Due to the high toxicity, potential of biological accumulation, recalcitrance to degradation and the known carcinogenic/teratogenic/mutagenic effects, the chlorinated organic compounds have been listed as priority controlled pollutants by the United States Environmental Protection Agency (EPA). In view of chlorinated pollutants contaminated sites, the traditional physical, chemical and biological remediation methods often impose relatively high costs and considerable impacts on the surrounding environment. The monitored natural attenuation (MNA) is an effective technology for site remediation and management and has been widely used internationally, which gradually attracts more and more attentions in China in recent years. It relies on the intrinsic potential of the pollutants to degrade naturally to meet the remediation requirements, and thereby would reduce treatment costs and lower on-site project risks. This paper focuses on the introduction of MNA technology, as well as the characteristics of chlorinated organic compounds such as the biodegradation pathways and mechanisms during the process of natural attenuation, the main degradation microbial communities and the key biodegradation enzymes. A preliminary discussion on the suitability of implementing MNA remediation on chlorinated organic compounds contaminated sites is provided.

To achieve the target of the efficient, green, safe and energy saving synthesis of dimethyl carbonate, a combined reaction system with energy saving is proposed for synthesis of dimethyl carbonate, methylal and dimethyl ether from methanol. Thermodynamics of single reaction and the complex system is analyzed by Aspen Plus software. The results show that there is thermodynamic equilibrium limit for the synthesis of dimethyl carbonate from methanol in gas phase, to improve significantly equilibrium concentration of dimethyl carbonate higher reaction pressure and lower reaction temperature is necessary, even so, large amount of unreacted methanol must be recycled which consume a lot of energy. When synthesis of dimethyl carbonate is combined with methylal and dimethyl ether synthesis, the equilibrium conversion of methanol can be improved observably from 0.5%—5.9% to 91.7%—96.3%. Based on the thermodynamic calculations and kinetics of these reactions, a series process of three catalytic reactors are proposed for synthesis of dimethyl carbonate, methylal and dimethyl ether in order, and the system including reaction and separation processes is simulated. The results show that the mixture of methylal and dimethyl carbonate can be separated by simple distillation and the separation of dimethyl carbonate-H₂O azeotrpoe need to employ pressure swing distillation. Mass concentration of three products can be reached above 99%. The process proposed could effectively solve the problems as follows: recycle of large amount un-reacted materials, high energy consumption, easy explosion and so on, which exist in the process for detached production of dimethyl carbonate and methylal.

The thermodynamic properties of R134a/R23/R14 ternary mixtures used in three-stage auto-cascade refrigeration systems were calculated based on the PR equation, and enthalpy and entropy were calculated by using dryness. The diagrams of pressure-enthalpy and VLE of R134a/R23/R14 mixture under the typical composition were given. The deviations of bubble pressure and vapor composition between simulation results and the experimental data were less than 1.3% and 1.2% for R134a/R23, 1.0% and 2.4% for R32/R134a, respectively. The deviations of 95% calculated values of R32/R125/R134a were between ±5%. The simulation results could meet the requirements of engineering calculation. Based on the experiment, the thermodynamic properties of the auto-cascade refrigeration system were analyzed in detail. The pressure-enthalpy diagrams of R134a/R23, R23/R14 and R134a/R23/R14 under the operating compositions were given, and the diagram of spatial pressure-enthalpy described the circle of this system clearly. This simulation program could analyze the system circle effectively.

An experimental study is undertaken on liquid mixing process in mini confined impinging jets reactor (CIJR) with excitation by using planar laser induced fluorescence (PLIF) technique quantitatively, and the jet inlet Reynolds number is in the range of 75 to 150. The results show that the mixing effect of two fluids significantly increases during the segregated steady flow translates to the dynamic chaotic flow regime in CIJR. The excitation affects the mixing process in CIJR and the mixing performance is enhanced in the segregated flow regime. However, the excitation has no significant influence on the mixing for the flow in the oscillation regime.

A capacitance measurement system for vertical upward gas-liquid two-phase flow has been established to explore the feasibility for measuring fluid phase-concentration by using concave capacitance sensor and double helix capacitance sensor. The experimental results prove that the concave capacitance sensor has poor measurement resolution, but double helix capacitance sensor shows high resolution in phase-concentration measurement. The fluctuation signals of the two types of capacitance sensors are analyzed by means of time frequency analysis. The time frequency representation can effectively identify flow patterns and characterize their motion clearly. Finally, the drift model of gas-liquid two-phase flow is employed based on the measurement signals of double helix capacitance sensor. Moreover, the phase superficial velocities are estimated for slug and churn flow patterns, and good prediction results are achieved. The results show that the double helix capacitance sensor possesses a good application prospect for measuring the flow parameter in gas-liquid two-phase flows.

An experimental study was conducted on gas-particle coaxial jets by PIV and high-speed camera. The effects of the coaxial jets form and the addition of swirl on the flow and mixing characteristics of particle phase were investigated. The results showed that the axial velocity of the granular jet exposed to an annular air jet was higher than that of the granular jet with a central air jet. In addition, the mixing effect of the case with an annular air jet was found to be much better. For the two coaxial jets forms, the particle axial velocity profile in the cross-section close to the nozzle was more even. The addition of swirl, especially for the strong swirl, could not only achieve the uniform distribution of the particle axial velocity in the far field, but also improve the mixing effect of the two-phase efficiently.

The mechanism of natural convection around horizontal and vertical heated microwires in silicon oil is studied by using the wire itself for temperature measurement. The comparison between present measured Nusselt numbers and those in literature shows that the present data agreed better with those of Tsubouchi than those of Fand. The horizontal microwire presents a larger Nu than the vertical one at low Rayleigh number. However, all of these experimental Nu are much larger than the numerically simulated values. In order to give a theoretical explanation on this phenomenon, heated microwire with weak vibration was used in the numerical simulations. The simulated Nu shows a perfect match with the measured data and are in agreement with the correlation of Tsubouchi with a deviation less than 5%. Therefore, an enhanced heat transfer mode due to weak wire vibration is proposed, to fill the gap between simulated and experimental results.

A mathematical model was developed to simulate the heat and mass transfer of evaporation and salt crystallization process of a saline (aqueous NaCl solution) droplet during depressurization. The model considered the formation of porous salt crust at the droplet surface, the air flow around the droplet caused by pressure drop, the mass diffusion of vapor through porous medium and the heat transfers due to evaporation and convection at the droplet surface. By comparing the numerical results with the experimental data, the validity of the present model was verified. Through numerical calculations, the variations of droplet surface temperature and droplet mass with time were obtained, and the different characteristics of droplet evaporation and crystallization process under low pressure environment and atmospheric environment were analyzed. The results showed that the temperature variation of a saline droplet during evaporation and salt crystallization process under reduced pressure can be divided into four stages: the stage of temperature drop, the temperature recover stage, the equilibrium temperature stage, and the temperature rising stage. During the equilibrium temperature stage, the movement of salt crust interface was slower, with the evaporation process, the size of liquid core decreased continuously, and then the movement of salt crust interface was quicker. The effect of ambient pressure on evaporation and salt crystallization process of a brine droplet was theoretically analyzed. With a lower ambient pressure, the equilibrium temperature was lower and the time for salt completely precipitated was shorter.

Through constructing a visual experiment platform of bubble absorption heat and mass coupled transfer characteristics in the vertical tube, the flow pattern characteristic and distribution regularity of bubble absorption process on R124/DMAC (2-chloro-1,1,1,2,-tetrafluoroethane / N', N'- dimethylacetamide) as working medium are studied. The result shows that the flow pattern characteristic and distribution regularity are influenced by the refrigerant vapor flow rate, absorption solution flow rate and its inlet temperature. Under large refrigerant vapor flow rate and high solution inlet temperature conditions, three kinds of flow patterns of churn flow, slug flow and bubble flow can be simultaneously observed in the bubble absorption tube. Under the condition which the vapor is completely absorbed in the absorption tube, the height of churn flow is no more than half of the total absorption height, while the height of slug flow is no more than 2/5 of the total absorption height. The rest of the absorbing height is occupied by bubble flow.

Signals of sound pressure oscillations during vapor condensation and transition of condensation regimes were investigated using a high-speed video camera and a hydrophone. Results indicate three different condensation regimes with the increase of subcooling and vapor injection rates, which are referred to as bubble oscillation regime, transition regime and capillary wave regime. In addition, two waveforms occur in the detected signals, of which sources are vapor bubble split-up and collapse. The kurtosis of the signals presents step changes, which is close to the transformation threshold of condensation regimes. The peak at frequency of 150—300 Hz appears in spectra in all condensation regimes, which may be resulted from the periodic variation in vapor volume. The peaks with frequency higher than 7000 Hz appear only in transition and capillary wave regimes and may be the resultant of the high-frequency oscillation in pressure caused by sudden collapse of vapor bubbles. The bubble collapse frequency increases with the increase of subcooling and vapor injection rates and is close to the frequency of the first peak in spectra with an error within ±20%.

The particles aggregation states and apparent volume of the stacked glass beads at different liquid content are studied experimentally. It shows that the liquid mainly exist as liquid bridges at low liquid content, while that in different pores connects to each other at higher liquid content. The apparent contact angle of water on particle surface determines the critical moisture content which separates the low and high moisture content. The transformation of liquid morphologies induces the variation of the liquid action on particles, which finally influences the particles aggregate state and leads to the change in the sample apparent volume. A model is developed to determine the critical liquid content by the apparent contact angle, from which the liquid begins to mainly exist as interconnectedness morphology other than isolated liquid bridges. The prediction from the model is in good agreement with the experimental data.

A kind of self-pumping hydrodynamic mechanical seal, that the liquid inlet groove was arranged on the stationary ring and the dynamic pressure groove was distributed on the rotating ring, was put forward based on the principle of centrifugal pump. The experimental scheme of the self-pumping mechanical seals was designed by orthogonal test. The numerical simulation experiments were carried out based on Fluent, including discussing the significant effects of every parameter on the face opening force and the leakage rate. The numerical results showed that the groove number N_g, the ratio of groove length and dam length γ, the ratio of groove width and ridge width d, and the pressure p were the significant factors affecting the opening force F_O and the leakage rate Q within the experimental ranges. Besides, the rotate speed n also affected Q significantly. Specifically, F_O was increased with increasing g, d and p, while decreased with increasing N_g. The influence of g, d, p and N_g on Q was similar to that on F_O. But Q was also increased with increasing n. The preliminary optimization of sealing structure was brought forward by analyzing the results of orthogonal test.

Aiming at the granulation of molten blast furnace slag by spinning disc, the visualization granulation experiment was conducted using water as the substance. The granulation process including film waving and ligament break-up was captured by high-speed camera. A self-compiled MATLAB program was employed to extract the data from the images. The ligament formation and the process of ligament break-up into droplets during centrifugal granulation were analyzed. Variation of ligament formation and droplet formation with operating conditions was investigated. The qualitative relationship between ligament formation and droplet formation was obtained. The impacts of Weber and Reynolds numbers on ligament number, ligament break-up length, droplets diameter distribution and average diameter were discussed. The results revealed that the ligaments were originated from surface instable waves of liquid film on the spinning disc and the droplets were formed by ligament break-up due to symmetric shocking waves spreading from the ends to the middle of ligament. The number of ligament increased with increasing rotary speed and the distribution of droplets became more highly concentrated as well, while the break-up length of ligaments and the average diameter of droplets were decreased as rotary speed increased. With increasing liquid flow rate, the number of ligaments increased, while the distribution of droplets became less concentrated. The break-up length of ligaments and average diameter were increased with higher liquid flow rate. Besides, larger ligament number or shorter ligament break-up length resulted in smaller droplets. Meanwhile, both of the Weber and Reynolds numbers had significant influence on the ligament formation, while only the Weber number had significant effect on droplet formation. By fitting the experimental data, correlations have been obtained to predict the granulation variation with different operational conditions quantitatively.

A series of acidic ether functionalized chloroaluminate ionic liquids were synthesized and studied. The catalyst with the highest acidity was screened out by FT-IR spectra using acetonitrile as infrared probe and used to catalyze the alkylation of isobutane with 2-butene. It was proved that the acidity of 1-methoxyethyl-3- methylimidazolium bromide aluminium chloride ([MOEMIM]Br/AlCl₃) was the highest when the molar ratio of AlCl₃ was 0.75. The high quality alkylate with a C₈ selectivity of 66.6%(mass) was obtained at 35℃ with the isoparaffin/olefin molar ratio (I/O) of 10, which was much better than that with non-ether functionalized chloroaluminate ionic liquids. The catalysts could be reused several times without obvious loss of activity.

Based on the flow pattern of perfect mixing and the age probability density exponential function of equilibrium catalyst in commercial FCC unit, a model equation was established by derivation of catalyst deactivation kinetics, in which equilibrium catalyst activity or micro-reactor activity was related to carbon and metal contents on catalyst, replacement rate of catalyst, temperature and steam partial pressure in regenerator. The mathematical model with high calculation precision for equilibrium catalysts activity or micro-reactor activity was developed through the simulation for operation data of commercial FCC unit and model parameter estimation. The comparison of model parameters indicated that the effect of V contaminate on catalyst activity is the biggest and the effect of Na is the smallest, while the effect of Ni and Fe is in the middle. The results predicted by the model showed that the activity or micro-reactor activity of equilibrium catalyst increases with the decrease of metal and carbon contents on catalyst and the increase of catalyst consumption. It would be advantageous to the activity or micro-reactor activity of equilibrium catalyst to reduce properly the catalyst hold-up or the temperature in regenerator.

Nickel-based catalysts supported on ZrO₂, SiO₂, and Al₂O₃ supports, were prepared by incipient impregnation method and evaluated using liquid phase hydrogenation of maleic anhydride. BET,XRD,H₂-TPR and TPO-MS were employed to characterize these catalysts. Their catalytic performance varied with supports used. Among all the catalysts, Ni/Al₂O₃ catalyst exhibited the highest activity for C=C hydrogenation, while there was the lowest activity for C=O hydrogenation. Ni/ZrO₂ catalyst had the highest C=O hydrogenation activity, and maleic anhydride conversion and γ-butyrolactone selectivity were 100% and 79.2% respectively under the reaction condition of 483 K, 5 MPa of H₂ and 8 h of reaction time. The re-use experiment of catalyst demonstrated that the stability of catalyst in liquid phase hydrogenation of maleic anhydride was better for Ni/ZrO₂ and Ni/SiO₂ than Ni/Al₂O₃. Both selectivity and stability of catalysts could be explained by the interaction between succinic anhydride and catalyst.

Novel TiO₂ nanofibers(NF) and TiO₂(NF)-graphene oxide (GO) supports were prepared by electro-spinning, and NiMo/TiO₂(NF) and NiMo/TiO₂(NF)-GO catalysts were obtained by incipient impregnation. The properties of supports and catalysts were characterized by N₂ absorption-desorption, X-ray diffraction, SEM, TEM, Raman spectra and NH₃-TPD. The effect of different loading of GO was investigated. The results showed that when the mass fraction of GO/TiO₂(NF) was 0.5%, the intermediate-strong acid sites increased to the maximum. Under the mild conditions of 280℃, 2.0 MPa, LHSV 4 h^-1 and H₂/feed ratio 400 (vol), the corresponding catalyst exhibited the excellent HDS performance.

The high cis-1,4-polyisoprene is prepared by Ziegler-Natta coordination polymerization. The effect of preparation method and condition of heterogeneous TiCl₄-Al(i-Bu)₃ two component catalyst on isoprene polymerization are investigated. The influence of several parameters on the catalytic activity, the gel content, intrinsic viscosity, microstructure and cis-1,4-content of the polyisoprene is examined in detail, including mole ratio of catalyst component, prefabricate temperature and aging time as well as catalyst dosage, polymerization temperature and time. The results show that the optimum conditions of catalyst preparation are as follows: the molar ratio of Al/Ti is 1.0, the temperature of prefabricate is at -40℃, the aging time is 2 h at room temperature, molar ratio of Ti/Ip(catalyst content)is 6×10^-3, the polymerization for 5 h at 50℃. Under these condition, the monomer conversion is 87.1% in the polymerization, the microstructure cis-1,4 content in obtained polymer is up to 91.76%.

Gum Arabic, an ideal raw material for preparing L-arabinose, can be catalytically hydrolyzed by sulfur acid to obtain the hydrolysate containing L-arabinose, D-galactose and L-rhamnose. In order to ensure the stability of subsequent purification process as well as product quality, optimization of the acid hydrolysis process is necessary. In this work, single factor experiments are performed to determine the key parameters of acid hydrolysis reaction. The effects of reaction time, acid concentration, temperature and solid-to-liquid ratio on the hydrolysis are investigated. The results show that the temperature affects more significantly on the yield rate of L-arabinose. The degree of hydrolysis as high as 85% and the relative purity of L-arabinose up to 85% or 87% can be obtained under the optimized hydrolysis conditions of 90 min reaction at 100℃ or 200 min reaction at 90℃ with 0.1 mol·L^-1 H₂SO₄ and solid-to-liquid ratio of 1:10 (g/ml).

Pluronic polymers P123, P105, F127 and F108, which have different chain lengths of PEO block were modified to generate aldehyde terminals for the conjugation with surface amine groups of CALB. The resulted Pluronic-CALB conjugates were characterized by SDS-PAGE and transmission electron microscopy. It was showed that the conjugates were dispersed well in toluene and appeared as nanoparticles with diameters ranged from 20 nm to 40 nm. The conjugates can be dispersed in methyl isobutyl ketone (MIBK) with temperature- responsive properties. The conjugate with a longer chain length of PEO block appeared a higher low critical solution temperature (LCST). The apparent activity of the conjugates in toluene at 37℃ was increased by 4 to 6 folds compared to the native counterpart. The recovery of CALB conjugates can be accomplished by precipitation at low temperature, making this enzyme conjugate suitable for industrial enzymatic synthesis in organic media.

Covalent organic frameworks (COFs) are considered as a new type of adsorbing material for hydrogen. In this work, density functional theory (DFT) has been applied to investigate the adsorption mechanism of H₂ on seven main clusters of COFs, and GGA/PBE is used in the calculation. The results indicate that the center of benzene ring is the most favorable site when H₂ molecular attacks vertically, in addition the center and oxygen atom of B₃O₃ ring are more favorable when H₂ molecular attacks parallelly. The increase of carbon atom number on organic cluters would be beneficial for adsorption of H₂. By calculation of different adsorption configurations for two H₂ molecules on COF-10 and COF-105, it is found that a cooperative effect between H₂ adsorption on these two COFs could be exist. Doping of alkali metals (Li, Na, K) and substitution of organic functional groups (methyl, sulfhydryl, amino) on COFs can significantly enhance the adsoroption energy, indicating that these chemical modifications are an effective way for enhancement of hydrogen adsorption capacity of COFs.

A code matrix-based synthesis method for multicomponent distillation sequences is described as well as its algorism. Four steps, such as grouping the components of feed, generating the basic search space of sub-column configurations, transforming 0-1 matrices into code matrices and eliminating configurations with separation constraints, are included in this method. The code matrices, whose element code includes the information about the column sequence number and the location of product withdrawing, are transformed from 0-1 matrices determined by matrix method. Thus, this method not only provides a complete set of separation configurations with sharp or non-sharp split but also can pick out all the desirable configurations with the constraints by logical programming. Additionally, the use of this method is illustrated by applying it to the ethylene glycol purification from dimethyl oxalate hydrogenation. Eight configurations are selected out and one configuration with the lowest total reboiler heat duty is identified by Aspen Plus optimization.

Nano white carbon black particles filled PDMS/PVDF composite membranes were prepared, and FT-IR, TGA and contact angle were used to characterize the physical and chemical characteristics of the composite membranes. By using soybean/hexane miscellas, the separation performance of the composite membranes was systematically investigated. The results indicated that by filling white carbon black to PDMS, the crosslinking density was promoted, and the hydrophobicity, thermal stability and solvent resistance were improved. The permeate flux was declined with increasing filling content of white carbon black, while the oil retention was risen from 96% to 98%. With the increase of oil concentration, both of the permeate flux and oil retention were declined. With increasing feed temperature, the permeate flux was risen while the oil retention was declined. Mass transfer characteristics of soybean oil and hexane through the membrane can be described by the solution-diffusion with imperfections model, and the experimental values of the micelle osmotic pressure were well in accordance with calculated values.

By taking the advantages of easy decomposition and catalytic function of basic magnesium carbonate, the mechanically stable porous carbon materials (MCM-Mg) are synthesized through rapid gelation of resorcinol with formaldehyde and subsequently carbonization. Compared with samples catalyzed by traditional carbonates, the synthesis process can obtain a well-developed porous structure. The resulted samples can withstand a pressure of up to 9.4 MPa. At 273 K, the equilibrium CO₂ adsorption capacities of MCM-Mg are in the range of 3.49—4.50 mmol·g^-1 at 0.1 MPa and can reach 1.87 mmol·g^-1 at 0.015 MPa. Experimental test of the MCM-Mg shows that the micropores play a major role in contribution of the amount of adsorbed CO₂. Importantly, MCM-Mg can adsorb 7.15 μmol CO₂ per S_micro, which surpasses most of the carbons prepared by activation. Dynamic breakthrough tests show that over such series of samples, CO₂/N₂ streams can be fully separated. The CO₂ release is achieved facilely in Ar purge at 298 K. The samples also exhibit stable performance for CO₂ separation under humid conditions and exhibit good regeneration capability.

For real-time optimization of batch processes, a batch-to-batch self-optimizing control approach is proposed based on necessary conditions of optimality approximation method. Firstly, the nominal optimal input trajectory is numerically obtained, which is further parameterized as a few decision variables to simplify the problem complexity. Secondly, the optimality conditions for the batch-to-batch optimization problem are analyzed, from which regression models are built using terminal measurements. The obtained regression models are further adopted as controlled variables to be tracked from batch to batch. The proposed method is applied to a simulated batch reactor. The results show that the new method can realize batch-wise self-optimizing control efficiently.

In a practical water using process, a temperature requirement exists. Thus, it is significant to consider the temperature constraint in water network integration to decrease the water and energy consumption at the same time. Besides, there are non-water process streams which only have temperature requirements in the process system. If these streams are integrated with water streams in the water network, better energy efficiency can be reached. In this paper, a method for optimizing water networks is proposed under the background of heat integration in whole process system. First, an LP model is established to obtain the initial status of the water network and stream data. Then, four rules for non-isothermal mixing are proposed by comparing the relative position of water streams with the background and whole process pinches to exclude the irrational non- isothermal mixing. Finally, the heat integration in the whole system is performed with minimal total annual cost as the objective function. A case study is used to show the feasibility of the method, which can get a decrease of 6.27% in the annual cost.

The concentrations of zinc ion and sulfuric acid in electrolytic solution are detected by off-line analysis with large time-delay, which will be detrimental to the on-line optimal control for zinc electrowinning process (ZEWP). It is very significant to predict the concentrations of zinc ion and sulfuric acid on line. The electrochemical reaction mechanism for ZEWP is analyzed, and a dynamic model for ZEWP is established based on the material balance and electrochemical equations. Based on the data collected from the practical ZEWP, the working conditions of the ZEWP are classified using FCM algorithm. The parameters of the dynamic model under different classes are identified, and the concentrations of zinc ion and sulfuric acid in ZEWP are predicted using the multi-condition fuzzy matching approach. The results obtained from the practical data show that the model can effectively predict the variation tendency of the concentrations of zinc ion and sulfuric acid, which is profitable to the optimal control for ZEWP.

Rational allocation of leaching rates is significant for the organization of leaching process production. Generally, each leaching rate is given by engineers with the help of their experiences, which makes the supervision of leaching process production with a large extent of fuzziness and randomness, and it does not guarantee that the adjusted total leaching rate is the maximum. In order to determine the optimal leaching rate of gold hydrometallurgy process, an optimization model is established with maximizing the total leaching rate of hydrometallurgy process as the goal. And the second-order oscillating particle swarm algorithm is applied to solve the model. Finally, an experimental research demonstrates the effectiveness of the established model and algorithm.

In the geological carbon dioxide (CO₂) sequestration in abandoned oil reservoirs, there usually exists a fluid system including CO₂, oil and brine, where the interplay between them is very important for the successful CO₂ storage. In this paper, molecular dynamics simulations were carried out to investigate the interfacial characteristics of the CO₂, n-hexane and NaCl solution system with different CO₂ fractions at the miscible state. CO₂ and n-hexane formed a miscible phase, and a clear interface was observed to separate the CO₂ and n-hexane mixture with brine. Both the interfacial width and roughness increased with increasing CO₂ composition, indicating the stronger interfacial interactions when water molecules contacted with CO₂, leading to the reduction of interfacial tension. The surface adsorption of CO₂ reached the maximum when CO₂ molar fraction equaled to 65%, as well as the deficiency of n-hexane. This implied the surfactant feature of CO₂ and the hydrophobicity of n-hexane towards the interface investigated. A special micro structure was observed at the interface, where CO₂, water and n-hexane molecules had own preferred arrangement tendency. The special interfacial characteristics found could explain the experimental IFT phenomena and the microstructure variation in the CO₂ injecting process, and could provide some theoretical guidance for CO₂ sequestration.

Aiming at the stability problem of corrosion inhibitor film of the high sulfur gas gathering pipelines with two-phase turbulent flow, the corrosion inhibitor film stability with typical pipe flow in high sour gas field was evaluated by using the dynamic corrosion test system with high temperature and high pressure cyclic reactor. The inhibitor prefilm stability was better when the flow velocity was below 6 m·s^-1 and it began partial failure when the flow rate exceeded 7.5 m·s^-1, while it was completely failure under the action of flow shear force when the flow rate reached 9 m·s^-1. The fluid dynamics study showed that the shear stress of 6.5 N·m^-2 was the critical point of the inhibitor film being overall damaged.

1,2,4-Butanetriol (BT) is an important organic synthetic intermediate. In this study, the metabolic network of Escherichia coli was reconstructed by heterogeneously expressing a keto acid decarboxylase (mdlC) from Pseudomonas putida ATCC12633 and a D-xylose dehydrogenase (xdh) from Caulobacter crescentus CB15, and knocking out xylA, yjhH and yagE which were the genes of xylose utilization pathway and intermediary metabolite pathway for D-1,2,4-butanetriol synthesis. The recombinant strain could synthesize D-1,2,4-butanetriol directly using D-xylose as precursor. Culture conditions such as temperature, medium volume, pH of fermentation broth were investigated at the titer of D-1,2,4-butanetriol of 3.96 g·L^-1 under suitable fermentation conditions. The relationship between glucose utilization and D-1,2,4-butanetriol synthesis was discussed. After modifying the phosphoenolpyruvate: sugar phosphotransferase system (PTS) by knocking out ptsG the reconstructed E.coli could utilize glucose and xylose simultaneously, leading to a higher D-1,2,4-butanetriol productivity.

The drying characteristics under isothermal condition of Hulun Buir pulverized brown coal with high moisture content of 40% was studied using thermo-gravimetric method. The effects of drying temperature and particle size on drying process were analyzed. The results showed that the constant rate stage was obviously observed, and the characteristics were closely related to drying temperature and free water content. The critical (MC_cr) and equilibrium (MC_eq) moisture content were obtained. The drying rate decreased with the decrease of particle size, but the effect of particle size was not obvious when the coal particle was enough small. MC_cr and MC_eq decreased with the increase of temperature, however, MC_cr increased and MC_eq decreased slightly with the decrease of particle size. The experimental results could provide a basis of selection and optimization of brown coal powder and drying process.

Catalyst is the key factor for formation of dioxins i.e. PCDD/Fs, for which there is not enough study currently. In this paper, the effect of different metal catalyst contained in model fly ash (MFA) on both PCDD/Fs concentration and distribution is studied under laboratory conditions. The results show that ZnO can inhibit the formation of PCDD/Fs. The catalytic effect of ZnCl₂ on PCDD/Fs is far more obvious than that of CdCl₂ and the concentrations of PCDD/Fs obtained are 341.78 and 16.32 ng·g^-1, respectively. PCDD/Fs formed by ZnCl₂ promotion is 338 times as many as that of ZnO, while the concentration of PCDD/Fs catalyzed by CdCl₂ is twice more than that of CdO. Principal component analysis (PCA) is used to research the effect of catalyst on PCDD/Fs distribution. It is observed that the change of distribution for 17 toxic PCDD/Fs catalyzed by different metal catalyst is significant. Meanwhile, the PCDD/Fs concentration rises with increase of O₂ content, but for PCDD/Fs distribution it has only limit influence.

A new online monitoring and evaluation device for the treatment countermeasures of circulating cooling water was developed,which is used for evaluation and optimization of water treatment countermeasures, and online monitoring of the core water quality parameters. This device can online monitor the heat exchanger fouling resistance, corrosion rate and core water quality parameters (pH, ORP, concentrated ratio) in real-time based on the fluid state, water quality, metal materials and heat transfer intensity of the power plant circulating cooling water, and can evaluate and adjust the concentration of the water treatment agent online. The monitoring system hardware including fouling resistance detector, corrosion rate detector, automatic dosing device, analysis instrumentation of water quality parameters and industrial computer was designed. And the software was developed by Delphi7.0 which can carry out monitoring parameter settings, real-time display, online control, historical data query and report printing. This device has been used in Unit 1 of the Power Plant of Shandong Yancon Croup Co., Ltd. The experimental results showed that the instantaneous fouling resistance and corrosion rate were less than 1.5×10^-4 m²·K·W^-1 and 0.005 mm·a^-1, respectively, and the concentration ratio of the circulating cooling water can increase from 2 times to 4 times. This device can evaluate the water treatment dosing programs in real-time, inhibit the growth of fouling resistance effectively, reduce the corrosion of the heat exchanger and improve the economic efficiency of power plants.

The effects of coal moisture on heating rate and product distribution for pyrolysis of coal in a fixed-bed reactor with or without internals were investigated. The results showed that the reaction time in the reactor without internals is approximately twice of the time in the reactor with internals. With utilization of internals to enhance heat transfer and regulate the pyrolysis gas flow direction inside the reactor, increasing the coal moisture content prolonged the time that required to heat up the coal at the bed center to the preset temperature and increased the light tar content, whereas the tar yield tended to first increase and then decrease and the yields of pyrolysis gas and water tended to increase. In contrast, there was not dramatic difference in the reactor without internals when varying the coal moisture. At a heating furnace temperature of 900℃, the increase of coal moisture from 0.41% to 11.68% (mass) increased the tar yield from 9.21% to 10.74% (mass) for the reactor with internals, but when the coal moisture content increased further to 15.93% (mass) the tar yield decreased to 10.26% (mass). The variation trend with coal moisture content in the average pyrolysis gas composition was similar for both reactors, and the higher heating value (HHV) became lower when the coal moisture increased.

Oil samples, obtained by retorting Huadian oil shale at five different final temperatures, were divided, according to boiling point, into light oil (<300℃) and heavy oil (>300℃). The light oil was analyzed using GC-MS and their components classified to find the regular pattern that is variation of oil chemical composition with final retorting temperature. ¹H and ¹³C nuclear magnetic resonance spectroscopy was employed to analyze the chemical structure of the compounds in the heavy oil. The results show that the majority of Huadian light shale oil is aliphatic series compounds. Among of them, n-alkanes, α-alkenes, n-alkanals and n-alcohols are of homology and all come from alkyl radicals. With the increase of final retorting temperature, length of carbon chains in light oil is shorter and there is more n-aliphatic hydrocarbons in heavy oil, because long chain aliphatic compounds were decomposed and the side chains in branched alkanes broken, while more aromatic ring condensation reactions took place which results in more aromatic rings formation in both light oil and heavy oil as well as increase of condensational degree in light oil.

A novel rotating drum biological contactor (RDBC) was operated with MBBR packing particles inside, by which anaerobic, anoxic and aerobic operating modes can be achieved by adjusting immersion level or rotating speed. The volume oxygen transfer coefficient (K_La) and power efficiency can reach 25.87 h^-1 and 228.62 g·(kW·h)^-1, respectively. Synthetic domestic sewage was treated with step feed post-denitrification process. The results showed that the optimal operating conditions were immersion level 2/3, rotating speed 8 r·min^-1 and DO 3.0 mg·L^-1 in aerobic tank, and immersion level 5/6, rotating speed 8 r·min^-1 and DO 1.0 mg·L^-1 in anoxic tank. In above conditions, when the influent average COD was 385.0 mg·L^-1, NH₄⁺-N 38.0 mg·L^-1, TN 38.0 mg·L^-1, total inflow 6 L·h^-1 (HRT=18 h) and flow distribution ratio 3:1, the remove rate of effluent COD, NH₄⁺-N and TN can reach 90.4%, 93.7% and 80.9%, respectively, which can meet the first level A discharge standards in China (GB18918—2002).

By adjusting the distribution ratio of influent flow into anaerobic and anoxic zones, the removal efficiency of pollutants in low C/N(COD/total nitrogen)<3.5 municipal sewage using modified step feed process was analyzed. Keeping the following conditions unchanged: hydraulic retention time (HRT) 10 h, sludge retention time (SRT) 10—15 d, volume of anaerobic zone:volume of total anoxic zones:volume of total aerobic zones 4:9:9, when the actual efficiency obtained and material balance calculation results were utilized to increase gradually the water ratio distributing to the first stage i.e. anaerobic zone, the best operating conditions could be found and 4 kinds of operating conditions determined. The results show that, at given C/N ratio, concentration of nitrogen oxides in anaerobic zone does not decrease with the increase of the water ratio entered into anaerobic zone, even appears the opposite situation. The simultaneous nitrification and denitrification(SND)and microbial assimilation effect intensity play crucial role in TN removal. The rise of water ratio entered into anaerobic zone improves the removal rate of phosphate due to the phosphorus release effect of phosphorus-accumulating bacteria is enhanced in anaerobic zone. Both nitrogen and phosphorus removals as well as subsequent optimization space are considered, one of optimized water distribution ratio is 6:3:1,and at this condition, the effluent concentration of COD, ammonia nitrogen, TN, phosphate is 45.98, 0.04,17.47 and 2.43 mg·L^-1 respectively.

This study was devoted to investigating the NO emission from combusting distilled spirit lees with high contents of moisture and nitrogen in a laboratory fluidized bed. The results showed that the NO emission increased with increasing excess air ratio and combustion temperature. The addition of extra water vapor into the combustion atmosphere for simulating the combustion of high-moisture fuel effectively decreased the NO emission, and about 46% (mass) of NO emission was reduced under appropriate conditions. In the N₂-base atmosphere containing CO or H₂, the metallic oxides containing in the ash of distilled spirit lees showed obvious catalytic activity on the reduction of NO, and the catalytic activity increased with increasing temperature. Water vapor in itself had not detective effect on reduction of NO, showing that its reduction of NO into N₂ would be implemented through its reactions with hydrocarbons to generate reductive gases such as H₂ and CO under the catalytic effect of ash.

The burner tilting up and the bias setting of AA tilting up angle was employed in order to reduce the temperature deviation of flue gas and reheat steam. The combustion processes in a 700 MW tangentially fired boiler with different burner tilting up angles were numerically simulated. The simulated results were fitted in with the measured data well. For greater burner tilting up angle, the swirling momentum moment in the furnace and the residual swirling momentum moment in the entrance of platen zone were reduced, while the flue gas deviation in the horizontal flue gas pass was lower. The bias setting of AA burner tilting up angle can reduce the flue gas residual swirling momentum moment of the entrance of platen zone considerably and lower the deviation of the flue gas temperature and velocity. The combustion tests showed that as an effective measures to reduce the temperature deviation of flue gas and reheat steam of this boiler, the burner tilting up for 11° and the bias setting of AA tilting up angle for 10° can reduce the temperature deviation of reheat steam from 20℃ to about 4℃.

Molecular dynamics simulations were carried out to study the structure and morphology of SDS adsorbed on nano-sized graphene surfaces in pure water and electrolyte solution. The effects of the layer numbers of the graphene on the adsorption self-assembly structure and the buoyant density of the SDS/graphene assemblies were explored. The simulation results show that the aggregate morphology was highly dependent on the layer number of the graphene in both solutions. The stretching of surfactants to solution was enhanced with increasing layer number, leading to expansion of the self-assembly structure. In the presence of electrolyte in the solution, the surfactant micelles of SDS were transformed from the rough multi-layer to hemi-cylinder structure. In the meantime, the buoyant densities of the SDS/graphene assemblies were found to increase linearly with increasing layer number of the graphene. This behavior provided a direct theoretical basis for graphene dispersion with controlled thickness using the density gradient ultracentrifugation in the surfactant aqueous solution.

Maleic anhydride grafted poly(propylene carbonate) (PPCMA)/thermoplastic starch (TPS), PPCMA/thermoplastic oxidized starch (TPOS) and PPCMA/DL-TPOS (TPOS modified by aluminate coupling agent) composites were prepared by melt blending. Effects of starch oxidation and content of DL and DL-TPOS on rheological behavior, morphology and mechanical properties of composites were investigated. The results of Fourier Transform Infrared Spectroscopy (FTIR) revealed that the reinforcement in mechanical properties of PPC/starch composites was probably resulted from hydrogen-bonding interaction between carbonyl groups of PPC and hydroxyl groups of starch. The compatibility between PPCMA and TPOS was better than that of PPCMA and TPS. The mechanical property, storage modulus (G'), loss modulus (G'') and complex viscosity (η^*) of composites were improved by oxidation of starch. Moreover, the dispersion of TPOS in PPC matrix became better when starch was modified by DL, improving the tensile strength of composites. For PPCMA/DL-TPOS composites, the tensile strength increased by 460% from 2.45 MPa to 13.72 MPa, when DL-TPOS content was from 0 to 40% (mass), while it decreased when the loading of DL-TPOS was 50% (mass). In addition, G', G'' and η^* of composites was improved with increasing DL-TPOS content.

The premixed stoichiometric methane-air deflagration is conducted in a transparent square cross-section duct. Effects of the ignition positions on the overpressure characteristics of the premixed methane-air deflagration flame propagating in the duct closed at one end and open at the opposite end are obtained. The experimental results show that the pressure waveform changes from no oscillation to weak oscillation with the equiamplitude then to sharp oscillation with the exponential increase amplitude as the ignition positions relative to the closed end of the duct are increased. The generation mechanism of the overpressure is closely dependent on the transient flame structures and the overpressure extrema of the oscillating waveforms always correspond to the flame position extrema. The oscillation periods of the overpressure waveforms during the phase of the exponential increase amplitude are linearly decreased with the time since ignition and well correlated with the length of the unburnt gas column. The oscillation is triggered by the venting of the flame front located at the open end of the duct, and then amplified by the flame-sound interaction in the unburnt gas column between the pressure wave and the flame front located at the closed end of the duct.