Heating coil inside the tank is widely used in biogas projects at home and abroad. The various factors affecting the heating and heat transfer of the tank were analyzed from the heat transfer efficiency and rate based on the first and the second laws of thermodynamics. It was found that from the view of the overall heat transfer coefficient, the thermal conductivity and wall thickness were comprehensive considered and then the maximum heat transfer rate was obtained with low speed mixing method by choosing the thick wall with the value of thermal conductivity of above 15 W·m^-1·K^-1. Meanwhile, the energy consumption of transfer process was analyzed from the view of heat transfer efficiency. It can be obtained that an appropriate increase in the inlet temperature of cold material can reduce the irreversibility of heat transfer and increase the utilization ratio of limited energy for heat transfer process with countercurrent mixing. Therefore, the high-efficient, energy saving and rational theoretical guidance was provided for biogas project using tank heating to achieve the unity of transfer heat rate and efficiency.

Wet steam condensation flows presents a high degree of non-equilibrium characteristics. At present, the condensation parameters are obtained by using semi-empirical formula, while heat transfer temperature difference and coupling problems are seldom considered. A simple condensation nucleation model and droplet growth model for non-equilibrium phase change of wet steam is established in this study. In order to calculate the wet steam parameters and condensation shock wave distribution of non-equilibrium condensation flows, the second-order TVD scheme is adopted. The influence of thermodynamic properties of inlet wet steam on the non-equilibrium condensation flow is examined, the influence of inlet pressure on the condensation characteristic is discussed, and various patterns of inlet subcooled temperature on nucleation rate, droplet number, condensation shock are summarized. It is found that as inlet pressure increases, the condensing location moves upstream. At a lower import subcooled temperature, the condensing position moves downstream. At higher Mach number, nucleation occurs. As the import subcooled temperature increase, the wetness of non-equilibrium condensation phase transition will be higher. After the onset of condensation shock, steam expands continuously along the nozzle and the flow pattern is similar to isentropic flow.

A visualization experiment was carried out to investigate the condensation flow patterns of the ethanol-water vapor mixtures in an array of microchannels under a wide range of concentration (2%—60%). The microchannel was a trapezoidal silicon one with a hydraulic diameter of 165.87 mm and a length of 50 mm. The visualization study indicated that the ethanol concentration remarkably influenced the flow regimes. Along the flow direction, annular, annular-streak, annular-streak-droplet, annular-churn, injection, droplet-injection and bubble flow patterns were observed in the vapor mixtures condensation of different inlet ethanol concentration (60%, 31%, 20%, 6%, 4%, 2%). Due to the Marangoni effect, the film of the annular flow was more fluctuant comparing with the pure steam condensation. With the decreasing of the ethanol concentration, the injection flow pattern became more regular and the droplet would appear in the injection flow area. The two-phase flow pattern maps of different inlet ethanol concentrations were also developed to describe the experiment. A correlation based on the critical quality correlation was proposed to indicate the transition of the two-phase flow patterns.

Three groups of CO₂ pipeline release experiments were performed using an industrial scale (256 m long, 233 mm id) instrumented pipeline with CO₂ pre-discharge phase of gas phase, gas-liquid phase and supercritical phase, respectively. The pressure response and the phase transition were recorded and analyzed in the process of CO₂ pipeline release. The results showed that when the pressure wave front arrived, the pressure fall and stagnation appeared in the process of gaseous CO₂ release. The phase of CO₂ in the pipeline during the gaseous CO₂ release was mainly in gas state, but the temperature at the end pipe decreased sharply, leading to the formation of gas-liquid homogeneous CO₂. The decompression multiple reflection led to multiple pressure fall sharply and rebound in the release of gas-liquid CO₂. Gas-liquid layered CO₂ transformed to gas-liquid homogeneous CO₂ in the phase transition process of gas-liquid CO₂, and then the gas-liquid homogeneous CO₂ at the top of pipeline transformed to the gas CO₂ and consequently the bottom. The pressure fall sharply and rebound appeared near critical region in the release of supercritical CO₂. When the pressure passed through the critical pressure line, the pressure change rate could be stagnation and slow down. The discharge of the supercritical CO₂, gas-liquid homogeneous CO₂ and gas CO₂ appeared in the process of supercritical CO₂ release.

The mass transfer process of growing bubbles has important effect on the design and optimization of gas-liquid contacting devices. By investigating a single carbon dioxide bubble growing in a sodium carboxymethyl cellulose (CMC) solution, the effects of gas velocity, concentration of CMC solution, and diameter of the needle on gas-liquid mass transfer were examined. The shape, surface area and volume of growing bubble were captured by a dynamic contact angle analysis instrument with a micro-CCD camera and the liquid mass transfer coefficient k_l was calculated. The results show that the mass transfer coefficient increased with the solution viscosity as CMC concentration increased from 0.2% to 0.8%, with the diameter of the needle changing from 2.5 mm to 4 mm, and with the gas injection rate increased from 1 ml·min^-1 to 9 ml·min^-1.

Condensation processes of vapor bubbles being injected into subcooled water with and without ultrasonic vibration were recorded by a high-speed video camera to analyze the effects of ultrasonic field on the condensation process and heat transfer of vapor bubbles. Experimental results indicated that the lattice shaped capillary wave formed on the bubble surface increased the condensation heat transfer area greatly and intensified the turbulence in the thermal boundary layer around the vapor bubble, enhancing condensation heat transfer and accelerating bubble condensation in the ultrasonic field. Based on experimental data of relatively large vapor bubbles at liquid subcooling of 15—60 K, empirical correlations were obtained for predicting the condensation heat transfer of vapor bubbles with and without ultrasonic, with deviations within ±30%.

An ammonia-based wet flue gas desulfurization (WFGD) simulation was built to simulate separately the two different aerosol formation mechanisms in ammonia-based desulfurization process of the inhomogeneous reaction mechanism and the entrainment mechanism. The electrical low pressure impactor (ELPI, Dekati Ltd.) was employed for the online measurement of aerosol concentration in the outlet flue gas after the WFGD scrubber. The pollutant PM sampler was used for aerosol sampling in the flue gas. The samples gathered were then scanned and analyzed by the field emission scanning electron microscope (FESEM). The results showed that the inhomogeneous reaction of NH₃ escaped from desulfurization slurry with the moisture and SO₂ in the flue gas was the dominating one of the two aerosol formation mechanisms in the ammonia-based WFGD, which produced the majority of the aerosols emitted from the scrubber. It was found that the aerosols were consisted mainly of submicron particles if counted in respect of numerical concentration and micron ones in respect of mass concentration. The amount of aerosols produced was depended mainly on the desulfurization solution pH along with the flue gas temperature at the inlet of WFGD, etc. The entrainment mechanism was of the secondary importance in the aerosol formation in the ammonia-based WFGD. The production of the aerosols was mainly related to the desulfurization solution concentration, the empty tower gas velocity, and so forth.

Residence time is a key parameter for the cyclones accompanied by heat and mass transfer or reaction process. The mean residence time of liquid phase in a gas-liquid cyclone was studied in a cold apparatus using the hold-up method. The results showed that the liquid residence times obviously decreased with the increase of the droplets loading, and less decreased with increasing inlet gas velocity. The main reason for the less effect of inlet velocity on the liquid residence time was that the gas-liquid interfacial shear stress was far less than the gravity of liquid film. A new model was developed to estimate the mean residence time of liquid phase in the gas-liquid cyclone based on a force balance on the liquid film. The predicted residence times were in good agreement overall with the measured values. However, the predicted residence times were higher than the measured values within the liquid film Reynolds number Re_l < 1200. The relationship between the model deviation and flow pattern of liquid film was discussed.

The viscosity properties of oil sludge from tank bottom and different methods for its viscosity reduction were investigated using HAKKE VT550 rotational viscometer. The viscosity reduction methods included heating range of 20—60℃, adding surfactant Triton X-100 aqueous solution with the concentration of 0.5% (by mass), and adding the organic solvents of 1-pentanol and 120^# solvent oil. The results indicated that the oil sludge exhibited the characteristics of both plastic fluid and pseudo-plastic fluid in the range of 0—600 s^-1 for the examined shear rate. The significant shear-thinning behavior can be attributed to the high content of solid particles in the oil sludge. The modeling analysis showed that the Casson model fitted well with the viscosity characteristic curve of the oil sludge with the highest determination coefficient R²=0.986. In comparison with heating to 50℃, the similar viscosity reduction performance can be achieved by adding 10% Triton X-100 solution (by mass) at 20℃ with the viscosity reduction of 50%. The rheological properties of sludge had a tendency to pseudo-plastic fluid behavior. Better performance can be achieved by blending the sludge with a certain amount of organic solvent. When 10% of 120^# solvent oil was added to the sample at 20℃ and 300 s^-1, the viscosity was reduced by 90% owing to the spatial structure of both the oil and the solid phase was destroyed. The sludge gradually exhibited Newtonian flow behavior.

An experimental setup of two-phase cooling loop driven by magnetic pump was built. The performance and start-up characteristics of the two-phase cooling loop are evaluated by the air enthalpy difference method. Experimental results show that the two-phase cooling loop driven by magnetic pump presents excellent performance for energy saving. Its start-up is quick and the system reaches a steady state after 600 s. The fluctuations of pressure and temperature in the system are caused by the superheat of the liquid refrigerant in the evaporator during the start-up. The cooling capacity of the system increases with the temperature difference, and increases rapidly with the mass flow rate and then decreases slowly. When the temperature difference is 10℃, the maximum cooling capacity is 3.429 kW and the energy efficiency ratio is 12.94. When the temperature difference is 25℃, they reach 9.241 kW and 29.7, respectively.

A test rig with a horizontal smooth tube was built to measure flow boiling heat transfer of nanolubricant/refrigerant. The experimental study on heat transfer characteristics of graphite-nanorefrigerant flow boiling inside a horizontal smooth copper tube, with total length of 2.5 m, outside diameter of 9.52 mm, inside diameter of 8 mm and wall thickness of 0.76 mm was performed. Influence of graphite on flow boiling heat transfer characteristics of nanorefrigerant/oil mixture was investigated. There were three kinds of fluid under experiment:R600a, R600a/oil and graphite nanorefrigerant/oil with different graphite mass fractions (0.05%, 0.1% and 0.2%). Flow boiling heat transfer coefficients of these fluid versus vapor quality were measured respectively in a horizontal smooth tube under the mass flow density of 150, 200, 250, 300 kg·m^-2·s^-1. The results indicated that the presence of graphite enhanced the flow boiling heat transfer. A correlation for predicting the flow boiling heat transfer coefficient of nanorefrigerant/oil mixture with graphite was proposed and it agreed with 94.5% of the experimental data within a deviation of ±15%.

Drag reducing nanofluids can reduce flow resistance and enhance fluid convective heat transfer. In this study, the convective heat transfer coefficient and flow resistance coefficient were determined experimentally at the Reynolds number of 4000—16000, with 0—0.5% mass fraction of graphite multi-walled carbon nanotubes, A1₂O₃, Cu, Al, Fe₂O₃, and Zn nanoparticles added into a concentration of 100—400 mg·kg^-1 cetyl trimethyl ammonium chloride (CTAC) drag reducing fluid. The ratio of the two fluids and preparation method were examined and the overall performance on convective heat transfer and flow characteristics was evaluated. The results show that the drag reducing fluid forming by sodium salicylate, CTAC and deionized water presents certain stability and significant drag reduction characteristic. At the drag reducing fluid concentration of 200 mg·kg^-1, the drag reduction performance is the best. Graphite nanoparticles give better overall performance in enhancing convective heat transfer and reducing flow resistance among the nanoparticles. At 0.4%(mass) of graphite nanoparticles, the overall performance factor K is five times that with deionized water, presenting the best heat transfer and drag reduction characteristics, so it has good application prospects. Finally, a correlation is obtained by fitting the heat transfer and flow resistance of the drag reducing graphite nanofluid in circular tube, which is in good agreement with the experimental values.

To study the thermal property of silica aerogel, a method is proposed for constructing three-dimensional mesoscopic physical model of nanoparticle porous materials, based on the random statistical theory. The spatial distribution of particles, particle size and porosity can be adjusted according to actual microscopic information of the porous material. D3Q15LBM model is employed to perform numerical simulation and analysis in mesoscopic scale. And the influence of particle diameter, porosity and other factors on thermal conductivity of porous media is analyzed. That is, the thermal conductivity will decrease with the increase of particle size for constant porosity; the thermal conductivity falls and then rises as the porosity increases for constant particle size; the uniformity of particle size plays an important role on the thermal property. The simulation results are nearly the same with the experimental ones. The research will be an excellent reference for optimization of thermal performance and prediction of effective thermal conductivity for aerogels.

With a homemade gas-solid heat transfer experimental setup, an experimental study was conducted on gas-solid heat transfer characteristics in a packed bed with sinter particles. The results show that the main factors affecting the gas-solid heat transfer process in sinter bed layer are gas superficial velocity and sinter particle diameter. With the increase of gas superficial velocity and the decrease of sinter particle diameter, the gas-solid heat transfer coefficient increases in the sinter bed. For given gas superficial velocity and sinter particle diameter, higher sinter particle temperature in the bed gives higher gas-solid heat transfer coefficient and lower Nusselt number of heat transfer. Due to the large calculation error, the existing prediction correlations are not suitable for the gas-solid heat transfer process in sinter bed. Based on the method of dimensional analysis, an experimental correlation for describing the gas-solid heat transfer characteristics in sinter bed is obtained by fitting the experimental data, and its mean deviation from experimental data is 4.22%, giving good prediction.

The jet bubbling reactor uses liquid jet to achieve the liquid mixing instead of mechanical stirring, which brings several advantages such as simple structure and low cost of maintenance and manufacturing. The research of its mixing characteristics plays a significant role in the design, optimization and scaling up of the reactor. Based on the air-water system, the electrolyte tracer (KCl solution) method was applied to investigate the influences of gas velocity and jet Reynolds number on the liquid mixing time with the cold model experimental apparatus. The mixing mechanism in jet bubbling reactor had also been analyzed from the perspective of power input. The results showed that within the experimental range (u_g from 0.0006 to 0.0343 m·s^-1, Re_j from 1.75×10⁴ to 7.00×10⁴), the introduction of gas bubbling strengthened the liquid mixing conditions. With the increase of superficial gas velocity, the liquid mixing time decreased at first and then increased. When the gas or liquid power input kept constant, the mixing time decreased with the increase of the total power input. Through the regression analysis of all the experimental data, relationship between liquid mixing time, and liquid and gas power inputs had been built up. An empirical correlation was proposed, and the calculated value was fitted well with the experimental data. Based on the obtained equation, the liquid mixing time was found to decrease at first and then increase with the increase of the gas power input if the total power input was remained constant. The transition point was around where gas input power occupied 61% of the total input power. At this point, the synergistic effect was the strongest.

Polyesterifications of ethylene glycol (EG) with maleic anhydride (MA) and tetrabromo phthalic anhydride (TBPA) without foreign acid were carried out under constant reaction temperatures of 162—192℃ (rather than at the constant oil-bath temperature) and at different molar ratios of diol to diacid of 1.2—1.8 (MA/EG). The different combinations of the reaction order on the basis of Show-an Chen model were discussed. 1-1 model can describe experimental results very well, and k_h[H₂O] was greater than zero. The reaction rate constants for both systems were calculated. Besides, It was found that the final COOH conversion was increased with increasing reaction temperatures and molar ratios of diol to diacid.

Chlorophenols are persistent organic pollutants with high toxicity. Dichlorophenols (DCPs) include six isomers due to different substituted position of chlorine atoms. Self-made Pd/polypyrrole(sodium dodecylbenzene sulfonate)/Ti electrode (Pd/PPy(SDBS)/Ti electrode) was employed to dechlorinate six DCP isomers. The effects of electrolysis current, initial pH and the initial concentration of target pollutant on the dechlorination process of 2,5-DCP were investigated. Under the selected conditions, i.e., applied current of 5 mA, initial pH of 2.5 and temperature of 25℃, dechlorination experiments of 2,3-DCP, 2,5-DCP, 2,4-DCP, 2,6-DCP, 3,4-DCP and 3,5-DCP with the same DCP concentration of 100 mg·L^-1 were conducted, respectively. Phenol was the main product and a small amount of monochlorophenol could be detected during the dechlorination of six DCPs. The reaction rate constants of six DCPs were 4.735×10^-2 min^-1, 4.609×10^-2 min^-1, 4.845×10^-2 min^-1, 4.317×10^-2 min^-1, 3.973×10^-2 min^-1 and 3.770×10^-2 min^-1, respectively. It showed that the degradation rates of DCPs were affected by pK_a, protonation and pH. The degradation difficulty of six DCPs was 2,4-DCP<2,3-DCP<2,5-DCP<2,6-DCP< 3,4-DCP<3,5-DCP.

The mechanism of ammonium bisulfate formation and decomposition over a commercial V₂O₅-WO₃/TiO₂ catalyst was explored using FT-IR. The results suggest that the formation of ammonium bisulfates mainly occurs in two ways: reaction between activated NH₃ adsorbed coordinatedly on Lewis acid sites of catalyst V═O groups and SO₂ under atmosphere containing O₂;and reaction between absorbed intermediate of metal sulfates VOSO₄ and gaseous NH₃. NO could react directly with NH₄⁺ in NH₄HSO₄, which could lower its decomposition temperature, promoting the catalytic decomposition of adsorbed bisulfates (ABS) on catalyst surface. So, there is mutual inhibition between NO removal and ABS formation. Loading of ABS deposited on catalyst surface also affects its decomposition and volatilization.

Batch distillation is a highly energy inefficient process. To reduce its energy consumption, an internal heat integrated multivessel batch distillation with constant total reflux operation (IHIMVBD) is proposed for separation of binary mixtures. The rectifier surrounded by a jacketed reboiler concentrically is operated at a higher pressure compared to that in the jacketed reboiler, so the heat transfers from the high pressure rectification tower to the low pressure still through the internal wall. For this purpose, an isentropic compression system is installed in the reboiled vapor line. In order to improve the thermodynamic and economic performance, an intensified IHIMVBD (Int-IHIMVBD) scheme is developed by introducing overhead vapor recompression mechanism in the IHIMVBD structure. This scheme is to additionally utilize the latent heat of compressed overhead vapor for vaporizing the reboiler liquid. The features of the IHIMVBD system and its intensified form are illustrated by separating a binary mixture of ethanol and n-propanol. The Int-IHIMVBD configuration shows promising energy saving and economic potential over the IHIMVBD and MVBD.

In order to reduce the non-uniformity of the flow distribution caused by excessively high bed, a new parallel connection device is presented. A mathematical model for a parallel connection vertical radial flow adsorber is established to simulate the flow field in the adsorption bed, and the characteristics of pressure drop and radial velocity profiles are obtained. This flow distribution is compared with that with height-increasing method with the same bed height. It is shown that the non-uniformity of radial static pressure drop and the energy passing through the bed are reduced significantly by using the parallel connection device. The revamped adsorber can maintain a high level of uniformity in the adsorption bed and avoid the influence of excessive height. The adsorption bed thickness of the upper unit is optimized to ensure the two units to be saturated simultaneously.

Foam separation behaviors of the collagen-peptide based surfactant (CBS) for dye removal from wastewater was studied using crystal violet solution as probe. The influences of pH, gas velocity, mass concentration of CBS, height ratio of foam phase to liquid phase (H_F/H_L), initial concentration of dye and concentration of ethanol on the removal extent of dye were investigated. The experimental results indicated that CBS exhibited good performance at alkaline condition. It was also found that the removal extent of dye was increased as the increase of gas velocity, but the enrichment ratio of dye was decreased. With increasing dosage of CBS, the removal extent of dye was increased at beginning and then decreased as further increasing the dosage of CBS, while the enrichment ratio was decreased all the time. Further investigation indicated that the removal extent of dye was superior when the H_F/H_L was around 3, and the appropriate amount of addition of ethanol was beneficial to foam separation. In addition, the removal extent of dye was 80% and the enrichment ratio of dye was 16 at optimal operation conditions. These results suggested that CBS can be used in the foam separation removal of dyes from wastewater.

In order to investigate chelating ability of sodium carboxymethyl cellulose (CMC) on copper ions, the absorption spectra of the copper ion complex with CMC were measured via ultraviolet spectrophotometry. The composition of the complex was discussed and its stability constants were calculated. The experimental results show that CMC exhibits adsorption peak at 196 nm. When c(Cu²⁺)/c(—COO^-) is less than 0.6, the absorption peak of the complex appears at 237 nm, —COO^- group of CMC is the main ligand and reacts with Cu²⁺ in a molar ratio of 2:1 to form complex CMC-Cu²⁺, and the complex stability constant is 1.88×10¹⁰. When c(Cu²⁺)/c(—COO^-) is from 0.6 to 1.0, the maximum absorption peak of the complex appears at 214, 237 nm. —COO^- and —OH are involved in the complexation reaction to form a new complex. When c(Cu²⁺)/c(—COO^-) is greater than 1.0, the maximum absorption is in 214 nm and —OH is the primary ligand. The paper also investigates the removal effect of Cu²⁺ by CMC chelating. Experiments show that CMC-Cu directly precipitates to complexes in the solution, with precipitates as floc. c(Cu²⁺)/c(—COO^-) of 0.5 is the optimal usage of CMC in the supernatant, and the removal rate of Cu²⁺ can reach above 96%.

To modify corncob by graft copolymerization, the methacrylic acid and a potassium permanganate- sulfuric acid redox system were used as monomer and initiator, carboxyl groups was introduced successfully. Scanning electron microscope (SEM), Fourier transform infrared spectrometer (FTIR) and zeta potential analysis were used to characterize corncob and the effects of adsorption conditions on the adsorption of Cd²⁺ in aqueous solutions and its mechanism analyzed. The results showed that the experimental data obtained could be represented with a Langmuir isotherm, the adsorption rate followed pseudo-second-order kinetics and the rate-controlling step was the chemical sorption. Under certain conditions the adsorption rate was affected by both intra-particle and film diffusion rates. The maximal adsorption capacities of Cd²⁺ for methacrylic acid grafted and crude corncobs were 28.00 mg·g^-1 and 5.96 mg·g^-1, respectively, indicating improvement of nearly 4 times (adsorption conditions: pH 7, the dosage 5 g·L^-1, temperature 30℃, adsorption time 6 h). The adsorption was a spontaneous endothermic process, the higher the temperature was, the greater the degree of spontaneous. During the process of adsorbing Cd²⁺, the groups on the surface of grafted corncob, including carboxyl, hydroxyl, amide and methyl groups could play important roles. It was found that there existed some wrinkles and white particles on the surface of grafted corncob after adsorbing Cd²⁺, and its porosity disappeared and electronegativity increased.

Aspergillus niger fermentation is the main way for the industrial production of citric acid. Modeling of Aspergillus niger from the perspective of cybernetics is significant for better understanding the metabolic behavior of this industrial microorganism. The metabolic pathways in Aspergillus niger during citric acid fermentation are investigated. Based on the simplified metabolic network, a cybernetic model describing the balance of intracellular metabolites and enzyme levels is constructed. Meanwhile, a first-order closed-loop regulator model is used to describe the transient enzyme pool establishment shortly after the inoculation. Combining with the bioreactor model, it is found that model simulations of intracellular enzyme concentrations are in coincidence with the measurements qualitatively, while the macroscopic state variables (biomass concentration, substrate concentrate and product concentrations) agree well with the offline assays.

A fault monitoring method based on distributed independent component analysis-principal component analysis (ICA-PCA) model is proposed, which is suitable for complex industrial process that cannot be divided into several sub-blocks through an automatic way and has non-Gaussian information. Firstly, an initial PCA decomposition is carried out upon the variables of the whole process. By constructing sub-blocks through different directions of PCA principal components, the original feature space can be automatically divided into several sub-feature spaces. In addition, a two step extractions of the ICA-PCA information are carried on upon all sub-blocks in order to extract both Gaussian and non-Gaussian information, establishing the new statistics and their statistic limits. Finally, the simulation of TE process shows that the proposed fault detection model is efficient and feasible.

There is a very prominent problem of water sensitive damage and liquid trap damage caused by drilling fluid during the exploitation process of shale gas reservoirs. A two-step dilution method for preparation of oil-in-water nanoemulsions used for the protection of shale gas reservoirs was introduced. The nanoemulsion could have small droplet sizes and fine dispersity. Selecting mixtures composed of Gemini hyamine surfactant GTN, Tween80 and n-butyl alcohol as surfactant component (referred to as S+A), the effects of mass concentration of NaCl on the properties of NaCl solution/(S+A)/n-octane systems was studied. The influence of the phase inversion temperature, emulsification methods and the structure of microemulsion on the droplet size of nanoemulsion was investigated. The instability mechanism of nanoemulsion system was researched. The results showed that increasing the concentration of NaCl could effectively change the microemulsion structure of NaCl solution/(S+A)/n-octane system, decrease the phase inversion temperature significantly and improve the emulsification efficiency. Oil-in-water nanoemulsions prepared by two-step dilution method had the smallest droplet size and the best dispersity at R_os 7:3 when the emulsification temperature approached the phase inversion temperature. The mechanism of instability can be attributed to Ostwald ripening in NaCl solution/(S+A)/n-octane system. Nanoemulsion had good performance for protecting shale gas reservoirs.

The influence of different types of epoxy resins on protection performance of magnesium-rich coating for AZ91D alloy was studied with scratch testing, electrochemical impedance spectroscopy (EIS), open circuit potential (OCP) and dynamic potential scanning. The results indicated that Mg-rich coating consisting of epoxy coating 618-593 showed poor protective performance. Magnesium particles in 6101-TY650 epoxy coating could significantly improve the protective effect for magnesium alloy substrate at the coating defects, however, their over the long-term protection performance was poor. Epoxy 618-T31 coating showed strong barrier properties. Then, the Mg-rich primer consisting of epoxy coating 618-T31 had a strong protective effect, indicating that the epoxy coating 618-T31 was suitable for the preparation of Mg-rich coating for AZ91D alloy. For AZ91D alloy, magnesium particles added in three types of epoxy coatings could provide cathodic protection to AZ91D substrate at coatings defects, prolonging the corrosion life of coatings. Meanwhile, magnesium particles were activated to provide cathodic protection for the magnesium alloy substrate to some extent, retarding the corrosion rate of magnesium alloy substrate.

The experiment was conducted using glutamic acid, glycine and phenylalanine as N-containing model compounds. During their reduction in chemical looping combustion (CLC), the effects of temperature and K element on NO_x release were studied. The results indicated that release of volatile-N was quick during whole CLC process, and yields of NO and NO₂ increased with increasing temperature, whereas N₂O concentration showed fluctuation. Higher nitrogen content in model compounds, more difficult for conversion from nitrogen to NO_x. K element showed no significant effect on NO_x release of the three amino acids during CLC process except that NO emission from phenylalanine.

Electro-spraying is an important technique to enhance combustion of liquid fuel in micro-scale. A new combustor with nozzle diameter of 0.8 mm and single electrode was designed and fabricated. Experimental studies on electro-spraying and combustion were carried out using alcohol as fuel. Results showed four different electro-spraying modes with the variation of nozzle potential. The specific charges were measured at different electro-spraying modes, which were lower at the pulsed-jet mode, increased greatly, and reached a stable value at the cone-jet mode. The atomized alcohol was ignited and combusted stably near the mesh, which can be regarded as a flame holder. The flame temperatures increased first and then decreased with the increase of equivalent ratio. The flame temperature reached the maximum value at the equivalent ratio of 1.0, and the maximum value increased with the increase of nozzle potential. At the equivalent ratio of 1.0, the combustion efficiency reached 89% and fuel conversion efficiency reached 90% at cone-jet mode. The stable electro-spraying mode and suitable equivalent ratio are very important to the enhancement of combustion of alcohol in micro-scale.

The slow pyrolysis of cellulose was conducted in a fixed bed reactor at a temperature ranging of 250—550℃. The formation and evolution characteristics of residual char was investigated by elemental composition analysis and two-dimensional infrared correlation spectroscopy. The inter- and intra-molecular hydrogen bonding networks in cellulose were identified and the change of hydrogen bonding patterns during the initial stage of pyrolysis was investigated. The decomposition of cellulose during slow pyrolysis was mainly focused on 250—360℃ with a maximum decomposition rate at about 300℃. The predominant reaction of cellulose carbonization at 250—300℃ was dehydration. Furthermore, the O(3)H…O(5) intra-molecular H-bonds were found to be the most sensitive to temperature, and it changes before that of the methylene groups. However, it changes after that of O(2)H…O(6) intra-molecular and O(6)H…O(3) inter-molecular H-bonds. In the initial stage of carbonization, the cleavage of O(6)H…O(3) intra-molecular H-bonds resulted in the formation of free hydroxyl groups and the tight cellulose structure was loosen up. With temperature rising, the cleavage of intra-molecular H-bonds and the subsequent dehydration generated large amount of carbonyl, double bonds and cyclic ethers in the char. At 300℃, the ring-opening of pyran structure together with the cleavage of glycosidic bond gave rise to the drastic degradation of cellulose. As a result, substantial amount of aliphatic hydrocarbons with double bonds and carbonyl functional groups were generated in the char. These groups were further underwent molecular rearrangement, condensation and aromatization and resulted in the formation of aromatic ring and aryl alkyl ethers. In 300—460℃, the predominant reaction of cellulose carbonization was deoxygenation, such as decarbonylation and decarboxylation. Meanwhile, the content of aliphatic hydrocarbons in char decreased gradually and that of the aromatic structure increased. The predominant carbonization reaction shifted from deoxygenation toward dehydrogenation as temperature exceeded 460℃, such as demethylation and demethylenation. The aromaticity of char increased with temperature and a highly condensed aromatic structures emerged in the char.

The special electrification of nano-Montmorillonite (MMT) was used to gain organic modified montmorillonite (O-MMT) with long alky side chain containing quaternary ammonium salt by ion exchange. The O-MMT obtained was used for preparing nano-composite EVA/O-MMT with melt blending method. The depressive effects of EVA/O-MMT on Changqing waxy crude oil were studied and compared with the pure EVA depressant. The crystallization characteristics of crude oil was investigated by differential scanning calorimeter (DSC) and morphology of their wax crystal with undoped/doped EVA/O-MMT analyzed using polarized light microscope. The result showed that there was the best performance when addition of EVA/O-MMT was at 50 mg·kg^-1. Compared with EVA, EVA/O-MMT could make crude oil gelation point further decrease 2.5℃, did average viscosity reduce 25% at 5℃, the maximum rate of viscosity reduction could be up to 28.2%, and the yield stress of crude oil decreased up to 55.5%. DSC results showed that the addition of nano-montmorillonite could rise the initial crystallization temperature of EVA, could widen the crystallization temperature range and reduce wax precipitation point of crude oil. Microscopic results showed the addition of EVA/O-MMT made wax crystal structure of crude oil more compact.

Using simulated experimental setup for flue gas desulphurization with limestone-gypsum, it was studied and analyzed that the relationship existed between properties of fine particles in flue gas formed in desulphurization process and particle size distribution, concentration, morphology, and elements composition of the limestone-gypsum slurry. The effects of flue gas component and desulphurization operation parameters on the fine particle emission were also experimentally investigated. The results show that large numbers of submicron particles are formed during the desulphurization process and their properties are close related to crystal properties of limestone-gypsum in desulphurization slurry. The desulphurization operation parameters such as empty column gas velocity and liquid-gas ratio have great influence on the quantity of slurry drops carried by flue gas out of the scrubber. The evaporation and entrainment of desulphurization slurry is the main source of fine particles formed during desulphurization and their formation can be reduced by the prevention of fine crystal formation in desulphurization slurry and operation parameter optimization.

The pyrolysis characteristics of oil sand at different heating rate was investigated by using a thermogravimetric analyzer. The results showed that the mass loss of oil sand sample contained four processes: desorption, low temperature pyrolysis, main pyrolysis and char condensation. The evolution order of CO₂, CO, C₂H₆, CH₄ and H₂ was determined via the micro fixed bed reactor coupled with mass spectra analyzer, and the corresponding initial releasing temperature were 155, 178, 146, 174 and 354℃, respectively. The composition and chemical structure parameters of liquid and solid products in different temperature ranges were studied by NMR spectroscopy and IR spectrometry. The results showed that the principle reaction before 350℃ was desorption of light oil, in which the aromatic carbon ratio amounted to 7.92% including the breaking of carboxylic and alkyl side chains. The oil sand pyrolysis process mainly occurred in the temperature range of 350—520℃. The aromatic carbon ratio of the obtained pyrolysis oil was 23.51%. By using Coats-Redfern method, the corresponding activation energy of low temperature pyrolysis and main pyrolysis process were 27.63 and 90.30 kJ·mol^-1, respectively, indicating that the activation energy of ring-opening and cracking reaction was higher than that of desorption of oil sand, decomposition of carboxyl and breaking of the weak bonds.

Chemical fractionation analysis is widely used to study the effect of alkali and alkaline earth metal (AAEM) species on the reactivity of biomass char. The influence of chemical fractionation analysis on the physical and chemical structures of biomass char was investigated in this study. The physical structures of biomass char were studied by the mercury porosimetry and scanning electron microscopy (SEM). The results showed that the influence of chemical fractionation analysis on the porosity and surface morphology of the biomass char was apparent. However, the effect of chemical fractionation analysis on the specific surface area of biomass char could be ignored. X-ray photoelectron spectroscopy (XPS) and Raman were used to identify the O-containing functional groups and the aromatic ring structures in the biomass char, respectively. The results indicated that the changes of the oxygen containing functional groups were little during the chemical fractionation analysis. The influence of the chemical fraction analysis on the aromatic ring structures could be ignored. During the chemical fractionation analysis, both NH₄Ac and HCl could change the cross-linking structures of biomass char.

Migration and volatilization features of arsenic in combustion processes for six coal samples selected from three different ranks were studied in a horizontal tube furnace at various temperature ranges. The mass change of arsenic in the combustion process was tracked and analyzed using the instruments and theoretical method of thermal analysis (TG/DTG) and coal analysis for these selected coal samples. The curves of arsenic mass loss and its rate were obtained by fitting these experimental results. The occurrence form of arsenic in the coals and corresponding ashes was determined by using a sequential chemical leaching method. The experimental results show that arsenic volatility and the releasing proportion increase with temperature, and the proportions varied from 30% to 67% at 1100℃. The mass loss rate of arsenic varies for different temperature regions, and a peak value of arsenic loss rate is observed at 800—900℃, mainly due to decomposition/oxidation of arsenic in sulfide form. Furthermore, lignite shows the highest mass loss ratio and rate of arsenic under the same temperature, followed by bituminous coals and anthracite. With temperature increases, organic arsenic volatiles easily into gas phase, and the interaction between acid-soluble and residual arsenic makes them migrate mainly into gas phase, and only a small part is transferred to its exchangeable form.

Nitrous oxide (N₂O) is one of the three main greenhouse gases (CO₂, CH₄, N₂O), about 265 times more effective than carbon dioxide (CO₂), and it may also destruct the ozone layer. In wastewater biological nitrogen removal process, autotrophic nitrification has been thought to be the major source of N₂O production. In this study, by testing the production of N₂O under different conditions, the relationship between N₂O production rate and ammonia oxidation rate during nitritation process was investigated in a laboratory batch-scale system with activated sludge for treating domestic wastewater. The experimental data indicated that the ammonia oxidation rate (AOR) increased with higher DO while N₂O production rate (N₂OR) increased first then decreased. Besides the AOR and N₂OR were by varying the initial ammonium (NH₄⁺-N) concentration in batch experiments. The max N₂OR was 1.29 mg N₂O·(g MLVSS)^-1·h^-1 when DO was 0.6 mg·L^-1. At low DO level, the increase of AOR would promote the N₂OR. On the other hand, higher AOR might not produce more N₂O when DO was high. There were different pathways of N₂O production under various conditions which led to the change of N₂OR. When DO was low, N₂O was mainly produced by nitrosyl radical (NOH), while increasing AOR promoted the N₂OR formation. However, nitrifier denitrification by AOB was the main way of producing N₂O at high DO level. This pathway might be inhibited by high DO, and thus even there was high AOR, the net production of N₂O was still less. In addition, the existence of was very important to N₂O production too.

Wastewater from cracking catalyst production line of petroleum refining industry is difficult to be treated with high density of salinity, high concentration of SS and ammonia, and low C/N. The research focused on the construction of electrocoagulation-partial nitritatiom-Anammox process, the performance and stability of the process towards cracking catalyst wastewater. The results showed that the system got strong stability to treat cracking catalyst wastewater. The effluent quality remained: turbidity< 30 NTU,NH₄⁺-N< 10 mg·L^-1,NO₂^--N< 3 mg·L^-1, NO₃^-< 40 mg·L^-1 and COD< 100 mg·L^-1. By the control of aeration time according to the concentration of ammonium nitrogen, the partial nitritation can be achieved stably and theNO₂^-/NH₄⁺-Nof effluent kept in 0.9 to 1.4 which can satisfied the need of the Anammox. The Anammox process can still show the Anammox effect markedly in the cracking catalyst wastewater with high salinity.

Polyether sulfone (PES)/polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer (P123, PEO₂₀PPO₇₀PEO₂₀, M_a 5800) nanofibrous membrane was prepared via electrospinning. The influence of P123 content on viscosity and surface tension of spinning solution was investigated as well as the effect on structures and properties of the formed nanofibrous membranes. The results showed that the viscosity and surface tension of spinning solution increased from 300 to 1000 mPa·s and 36.5 to 37.8 mN·m^-1 with increasing P123 content from 3% to 9%, respectively. The diameter of the obtained PES/P123 nanofibers was about 360 nm. The formed PES/P123 nanofibrous membranes had a uniform distribution, smooth surface and good mechanical and swelling properties. They also had large specific surface area (>39 m²·g^-1) and porosity, and could be used as catalyst support.

Thermal-expandable polymer microspheres with core-shell structure were synthesized by suspension copolymerization of vinylidene chloride-acrylonitrile-methyl methacrylate (VDC-AN-MMA) in the presence of pentane as a foaming agent. The influence of water phase additives, such as sodium chloride, citric acid and potassium dichromate, on the particle structure and thermal expansion properties of polymer microspheres were investigated. The results showed that the additions of sodium chloride, citric acid and potassium dichromate could significantly reduce the number of un-expandable fine polymer particles. To be specific, when the loading of sodium chloride, citric acid and potassium dichromate was 4%, 2.5%—5.0% and 0.05%—0.1% (based on monomers), respectively, the prepared expandable microspheres exhibited narrow particle size distributions, regular morphology and good encapsulation of foaming agent by polymer. Few particles were unexpanded and the expansion of particles was uniform after the heat treating of the microspheres.

By controlling the pH of the solution, single-layer dopamine modified multiwalled carbon nanotubes (micaDA-MWCNTs) were prepared under acid condition. Multiwalled carbon nanotubes/chitosan (CS/micaDA-MWCNTs) composites were prepared by covalent grafting method with glutaraldehyde as a bridge material between chitosan and multi-walled carbon nanotubes (MWCNTs). The structure and nature of CS/micaDA-MWCNTs composites were characterized by transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FT-IR) and thermal gravimetric analysis (TGA). The results showed that about 6 nm membrane layer of chitosan was well-distributively coated on the surface and the end of MWCNTs. The effective biocompatible strategy of dopamine monolayer film coated carbon nanotubes can not only achieve the purpose of modification with less damage of carbon nanotube structure, but also increase significant amounts of surface active groups of MWCNTs, thereby increasing the content of grafted chitosan. Thermogravimetry analysis (TGA) data showed the chitosan graft was approximately 71.78%. CS/micaDA-MWCNTs had the advantages of both CS and MWCNTs in bacteriostasis, sustained-release effect and diatom growth inhibition. Antifouling experiments indicated that the composites had an efficient broad-spectrum of antibacterial activity against E. coli, S. aureus, Vibrio anguillarum, Navicula parva and Navicula rows.

The activated carbon fiber (ACF) felt with H₃PO₄ pretreatment was used as raw materials, adopting dipping calcination method to prepare Al₂O₃/ACF composite electrode materials. The micro-structure and electrochemical performance of the activated carbon fiber before and after loaded with Al₂O₃ were characterized by using scanning electron microscopy (SEM), Brunauer-Emmett-Teller gas adsorption method (BET), X-ray diffraction (XRD), energy X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR), respectively, and then using homemade improvised electric adsorption desalination device to test the electric adsorption performance for NaCl model wastewater. The results showed that Al₂O₃/ACF composite electrode materials were prepared with success by adopting the dipping calcination method. There was flocculent or granulate Al₂O₃ in the surface and pores of Al₂O₃/ACF complex, and the specific surface area was decreased from 1244.37 m²·g^-1 to 974.59 m²·g^-1. Meanwhile, the content of Al was 1.06% and Al₂O₃ with amorphous was existed on the surface of activated carbon fiber. The Al-O bonds were found on the surface of Al₂O₃/ACF electrode materials with increasing specific capacitance of 76.5% in comparison with the original activated carbon electrode. After loaded Al₂O_3, the electric double layer capacity of ACF electrode materials was increased, the electric adsorption performance was improved, the desalination efficiency was promoted more than 2.3 times as original and the electrode was reproducible. Al₂O₃/ACF composite materials can be used as the electrode materials for the removal of the inorganic ions in wastewater.

With diarylethene as one co-monomer, two backbone diarylethene polymers were synthesized through convenient routes. The solubility, photochromism and fatigue resistant property were studied. The two obtained polymers showed the reversible photochromic ability and excellent fatigue resistance. In the synthesis process of the two polymers, diarylethene and copolymer units were connected using rigid and flexible connections, respectively, and thus obtained diarylethene polymers with different spectral properties and molecular weight.