Lignin is a cheap and renewable resource with rich aromatic units. It can be efficiently transformed into highly value-added fine chemicals such as phenolic monomers and other high-grade biofuels such as arenes and alkanes through catalytic depolymerization methods, which has long been regarded as an important constituent part of biomass resources comprehensive utilization approaches. This process is able to replace the chemicals production from the fossil fuel partly. Among the lignin depolymerization methods, the catalytic hydrogenolysis process can directly convert lignin into liquid fuel with low oxygen contents, and these biofuels show a great potential in the replacement of traditional energy sources. This paper focuses on the catalytic lignin depolymerization methods. The recent progress at home and abroad is reviewed based on the catalysts, solvents, catalysis mechanism and catalyst recyclability. Wherein, the catalytic hydrogenolysis method is emphatically introduced in detail. Furthermore, the current technique challenges during the lignin catalytic depolymerization process are summarized. Many future technologic explorations and suggestions for the efficient application of lignin are proposed.

The research status on the composition, structure and leaching stability of scorodite, a well known arsenic solidification mineral, was reviewed. The scorodite samples prepared under different conditions had varying compositions due to the inclusion of sulfate together with the change of crystal water amount. Two structure models of scorodite were proposed as bidentate binuclear model and bidentate mononuclear model separately, but there was controversy on which one being true. The solubility product of scorodite fluctuated between 10^-21.17and 10^-25.83. The leaching stability of scorodite was higher in weak acidic (pH 2-6) solutions under oxidative conditions than that in strong acidic and alkaline solutions or under reductive conditions. Thus, it was concluded that scorodite could be stockpiled safely but in weak acidic (pH 2-6) and oxidative environment.

Using transition metal complexes to catalyse ethylene oligomerization is an important route for preparing α-olefins. The partially catalytic systems have entered the stage of pilot and industrial production. However, the recent researches have suggested that the oligomerization products of some transition metal catalysts in toluene solvent may react with toluene directly as Friedel-Crafts alkylation reaction, which could open a new way for the production of alkylbenzene. This paper reviews the progress of Friedel-Crafts alkylation reaction in ethylene oligomerization in recent years. The influence of the structure of catalysts, catalytic system and process conditions on the alkylation reaction is described in detail. Meanwhile, it gives the Friedel-Crafts alkylation reaction process in ethylene oligomerization, which would be of great significance to design the catalysts that could catalyse ethylene oligomerization to make mixed alkylbenzenes.

In this work, the solubilities of the salt minerals and the densities of solution in two ternary systems of lead chloride-zinc chloride-water and calcium chloride-lead chloride-water were measured at 373 K by using an isothermal solution saturation method. Based on the determined equilibrium solubility data and the corresponding equilibrium solid phase, the phase diagrams and density diagrams of the two systems were plotted. According to the phase diagrams, univariant solubility curves and solid crystalline areas were discussed. The results showed that the two ternary systems were simple without any double salt or solid solution. The phase diagrams of two ternary systems were constituted of one invariant point, two univariant solubility curves and two solid crystalline phase regions. The solid phase was determined by the XRD. And the results of the experiment were simply discussed.

Spray cooling is widely used in industries. Cryogen spray cooling has been implemented for the epidermis protection during laser surgery. For the improvement of cooling efficiency, the surface temperature was measured to calculate the surface heat transfer characteristics by the reverse heat conduction method. In order to investigate the influence of temperature measurement methods on the experimental result, a transient spray cooling rig was constructed to study the different heat transfer characteristics by using the thin film thermocouple (TFTC) fabricated by magnetron sputtering, the fine thermocouple (FTC) and the slice thermocouple (STC). The result suggested that the TFTC had the most sensitive thermal response, which can accurately reflect the temperature variation and corresponding heat flux. As for the FTC and STC, due to the limitation of indirect measurement, there was an obvious lag in temperature variation, which affected the subsequent analysis such as heat flux and apparent convective heat transfer coefficient. The employment of thin film thermocouple ensured the precise investigation of surface heat transfer during transient spray cooling, with reliable reference for clinical treatment.

Schlieren system was built to visualize the phenomenon of Rayleigh convection perpendicular to the gas-liquid interface during the absorption of carbon dioxide into pure ethanol in the special mass transfer device. As the absorption progressed, the stability of liquid layer weakened and disturbances aggravated the instability, which led to turbulence in the interfacial vicinity and went on to develop plume convection down to the bulk liquid with the growth and integration of convective cells. Quantitative method was applied to obtain the concentration contours of the liquid phase. Concentration distribution and variation of instantaneous mass transfer coefficient represented the onset and development of Rayleigh convection and its reinforcement effect on the mass transfer process. Interfacial concentration distribution and critical Rayleigh number explained the mechanism in which the nonuniform mass transfer contributed to the trigger of turbulence. The experimental results showed that the downward high concentration flows promoted the exchange of the liquid between interfacial vicinity and liquid bulk, showing that Rayleigh convection can enhance the mass transfer process.

At ambient temperature and pressure condition, the outwardly propagating characteristics of quiescent ethane/air, propane/air and n-butane/air flames were experimentally investigated in a visible constant-volume micro-chamber with 35 mm diameter and 2 mm height respectively. The results showed that the flammable equivalence ratio ranges of these three fuels were different in the micro chamber. The sequence of them was ethane >propane >n-butane. Both smooth flame-front and wrinkled flame-front shapes were observed during flame propagating of these fuels. The flame speed was lower in the micro chamber than that in conventional combustion chamber, and the flame speed declined along the radial direction during flame propagating. With the increase of equivalence ratio, the flame-front was prone to appear wrinkles and crack. In addition, at high flammable equivalence ratio, sometimes, the flame propagation had a brief stagnation.

The flow field nearby standard Rushton impeller in a stirred vessel was investigated by volumetric three-component velocimetry (V3V) measurements, which about 18000 vectors were captured in a cubic volume of approximately 140 mm in height by 140 mm in width by 100 mm in depth. The characteristics of three-dimensional flow field and the structure of trailing vortices were derived from velocity data. The distributions of radial, axial and tangential velocities in 30° cross-section behind the impeller were analyzed and the distributions of radial and axial velocities by V3V were in good agreement with these by 2D-PIV (particle image velocimetry), especially for trailing vortices in the region of discharge streams. The 2D-PIV study on development of trailing vortices shows that the trailing vortices had an upward inclination at an angle of 10° to the horizontal line as a result of influence by the liquid free surface. The traces of movement were asymmetrical between upper and lower trailing vortices in a way that the movement and decay of the lower vortex were slightly faster than the upper one, which is consistent with the V3V results. Further, trailing vortices were still visible at 60° angle behind the impeller blade. Compared results of both V3V and 2D-PIV to that of pseudo-isotropic approximation, the normalized turbulent kinetic energy (k/V_tip) by pseudo-isotropic approximation was overestimated 25%-33% at locations of trailing vortices and the impeller, where turbulence tends to be anisotropic.

Uniform and stable nanorefrigerant coolants of 0.05%-0.4% Al₂O₃/R141b (mass fraction) were prepared by ultrasonic vibration and used to investigate nanoparticle concentration on pressure drop of gas-liquid two-phase boiling flow of a nanorefrigerant in micro channels. A micro heat exchanger was fabricated by direct metal laser sintering (DMLS) with designed capacity of system pressure at 176 kPa and inlet temperature at 40℃. At conditions of heat flux 21.2-38.2 kW·m^-2 and mass flow rate 183.13-457.83 kg·m^-2·s^-1, the experimental results show that the nanoparticle concentration had significant impact on pressure drop of Al₂O₃/R141b nanoparticle coolant boiling flow in micro channels and the pressure drop decreased with the increase of nanoparticle concentration. After added Al₂O₃ nanoparticles to pure R141b coolant, pressure drop of the pure refrigerant in micro channels was reduced by 5.5%-32.6% depending on mass faction of nanoparticles. Scanning electron microscopy (SEM) and static contact angle measurement revealed that deposition of some Al₂O₃ nanoparticles on the microchannel surface increased surface wettability, which might lower pressure drop of Al₂O₃/R141b upon increase of nanoparticle concentration. Considered three classic pressure drop models and correlations of Qu-Mudawar's and Zhang's for gas-liquid two-phase boiling flow, a revised correlation was developed that 85% of the experimental data points on pressure drop were fallen within a ±15% range of model calculation. The revised correlation can effectively predict the experimental results under these conditions as supported by small MAE number of 11.7%, which was relative deviation between experimental results and revised model predictions.

Heat recovery steam generator (HRSG) is the most important part of the waste heat utilization, and the start-up, shutdown and off-design operation of the HRSG directly determines its life and efficiency. Based on the thermodynamic properties and mass, momentum and energy conservation equations, and taking Matlab/Simulink as the research platform, a dynamic simulation model of the single phase heat transfer surface of HRSG is built in this paper. Combined with the experimental data of the HRSG designed by research group in a cement plant, the parameter optimization of the dynamic model is carried out based on genetic algorithm and particle swarm optimization algorithm. The results show that after optimization, the dynamic model of the waste heat boiler is matched with the experimental data, and the error of the model is 0.93%-4.39%. The dynamic model can be used to simulate the temperature change of the heat transfer surface under different working conditions. And through the comparison of the two algorithms, it shows that particle swarm optimization algorithm has obvious advantages in parameter optimization. The fitness function convergence value is better, and in the convergence iteration, it finishes between the 54 and 64 generation. The genetic algorithm achieves convergence after the 93 generation.

The combustion characteristics of premixed C₁-C₄ alkane jet flames were studied experimentally with a slit burner between two parallel walls. The effects of wall temperature, the distance between two walls, equivalence ratio and fuel type on flame pattern and stability were investigated. The flame images were captured by using a high-speed charge-coupled device camera. The results indicated that the flames experienced three states with the decrease of the distance between the walls, i.e., stable flame, pulsating flame and flame extinction. It was found that the pulsating flames only existed in a very narrow range before reaching the extinction distance. The flame pulsation frequency increased monotonically with the wall temperature. For the same fuel, the frequency was independent to the distance between two walls at a fixed wall temperature and equivalence ratio. Meanwhile, the flame pulsation frequency and the range of the pulsation zone were related to the type of fuel for premixed C₁-C₄ alkane flames. Generally, the methane flame showed the lowest pulsation frequency and narrowest pulsation zone, while these characteristics were almost the same for C₂-C₄ alkane flames.

To understand the effect of fin structure on heat transfer and resistance, numerical simulation and validation experiments were performed on super slit finned tube heat exchangers with different fin pitches P_f and slit heights S_h. When R_e was less than 7200, heat transfer and resistance performance was improved with P_f increase. When R_e was greater than 7200, heat transfer was improved but resistance was declined with P_f decrease. In case of S_h increase, heat transfer declined first and enhanced later, whereas resistance showed an opposite trend. With regard to five super slit finned tube heat exchangers with different fin structures, the comprehensive flow and heat transfer performance were improved while the actual heat transfer area was decreased with P_f increase, which a consideration of all factors should be required. A good agreement was observed between the numerical simulation and experimental results when R_e was in the range of 2734-6712, indicating that the numerical simulation method could predict the heat transfer and resistance characteristics of super slit finned tube heat exchangers. These results would set a basis for optimization between structure and performance of these heat exchangers.

BTX was prepared by Pt/Y catalyzed hydrogenation of the whole or light fraction of hydrogenated FCC diesel in fixed bed reactor at reaction condition of temperature at 380℃, pressure at 3 MPa, volume ratio of V(H₂) over V(feed) at 1000, and WHSV at 1.0 h^-1. The overall selectivity of (C₆+C₇+C₈) arenes was 9.4% and 33.9% for the whole and light fraction of the hydrotreated FCC diesel, respectively. GC-MS study on feeds and liquid products showed that BTX were mainly produced through hydrogenation saturation and cracking of heavy arenes along with intermediate products of mononuclear aromatics such as alkylbenzenes, indane, tetralin, and indenes. By analysis of feeds, fresh and used catalysts via N₂-physisorption, NH₃-TPD, XRD, and TG, it was found that adsorption of high sulfur- and nitrogen- compounds in the whole fraction of FCC diesel quickly lead to catalyst toxication whereas slow accumulation and active site coverage on catalyst surface by sulfur- and nitrogen- compounds in the light fraction of FCC diesel gradually lead to catalyst deactivation.

BiOCl/g-C₃N₄ heterojunction catalyst was synthesized by a hydrothermal method using KCl, Bi(NO₃)₃ and g-C₃N₄ as precursors, over which the photocatalytic reduction of CO₂ under visible light irradiation was conducted. The catalytic activity and the stability during CO₂ photoreduction was studied. Moreover, effects of molar ratio of BiOCl to g-C₃N₄, usage amount of catalyst and illumination intensity on the photocatalytic reduction of CO₂ was investigated. It suggests that the BiOCl/g-C₃N₄ heterojunction catalysts showed much enhanced photocatalytic activities for the reduction of gaseous CO₂ with water vapor in comparison with BiOCl and g-C₃N₄. The BiOCl/g-C₃N₄ catalyst with molar ratio of 1:1 exhibited the highest photocatalytic activity for CO₂ reduction under the optimal conditions of 0.1 g catalyst and 2.413×10^-6 einstein·min^-1·cm^-2 of illumination intensity. Moreover, the catalyst maintained stable performance even after five cycles of test. Techniques of X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller analyses and UV-vis absorption spectroscopy were conducted on the catalyst, and it is speculated that the effective separation of photogenerated electrons and holes due to the formation of p-n heterojunctions between BiOCl and g-C₃N₄ accounted for the improved photocatalytic activities of BiOCl/g-C₃N₄.

A dealuminated Y molecular sieves supporting copper (Cu-DUSY) catalyst was prepared by impregnation technique using Cu as metallic active ingredient and modified USY molecular sieves as carrier, which USY modification was dealuminated in non-buffered citric acid. Physicochemical characterization by XRD, FT-IR, BET, NH₃-TPD, Py-IR and TG-DTA showed that the Cu-DUSY catalyst had excellent thermal stability and steady crystal structure. Cellulose alcoholysis catalyzed by Cu-DUSY yielded 48.2%(mol) of ethyl levulinate (EL) at 200℃ for 3 h. The recycled Cu-DUSY catalyst remained high activity with EL yield above 40%(mol) after being used four times.

Cu-ZSM-11 molecular sieve was prepared by the microwave ion-exchange method. The heating behavior of several kinds of metal oxides under microwave irradiation was investigated. Some metal oxide(MnO₂ >CuO >Ni₂O₃)which is of good absorption property for microwave was selected to be used for mixing with Cu-ZSM-11 catalyst to prepare the microwave catalysts. Direct decomposition of NO over the microwave catalyst MeO_x/Cu-ZSM-11 was conducted with microwave irradiation, and their performance was investigated under microwave irradiation and traditional heating modes respectively. The results show that the conversion rate of decomposing NO is significantly higher under microwave irradiation than under traditional heating; and at catalyst bed temperature 350℃, the NO conversion is achieved up to 99.30% and N₂ selectivity 99.9%. Furthermore, under microwave irradiation, the conversion of decomposing NO is higher for the mixture catalyst MeO_x/Cu-ZSM-11 than for alone metal oxides and alone Cu-ZSM-11, indicating that microwave irradiation plays important role in catalytic decomposition of nitrogen oxide. The results indicate also that over MeO_x/Cu-ZSM-11 with microwave irradiation, oxygen concentration in steam has almost no influences on its catalytic activity for NO decomposition, i.e. microwave irradiation can remove oxygen inhibition in decomposition reaction and keep unique selective effect. Similarly, the influence of water vapor in stream is also much less under microwave irradiation. The exit gas temperature is almost not change for Microwave-assisted reaction, and is the same as the reaction temperature 500-600℃ for conventional heating mode reaction.

β-cyclodextrin (β-CD) filled poly(ether block amide) (PEBA) membranes (β-CD-f-PEBA) were prepared by solution casting method to recover phenol from dilute solution by pervaporation (PV). The physicochemical structure of the membrane was studied by SEM and FTIR. The results showed that the β-CD were dispersed uniformly within the polymer phase and a good adherence was obtained between the β-CD and PEBA just by physical crosslinking. The mechanical properties of the membrane were tested by tensile test. Effect of the phenol concentration and β-CD concentration on the swelling behavior were studied in terms of degree of swelling (DS). The swelling experiments indicated that DS increased significantly both with the phenol concentration in feed solutions and the β-CD concentration in PEBA basic membranes. The solubility parameters of PEBA, phenol and water were calculated by the group-contribution method. The solubility parameter difference between PEBA and phenol was smaller than that between PEBA and water, which meant the PEBA owned high phenol selectivity than water. The adsorption and diffusion separation factor of the β-CD-f-PEBA membrane was used to conform the controlling step of the PV process. The PV performance of β-CD-f-PEBA membrane were investigated at different operating conditions. With the increase of β-CD content, the β-CD-f-PEBA membranes displayed significant improvement in the permeation flux and the separation factor. The β-CD-f-PEBA membrane containing 0.5% (mass) β-CD showed the best separation results with a total flux and separation factor of 3062.9 g·m^-2·h^-1 and 43.3, respectively. With increasing temperature, both the total flux and separation factor increased. The activity energies of phenol and water flux were calculated according to Arrhenius equation with values of 97.19 kJ·mol^-1 and 52.12 kJ·mol^-1, respectively. The result of repeated experiments showed good long term stability of β-CD-f-PEBA films.

D-glyceric acid, one of the promising glycerol derivatives, has various biological functions such as accelerating ethanol and acetaldehyde oxidation. Plenty studies on the synthesis but few studies on downstream processes to recover D-glyceric acid were available. A static equilibrium adsorption was performed to study isothermal thermodynamics and kinetics of D-glyceric acid adsorption onto 201×7 strong basic anion exchange resin. The results showed that the adsorption process followed the Freundlich isothermal model at different pH and temperature conditions, which the maximum adsorption capacity decreased with increasing initial pH. The change of adsorption enthalpy was 14.77 kJ·mol^-1 at 293-308 K, suggesting an endo-thermic adsorption process. Raising temperature improved adsorption rate with limited influence on equilibrium adsorption capacity. The Dynamic Boundary Model was used to investigate adsorption kinetics with a focus on effects of D-glyceric acid concentration, resin particle diameter and adsorption temperature. The results suggested the particle diffusion was rate-limiting step of the adsorption process. The adsorption rate increased with the increase of D-glyceric acid concentration and temperature, but decreased with the increase of resin particle diameter. The general kinetics equation was obtained with the rate constant of exchange (k₀), reaction order (a) and the apparent activation energy of reaction (E_a) as following k₀=1.22×10^-3, a=0.631, E_a=14.90 kJ·mol^-1.

The synergetic production among upstream and downstream enterprises is a critical step toward supply chain optimization across petrochemical industry. However, because of complexity and independent design of petrochemical process, such a synergetic operation between facilities is available only in a few conglomerate corporations with coordinated manufacturing systems. An optimized model for integrated logistic planning in independently operating petrochemical companies was proposed on a basis of current supply chain model of independent refinery and olefin plants. In this mixed-integer linear programming (MILP) model, maximum operation profit was targeted as optimization condition and analyzed in three scenarios corresponding to normal, depressed and active marketing demands. Results of case study showed that, compared to independent operations, the integrated optimization and united operation among petrochemical companies could reduce material storage and overall cost, improve resource allocation, and increase operation profit.

A genetic neural network was presented to predict the critical temperature of refrigerants. The inputs of the network included molecular groups and a topological index, and the output was the critical temperature. 16 molecular groups divided can cover most of the refrigerants or working fluids in refrigeration, heat pump and Organic Rankine Cycle research. The chosen topological index was able to distinguish all refrigerant isomers. The critical temperatures of refrigerants were estimated by the neural network after obtaining the optimized network structure and initial parameters by genetic algorithm. At the same time, in order to improve network generalization ability of prediction, 200 data points were divided into three data sets including the training, validation, and test sets. The calculated results based on the developed network showed a good agreement with experimental data. The network can distinguish all refrigerant isomers and compared with the experimental data. The average absolute relative deviations for training, validation and test sets were 1.18%, 1.69% and 1.28%, respectively.

The time-lag of downcomer caused by the influence of volume on liquid flow and mass transfer has been ignored for establishing the dynamic model of distillation column succinctly. And there is some discrepancies with commercial column. Based on the information of a commercial ethylene column, the paper set up the mechanism model of the theoretical downcomer. In addition, the improved model is the integration of the downcomer model and equilibrium stage model. The simulations of the improved model and equilibrium stage model were achieved by gPROMS, and the differences between them were shown by the comparison of the simulation results. The differences indicated that the accuracy of dynamic model by considering the influence of downcomer. Furthermore, a controller was designed for the improved model and equilibrium stage model, and there was a difference between the control parameters. It was to say, the controller designed on the foundation of ignoring downcomer may be not suit for commercial columns. Thus, considering the influence of downcomer was significant for studying the method of distillation column modeling which was the foundation of the analysis, control and optimization for distillation column.

In the distillation columns, feed composition and temperature always affect the mass exchange and energy utilization, and improper feed-location can cause bad behavior of the separation and energy. To solve the feed position problem of the multi-feed distillation column, a method that identifies improper feed locations is proposed. By defining the conception of the heat transfer temperature driving force and heat transfer rate, mass transfer driving force and mass transfer rate of the tray, the method using the heat/mass transfer composite curve for the bottleneck identification is presented and applied to identify bottlenecks of the multi-feed demethanizer. The strategy that adjusts the feed locations for the process reengineering can achieve the goal of the debottlenecking for the distillation. Process simulation and bottleneck analysis show that the proposed method can identify the feed bottleneck of the demethanizer and the process reengineering can realize the debottlenecking operation. The heat and mass transfer characteristics of the whole tower become better with saving more cold energy.

For large-scale super-structure optimization on non-convex and non-linear heat exchanger network, conventional intelligent optimization algorithms have poor efficiency and easily fall into local optima. Adaptive competitive swarm optimization algorithm was proposed to optimize no-split stream heat exchanger networks with targeted total annual cost. This method improved abilities of both global and local optimization by attenuated learning of average particle positions and self-adaptive adjusting on weight average of speed. Simulation on two typical cases showed that the proposed algorithm sharply reduced cycles of model being used, shortened optimization time and achieved better optimization results in comparison with quantum particle swarm algorithm.

In view of the problem that objective function is difficult to calculate online, a process-data-based online economic performance grading assessment method is proposed. Autoregressive projection to latent structure algorithm (AR-PLS) is used to decompose input data matrix. Then, offline models of different performance grades are established in the subspace related to output latent variable, and thus the unrelated-output variation is eliminated. Afterwards, a similarity-grid model is designed using strategy of “calibration zoning, then comparing the similarity of adjacent grades”. The method can divide process performance into steady performance grade state and transition state. Performance variations caused by factors excluded in offline model can be identified to enrich the offline database further. When the evaluation result is nonoptimal, the cause of performance variation can be diagnosed by the variable contribution. Finally, ethylene cracking process data test shows the method can help to detect performance deviation in time and accurately.

Level Set method is one of the dominant methods to calculate and track evolution of interfaces because it can efficiently handle complex topology change of interfaces and large deformation. This method often suffers from large amount of numerical dissipation and high order accurate numerical discretization in time and space is used to improve mass conservation properties, which leads to an increase of computational overhead. When octree adaptive mesh technology is incorporated into Level Set to capture moving interfaces, the amount of computational meshes and memory usage is reduced and the calculation precision and efficiency are enhanced by adaptive octree mesh refining or coarsening according to interface distance. Because octree mesh is non-uniform and layer numbers of neighbor grids may be different, the WENO formula could not be directly applied to set values of octree grids. A discretization model and a technique of re-initializing distance field were proposed to calculate value of neighbor octree grids as well as to reduce mass loss in Level Set function. Numerical simulation on moving interface in rotation flow field of Zalesak sphere, in shear flow field of sphere and in cast filling process of square cavity benchmark indicated that combination of Level Set method and octree adaptive mesh technology could successfully capture moving interface. The interface-tracking precision was enhanced by refinement of octree meshes and increase of maximum octree mesh layers. When the maximum octree mesh layer was increased from 8 to 9 in the shear flow field, mass conservation of the sphere was obviously improved and numerical dissipation caused by Level Set method was significantly reduced.

Two γ-Al₂O₃ washcoats on FeCrAl substrate were prepared by dip-coating boehmite sol gel or γ-Al₂O₃ slurry. The effects of coating solution on the washcoat properties were extensively studied. The washcoat morphology, crystal structure, texture and adhesion to substrate were investigated by SEM, XRD, nitrogen physic sorption and ultrasonic vibration. At coating loading less than 3%(mass), boehmite washcoats were crack-free but γ-Al₂O₃ washcoats were crack-rich. At coating loading above 8%(mass), boehmite washcoats developed crack, flake and delamination whereas γ-Al₂O₃ washcoats developed only crackings without delamination. In case of requirement for relatively low coating loading (<8%), boehmite washcoats were more suitable as carrier for monolithic catalysts due to higher specific surface area and pore volume than γ-Al₂O₃ washcoats. γ-Al₂O₃ washcoats were preferred as catalyst carrier if higher coating loading was needed (>8%).

Cavitation occurrence in liquid film has a direct impact on hydrodynamic lubrication performance of mechanical seals. A physical model of liquid film seal in spiral grooves was built with consideration of surface roughness and the JFO cavitation boundary condition on mass conservation. The anomalous physical domain composed of spiral curves was transformed into an inerratic computational domain by coordinate transformation. Finite control volume method was adopted to discretize the liquid film governing equation and the Gauss-Seidel relaxation iterative algorithm was used to solve the algebraic iterative equation. The cavitation occurrence in liquid film was analyzed by multiple factors of liquid film thickness, surface roughness, upstream/downstream pumping function, grooving position of spiral groove and cavitation pressure. Results show that cavitation occurrence was easily strengthened at thin films but weakened at thick films. Effects of surface roughness on cavitation or pressure distribution was depressed or even disappeared with increase of liquid film thickness. In case of upstream pumping seal, the circumferential width of cavitation was larger than that of downstream pumping seal, the width for middle grooving seal was larger than that of inner grooving seal, as well as the width enlargement with increase of inner dam reached to maximum when the radial width of inner dam was equal to that of outer dam. However, in case of downstream pumping seal, the width of middle grooving seal was smaller and decreased with increase of the inner dam. Effects of grooving position on cavitation were closely related to the function of spiral groove. Cavitation shranked at lower cavitation pressure but promoted at higher cavitation pressure. High cavitation pressure was beneficial to improving load-carrying capacity of the liquid film.

A three-dimensional fluid-solid coupling mathematic model of a cone-pore-combined mechanical seal was established by considering interactions of pressure distribution change of fluid film between two end faces and stress deformation of sealing rings. A numerical iteration method was developed to solve the coupling model so as to obtain pressure distribution of the fluid film and surface deformation. The influence of structural parameters of the tapered end face on sealing performance was analyzed at various working conditions. The results showed that diamond-shaped pores created dynamic pressure effect, which produced circular and radial wave deformation at the end faces, and static pressure effect, which changed impact accordingly within the end face region with the increase of taper Ф and cone width ratio γ. The convergent seal of the tapered end face at Ф=5-6 or Ф=2-4 and γ=0.8-1.0 should be selected for low pressure and low to medium speed equipment. The convergent seal of the cone end face at Ф=2-3 and γ=1.0 or γ=0.2 should be selected for high pressure and high speed equipment. Changing tapered end face structure could effectively modify characteristic parameters of the cone-hole combined mechanical seal and automatically adjust seal performance during operation, which is especially suitable for variable work conditions. In addition, the change of balance coefficient B and film thickness h caused by structure change of the tapered end face could made up defects of small dynamic pressure effect at low speed to achieve large opening force and could also work under large h so that the flatness and polish requirement for seal end face might be reduced.

New V₂O₅ nanofilm electrodes without binder and conductive agents were fabricated by sintering the V₂O₅ film precursor at 300℃ on stainless steel substrates, which were coated from CTAB-containing V₂O₅ sol gel electrolyte by electrodeposition. X-Ray diffraction (XRD) indicated that V₂O₅ in the new V₂O₅ film was hydrated V₂O₅·nH₂O and the film had lager interlamellar spacing than V₂O₅ film prepared without CTAB. Field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM) results showed that the new V₂O₅ film possessed a rough porous surface morphology. X-Ray photoelectron spectroscopy (XPS) results suggested that the new V₂O₅ film electrode contained more V⁴⁺ than the V₂O₅ film electrode prepared without CTAB. Electrochemical study demonstrated that the new V₂O₅ film electrode had excellent Na⁺ insertion/extraction stability. Compared to the V₂O₅ film electrode prepared without CTAB, the new V₂O₅ film electrode exhibited better electrochemical reaction reversibility, enhanced Na⁺ diffusion performance, and higher sodium storage specific capacity, which could be a very promising cathode material for sodium ion batteries.

A high performance LiMnPO₄/graphene nanocomposite as cathode material for lithium-ion batteries was prepared via surface modification of 3-aminopropyltrimethoxysilane (APS) on LiMnPO₄ nanoparticles and electrostatic self-assembly of positively charged APS-LiMnPO₄ nanoparticles and negatively charged graphene oxide. Successful APS modification on LiMnPO₄ was demonstrated by the existence of 3-aminopropyl and Si-O-C groups in FTIR spectra. LiMnPO₄ nanoparticles (ca. 25 nm) were found uniformly distributed on the surface of graphene sheets. The intimate contact of LiMnPO₄ nanoparticles with graphene conductive network allows achieving fast electron transfer between the active material and charge collector and accommodating volume expansion/contraction of LiMnPO₄ nanoparticles during electric discharge/charge process. The nanocomposite cathode material could deliver an initial capacity of 142.2 mA·h·g^-1 at 0.05 C and maintain 90.5% capacity after 50 cycles, which were significant better than no APS-modified counterpart.

The volatile-char interaction is a common phenomenon during the biomass pyrolysis. In order to study the effect of volatile-char interaction on pyrolysis biochar, the one-stage fluided bed/fixed bed reactor and Py were used in the experiment. The AAEM analysis was carried out with/without the volatile-char interaction. The effect of volatile-char interaction on pyrolysis biochar reactivity was analyzed. The results showed that with increasing pyrolysis temperature from 700℃ to 900℃, the pyrolysis char yield was increased due to the volatile-char interaction as compared with the weak interaction. In the process of pyrolysis, the increase of precipitation of K was caused by the volatile-char interaction. The migration and precipitation characteristics of Ca/Mg elements did not have a significant change. The biochar sensitivity to temperature was reduced by volatile-char interaction and the reactivity of biochar was decreased with increasing temperature.

A Na⁺-exchanged coal (Na-form coal) containing sodium carboxylate, was prepared by ion exchange of an acid-washed Zhunong coal (H-form coal). A H-form-1 coal, prepared from the acid-washing of Na-form coal, was set as a blank. Pyrolysis of the two samples was performed in a fixed-bed reactor. The portable infrared gas analyzer, FTIR and thermogravimetric analyzer were employed to investigate the composition and yields of volatiles, the decomposed components, the variation of functional groups and the char reactivity. It shows that, in presence of sodium carboxylate the production rates of volatiles and release of CH₄, C₂H₄ and C₂H₆ were inhibited when temperature was above 600℃, while the production of CO was promoted at temperature above 800℃. Besides, the tar yield is remarkably inhibited at 700℃. The char reactivity was significantly improved due to sodium carboxylate especially at 700℃. The presence of sodium carboxylate in coal greatly affects the variation of functional groups during the pyrolysis.

In this study, ex-situ catalytic pyrolysis using HZSM-5 zeolite catalyst was studied to obtain aromatic hydrocarbons, olefins and nutrition rich bio-char from sewage sludge. The experiments were applied in the pyrolyzer-gas chromatography-mass spectrometer/flame ionization detector/thermal conductivity detector system (Py-GC-MS/FID/TCD). The sewage sludge was dried and grinded for pyrolysis experiment. Pyrolysis temperature and catalysis temperature were investigated to obtain an optimal condition in terms of hydrocarbon (aromatic hydrocarbons and olefins) production. The optimal pyrolysis and catalysis temperatures were 500℃ and 600℃, respectively. Carbon yields of olefins and aromatic hydrocarbons were 24% and 19%, respectively. The main olefins produced from sewage sludge were ethylene and propene, accounting for more than 95% of the total olefins. The main aromatic hydrocarbons produced from sewage sludge were benzene, toluene, and xylene, accounting for more than 75% of the total hydrocarbons production. The N and C migration experiment showed that 32% of the C and 51% of the N were kept in the bio-char. The fate of inorganic minerals during the process was also investigated. Negligible amounts of metals volatilized during pyrolysis, suggesting that the catalyst poisoning during pyrolysis of sewage sludge may not be a major problem so that the catalyst can be reused and the bio-car can be collected from the reactor. Most of the nutritious elements were still kept in the bio-char, and then the char can be used as potential agriculture application. This study suggested that the catalytic pyrolysis can be used to convert sewage sludge into value-added chemicals and nutrient-rich bio-char.

In this study, biochars produced from three different particle sizes of sewage sludge (d≤0.15 mm, 0.15 mm <d ≤0.27 mm, and d>0.27 mm) using the fixed bed reactor at a temperature of 500℃. Pyrolysis characteristics of sludge and the heavy metals distributions in sludge and its biochar were investigated, respectively. Moreover, the leaching toxicity of heavy metals in sludge and its biochar were assessed applying toxicity characteristics leaching procedure (TCLP) method. The experimental results showed that with the increase of sludge particle size, the biochar and gas yield obtained from pyrolysis process decreased, while tar yield was an opposite trend. During the pyrolysis process of sludge, the most heavy metals in the sludge were accumulated in biochar except As and their relative enrichment factors were all higher than 90%. The contents of Cu, Zn, and Ni in the sludge increased and decreased for the contents of Cr and Pb with augmenting of particle size. Although the leaching pattern of the heavy metals was different between biochars obtained from the different particle sizes of sewage sludge, the pyrolysis technology significantly suppressed the heavy metals leaching from biochars. The TCLP-leaching rates of most heavy metals except As and Zn from biochar were all lower than 3.0%.

Taking actual domestic wastewater (C/N=2.6-4.1) as influent substrate and polyurethane filler as biological carrier (filling rate was 25%), the simultaneous nitrification and denitrification (SND) was achieved in sequencing batch biofilm reactor (SBBR) in a short period of time (98 d) with gradually increased nitrogen loading. The results of real-time qualitative polymerase chain reaction (qPCR) confirmed the enrichment of nitrifying bacteria in the reactor. The system had a good effect of organic matter and nitrogen removal in the formal running period. The concentration of COD,NH₄⁺-N and TN of the effluent water was 38.28 mg·L^-1, 1.23 mg·L^-1 and 8.23 mg·L^-1, respectively. Most of COD was taken up and converted to polyhydroxyalkanoate (PHA), and the storage products were used for denitrification, which removed a large amount of nitrate. The removal efficiency of TN and SND was calculated as 82.95% and 70.57%, respectively, and the NO₂^--N concentration always kept low level. Since the nitrification and denitrification reactions took place in the same reactor and conditions, the system could maintain pH in a steady conditions by that the increasing basicity in the denitrification process can complement the consuming basicity in the nitrification process. Furthermore, the reaction time can be effectively controlled and the power consumption can be decreased through the curve change of DO and pH to judge the operation status of SND.

In order to efficiently utilize carbon source of low C/N ratio domestic sewage, two methods (reducing organics input and increasing carbon source consumption through denitrification) were introduced through the partial nitritation SBR. In this study, five factors, i.e. influent volume, drainage ratio, aeration time, precipitation time and stirring time after aeration were investigated to assess the effect on the utilization efficiency of carbon source(the ratio between the quality of carbon source consumption through denitrification and the total organics input). The results showed that when the drainage ratio was decreased from 50% to 35%, the utilization efficiency improved from 15.1% to 24.8%; when the aeration time was increased from 2 h to 2.25 h, the utilization efficiency increased from 24.8% to 27.5% and when 1.5 h of stirring time after aeration was added, the utilization efficiency increased by 3.8%. Meanwhile, the nitrite accumulation rate of the effluent was 94.8% and the NO₂^--N/NH₄⁺-N was 1.7, indicating that the partial nitrification was stably maintained, and the effluent was more proper for simultaneous anammox and denitrification (SAD) process. All in all, the organics utilization efficiency was promoted gradually through the adjustment of the operational parameters above, by which the aeration energy for consuming organics was saved, and then the multiplication of aerobic heterotrophic bacteria was weakened which avoided striking the ammonia oxidizing bacteria (AOB) effectively, keeping the nitritation effect stable.

The effect of latex concentration in ABS resin emulsion graft section wastewater on demulsification efficiency was investigated with PAC as demulsifier. The results indicated that there were optimized ranges of reagent dosage in different latex concentrations, as the undersize or oversize dosages could all lead to poor demulsification efficiency. When the latex COD concentration decreased from 13012 mg·L^-1 to 192 mg·L^-1, the optimized ranges of reagent dosage moved right, increasing from 6.1-10.8 mg·g^-1 to 7.7-13.8 mg·g^-1. The optimum COD removal efficiencies dropped from 99.30% to 91.24%. The optimum reagent dosages per latex COD unit increased by about 40%. The demulsification mechanism of latex wastewater by PAC was mainly adsorption-charge neutralization. With increase of PAC dosage, the colloid Zeta potential increased, and the latex could realize demulsification effectively in the range of -23-13 mV.

W₂C/AC catalysts with different tungsten loadings were prepared by using the activated carbon (AC) as the carrier. These catalysts were mechanically mixed with the pine milled wood lignin (MWL) for Py-GC/MS (pyrolysis-gas chromatography/mass spectrometry) experiments to investigate the catalytic effects of tungsten loading and catalyst-to-MWL ratio on the distribution of pyrolytic products. Moreover, the actual yields of major pyrolytic products (aromatic hydrocarbons and phenolics) were quantitatively determined by the external standard method. The results indicated that the W₂C/AC catalyst could promote the pyrolytic depolymerization of MWL to generate momocyclic phenolic compounds. Furthermore, it could catalyze the decarbonylation, demethoxylation, dehydroxylation and hydrogenation reactions of phenolic compounds to form stable phenolics (without the carbonyl group, methoxyl group and unsaturated C=C bond) and aromatic hydrocarbons. Among the four W₂C/AC catalysts, the 10%-W₂C/AC possessed the best catalytic capability. The maximal yield of total pyrolytic products was obtained at the catalyst-to-MWL ratio of 5, and the total yields of aromatic hydrocarbons and phenolics at this condition reached 102.1 mg·g^-1 and 191.1 mg·g^-1, compared with the values of 21.2 mg·g^-1 and 151.0 mg·g^-1 in the absence of the catalyst.

The biochars derived from nine kinds of leaves by one-step pyrolysis were employed as counter electrodes in dye-sensitized solar cells (DSSCs). Based on comprehensive analysis on the microstructure, crystal structure and electrochemical properties of biochars, the intrinsic causes to induce the difference of the photovoltaic properties of the biochars based DSSCs were investigated emphatically. The results indicated that the conversion efficiencies of DSSCs consisting of biochars counter electrodes derive from various leaves ranged from 1.00% to 1.85%. Among them, the palm leaf bring about the best efficiency, followed by camphor leaf, poplar leaf, maple leaf, red after-wood leaf, toona leaf, firry leaf and pine needles, and the cassia leaf with the least efficiency. The pore structure of biochars was believed as one of key factors to induce the difference of the photovoltaic properties of the DSSCs. Since the biochar prepared from palm leaf possessed unique oriented pore structure which could shorten the diffusion length of electrolyte and improve the catalytic activities, the DSSC with the best efficiency was obtained. Especially, all the biochars based DSSCs showed higher efficiency than the graphite based device. The efficiency of the graphite based DSSC is 0.77%. The high performance of biochars based DSSCs can be attributed to the favorable characteristics of the biochars, such as hierarchical pore structure and glassy carbon skeleton. The low temperature (120℃) treatment process can be employed to fabricate a low-cost counter electrode for both glass based DSSCs and flexible DSSCs.

The study aimed to reveal the reason why carboxymethylated lignin (CML) had better dispersion properties than sulfomethylated lignin (SAL). It was found that hydrophilic property of CML was weaker than that of SAL by measuring the amount of hydrophilic group of CML and SAL, relative molecular weight and pure water contact angle on lignin coating. The measured adsorption isotherms of two lignin dispersants on carbendazim particles showed that the adsorption capacity of CML was higher than that of SAL, indicating that CML was easier to be absorbed on carbendazim particles than SAL. It was also found that the adsorption ability of CML was larger than that of SAL under the application of the Langmuir and Freundlich adsorption isotherm equations. It indicated that the adsorption affinity between weak hydrophilic CML and pesticides was stronger, and the adsorption between lignin and pesticides may be based hydrophobic adsorption. Further more, through simulate calculating the π-π force between lignin dispersants and carbendazim, it was found that the CML was easier to form a stable π-π effect with pesticides and to promote the adsorption. Due to the stronger adsorption affinity between CML and pesticides, the absorption capacity of weaker hydrophilic CML was higher, and thus CML can improve the Zeta potential of carbendazim particles, showing better dispersion properties.

Owing to the large scale area-to-volume ratio involved, hollow fiber membranes (HFMs) provide a tremendous amount of surface area for cell adhesion. Therefore, HFMs are widely used for large-scale expansion of cells. Traditionally, trypsinization is empolyed to harvest adhered cells from the surface of HFMs. However, this proteolytic enzyme treatment will destroy cell viability and function. Therefore, this study prepared a serious poly(N-isopropylacrylamide) (PNIPAAm) grafted HFMs (PNIPAAm-g-HFMs) with different grafted amounts, and the fibroblasts culture and detachment from PNIPAAm-g-HFMs with temperature reduction was also investigated. ATR-FTIR and elemental analysis results indicated that the PNIPAAm was covalently grafted on HFMs successfully via free radical polymerization in the presence of cerium (Ⅳ). Dynamic contact angle measurements showed that the surface contact angle of water on PNIPAAm-g-HFMs decreased significantly when the temperature dropped below LCST. Additionally, the protein adhesion assay results further confirmed that PNIPAAm-g-HFMs exhibited thermo-responsive property, namely hydrophilic-hydrophobic phase transition with temperature changed. MEFs adhered, spread and grew well on the surface of PNIPAAm-grafted HFMs except HFMs-0.2 at 37℃. In addition, the experiment of cell detachment showed that the cell can be released from PNIPAAm-g-HFMs with decreasing temperature and detachment efficiencies were above 90%. In conclusion, the PNIPAAm-g-HFMs with thermo-responsive property can be an attractive candidate for cell large-scale expansion and cell detachment with temperature reduction.

Tungsten carbide and titania (WC/TiO₂) nanocomposites were fabricated by surface modification of rutile titania reacting with ammonium metatungstate and followed by in situ reduction and carburization of the modified rutile in CH₄/H₂ atmosphere. The influence of temperature and time of in situ reduction and carburization on phase structures of WC/TiO₂ nanocomposites were investigated by XRD characterization on nanocomposites, and the formation mechanism of crystal phases in WC/TiO₂ nanocomposites was discussed. The morphology and thermal stability of WC/TiO₂ nanocomposites were studied by SEM and TG-DTA, respectively. Electrocatalytical properties of the WC/TiO₂ nanocomposites with different phase structures were investigated by cyclic voltammetry. Results showed that WC/TiO₂ nanocomposites composed of both WC and TiO₂ crystal phase exhibited the best catalytic activity for p-nitrophenol (PNP) electroreduction.

Using trimethylolpropane triglycidyl ether (TMPGE) as a core molecule, star hydroxyl polyesters (SHPs) were synthesized via the ring-opening reaction of epoxy groups and carboxyl groups. The influence of the categories and molar ratios of raw materials on the properties of SHPs were investigated. The structures and molecular weights of SHPs were characterized with Fourier transform infrared spectrometer (FTIR), nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). The results showed that the SHPs prepared from oleic acid had the lowest viscosity. IR and ¹H NMR spectra indicated that the target SHPs were successfully prepared and possessed similar molecular skeleton structures. The GPC curves displyed that the measured molecular weights of SHPs approached to the theoretical values, and the polydispersity indexes (PDI) of SHPs were in the range of 1.10 to 1.28. The film properties of SHPs cured by the toluene diisocyanate adduct were tested and found that the cured films exhibited excellent adhesion, flexibility and high hardness. Especially, the solution viscosity of SHP-2 was less than 220 mPa·s at 80% solid content and the VOC contents of 2K-PU from SHP-2 was low to 320 g·L^-1.

In order to improve sunlight utilization as well as to recycle and reuse photocatalyst of titanium dioxide, Pr³⁺:Y₂SiO₅/TiO₂/ACF composites were prepared by sol-gel technique of anchoring upconversion fluorescent material and nano-titanium dioxide on activated carbon fiber (ACF). Structures and properties of the Pr³⁺:Y₂SiO₅/TiO₂/ACF composites were characterized by XRD, FT-IR, SEM, FS, and UV-vis DRS. Photocatalytic activity of the composites in the visible light region was evaluated with methylene blue solution as model pollutant and studied the effect of fabrication conditions such as calcination temperature and number of coating layers. The experimental results showed that TiO₂ in Pr³⁺:Y₂SiO₅/TiO₂/ACF composite contained both anatase (34.1%) and rutile (65.9%) when prepared by double coating and 800℃ calcination. This composite had the highest visible-light photocatalytic activity which degraded methylene blue (15 mg·L^-1) high as 93.8% in 12 h. The photodegradation followed pseudo first order kinetics with reaction rate constant is 0.2471 h^-1. Pr³⁺:Y₂SiO₅/TiO₂/ACF composite remained degradation rate above 75% after recycled and regenerated for use four times.

In this work, a simple one-pot hydrothermal method was developed to synthetize CuS/C composite in one-step by using copper nitrate trihydrate (Cu(NO₃)₂·3H₂O) as copper source, thiourea as sulfur source and D-glucose sodium as complexing agent. The composition, microstructure and morphology of the CuS/C composite were characterized by X ray diffraction (XRD), Raman spectroscopy, organic element analyzer and scanning electron microscopy (SEM). It was found that the as-synthesized composite was mainly composed of novel petaloid CuS microspheres, which provided many paths for ion diffusion and increased specific area with about 6% of amorphous carbon microspheres (mass fraction). The composite exhibited a maximum specific capacitance of up to 719 F·g^-1 at 1 A·g^-1, while the specific capacitance was 382 F·g^-1 at 1 A·g^-1 for CuS prepared without using complexing agent. The long-term constant current charge-discharge test showed that the CuS/C composite exhibited excellent long cycle life with capacitance retention of 80% after 1000 cycles at 1 A·g^-1. Although due to low melting point (220℃) of CuS, heat treatment at high temperature cannot be employed to transform the amorphous carbon microspheres into crystalline carbon for further improving the electrochemical properties, the one-pot hydrothermal method was likely to open a new way for directly synthetizing transition metal compounds/carbon composite materials by a one-step process, especially for transition metal compounds with high melting point/carbon composites with the possibility of carbonization treatment at high temperature.

Norbornene imide (NI), which was prepared from carbic anhydride and p-aminophenol, together with 4,4-2 amino diphenyl ether (ODA) and paraformaldehyde, was used to synthesize norbornene-imide-functionalized benzoxazine (NI-BOZ) via Mannich reaction. A novel thermosetting resin was obtained from high temperature curing of NI-BOZ. Structure of NI and NI-BOZ were characterized by FTIR, ¹H NMR and ¹³C NMR. Curing kinetics of NI-BOZ was monitored by DSC and thermal properties of poly(NI-BOZ) were evaluated by DMA and TGA. The results showed that the activation energy of NI-BOZ thermal curing was 86.27 kJ·mol^-1 and the reaction order was 0.91. Poly(NI-BOZ) had glass transition temperature (T_g) of 215℃ in air environment. The polymer had 5% mass loss at 445℃, 10% mass loss at 467℃ and 63% char yield at 800℃ under nitrogen.

“Green” synthesis of bimetallic nanomaterials has drawn considerable attention in the field of nanotechnology. Au-Ag bimetallic nanomaterials were synthesized using extract of Artocarpus heterophyllus Lam leaves as reducing and capping agent. As a result of greater influence of temperature on nucleation and growth of Ag nanoparticles than the Au nanoparticles, Au-Ag alloys with a ratio of Au to Ag in 3:1 were obtained at 333 K, while alloys with a lower ratio of Au to Ag (1:1) were obtained at 363 K. This influence was illustrated by determining the nucleation and growth of Au and Ag nanoparticles using UV-Vis spectrophotometry method respectively, and it was also confirmed by FTIR analysis that only partial biomolecules were oxidized in the synthesis of Au-Ag (3:1) alloys. Au-Ag bimetallic nanoparticle with a ratio of Au to Ag in 1:1 generated a significant Raman enhancement in probing of Rhodamine 6G.