (JPDF) between the instantaneous concentrations of the reactant and product terms is “heart-shaped”, and generally speaking, the circumstances that instantaneous concentrations of reactant A and reactant B are close to the average value, are associated with high rates of chemical reactions.

Using water as the working fluid, the coupling characteristics of low Reynolds number pulsating flow and flexible wall in triangular channel were experimentally studied. Experiments of heat transfer and flow resistance were carried out in detail under the impacts of Womersley number (W), pulsating amplitude (A) and rigidity (K_b). Moreover, the dynamic response relation between flexible wall and pulsating flow was investigated to illuminate the effects of flexible wall deformation and vibration frequency on heat transfer and flow resistance. The results indicate that the dual effects of heat transfer enhancement and drag reduction are achieved by pulsating flow in the triangular channel with flexible wall, but heat transfer efficiency increasing by 0-50% is relatively weak. Besides, the reason why flow resistance and enhanced heat transfer efficiency decease is that deformed flexible wall results in increasing the cross-sectional area of the flexible wall (the fluid velocity decreases), and the pulsation energy is weakened with the increase of W and A. Furthermore, the reduction of enhanced heat transfer effect cased by flexible wall vibration and deformation gradually tends to be dominant with the increase of W . The reduction of flow resistance is mainly caused by the deformation of the flexible wall, and the flexible wall vibration frequency has less effect on the energy dissipation of pulsating flow.

The suspended particle flow of viscoelastic surfactant solution widely exists in nature and industrial production. The nonlinear rheological properties and stress relaxation effect of viscoelastic surfactant solution have a significant impact on the particle settlement. The FENE-P and Giesekus constitutive models were used to study the sedimentation characteristics of particles in surfactant solutions. The hydrodynamics of the viscoelastic fluid is solved regarding the settling spherical particle as the reference system. Firstly, the rheological properties of the FENE-P and Giesekus fluids are obtained from the numerical solution of constitutive equations under the planar shear flow and the uniaxial tension conditions. It shows that both constitutive models exhibit not only the shear thinning but also the tension hardening, and the shear band appears when the mobility factor is larger than 0.8 for Giesekus fluids. The numerical results show that the elasticity of the fluid causes the instability of the settling velocity of the particle at the beginning. The stronger the elasticity of the fluid is, the stronger the instability of the settling velocity of the particle is. While the shear thinning weakens the instability of the settling velocity of the particle. The shear thinning and tension hardening affect the flow simultaneously and a negative wake is formed behind the particle. The negative wake region enlarges when the shear thinning and tension hardening are enhanced, and the negative wake is also enhanced with the increase in the fluid elasticity. However, the simulated settling velocity of the sphere using the FENE-P and Giesekus models becomes steady after a while, and the sphere reaches a constant terminal velocity eventually. It shows some difference from the unusual experimental phenomenon, e.g. the continuous velocity fluctuation of the settling sphere in actual surfactant wormlike micellar fluids. Thus, the FENE-P and Giesekus models are incapable when they are used to describe the particle behaviors in these surfactant wormlike micellar fluids. The breakage and reformation of the micro-scale wormlike micelles in surfactant solutions caused by the reversed velocity in the negative wake region may be the reason for the fluctuation of the settling velocity of a particle in this kind of viscoelastic fluids. Therefore, an advanced constitutive model is needed to clarify the phenomenon in the future study.

In order to improve the numerical design efficiency of flat tube-bank-fin heat exchanger with sine wave fin, the calculation results of FVM (finite volume method) were used as sample data to build a POD reduced-order model to study the flow and heat transfer characteristics on the air side. The results show that the relative deviation between the temperature field reconstructed by POD and the calculation results of FVM is concentrated in the sinusoidal fin surface region. And the relative deviation decreases along the mainstream direction. The velocity distribution difference between the two methods is mainly concentrated in the mainstream region. The calculation accuracy and efficiency of POD reduced-order model decrease with the increase of the number of variable parameters. The maximum average relative deviation between the physical field reconstructed by POD reduced-order model and FVM results is 2.921%, and the average computational speed is 11752 times faster than the traditional FVM calculation speed.

A visual experimental device was built to study the distributive mixing process in a horizontal self-cleaning single-shaft kneader. Meanwhile, the finite element method (FEM) with the mesh superposition technique (MST) was adopted to obtain the velocity distribution, shear rate distribution and mixing index distribution in the single-shaft kneader with a highly viscous Newtonian fluid. Then the particle tracking technique was used to analyze the whole and local distributive mixing process in the kneader. The statistical analysis was performed based on the particles’ trajectories to calculate the length of stretch and mixing efficiency. The effect of kneader configuration on the flow filed and mixing process was also investigated. Results show that the experimental data agree well with the FEM simulation results. There exists the periodical intermeshing interaction between the static kneading bars on the kneader wall and the dynamic kneading bars on the rotating shaft, which improves the self-cleaning performance, shear rate, whole and local distributive mixing process, disperse mixing ability and mixing efficiency. The length of stretch exponentially increases with time and the time averaged mixing efficiency remains positive during the mixing process.

A dimensionless mathematical model was formulated to theoretically study the behavior of propane dehydrogenation (PDH) in porous membrane reactors for propylene production. The effects of catalytic activities, membrane characteristics, and operating conditions on membrane reactor performance were investigated in detail in terms of propane conversion, propylene yield, and hydrogen yield and purity. The simulation results indicate that PDH can be significantly improved after the in-situ removal of the produced hydrogen during the reaction by using a hydrogen-permselective membrane, and the enhancement is largely affected by the catalyst, membrane, and operating conditions used in the reaction. A highly active catalyst plays a fundamental role in PDH in membrane reactors, which provides a high hydrogen production rate in the reactor. Furthermore, a highly permeable and selective membrane allows a highly efficient hydrogen extraction rate, which breaks the limit of thermodynamic equilibrium and significantly promotes PDH conversion in the membrane reactor due to the equilibrium shift effect. Compared with Pd-based membrane reactors, porous membrane reactors, which have a H₂/C₃H₈ selectivity larger than 100 and the same hydrogen permeance ranging from 10^-7 mol·m^-2·s^-1·Pa^-1 to 10^-6 mol·m^-2·s^-1·Pa^-1_, show a comparable PDH conversion but a lower hydrogen purity. The membrane reactor performance is much superior to that of conventional fixed-bed reactors due to the equilibrium shift effect, particularly under a low reaction temperature and a high feed pressure. A very high propane conversion and hydrogen yield can be obtained in the membrane reactor even at a relatively low reaction temperature, and both show a maximum with increasing the feed pressure. This simulation study can provide useful technical guidance for the efficient intensification of PDH reaction in a membrane reactor in practical applications.

Fischer-Tropsch synthetic water contains a variety of high value-added oxygen-containing organic compounds such as alcohols, ketones, and acids. However, due to the large amount of water and the complex azeotrope system, it is usually necessary to perform preliminary separation first. In this study, four alternative preliminary separation processes, direct two-column distillation, pervaporation-two-column distillation, direct dividing wall column distillation, and pervaporation-dividing wall column distillation, were designed first. According to the pervaporation experimental data, the pervaporation process model was constructed and simulated in Aspen Plus, and the optimal process parameters and simulation results of the distillation process were obtained through sensitivity analysis. The energy consumption and effective energy loss of the four processes were compared. The results show that the pervaporation-dividing wall column distillation process has obvious energy-saving advantages. Compared with direct two-column distillation, the energy consumption could be reduced by 15.85%, and the effective energy loss could be reduced by 45.74%. After pre-concentration by the pervaporation membrane, the concentration of the solution could enter the appropriate separation concentration range of the dividing wall column, so as to give full play to the advantages of the dividing wall column. Since the energy required for pervaporation could be provided by low-grade heat sources such as waste heat, the loss of effective energy could be significantly reduced in the coal chemical industry with sufficient waste heat. For this process, when the price of pervaporation membrane is lower than 438 CNY/m², the coupled process of pervaporation-dividing wall column distillation would show higher economy.

In this paper, a mixed integer nonlinear programming (MINLP) model for distillation columns optimization is established from the perspective of structural optimization. In order to eliminate integer variables, the bypass efficiency model is introduced to transform the MINLP problem into a nonlinear programming (NLP) problem. An optimization method is proposed to solve the NLP problem. In this method, the trust region optimization algorithm which commonly used in structural optimization is used and the pseudo-transient continuation model is used to assist the steady-state simulation in optimization. The optimization method proposed in this paper is used to optimize three distillation cases. All the cases can get satisfactory optimization results starting from different initial points. The results show that the proposed optimization method has good robustness and can still effectively solve the complex partial thermal coupling distillation process. The trust region algorithm also shows good convergence in the optimization of distillation column.

In order to understand the dynamic characteristics of cement precalciner, a one-dimensional hybrid model combined of reaction mechanism and neural network was constructed. Feasibility of this method was verified by comparison with industrial data. The results show that the hybrid model can accurately calculate temperature, gas concentration and other parameters in the furnace. Distribution of each parameter along the direction of flue gas flow is consistent with the actual situation. Based on the proposed model, the steady-state distribution characteristics of various state parameters in the furnace were studied. Furthermore, step response tests were carried out. Dynamic responses of temperature and NO _x concentration at furnace outlet were researched when the coal feeding rate, limestone feeding rate, ammonia injection rate and other manipulated parameters were changed respectively. The relevant dynamic characteristics obtained from the research can provide reference for the analysis, design and optimization of the control system.

Adjusting operation conditions of a distillation column is one of the effective ways to save energy consumption of the column. However, operation conditions of a distillation column will affect the energy consumption of both the column and the heat exchanger network. Based on the cold and hot composite curves with all streams including the reboiler, condenser, and process streams, this paper analyzes the influence of the pressure variation of an across pinch distillation column on the utility consumption of the whole process. The stripper column in a continuous reforming process is taken as a case study. The results show that the reduction of the column pressure can increase the heat duty of condenser and decrease the heat duty of reboiler. However, for the streams from the top or bottom of the column, the reduction of the column pressure can save cooling utilities but increase heating utilities. The overall energy saving effect of the unit is the comprehensive effect of the condenser, reboiler and streams from the top or bottom of the column. Analysis of the stripper of a continuous reformer shows that when the tower pressure is reduced by 200.0 kPa, the heating utility usage will be reduced by 577.5 kW.

Aiming at the problem that the heat exchange network optimized by the heuristic method is easy to fall into the local extreme value in the later stage of optimization, a damping optimization method is proposed, that is, by introducing the concept of delay probability, the structure with a certain probability will not accept the cost reduction, the structure will be delayed from forming a fixed structure match, and will avoid falling into local optimum due to insufficient optimization of integer variables due to too fast optimization of continuous variables. By discussing the optimization characteristics of different stages and the causes of optimization falling into local extreme, a phased delay strategy is proposed to reasonably adjust the delay conditions and the value of delay probability, to improve the global search ability of the algorithm. Finally, four different scale examples are used to verify the results. The results show that the method can effectively jump out of the local optimal solution and promote the further optimization of the structure.

By applying the high-density triple bed circulating fluidized bed (TBCFB) to a series-parallel integrated polygeneration system, a coal-based polygeneration system based on carbon cycle process and parameters co-optimization is proposed, which can promote the high-quality and high-efficiency conversion of low-rank coal resources. The carbon cycle is embodied in two aspects. First, this system uses a pyrolysis gas cycle as the pyrolysis atmosphere, which can increase the tar yield and realize the high-quality conversion of low-rank coal.The second is the use of oxygen-enriched combustion in TBCFB, which can increase the concentration of carbon dioxide in the flue gas. While, using the flue gas instead of nitrogen directly as a working fluid for gas turbine power generation also reduces nitrogen consumption. The Aspen Plus is used here to investigate the influence of unreacted syngas circulation ratio and flue gas injection rate on the process via performing material, energy and exergy balance calculations for polygeneration systems. In addition, with energy efficiency as the optimization goal, suitable operating conditions are further found for the coal-based polygeneration system with carbon cycle. The results show that when the flue gas is used for gas injection in the power unit, the energy utilization efficiency of the coal-based polygeneration system with carbon cycle reaches 49.7%, which is higher than that of the traditional system using nitrogen as the pyrolysis atmosphere. Compared with the traditional unit production system, the coal-based polygeneration system can save 13% of energy, which is equivalent to reducing carbon dioxide emissions by 14.9×10⁴ tons per year for a system with an annual capacity of 30×10⁴ tons of coal.

In order to ensure the stable operation of the dynamic sealing of aero-engines, for the floating foil gas film seal, the bump foil stiffness model considering the Coulomb friction is adopted, and the central difference method and the over-relaxation iterative method are used to couple the foil deformation equation, pressure control equation and gas film thickness control equation. And the small disturbance method, combined with the balance between pressure and foil deformation, obtain the flow field distribution of the wedge-shaped lubricating gas film, and the influence of working condition parameters, foil structure parameters and linear dynamic pressure groove distribution position on the static and dynamic characteristics of the seal is analyzed. The research results show that: Benefiting from the deformation of the sealing surface, the floating foil gas film seal can independently adjust the gas film gap according to operating conditions; The gas film floating force and leakage of the inlet straight groove are bigger than those of the middle straight groove; The sealing characteristics are closely related to the gas film pressure and the sealing gap, but they are little affected by the Coulomb friction effect; Both the Coulomb friction effect and the thickened foil increase the rigidity of the foil to a certain extent, making the sealing surface “rigid"; The comprehensive performance of the floating foil air-film seal in the high-speed service environment is good. The research results laid a theoretical foundation for the structural design and experimental testing of the floating foil gas film seal in the future.

The automatic control of biologically fermented glycerol to produce 1,3-propanediol is the key problem to be solved in its industrial application. First, according to the mathematical model of the fermentation for Klebsiella pneumoniae to produce 1,3-propanediol, the multi-steady characteristics of continuous process were studied through the numerical continuation analysis for mathematical functions. Thereby, it was found that under different initial glycerol concentration or dilution rate, the system exhibited multi-steady state phenomenon. Through two-factor analysis, the critical region where multi-steady state occurs was determined, and the steady state in this region was unstable. After that, based on the feedback control theory and the results of multi-stability, the dilution rate control strategy affected by the concentration of residual glycerol and product 1,3-propanediol was designed. In the continuous fermentation, the settling time was shortened from 81.27 h to 34.11 h, which could significantly reduce the loss of glycerol in the early stage of fermentation. Meanwhile, the yield of 1,3-propanediol was increased from 0.478 mmol·mmol^-1 to 0.563 mmol·mmol^-1 and the production productivity was increased from 85.70 mmol·L^-1·h^-1 to 101.10 mmol·L^-1·h^-1. The results showed that the feedback control of the dilution rate significantly improved production performance, which can be adopted as a feeding guide for continuous culture in practice.

Solar energy is a kind of sustainable energy, however, its random and intermittent fluctuation characteristics restrict its large-scale and high permeable applications. In this paper, based on the analysis of the basic characteristics of wind power and light, and through the data mining and integration from the databases of the international Meteorological Organization and space agencies, the frequency spectrum analysis and filtering analysis are applied to reveal that both wind power and photovoltaic power have daily (24 h) and annual (8760 h) fluctuation cycles. The phase differences between the wind energy and the solar energy fluctuation period are pointed out, which constitutes the scientific basis for energy complementarity to suppress the fluctuation. The data analysis of several regions in north and northwest China shows that the phase difference between wind energy and solar energy is around 7 hours daily and around 5 months annually. The coupling of the wind energy and the solar energy alleviates the individual energy fluctuation. Therefore, the design criteria and model of capacity configuration of large-scale stable wind-photovoltaic power to hydrogen production and supply system were established, and appropriate battery sets and hydrogen storage tanks were selected to achieve 7500 t/a hydrogen supply. The unit cost of hydrogen production of the system is 25.5 CNY/kg H₂, which is significantly lower than the cost of hydrogen production from wind or photovoltaic energy alone; the CO₂ emission intensity of the system is 2.34 kg CO₂/kg H₂, which is superior to the uncomplementary coupled solar hydrogen production system.

Biochar production by sewage sludge pyrolysis is an effective approach for sludge treatment and resource utilization. By controlling the pyrolysis time, regulating the active sites on the surface of sludge biochar, and changing the composition of active species in the peroxymonosulfate (PMS) system, the efficient degradation of ciprofloxacin (CIP) can be achieved. Research found that the sludge-derived biochar exhibited high PMS activation performance, achieving nearly 90% removal of CIP at pyrolysis time of 120 min and pyrolysis temperature of 700℃. The mechanism exploration showed that ¹O₂ played a major role in the system. The C\stackrel{\text{?????}}{?}O, pyrrolic N and —OH sites might accelerate the production of ¹O₂. Besides, C—O, pyridine N, lattice oxygen and Fe sites promoted the release of ^?OH and SO₄^?-. Graphite N played a positive role in PMS activation to produce SO₄^?-.

The atmospheric conditions of low pressure and low oxygen in high altitude areas affect the decomposition process of cement raw meal in the decomposition furnace, and it is of great significance to explore the decomposition characteristics of cement raw meal under these conditions. An experimental system was constructed to simulate a suspension furnace in high-altitude areas with low pressure, and was studied the reaction process of cement raw meal in the calciner. Also, the effects of pressure and temperature and O₂ concentration on the decomposition characteristics of cement raw meal were studied by changing the reaction conditions. The research results show that the decomposition of cement raw meal under low-pressure conditions conforms to the random nucleation and growth model. As the reaction pressure gradually decreases, the decomposition rate of cement raw meal gradually increases, and the specific surface area and pore volume of the reaction product gradually increase. But low-pressure conditions will aggravate the incomplete combustion of fuel and reduce the decomposition ratio of cement raw meal. The reaction rate of fuel and cement raw meal will gradually increase with the rise of reaction temperature, but the decomposition ratio of cement raw meal will increase firstly and then decrease. Under low-pressure conditions, the fuel reaction ratio and reaction rate increase with the increase of O₂ concentration, which can increase the decomposition rate of the reactant. Therefore, in high altitude areas, the decomposition rate and decomposition ratio of cement raw meal can be increased by appropriately increasing the reaction temperature or increasing the O₂ concentration of the reaction atmosphere.

Injecting kinetic hydrate inhibitors is an effective method to prevent the blockage of natural gas hydrate pipelines. In this paper, based on the structure of polyvinyl caprolactam (PVCap), oxyethyl and ester groups are introduced into the molecular chain end of PVCap to synthesize a new kinetic hydrate inhibitor PVCap-XA1. The inhibition performance of PVCap-XA1 on the formation of methane hydrate was evaluated in a high-pressure constant-volume cell, and the effects of PVCap-XA1 on the structure and morphology of methane hydrate were studied by powder X-ray diffraction, Raman spectroscopy and scanning electron microscopy (Cryo-SEM). The results showed that PVCap-XA1 had better inhibition than PVCap under the same experimental conditions. Microscopic tests showed that the addition of PVCap-XA1 did not change the crystal structure of methane hydrate, but distort the crystal plane of methane hydrate, and reduced the ratio of I_L/I_S. Meanwhile, the addition of PVCap-XA1 makes the microscopic morphology of methane hydrate change from porous and orderly to denser, which was not conducive to the passage of gas.

The reduction of NO by Shenmu coal char was studied at 450℃, and the relationship between the influencing factors of coal char denitrification and its surface carbon-oxygen functional groups was explored by Raman, FT-IR, XPS and other analytical methods. Combining the results of isothermal experiments and characterizations, close connection between influencing factors and carbon-oxygen complexes was revealed. The effect of coal char preparation temperature, oxygen concentration in flue gas as well as influence of metallic elements could be in connection with carbon-oxygen complexes on coal char surface. More specifically, lowering pyrolysis temperature, increasing oxygen concentration, and loading metals were all conducive to the retention and formation of thermally stable C—O species on coal char surface. Strong linear relationship was discovered via XPS method between thermally stable C—O species and experimental evaluation indexes (R²>0.96). Carbon-oxygen complexes, especially thermally stable C—O compounds, played a key character in NO reduction by coal char.

Heavy metal complexes formed by heavy metals and organic complexing agents in industrial wastewater are one of the pollutants that are difficult to effectively remove by conventional water treatment methods. Although photocatalytic oxidation would be a candidate technically for complex degradation, the high recombination ratio of electron-hole pairs generated by TiO₂ limits the application. Microbial fuel cells could suppress recombination of pairs by applying a bias voltage to the photocatalytic unit, which ultimately manifests as an efficient decomplexation reaction. In this work, the coupling of MFC and photocatalytic oxidation was proven to be efficient to improve the removal of Cu-EDTA and Cu²⁺ simultaneously. The results show that the photocatalytic unit matched with single MFC, double MFC connected in series, and double MFC connected in parallel lifted the removal rate of Cu-EDTA up to 52.6%, 73.57%, and 61.54%, respectively, while the removal of Cu²⁺ went to 18.09 %, 36.87% and 21.09%. Accordingly, it was shown that the coupling with MFC connected in series could enhance the removal efficiency of the photocatalytic unit to a greater extent.

The discharge of chemical wastewater in China is huge, and the inorganic phosphorus contained in wastewater can lead to eutrophication of fresh water. Using sodium alginate from a wide range of sources and environment-friendly as the carrier, the bagasse biochar with high specific surface area prepared by one-step microwave pyrolysis and activated method as the additive, and ferric chloride as the cross-linking agent, three kinds of adsorbents (SA- Fe, SA-C-Fe and SA-C-Fe(C)) were prepared by the sol-gel method and the embedding method, and they were used to perform inorganic phosphorus removal experiments. The results showed that the adsorption process of the three materials conforms to the quasi-second-order kinetic model. The entire adsorption process of SA-Fe gel spheres and SA-C-Fe gel spheres conforms to the Langmuir isotherm model, and the maximum adsorption capacity of SA-Fe spheres and SA-C-Fe spheres to be 53.79 mg/g and 78.75 mg/g, respectively. The removal process of inorganic phosphorus by SA-C-Fe(C) gel spheres conforms to the Langmuir-Freundlich adsorption isotherm model. SA-C-Fe gel spheres have three adsorption mechanisms: ligand exchange, electrostatic attraction and surface deposition, with the highest adsorption capacity. After carbonization of SA-C-Fe(C) microspheres, the number of hydroxyl functional groups was reduced, the ligand exchange was weakened, and iron oxide deposits were formed, with the lowest adsorption capacity.

Flue gas from coal-fired power plants contains profuse water vapor. The direct emission of wet flue gas may lead to visual pollution and a series of environmental problems. Herein, we report the use of hydrophobic Al₂O₃ ceramic membrane modified by n-octyltriethoxysilane to construct air-cooling condenser for flue gas dehumidification and water recovery. Compared with conventional impermeable hydrophobic steel tube, porous hydrophobic ceramic membrane can condense vapor more efficiently. With the same water contact angle of 120°, the flue gas temperature drop of the ceramic membrane is 1.3—2.5 times higher than that of the 304 steel tube. The parametric study of the hydrophobic ceramic membrane has been done. The water flux improves with the increase of flue gas flowrate, flue gas temperature and sweeping factor, but decreases with the increase of transmembrane pressure difference and sweeping gas temperature. The water recovery efficiency decreases with the increase of flue gas flowrate, transmembrane pressure difference and sweeping gas temperature, and improves with the increase of sweeping factor. The water recovery efficiency increases first, then tends to be stable, and lastly decreases with the increase of flue gas temperature. Under experimental conditions, the water flux of 0.6—5.2 kg·m^-2·h^-1 and water recovery of 7.6%—57.4% are achieved. At low cooling medium flowrate, the condensation performance of hydrophilic ceramic membrane using water cooling is better. With the increase of cooling medium flowrate, the condensation performance of the air-cooling hydrophobic ceramic membrane rapidly improves and is gradually close to the performance of the water-cooling hydrophilic ceramic membrane. Air cooling enhanced by hydrophobic ceramic membranes is promising to replace water cooling to reduce water consumption. Hydrophobic ceramic membrane condensers can efficiently recover water from flue gas to alleviate water-energy-environment collisions in industrial processes.

In order to improve the treatment efficiency of ink wastewater using Fe/C microelectrolysis process, the compositions of conventional Fe/C fillers were changed by using metallic manganese, and the process conditions of microelectrolysis was optimized by using response surface methodology. The changes of organic matters in the wastewater and surface structure of the filler before and after the treatment of ink wastewater were analyzed by using three-dimensional fluorescence spectra, UV-Vis spectra and GC-MS, respectively. The flocculation and degradation mechanisms of ink wastewater were explored. The results showed that under the conditions of initial pH 2.79, reaction time of 1.58 h, Fe/Mn molar ratio of 3.11 and the filler dosage of 93.36 g/L, removal efficiency of COD reached 87.9%. The difference between the predicted value (87.8%) and the measured value was 0.1%. The response surface methodology could accurately predict the changes of the removal efficiency of COD. After being treated by Fe/Mn/C micro-electrolysis process, the Zeta potential of ink waste water increases, and the flocculation effect is enhanced. Fe/Mn/C microelectrolysis process could destroy the structure of benzene ring and conjugated double bonds, and it could efficiently degrade soluble microbial metabolites, aromatic protein substances and humic acids. During the microelectrolysis process, iron and manganese oxides were formed on the surface of the filler and some of the oxides adhered to the surface of the activated carbon.

Coal gangue or fly ash and red mud synergistic sodium reduction roasting can realize the form transformation of iron, aluminum, silicon and other elements contained in it, making it easy to separate and recycle. However, a research on the difference of sodium reduction roasting reaction between coal gangue - red mud system and coal fly ash-red mud system has not been reported. In this paper, the influence of atmosphere type, sodium additive amount, roasting temperature and roasting time on the phase composition of the reductive roasted product from coal gangue-red mud and coal fly ash-red mud system was investigated by X-ray diffraction analysis method. In addition, the difference of iron magnetization and aluminum-silicon activation between coal gangue-red mud and coal fly ash-red mud system was analyzed. The results showed that coal gangue-red mud and coal fly ash-red mud systems can simultaneously realize the magnetization of iron-containing phase and the activation of aluminum-silicon phase during the sodium reduction roasting process. The iron-containing phase and the aluminum-silicon phase showed regular changes with the change of sodium additive amount, roasting temperature and roasting time. The sodium additive amount, roasting temperature and roasting time for the coal gangue-red mud system were slightly lower than those for the coal fly ash-red mud system with the same degree of iron magnetization and aluminum-silicon activation. It is mainly related to the occurrence, content and microstructure of reducing substances and aluminosilicate minerals in coal gangue or coal fly ash. This study will provide a theoretical guidance for the feed selecting during the recovery of valuable elements by sodium reduction roasting of coal-based solid wastes (such as coal gangue, coal fly ash) and red mud.

p-Toluenesulfonic acid (TSA) and maleic acid (MA) are important acid hydrotropes for lignocellulose fractionation in recent years. The delignification mechanism of TSA and MA fractionation of eucalyptus wood chips was studied. The results were as follows: (1) Both acid hydrotropes have high delignification efficiency. The delignification rate of TSA was 67.94% and that of MA was 65.14%; (2) The delignification rate of TSA was higher than that of MA at the same hydrotrope concentration; (3) TSA hydrotropic lignin has higher β-aryl ether linkage content than that of MA lignin under mild condition, the β-aryl ether linkage content of acid hydrotrope dissolved lignin was reduced with the increasing fractionation severity; (4) More than 90% cellulose was well retained after fractionation, but the hemicellulose degradation rate increased with the reaction severity; (5) The contact angle decreased with the increasing hydrotrope concentration, so the wetting ability of lignin increased, and delignification rate increased also, the size of lignin aggregate in acid hydrotropes decreased. In conclusion, delignification of hydrotropes is a combined effect of wetting dissolution, aryl-ether linkages cleavage and hemicellulose degradation etc. The research can provide a reference for the process optimization and mechanism of delignification under mild conditions.

Studies have shown that enzyme-induced carbonate precipitation (EICP) has great potential for strengthening soft clays and calcareous sands. However, the applications of the EICP method to solidification and immobilization of heavy metal ions are remarkably limited. In addition, the speciation of carbonate precipitation and its linkage to the degradation of the treatment efficiency when subjected to the effect of Cu²⁺ remain unclear. In this study, a chitosan-assisted enzyme-induced carbonate precipitation measure to improve the copper wastewater treatment efficiency by securing the urease activity was proposed. The results from the test tube experiments and numerical simulations showed that both higher and lower \mathrm{N}{\mathrm{H}}_{\mathrm{4}}^{+} concentrations, corresponding to higher degrees of urea hydrolysis, have implications for treatment efficiency. When the pH is as high as 9, the solution will produce a large amount of copper ammine complexes, reducing the processing efficiency. The calcium source and chitosan additions are considered useful in modifying pH surrounding conditions and preventing the urease activity from degrading by the effect of Cu²⁺.

The VUV/UV/NaClO and UV/NaClO processes were used to degrade thymol (Tml), and the synergistic factor (R) was used as the evaluation index to explore the effects of NaClO concentration and pH on Tml removal and synergistic effect. Meanwhile, using nitrobenzene (NB) and benzoic acid (BA) as probe compounds, the concentrations of HO· and Cl· in steady state, their contributions to Tml degradation, and their secondary reaction rates with Tml in two technologies were determined. The results show that the degradation of Tml using VUV/UV/NaClO and UV/NaClO technologies is in accord with the pseudo-primary reaction kinetics, and the first-level kinetic constants of k_VUV/UV/Cl and k_UV/Cl are determined to be 0.0113 s^-1 and 0.00479 s^-1, respectively, which is positively correlated with NaClO concentration. VUV/UV/NaClO and UV/NaClO processes had significant synergistic effects on the degradation of Tml, and the corresponding synergistic factors R_VUV/UV/Cl and R_UV/Cl showed an initial increase and then decrease with the increase of NaClO concentration and pH. The maximum R_VUV/UV/Cl and R_UV/Cl were determined to be 1.9 and 2.1 when the NaClO concentration and pH are 0.3 mg·L^-1 and 7, respectively, and the corresponding synergies were 90% and 110%. The contribution rates of HO· in the VUV/UV/NaClO and UV/NaClO processes were calculated to be 42.7% and 37.6%, respectively, while the contributions of Cl· were 42.4% and 28.5%, respectively. HO· and Cl· were the dominated contributors in the two processes.

The waste acid fluidized bed regeneration technology can efficiently recover acid and metal ions, and has a broad application prospect. The effect of temperature in the dense phase zone and initial bed size on the regeneration and recovery characteristics of acid and metal ions in waste mixed acid (HNO₃+HF) was investigated by using a self-built fluidized bed thermal state experimental setup and combining SEM, ion chromatography and XPS characterization methods. The results show that the fluidized bed method can effectively achieve the regenerative recovery of acid and metal elements in waste mixed acid, and the amount of metal oxide adhered to the surface of the bed material increases with the increase in temperature of the fluidized bed dense phase zone, reaching a peak at 850℃. The amount of adherence decreases slightly as the temperature continues to rise. By increasing the initial particle size of the bed material, the amount of metal oxide adhered to the surface of the bed material will be significantly increased. The amount of NO _x and HF generation increases with the increase of temperature in the dense phase zone of the fluidized bed, reaching a peak at 750℃, and then decreases significantly after continuing to increase the temperature, while the amount of NO _x generation will decrease slightly as the initial particle size of the bed material increases, and the temperature in the dense phase zone corresponding to the peak of HF generation is delayed to 800℃.

Color photoresist is the key material for the preparation of color filters. In order to develop the color filters with higher resolution, organic dyes replacing conventional pigment-based system offers a promising alternative. However, the photothermal stability of dye molecules is an urgent problem to be solved. Therefore, it is desirable to explore effective strategy to improve the stability of dye molecules from the perspective of molecular structure innovation. In this paper, we report nine blue dyes based on anthraquinone scaffold with different substituents. These dyes were prepared from the reaction between 1,4,9,10-anthracyl alcohol and amine-end substituents. The relationships between the dye molecular structures and the photophysical/photothermal properties were investigated. All dyes exhibit double-peaks absorption spectra with the maxima in the range of 590—600 nm and 630—650 nm, respectively, and high molar extinction coefficient. The dyes that contain triethylene glycol and triethylene glycol monomethyl ether chains show better photothermal stability than the alkyl and amine-alkyl substituted dyes. The decomposition temperature of the ether chain dyes reaches 300℃ and the mass loss ratio is about 2% after heating at 230℃ for 0.5 h. Meanwhile, the color difference value is below 1.73 after continuous illumination at 365 nm wavelength for 8 h. Our work laid the foundation for further developing dyes with good performance that can be used in color photoresist.

Based on multi-walled carbon nanotube (MWCNT) and aluminum nitride (AlN) particles with different modification, to improve the dispersion and interfacial compatibility with PVDF matrix, and reduce the interfacial thermal resistance. After solution blending, the mixture of filler and matrix is pressed into a dense film by hot pressing to improve the thermal conductivity of PVDF. By this method a three-dimensional hybrid network structure was expected to be constructed. TEM tests showed that the dispersion property of the modified fillers was improved, and SEM showed that the two fillers successfully formed a three-dimensional hybrid network structure in PVDF matrix. When the filler content is 50%, the thermal conductivity of the a-AlN-PVDF composite film reaches 300% of the original film, and the breaking strength becomes 92% of the original film. When the volume ratio of MWCNT to AlN is 1∶1 and the mass fraction of the modified mixed filler is 50%, the thermal conductivity becomes 565% of the original film and the breaking strength becomes 51% of the original film.

Using biomass-based crude glycerol as the main raw material, a one-pot method was used to synthesize crude glycerol-based polyol, and the polyurethane foam material was prepared by further foaming. On the basis, the modified polyurethane oil absorption material was prepared by hydrophobic modification with methyl trichlorosilane. The morphology, thermal stability and the contact angel of the polyurethane foam before and after modification were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy and thermogravimetric analysis. The oil absorption properties of the modified polyurethane oil absorption material were also tested. The results showed that polysiloxane was successfully synthesized on the foam surface after the modification of methyl trichlorosilane. The water contact angle increased from 130° to 140°, indicating that the hydrophobicity of the oil absorption material was improved. The adsorption capacity of modified polyurethane oil absorption material for eight kinds of organic substances such as ethanol, methanol and chloroform, etc., ranges from 16.7 g/g to 45.2 g/g. After 50 cycles, the adsorption capacity of the oil absorption material for diesel and soybean oil was 95.8% and 97.6% of the maximum adsorption capacity, respectively, showing excellent oil absorption performance.

Massive accumulation and landfill of municipal sludge will damage the local ecological environment around the city. Incineration can realize the harmlessness of municipal sludge, however, the heavy metals inside the incinerated slag are difficult to be effectively fixed. In order to effectively fix the heavy metals inside the incinerated slag and recycle the slag to produce low-cost shape-stable phase change composites, this work proposed the sludge incinerated slag as skeleton material, and five slag-based shape-stable phase change composites were prepared with sodium nitrate as phase change material with different mass ratio of incinerated slag to sodium nitrate by cold-compression & hot-sintering method. Then, the thermal performance, micromorphology, mechanical performance and chemical compatibility between the slag components and the sodium nitrate were investigated. Results shows that the shape-stable phase change composite with the mass ratio 5∶5 of slag to sodium nitrate, namely the sample SS3 possesses the best heat transfer and thermal energy storage performance as well as excellent high-temperature thermal stability, which fixed the heavy metals inside properly. Moreover, a good chemical compatibility between the slag components and the sodium nitrate is observed and the sample SS3 achieves the thermal energy storage density of 409.25 J/g and the maximum thermal conductivity of 0.955 W/(m·K) in the range of 100—400℃ and the mechanical strength of 139.65 MPa. In addition, the sample SS3 possesses excellent heat transfer and thermal energy storage performance after 500 heating/cooling cycles, which indicates that sludge incinerated slag is suitable for preparing low-cost shape-stable phase change composites as skeleton materials.