Multiphase reactors are most widely encountered in chemical, metallurgical, energy and pharmaceutical industries. Because multiphase flow in reactors is generally unstable, nonlinear and non-equilibrium in nature, many challenges are exerted to multiphase flow detection technology. It has always been one of the frontier studies in process engineering to accurately measure and comprehend multiphase hydrodynamics, as well as to discover and master rules for design and scale-up of multiphase reactors. Magnetic resonance image (MRI) technology, an advanced non-invasive detection method, can obtain accurate and detail information of multi-dimensional transient fields, such as transient solid concentrations, velocity (fluctuating) fields, flow pattern recognition, bubble vortex structure, particle clustering, and meso-scale heterogeneous structures. Additionally, MRI could have good prospective applications for validation and improvement of numerical models. This review discussed MRI principle, analyzed current status of MRI application for gas-solid and gas-liquid flow hydrodynamics, and prospected promising future directions.

The mathematic model between the phase distribution of object beam and the mutual diffusion coefficient of binary solution was established based on the one-dimensional and infinite model. A novel experimental method for measuring the mutual diffusion coefficient of binary liquid mixtures was proposed based the existing digital holographic interferometry. For the presented method, the mutual diffusion coefficient is determined directly through the phase distribution curve of object beam, which can obviously avoid the influence of ambient noise on the experimental result. The requirement of the optical condition in the lab was considerably reduced. The relative combined uncertainty of mutual diffusion coefficient is around 0.7%. The mutual diffusion coefficient of KCl aqueous solution at 0.33 mol/L and 25℃ was measured. The result is in good agreement with literature data, which proves that the new measuring principle is feasible and correct. With the new method and experimental apparatus, the mutual diffusion coefficient of methanol/cyclohexane binary mixture was measured and analyzed near the immiscible concentration region. Based on the experimental result, the Spinodal line, which is used to describe the boundary between the thermodynamic instable region and the metastable region, was predicted for methanol/cyclohexane binary system.

Understanding the mechanism of fluid droplets attached to micro/nano channels being displaced by another fluid can shed light on the transport law in unconventional oil and gas development. The cross-scale nature of the process and the strong interaction between droplet and displacement fluid determine that a hybrid simulation method must be used. In previous researches, the commonly used interface conditions of adding an external force interfere with the transfer of shear stress from the continuous domain to the molecular domain, resulting in incorrect calculation of the flow resistance. A new method of arranging a virtual wall instead of adding a force was used to solve the problem of incorrect shear stress transfer. Based on this new method, the cases are compared where the droplets are monoatomic molecules and butane, and the cases that the wall is completely rigid and the wall particles are allowed to vibrate, respectively. The results show that the traditional method of adding a force could lead to errors up to 65% in the flow drag, while arranging a virtual wall could keep error within 1%, thus has significant advantage. The introduction of droplet molecular structure and the wall particle vibration both have a great influence on the flow resistance.

Paraffin wax in the partition wall type heat exchanger encumbers the heat transfer rate of the system because of its low thermal conductivity. The heat exchange rate of the heat storage system can be greatly improved by direct heat exchange between paraffin and air. Paraffin wax and air were used to study the heat transfer characteristics of air-paraffin direct contact heat transfer. The air at room temperature was injected into high-temperature (100-150℃) liquid paraffin through a distributor. This work examines the effects of superficial gas velocity, static liquid height and heat exchange temperature difference on the volumetric heat transfer coefficient and gas holdup rate in paraffin-air bubble heat transfer system. The results show that the volumetric heat transfer coefficient and the gas hold up increase by increasing the superficial gas velocity, and, for gas holdup, the growth rate is faster at lower superficial gas velocity. Increasing the height of the static liquid height will only lead to a decrease in the volumetric heat transfer coefficient and the gas holdup in the experimental conditions, and the effects of changing the gas liquid temperature difference on the volumetric heat transfer coefficient is not obvious. In addition, these effects are formulated in forms of empirical equations.

Atomization of high viscous non-Newtonian fluid into gas by spinning disk promotes intimate contact between the two phases. The size of droplets is directly determined by the ligament breakup characteristics, which is the key factor to affect the qualities of product. For spinning disk atomizer in this paper, the ligament breakup characteristics are analyzed, the ligament spacing model concerning with both the surface tension and viscous forces is proposed. Meanwhile, the ligament breakup mechanism is summarized. The results indicate that the viscosity always produces damping effect for the formation of ligament. With the increasing of viscosity, the ligament spacing will also increase. In general, the ligament number is influenced by the linear velocity of liquid film at the disk rim, while it becomes stable in fully-ligament mode. The disk with larger diameter and slower speed is advisable in the actual atomization process. For high viscous non-Newtonian fluid, the ligament number can be predicted by the Weber number, the equivalent Reynolds number and the flow index. This paper supplies the theoretical basis and further application for the design and optimization of centrifugal atomization of high viscous non-Newtonian fluid.

The flow characteristics in the triangular grooved channel by pulsating flow at low Reynolds number has been investigated. The influence of several main parameters on flow resistance is analyzed. The parameters are Reynolds number, Womersley number and pulsating amplitude. The results show that, flow resistance in the triangular grooved channel by pulsating flow is higher than that in steady state. Flow resistance in pulsating state increases with the pulsating amplitude, and there is a Womersley number for the highest flow resistance. It also measures that the imposed pulsating flow causes phase difference between the curve of velocity and the curve of pressure drop. In addition, the phase difference is determined by Womersley number, but irrelevant to the pulsating amplitude. To explore the cause from what has been discussed above, the mathematical model of pressure drop is established. The reason why flow resistance in pulsating state is higher than that in steady state is that,compared with steady state, there is a Δp_r in the mathematical formulas of pressure drop in pulsating state, and the average value of the Δp_r in a cycle is more than 0. The pressure drop of form drag is mainly affected by Womersley number, and the total pressure drop increases with the pulsating amplitude. The results from theoretical analysis also indicate that, the accelerating pressure drop induces the phase difference, and the value of phase difference is affected by frictional resistance, form drag and accelerating pressure drop.

Monodisperse droplet spray dryer (MDSD) has demonstrated great advantages in the production of uniform sized particle products. The drying performance of such facility is improved. By resorting to the discrete phase model (DPM) and the reaction engineering approach (REA) based on drying model, a 3D CFD model is developed to describe a complete MDSD consisting of a small droplet pre-dispersion chamber and a big drying chamber. The model allows to investigate the influence of introducing swirling flows in the pre-dispersion chamber and the drying chamber on particle trajectory and drying dynamics. It is shown that the introduction of the swirling flow at an air inlet angle of 30° can offer decent performance. When both chambers have swirling flows, the co-current scheme is 2% better than the counter-current scheme in terms of reaching lower particle moisture content. Compared with the case without any swirling flow, the particle moisture content can be 30% lower. To achieve the same moisture content, with the introduction of the swirling flow, the dryer can be shortened by nearly 12%.

An investigation was conducted to quantify the unsteady heat transfer and phase changing process of a large droplet impinging onto cold surface under different surface temperature, through high speed imaging and infrared thermal imaging technology. In addition, a new method of deicing was presented. The deicing experiment using high-frequency nanosecond pulse dielectric barrier discharge plasma actuator was conducted, and thermodynamic analysis was also carried out. The results reveal that cold surface temperature has little effect on the spreading process, but has obvious effect on receding process,oscillation process and final ice shape. The icing starts at the bottom of the droplet, with the decrease of the wall surface temperature, the temperature difference between droplet and cold wall surface get bigger, hence the underlying liquid droplet freeze faster, the liquid film on the top of droplet get thinner, and the time needed for freezing phase change get shorter. By using high-frequency nanosecond pulse dielectric barrier discharge, the deicing effect is obvious, and the discharge area acts seem as a “heat source”. According to the way it functions, the process of deicing can be divided into two stages.

Liquid affects particle circulation in spray gas-solid fluidization by forming different extent of particle agglomerates and directly reduce heat and mass transfer of the reactor. Ethylene glycol solutions of various viscosities were sprayed onto fluidized bed to artificially create agglomerates. The results showed that liquids of different viscosities would form different agglomerates in fluidized bed, which can be divided into four groups by agglomerate size, including microaggregation, nucleation agglomerates, coherence agglomerates, and paste agglomerates. Recursive analysis of differential pressure fluctuation signal in flow process indicated some obvious differences in recursive pattern structure under different agglomeration conditions. Further analysis finding on distribution of recursive feature indices of 50 flow conditions was used to identify agglomeration structures which 96.39% overall recognition rate was achieved. Therefore, agglomerated state in fluidized bed was quickly identified by recursive analysis of differential pressure signal.

The modified lattice Boltzmann method (LBM) and discrete element method (DEM) were combined to simulate the bubble movement in bubbling bed of single port jet, based on the LBM-DEM four-direction coupling model. Fluid phase used the classical D2Q9 model of LBM, particle phase was solved by the discrete element soft sphere model, particle drag force was solved by adopting the Gidaspow model, and fluid-solid coupling was based on the Newton's third law. The above model was solved by the Fortran language procedure. The bubble evolution process in bubbling bed was simulated and compared with the related experiments, which effectively verifies the accuracy of the present model. Meanwhile, the particle velocity, particle volume fraction and energy distribution in the bed were analyzed. The results show that the distribution of particle time-averaged velocity can show the motion strength of particles, and reflect the bubbles' movement process. The voidage in the bed and the distribution of particle volume fraction have the high consistency in predicting the bed expansion height. The initial accumulation effect makes that potential energy of particles is always larger than kinetic energy of them in the bed. In addition, potential energy increases, but kinetic energy gradually decreases with particle density.

An investigation on single side condensation of vapor inside a horizontal rectangular tube was performed. The influences of tube aspect ratio on flow pattern, heat transfer coefficient and pressure drop were analyzed. Annular flow, annular-wave flow, wave flow, slug flow, plug flow and bubbly flow are observed. Flow pattern appearing in larger aspect ratio tube was more comprehensive than in small one. The area occupied by the annular flow increased with the decrease of the aspect ratio, but the difference gradually decreases with the increase of mass flow rates. Heat transfer coefficient and pressure drop increased with aspect ratio decreased while mass flow rate was small. With the mass flow rate increased, the difference for heat transfer coefficient decreased while for pressure drop increased.

The simultaneous calcination/sulfation reaction is the real reaction process of limestone in circulating fluidized bed (CFB) boiler. To obtain the true calcination process of limestone in CFB, the combined effect of H₂O and SO₂ on the calcination kinetics and pore structure of limestone during simultaneous calcination/sulfation reaction under CFB conditions was studied in a constant-temperature reactor. H₂O (0-15%) can accelerate the calcination of CaCO₃. The SO₂ in flue gas decreased the calcination rate of limestone particles. This phenomenon was explained by a mechanism based on the measurement of pore structure, namely that SO₂ reacted with CaO layer, and the formed CaSO₄ would fill or block the pore in CaO layer, decrease the pore volume, increase the diffusion resistance of CO₂, and consequently impede the calcination reaction. H₂O and SO₂ can work synergistically on changing the calcination rate,and an increase of the calcination rate was found under 15% H₂O and 0.3% SO₂ compared to that without either. This may be because intrinsic reaction played a major role in the rate controlling step of calcination, and H₂O accelerated the intrinsic calcination directly. The effect of other factors like temperature and particle size on the calcination rate in the presence of H₂O and SO₂ were also tested. H₂O also accelerated the sintering of CaO significantly, and along with SO₂, the pore volume and surface area of CaO decreased further.

RuCu/TiO₂ bimetallic catalysts which were prepared via chemical reduction methods and the synergetic effect between Ru and Cu in the detoxification of ammonia-wastewater to nitrogen via catalytic wet air oxidation (CWAO) were investigated. The results showed that the addition of Cu in Ru/TiO₂ can effectively improve the selectivity of N₂, while the presence of Ru in Cu/TiO₂can greatly enhance the catalytic activity of the catalyst. The catalyst (1Ru2Cu/TiO₂) with 1% and 2% loading of Ru and Cu has the best catalytic performance among the prepared catalysts. With the reaction conditions of 0.5 MPa,150℃,[NH₃]₀=1000 mg·L^-1,pH=12 and the application to the simulated wastewater was about 33 L·(kg cat)^-1·h^-1, 1Ru2Cu/TiO₂ achieved 87.7% ammonia conversion and 85.9% N₂ selectivity. The characterization results demonstrated that the synergetic effect of Ru and Cu played a key role in the catalytic of the ammonia to nitrogen, mainly reflects in the following:the strong interaction between Ru and Cu results in good anti-leaching of 1Ru2Cu/TiO₂ catalyst, leading to excellent stability for the catalyst. The electron transfer between Ru and Cu makes 1Ru2Cu/TiO₂ has a moderate oxygen affinity, which has effectively enhanced the catalytic activity of the catalyst.

The vapor liquid equilibrium test bench was set up, and the data of vapor liquid equilibrium of CO₂ in aqueous mixture of 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim] [BF₄]) and monoethanolamine (MEA) were measured. The desorption energy consumption of this absorbent was calculated. The results showed that with the increase of temperature, the corresponding CO₂partial pressure of the solution increased, and the change of the mass fraction of[Bmim] [BF₄] had little influence on the vapor liquid equilibrium. Compared with 30% MEA, the main advantage of this absorbent in terms of energy consumption lies in the reduction of sensible heat and latent heat during desorption. The reaction heat decreased significantly after the CO₂ loading was greater than 0.45, and the decrease of latent heat was mainly due to the decrease of the partial pressure and mole fraction of H₂O in gas phase in the desorption tower. When the mass fraction of[Bmim] [BF₄] was bigger than 30%, the energy consumption of sensible heat could be decreased by more than 30%, and the main reasons for the decrease were the decrease of specific heat capacity and the increase of amine concentration in rich phase liquid.

Based on the strong interaction energy between the coordinatively unsaturated metal sites (UMSs) and the gas molecules, M-BTC(M=Cr, Mo, Ni), isostructural with HKUST-1 (Cu-BTC), were successfully synthesized via the coordination reaction of the high activity divalent metal (Cr²⁺/Mo²⁺/Ni²⁺) and organic ligand (H₃BTC), and then to gain insight into the impact of gas-metal interactions on the selective adsorption of CH₄ from N₂ by comparing with classical materials (Cu-BTC). The results show the good CH₄ selective adsorption properties of M-BTC (M=Cr, Mo, Ni) with UMSs. Among these materials, Ni-BTC with unsaturated Ni²⁺ sites presents the highest adsorption heat value for CH₄, leading to the excellent CH₄/N₂ adsorption separation properties; but the Cr-BTC with high Cr²⁺ activity shows the lower ability for CH₄/N₂ separation than Cu-BTC. Combined the IAST calculation results, we verified the ability for the selective adsorption of CH₄ molecules on M-BTC (M=Cr, Mo, Ni) and Cu-BTC followed as Ni-BTC > Mo-BTC > Cu-BTC > Cr-BTC.

To achieve the maximum recovery of ionic liquid recycling, the electrodialysis-vacuum membrane distillation integrated process was proposed to concentrate the low concentration mass fraction (the same below) in 1%-5% ionic liquid. It achieved effective and operational membrane integrated concentration control process. The influence of operating parameters in ED process, including voltage, initial concentration, and the volumetric feed ratio was analyzed and a maximum concentration was obtained. The[AMIM]Cl aqueous solution can be condensed to 48.2% after switched to the vacuum membrane distillation process.

To overcome the problem of batch process caused by the traditional process dynamics multistage characteristic, the multiphase auto regression-principal component analysis (AR-PCA) monitoring method is proposed based on affine propagation (AP) clustering optimized with a population diversity-based particle swarm optimization algorithm (PDPSO). The method introduced PDPSO method to improve the AP clustering. It avoided the blindness of common method that indirectly chose the preference based on the clustering evaluation index. Then we established the AR-PCA model for the data samples of the multiphase fermentation process to eliminate the dynamic characteristics of each stage and the auto-and-cross-correlation between variables. Finally, the PCA model is established for the residual of the AR model for fault monitoring of the batch process. The method is applied to the process of penicillin fermentation. Experiments show that the method can effectively divide the process into different phases and reduce the false and leak alarms.

The extreme learning machine (ELM) problem can not quickly and accurately predict heat rate. Combined with swarm intelligence optimization algorithm, an ameliorated symbiotic organisms search algorithm and extreme learning machine (ASOS-ELM) comprehensive modeling method is proposed. This method uses the ameliorated symbiotic organisms search (ASOS) algorithm to optimize the parameters of the ELM hidden layer activation function to obtain the optimal ELM model. Firstly, the initial heat rate prediction model is established with ELM, and the root mean square error (RMSE) of the output heat rate is used as the fitness value of the algorithm. Then the appropriate ELM parameters are found through the ASOS algorithm to obtain an accurate heat rate prediction model. The performance of the heat rate prediction is compared with the traditional ELM model, support vector regression (SVR) model optimized by the ASOS algorithm, ELM optimized by improved particle swarm optimization (PSO) and basic symbiotic organisms search algorithm (SOS). The results show that the ASOS-ELM model has a precise forecasting ability and rapid convergence speed when dealing with complex data models, which provides a new idea for modeling the heat rate of a steam turbine.

Cavitation occurrence in the liquid film affects the lubrication performance of mechanical seals. A mathematical model of spiral groove liquid film seal was established based on the mass-conserving JFO cavitation boundary condition. The Reynolds governing equation was solved by the streamline upwind finite element method, and cavitation distribution was obtained. The calculation result was verified by cavitation visualization experiment. The influence of spiral groove geometrical parameters on cavitation characteristics were analyzed with the critical speed and critical pressure of cavitation as the characterization. The results indicate that the cavitation area in spiral groove is of wing section type, and it increases with increasing rotating speed and decreases with increasing inner pressure. The maximum circumferential length of cavitation is located near the groove radius. The critical speed of cavitation increases with the increase of groove number and depth, but decreases with the increase of spiral angle, radial seal dam extent and groove width ratio. The changing trends of critical pressure of cavitation with geometrical parameters are opposite to those of critical speed of cavitations. The effective control of cavitation can be achieved by reasonable selection of geometrical parameters.

Reduced graphene-based iron oxide composite was prepared via thermal chemical deposition method and used to remove glyphosate (GLY) contaminated water by a dynamic adsorption experiment. Influences of GLY concentration, solution pH, flow rate and filler bed height were analyzed. The dynamic adsorption mechanism was characterized by SEM-EDS, XPS and BET, as well as Thomas, Yoon-Nelson and Yan adsorption models. The results demonstrated that the glyphosate adsorptivity increased and the breakthrough time decreased with the increase of the initial glyphosate concentration, however, breakthrough time prolonged when increasing the adsorbent quality. In contrast, the glyphosate adsorptivity and the breakthrough time decreased with an increase in the pH value and flow rate. The fitting results matched Thomas, Yoon-Nelson and Yan model well, and the theoretical adsorption capacities were in close agreement with the experimental data. To study the dynamic adsorption process and the adsorption microscopic mechanism is of vital theoretical and practical significance for the popularization of graphene materials and the treatment of glyphosate contaminated water.

The Zhundong coal reserve in China is abundant and characterized by high sodium content. The present work investigated the chemical looping combustion (CLC) performance using the high sodium-based Zhundong coal as fuel, CO₂ as gasification agent and iron ore as oxygen carrier. The experiments were performed in a bubbling fluidized bed reactor. Effects of coal particle size, reaction temperature, fluidization velocity and coal char particle size on the escaping behavior of combustible gases during CLC process of coal or coal char were evaluated. Meanwhile, the effect of minerals in the coal on char gasification was investigated. The results indicated that in the CLC process using bubbling bed as reactor, segregation is present due to the large difference of fluidizing properties between oxygen carrier materials and coal. Volatile as well as char conversion are influenced in CLC process due to the presence of segregation. A high fluidization velocity remarkably enhances the mixing between oxygen carrier and solid coal/char particles and reduces the negative influence of segregation. Consequently, the combustible gases escaping is reduced and char gasification rate is increased. The minerals in coal char can maintain fast gasification rate of coal char.

A 5 kW_th two-stage fuel reactor of chemical looping combustion facility was successfully built to carry out the characteristic research of coal chemical looping combustion. The experiment focused on the influence of temperature and gasifying agent on the combustion compensation efficiency, carbon supplementation, outlet gas component, oxygen demand and carbon capture efficiency. The results showed that high temperature can significantly improve the combustion efficiency in which the CO₂ concentration was up to 92.1% at 900℃. With the increase of temperature, CO₂ capture efficiency and combustion compensation efficiency increased to 99.6% and 83.4% respectively, while the oxygen demand and carbon supplementation decreased to 12.1% and 4.8%. The CO₂ serving as gasifying agent had an adverse effect on reaction efficiency that the oxygen demand was increased to 23%. In addition, there was a small amount of particles agglomeration in FR-Ⅰ, but had a limited influence on fluidization.

This paper reports an experimental research of a new type of air source heat pump system in summer. This system can operate efficiently in winter, and improve the performance in summer operation. Through constructing the experimental platform for heat pump system, the effects of outdoor air dry bulb temperature, relative humidity, chilled water flow rate, cooling water flow rate and outdoor air flow rate in summer conditions on system performance can be acquired. It is concluded that the COP of air source heat pump air conditioning system increases with the decrease of outdoor air humidity, the increase of cooling water flow rate and the increase of chilled water flow rate. The effects of outdoor air flow rate on system performance can be ignored. At the condition of outdoor air dry bulb temperature 35℃ and relative humidity 45%, the COP of system can reach 3.23, more than the COP of compressor rated, which fully demonstrated that the system can run stably and efficiently in summer.

Selective leaching of arsenic and copper in copper smelting dust was investigated by Na₂S-NaOH leaching process with assistance of ultrasound method. The results showed that ultrasound wave could enhance alkaline leaching capacity and separation of arsenic and copper. The corresponding leaching ratios of arsenic and copper reached to 88.81% and 0.025% at the condition of 5 min discharge time, 80 W discharge power, mass ratio of Na₂S, NaOH to ash 0.4:1, liquid-solid ratio 20:1, temperature 75℃ and stirring speed 400 r·min^-1. The leaching process with Na₂S-NaOH assistant with ultrasound reduced arsenic and increase copper content in soot from 0.85% to 0.58% and from 2.21% to 2.30%, and the leaching rate of As increased 9.21%, the leaching toxicity concentration of As was reduced from 12.66 mg·L^-1to 2.84 mg·L^-1, compared with alkaline leaching, respectively. Kinetics of alkaline assisted with ultrasound leaching of arsenic in copper smelting dust was controlled by hybrid reaction and its leaching kinetic equation followed the reacted shrinking core model, its apparent activation energy was 0.114 kJ·mol^-1, and the reaction system was balanced within 5 min. XPS, XRD and speciation analysis of heavy metals indicated that ultrasound wave was able to oxidize As(Ⅲ) to As(Ⅴ), which was propitious to leaching of arsenic. In conclusion, ultrasound wave assisted Na₂S-NaOH leaching process proved to be an efficient way of removing both arsenic and copper from soot, so the soot could be further utilized after toxic content reduction.

During waste incineration, PbO (difficult to volatilize) can be chlorinated to PbCl₂ (easy to volatilize) by the interaction of NaCl and Si/Al in ash at high temperature. The mechanisms of this transformation were investigated by analyzing the release of chlorine and lead in the view of indirect and direct chlorination during the tube furnace incineration at rising temperature. During the indirect chlorination initialized at 700-800℃, oxygen containing water vapor was found more favorable to reaction than oxygen without water vapor, while Al₂O₃ was more favorable than SiO₂. NaCl was found as vapor to participate indirect chlorination. During the direct chlorination through SiO₂, PbO reacted with SiO₂ first to form silicate at about 500℃, and then reacted with NaCl vapor produced initially at about 650℃. During the direct chlorination through Al₂O₃, PbO reacted with Al₂O₃ first to form aluminate at 700-800℃, and then reacted with NaCl. When Al₂O₃ was mixed with SiO₂, the direct chlorination properties turned from SiO₂ matrix type to Al₂O₃ matrix type, and the initial chlorination temperature increased from about 650℃ to 700-800℃.

The electrochemical coupling system was used on the pretreatment of coking waste water with high organic loading and biological inhibition. The sludge-derived activated carbon(AC) particle electrodes were prepared from in-site sludge and characterized, indicating that surface oxygen groups contained hydroxyl, ether, carbonyl, carboxyl, etc., which could accelerate catalytic reaction. The effects of cathode aeration were investigated and degradation mechanism of organic contaminants was analyzed. The results showed that aeration was beneficial to open-loop reaction. Based on the Central-Composite response surface method, the separate action and interaction effects of impressed voltage, initial pH, aeration rate, and AC filling ratio were evaluated, and COD removal rate was used as the evaluation index. The significance of influencing factors followed the order:AC filling ratio > initial pH > aeration rate > impressed voltage, and the most significant interaction occurred between initial pH and aeration rate. The optimal conditions were determined to be impressed voltage 15 V, pH 5.8, aeration rate 12.4 ml·min^-1, AC filling ratio 50%, and reaction time 45 min. Then COD removal rate reached 46.8%. Under optimal conditions, COD of the treated waste water decreased from 4700 mg·L^-1 to 2500 mg·L^-1, and chroma removal rate was 50% with low energy consumption of 0.971 kW·h·(kg COD)^-1. And B/C increased from 0.05 to 0.37, indicating the biochemical properties were improved. Therefore, the electrochemical technique can efficiently pretreat the coking waste water and improve its biodegradability.

The reaction and regeneration behavior of melamine (MN), a kind of solid organic amine, with SO₂ was studied. The results show that MN desulfurization rate is above 99% for 140 min at simulated flue gas:0.35%SO₂+ 5%O₂ + N₂, 40℃ and 4% MN (mass fraction). Meanwhile, the breakthrough sulfur capacity (200 mg/m³ SO₂ in outlet flue gas) is 0.33g SO₂/(g MN). The analysis of MN desulfurization and regeneration products by XRD, FTIR, SEM and TG-MS shows that MN reacts with SO₂ to produce melamine sulfite firstly, and then melamine sulfite is oxidized to melamine sulfate partly by oxygen in the flue gas. Adding 0.1% p-diphenylamine can effectively inhibit the melamine sulfite to be oxidized. Melamine sulfite can be heated and regenerated in 75-150℃, but the melamine sulfate cannot be regenerated by heating. The oxidation rate of melamine sulfite decreased from 36% at 5%O₂ to 13% at 5%O₂+ 0.1% p-diphenylamine. When products were heated at 150℃ for 2 h desulfurization, the regeneration rate of melamine increased from 58% at 5%O₂ to 94% at 5%O₂+ 0.1% p-diphenylamine. MN has excellent desulfurization and regeneration performance in the anti-oxidation mode.

This paper aims to set up the theoretical model for co-absorption of SO₂ and CO₂ into sodium based solutions. Instantaneous reaction for SO₂ hydrolysis is assumed. For the hydrolysis of CO₂, there are two assumptions:finite kinetics and instantaneous reaction. Based on these two assumptions, the absorption rates of SO₂ were separately calculated and compared with dynamic experiments in the well stirred reactor. The trend for the absorption rate of SO₂ was well predicted by the instantaneous reaction for CO₂. The relative error for the absolute rates of SO₂ is high. The prediction based on the finite kinetics for CO₂ hydrolysis at pH>3 agrees well with experiments. The influences of CO₂ on the SO₂ absorption rate is primarily through gas phase mass transfer coefficient and total sulphur concentration at the same pH. Depending on the existence of CO₂ on SO₂ absorption rate, five pH regimes for interaction were observed. At pH>11.42, the absorption rate of SO₂/N₂ is higher than that of SO₂/CO₂ due to the influence of gas phase mass transfer coefficient. At 7.8 < pH < 11.42, the absorption rate of SO₂/N₂ is similar with that of SO₂/CO₂ due to the counteraction of gas phase mass transfer coefficient and total sulphur in liquid. At 5.41 < pH < 7.8, the absorption rate of SO₂/CO₂ is higher due to the influence of total sulphur in liquid. At 2.8 < pH < 5.41, the absorption rate of SO₂/CO₂ is relative lower primarily due to the influence of gas phase mass transfer coefficient. At pH < 2.8, the absorption rate of SO₂/N₂ is similar with that of SO₂/CO₂ due to liquid phase controlled region. Conversion of carbon and sulphur based ions at different pH and controlling regions for SO₂ absorption rate were obtained. The work provides guidance for the design and operation of flue gas cooler for oxy-fuel combustion flue gas.

CO₂ air-source heat pump can operate stably in cold area, which is expected to be popularized and applied in the field of space heating. To evaluate the performance of CO₂ air-source heat pump heating objectively and reasonably, the supercritical CO₂ air-source heat pump heating system in cold region was built. According to outdoor ambient temperature and heating load, the heating period is divided into five different stages, and the heating operation parameters of CO₂ air-source heat pump are adjusted in different stages. The results show that the CO₂ air-source heat pump can meet the heating demand in cold area, and the average performance coefficient of the heating system in the heating periods can reach 2.236, at the same time the heating room has good comfort. Taking coal-fired boiler and gas-fired boiler as reference, the energy utilization efficiency and CO₂ emission amount of three kinds of heat source heating are compared and analyzed by using equivalent electricity method. The results show that the energy utilization efficiency of CO₂ air source heat pump heating is higher than that of gas boiler heating and is slightly lower than that of coal-fired boiler heating after considering the energy grade. The CO₂ emission amount of CO₂ air-source heat pump heating is higher than that of gas-fired boiler heating, but 20.89% less than that of coal-fired boiler heating.

Characteristics of NO oxidation by H₂O₂ thermal decomposition in different size reactors in drop tube furnaces were studied. The effects of different H₂O₂ evaporation conditions on NO oxidation ratio were compared. The effects of gas temperature, H₂O₂ concentration, H₂O₂:NO, initial NO concentration and gas flow rate on NO oxidation ratio were analyzed. The oxidation product was detected and the generation pathway of the product was analyzed. The results showed that the rapid evaporation of H₂O₂ was the precondition for NO oxidation by H₂O₂ thermal decomposition. Reducing H₂O₂ droplet size or liquid film thickness could accelerate H₂O₂ evaporation and decomposition rate which enhanced NO oxidation ratio and broadened the NO oxidation temperature range. Ensuring the evaporation rate of H₂O₂ decreased the effect of H₂O₂ concentration on NO oxidation. When H₂O₂:NO < 10, the NO oxidation ratio increased with the increase of H₂O₂:NO; when H₂O₂:NO>10, the NO oxidation ratio did not change with it. H₂O₂ thermal decomposition had higher oxidation efficiency for high concentrations of NO. The main product of NO oxidation by H₂O₂ thermal decomposition was NO₂. HO₂· directly oxidized from NO to NO₂. However, ·OH converted NO to HONO firstly, and then further oxidized HONO to NO₂.

To improve the desulfurization efficiency of flue gas circulating fluidized bed (FG-CFB), some synergists, such as hygroscopic agent, surfactants and catalyst, were added into the slaked lime. The experiments of desulfurization were carried out in FG-CFB. The results showed that the desulfurization efficiencies of 97.14%, 97.70% and 98.45% were achieved in which magnesium chloride(MgCl₂), sodium dodecyl benzene sulfonate(SDBS), and adipic acid were added 1.3%, 0.03%, and 1.2% respectively. The desulfurization efficiency of 99.19% was obtained when hygroscopic agent, surfactant and catalyst were added into desulfurizer together with the mass fraction of 1.3%, 0.03% and 1.2%. Synergetic mechanism of MgCl₂, SDBS and adipic acid were analyzed on the removal efficiencies of desulfurization. The desulfurization efficiency of flue gas circulating fluidized bed can be improved with a suitable content of hygroscopic agent, surfactant and catalysis in the desulfurizer and the outlet concentration reaches ultra-low emissions requirements.

Selective catalytic reduction (SCR) technology is usually used in coal combustion power plant to reduce NO_x emission. The effects of SCR DeNO_x on PM emission are still unclear. In this work, PM and fly ash before and after SCR was sampled. Particle size distribution (PSD) and chemical composition of PM was analyzed. Computer-controlled scanning electron microscope (CCSEM) was used to analyze the fly ash and obtain the composition distribution property of individual PM particles. The effect of SCR DeNO_x on PM emission characteristic and its mechanism was investigated. The results show that PM is bimodal distribution before and after SCR. After the flue gas flows through the SCR, PM_0.21 decreases 62%(mass) and PM_0.21-1 increases 19%(mass). The relative amount of SO₂ in PM₁ increases 6%(mass) and SiO₂ and Al₂O₃ decrease, while the variation of CaO is insignificant after SCR. The amount of PM_1-10 decreases 17%(mass) after SCR. Insignificant change of its chemical composition is observed after SCR. However, the chemical composition distribution of individual PM_1-10 particle becomes more homogeneous after SCR. It suggests that significant interaction between PM₁₀ has happened in or after SCR. Therefore, decrease of PM_1-10 after SCR is not only because of PM₁₀ deposition in the SCR, but also because of particle interaction.

The efficient conversion of hemicellulose is a key step in improving the utilization of all components of sweet sorghum bagasse. Sweet sorghum bagasse was pretreated by subcritical hydrolysis. The effects of different reaction temperature (160-200℃) and reaction time (10-60 min) on the yield of xylose(C-5 sugar) and byproducts were investigated by subcritical hydrothermal pretreatment. The experimental conditions were described by intensity factor. The effects of various organic acids on the subcritical hydrolysis of hemicellulose, including acetic acid, lactic acid and acetic acid+lactic acid were further investigated. The results showed that the maximum xylose concentration was 4.79 g·L^-1at the severity of 3.96(180℃, 40 min), during the subcritical hydrothermal pretreatment without added acid. The addition of organic acids could enhance the hydrolysis reaction and increase xylose concentration. Compared to the treatment with acetic acid or lactic acid alone, the combined use of acetic acid and lactic acid can effectively promote the degradation of hemicellulose and inhibit the formation of by-products. The maximum xylose concentration was 7.92 g·L^-1, which was obtained at 180℃, for 40 min, and with the addition of 1%(mass) acetic acid+lactic acid(lactic acid:acetic acid=6:4).

Graphene oxide/basic aluminum sulfate (GO-BAS) composites were prepared via hydrothermal method using graphene oxide (GO), aluminum sulfate and urea as raw materials. The composites were blended with piperazine (PIP) solution as the water phase, trimesoyl chloride (TMC) was desolved in the hexane solution as the organic phase. The GO-BAS doped polyethersulfone/polyamide (PES-PA-GO-BAS) composite nanofiltration membrane was synthesized by interfacial polymerization method which forms a polyamide functional layer on the polyethersulfone (PES) ultrafiltration substrate membrane. It's performance was studied at a lower working pressure(0.3 MPa). The inorganic salt solutions rejection of the composite membrane as follows:Na₂SO₄(91.08%) > MgSO₄(83.42%) > MgCl₂(68.97%) > NaCl(17.62%), and the pure water flux up to 24.19 L·m^-2·h^-1, which is improving nearly 60% than the polyamide membrane. The nanofiltration membrane has a good alkali resistance and operation stability.

A novel PLA/PBAu block copolymer was synthesized by using the hydroxyl terminated poly(lactic acid) (PLA) and poly(butyl acrylate urea) (PBAu) as prepolymer and the hexamethylene diisocyanate (HDI) as chain extender. To determine the optimum synthesis condition for the chain extension, the effects of the amount of chain extender, the chain extension temperature and the amount of catalyst on the PLA/PBAu block copolymer molecular weight were studied. The structure and properties of the films were studied by nuclear magnetic resonance, gel permeation chromatograph, differential scanning calorimetry and scanning electron microscope. The results showed that the PLA/PBAu block copolymer was successfully synthesized, and the molecular weight of the copolymer can reach to 10⁵ with glass transition temperature of 41℃. The crystallization of copolymer films increased with the increase of PBAu content. The accelerated degradation experiment of block copolymers was studied with NaOH solution as the degradation solution. The results showed the degradation rate of copolymer can be significantly improved when the content of PBAu was 30%. The degradation rate of block copolymer could be controlled by adjusting the content of PLA and PBAu prepolymer.

Four nitrogen heterocyclic ester or amide derivatives based lubricant additives, namely Ⅰ-Ⅳ, were designed and synthesized. The molecular structures were characterized by ¹H NMR and MALDI-TOF-MS. The oil solubility, thermal stability and corrosion resistance of these additives were studied. The tribological properties of additives in liquid paraffin (LP) were systematically investigated on a four-ball test machine. The surfaces morphology and elementary composition of the worn scar were recorded on a scanning electron microscopy (SEM) and an energy dispersive spectroscopy (EDS). The results show that the four additives exhibit excellent oil solubility, high thermal stability and good corrosion resistance. When the addition of additive Ⅰ is 1% (mass fraction), the wear scar diameter (WSD) and coefficient of friction were 33% and 26% which are lower than that in non-added liquid paraffin. The SEM images suggest that the addition of all the four additives can significantly reduce WSD and decrease surface wear. The EDS results indicate that the additives formed a complex reaction film in the process of friction.

The flower-like and dendritic silver micro-nanocrystals with multi-stage structure were prepared by liquid phase reduction method by adjusting the molar ratio of oxidant silver nitrate to reducing agent ascorbic acid. The effects of reaction media on the size and morphology of silver crystallite was investigated. The morphology, crystal structure, optical and catalytic properties of the products were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD), surface enhanced Raman scattering spectroscopy (SERS) and UV-Vis reflectance spectroscopy (UV-Vis). The XRD results show that both the flower-like and dendritic silver micro-nanocrystals have face-centered cubic crystal structure, and (111) plane is the dominant crystal plane exposed on the surface of Ag crystals. The SERS surveys show that the hierarchical structure Ag micro-nanocrystals are excellent substrates for SERS. The UV-Vis diffuse reflectance spectra shows that the dendritic silver has a strong absorption peak at 352 nm because of the finer microstructure. The catalytic reduction experiment of 4-nitrophenol by sodium borohydride on the silver crystals reveals that the dendritic silver shows excellent catalytic activity.

Nano-metallic Cu and carbon material graphene nanoplatelets(GnPs) were chosen to modify organic phase change material(PCM) myristic acid(MA). The Cu/MA hybrid PCMs were prepared by adding the Cu at different mass fraction(1%, 2%, 3%, 4%) into MA, and the GnPs/MA hybrid PCMs were produced by adding the GnPs at various mass fraction(1%, 2%, 3%) into MA. Thermal properties of the hybrid PCMs were determined by using differential scanning calorimetry(DSC) analysis and transient hot-wire method. Besides, the microscopic, chemical and crystalline structure of the hybrid PCMs were characterized by scanning electron microscope(SEM), fourier transformed infrared(FT-IR) and X-ray diffraction(XRD). The results indicated that solid and liquid thermal conductivity of the Cu/MA hybrid PCMs increased linearly with the increase of Cu content. The solid thermal conductivity of 1%(mass) GnPs/MA hybrid PCM significantly raised by 101.51% compared to that of pure MA, and the thermal conductivity of hybrid PCMs kept increasing with the increase of GnPs mass fraction but increment extent slowed down. FT-IR spectra showed that the interactions between Cu and MA, and GnPs and MA were physical. DSC analysis demonstrated that both supercooling degree and phase change latent heat of MA reduced with the addition of Cu or GnPs. With the increase of mass fraction, the phase change latent heat of hybrid PCMs decreased gradually. The time of thermal energy release of 4%(mass) Cu/MA and 3%(mass) GnPs/MA hybrid PCMs decreased by 23.4% and 38.7% respectively compared to that of pure MA. After 4%(mass) Cu/MA and 3%(mass) GnPs/MA hybrid PCMs experiencing 300 accelerated thermal cycles, the crystalline structure and phase change temperature basically stayed unchanged, while phase change latent heat reduced to approximate 168 J·g^-1 and 181 J·g^-1 respectively, which still met the requirements of heat storage and release. Both materials had good thermal cycling reliability.

The preparation of gas separation membranes with high permselectivity is the key for CO₂ efficient recovery. To improve the CO₂ separation performance of membrane, halloysite nanotubes (HNTs) with hollow and tubular structure were incorporated into polyvinylamine (PVAm) aqueous solution to fabricate PVAm-HNTs coating solutions. PVAm-HNTs/polysulfone (PSf) mixed matrix membranes (MMMs) were prepared by coating PVAm-HNTs solutions on PSf ultrafiltration membranes. The PSf membrane is the supporting layer, and PVAm-HNTs coating layer is the functional layer, which is the key for CO₂ separation. The structure and morphology of HNTs were characterized by XRD and SEM. The morphology and structure of the membranes were analyzed by FTIR and SEM. The effects of HNTs content, feed pressure, and the thickness of PVAm-HNTs coating layer were systematically investigated by using pure CO₂ and N₂ pure gas. The CO₂/N₂[15/85(volume)] mixed gas separation performance also were investigated. The good interfacial interaction is attributed to the electrostatic attraction between PVAm and negatively charged HNTs. At testing temperature of 25℃ and feed gas pressure of 0.1 MPa, PVAm-HNTs/PSf-1%(mass) MMMs with wet coating thickness of 50 μm exhibited long-term performance stability, and the CO₂separation performance maintained high CO₂ permeability of 178 GPU with CO₂/N₂ selectivity of 83 for CO₂/N₂ mixed gas over 120 h.

To observe the effect of nanoparticle on the thermal physical properties of the low melting point eutectic mixed nitrate salt. In this study 1% (mass) SiO₂ nanoparticles with the average size of 20 nm were doped into the mixed salt[Ca(NO₃)₂·4H₂O-KNO₃-NaNO₃-LiNO₃] to obtain molten-salt nanocomposites at different dispersion condition by the high temperature melting dispersion method. Specific heat capacity and thermal diffusivity of the nanocomposites were analyzed by differential scanning calorimeter (DSC) and laser flash apparatus (LFA). Then the thermal conductivity was gotten. The results show that at the stirring rate of 600 r/s the thermal physical properties of the molten-salt nanocomposites vary with the mixing time (15, 45, 90, 120 and 150 min). At the mixing time of 45 min, the thermal physical properties of the molten-salt nanocomposites reach the optimum enhancement. The average enhancement of the specific heat capacity, thermal diffusivity and thermal conductivity was 11.5%, 12.9%, and 26.4%, respectively. The scanning electron microscope (SEM) found that a large number of special nanostructures (resembling chain-like nanostructures) existed on the surface of solid molten-salt nanocomposites. The special nanostructures with large specific surface area and high surface energy may enhance the specific heat capacity and thermal conductivity of the molten salt nanocomposites.

Hierarchical porous polypyrrole films have been successfully prepared by interfacial self-assembly polymerization with assistance of the long-chain surfactant OP10. The molecular structure, micromorphology and electrochemical performance of obtained polypyrrole were characterized. The results showed that introducing OP10 into interfacial polymerization had no effect on the molecular structure of obtained polypyrrole but a significant impact on its micromorphology. When the dosage of OP10 was optimized at 0.02 g, polypyrrole could self-assemble to form a hierarchical porous structure including nanopores (~100 nm), submicron pores (200-1000 nm) and micron pores (1-3.5 μm). Because of relatively larger active surface area and higher total pore volume, hierarchical porous polypyrrole, as the electrode material, possessed a maximum specific capacitance up to 357 F·g^-1 which is 70% higher than that prepared by traditional interfacial synthesis at the same conditions. Furthermore, 87.6% of the initial specific capacitance was still retained even after 2000 charge-discharge cycles, indicating the excellent cycling stability of the prepared polypyrrole.

To study the coupled relationship between the flame propagation and the pressure built-up of gas explosions, the test was carried out in a 5 L quartz duct with different concentrations of NaHCO₃. The results showed that the pressure waveform of gas explosions gradually changed from a single-peak curve to a bimodal curve with the increase of the mass concentration. Moreover, there are more small particles per unit volume as the suppressant concentration was large enough, which would inhibit the flame propagation firstly and then prolonged the endothermic time of larger powders, making the flame front be further inhibited. In the middle and late stages of the flame propagation, the settlement of large particles resulted in the uneven distribution of powders in space, which significantly affected the inhibition efficiencies. The distribution of powders in the duct can be divided into three regions:the combustion zone with low powder concentration, the sedimentation and collection zone of large particles with high mass concentration and the suspension zone of small particles with low powder concentration. The time dependence of the flame front velocity was similar to that of overpressure. Although the flame front velocity can reflect the intensity of the combustion to some extent, the rise and fall of the overpressure cannot determine entirely by the trend of the flame front velocity. The explosion overpressure wouldn't decrease immediately with the transient reduction of the flame front velocity when the flame front velocity was large enough.