Thiswork provides amethod to explore the transport property of the electrolyte aqueous solutionswith one or two ionic liquids, especially focus on their electrical conductivity. The conductivities were measured for the ternary systems NaCl-[C₆mim][Cl] (1-hexyl-3-methylimidazolium chloride)-H₂O, [C₆mim][BF₄]-[C₆mim][Cl]-H₂O, NaNO₃-[C₆mim][BF₄](1-hexyl-3-methylimidazolium tetrafluoroborate)-H₂O, and [C₄mim][BF₄] (1-butyl-3- methylimidazolium tetrafluoroborate)-[C₆mim][BF₄]-H₂O, and their binary subsystems NaNO₃-H₂O, NaCl-H₂O, [C₆mim][BF₄]-H₂O, [C₆mim][Cl]-H₂O, and [C₄mim][BF₄]-H₂O, respectively. The conductivities of the ternary systems were also determined using generalized Young's rule and semi-ideal solution theory in terms of the data of their binary solutions. The comparison showed that the two simple equations provide good predictions for conductivity of mixed electrolyte solutions and the mixed ionic liquid solutions based on the conductivity of their binary subsystems.

To reduce heat loss and save cost, a combination decision model of reverb aluminum holding furnace linings in aluminum casting industry was established based on economic thickness method, and was resolved using simulated annealing. Meanwhile, a three-dimensional mathematical model of aluminum holding furnace linings was developed and integrated with user-defined heat load distribution regime model. The optimal combination was as follows: sidewallwith 80mmalumino-silicate fiber felts, 232mmdiatomite brick and 116mmchamotte brick; top wall with 50 mm clay castables, 110 mm alumino-silicate fiber felts and 200 mm refractory concrete; and bottomwallwith 232mmhigh-alumina brick, 60mmclay castables and 68mmdiatomite brick. Lining temperature from high to low was successively bottom wall, side wall, and top wall. Lining temperature gradient in increasing order ofmagnitude was refractory layer and insulation layer. It was indicated that the results of combination optimization of aluminum holding furnace linings were valid and feasible, and its thermo-physical mechanism and cost characteristics were reasonably revealed.

The impeller configuration with a six parabolic blade disk turbine below two down-pumping hydrofoil propellers, identified as PDT + 2CBY, was used in this study. The effect of the impeller diameter D, ranging from 0.30T to 0.40T (T as the tank diameter), on gas dispersion in a stirred tank of 0.48 m diameter was investigated by experimental and CFD simulation methods. Power consumption and total gas holdup were measured for the same impeller configuration PDT + 2CBY with four different D/T. Results show that with D/T increases from 0.30 to 0.40, the relative power demand (RPD) in a gas-liquid system decreases slightly. At low superficial gas velocity V_S of 0.0078 m·s^-1, the gas holdup increases evidently with the increase of D/T. However, at high superficial gas velocity, the systemwith D/T=0.33 gets a good balance between the gas recirculation and liquid shearing rate, which resulted in the highest gas holdup among four different D/T. CFD simulation based on the two-fluid model along with the Population Balance Model (PBM) was used to investigate the effect of impeller diameter on the gas dispersion. The power consumption and total gas holdup predicted by CFD simulation were in reasonable agreement with the experimental data.

Dynamical properties of liquid in nano-channels attractmuch interest because of their applications in engineering and biological systems. The transfer behavior of liquid confined within nanopores differs significantly from that in the bulk. Based on the simple quasicrystal model of liquid, analytical expressions of self-diffusion coefficient both in bulk and in slit nanopore are derived from the Stokes-Einstein equation and the modified Eyring's equation for viscosity. The local self-diffusion coefficient in different layers of liquid and the global self-diffusion coefficient in the slit nanopore are deduced fromthese expressions. The influences of confinement by porewalls, pore widths, liquid density, and temperature on the self-diffusion coefficient are investigated. The results indicate that the self-diffusion coefficient in nanopore increaseswith the porewidth and approaches the bulk value as the pore width is sufficiently large. Similar to that in bulk state, the self-diffusion coefficient in nanopore decreases with the increase of density and the decrease of temperature, but these dependences are weaker than that in bulk state and become evenweaker as the porewidth decreases. Thiswork provides a simplemethod to capture the physical behavior and to investigate the dynamic properties of liquid in nanopores.

Supercritical adsorption equilibrium has a significant role in defining supercritical adsorption behavior. In this paper, the adsorption equilibrium of citric acid from supercritical CO₂/ethanol on a cyano column was systematically investigatedwith the elution by characteristic pointmethod. Equilibriumloadingwas obtained at 313.15 K and 321.15 K with supercritical CO₂/ethanol densities varying from0.7068 g·cm^-3 to 0.8019 g·cm^-3. The experimental results showed that the adsorption capacity of citric acid decreasedwith increasing temperature and increasing density of the supercritical CO₂/ethanol mobile phase. The adsorption equilibrium data were fitted well by the Quadratic Hill isotherm model and the isotherms showed anti-Langmuir behavior. Themonolayer saturation adsorption capacity of citric acid is in the range of 44.54mg·cm^-3 to 64.66mg·cm^-3 with an average value of 56.86 mg·cm^-3.

Polypiperazine-amide membranes were modified with poly(ethyleneimine) (PEI) by self-assembled method, through which PEI molecules were fixed on the membrane surface by ionic interaction. In the experiments, the PEI concentration ranged from50 to 2000 mg·L^-1 while the depositing time was fixed at 20 min. The results showed that low PEI concentration resulted in a slight increase of pure water flux, which was attributed to the enhanced membrane surface hydrophilicity. The PEI adsorption on membrane surface had less effect on the rejections to neutral PEG and sucrose, but improved the rejections to divalent cationic ions and methylene blue as the result of reversion of the membrane surface charge from negative to positive according to the XPS analysis and zeta potential measurements. The membrane modified at PEI = 1500 mg·L^-1 exhibited high rejection to methylene blue (MB) and is potential to be applied in the treatment of effluents containing positively charged dyes.

Iminodiacetic acid functionalized polyglycidyl methacrylate grafted-carbon fibers (PGMA-IDA/CFs) were prepared for Ni(II) removal from aqueous solutions. The effects of solution pH value, temperature and adsorption time were investigated. The maximum adsorption capacity of Ni(II) on PGMA-IDA/CFs is 0.923 mmol·L^-1 · g^-1 at pH 5.2 and 50 ℃. Kinetic data indicate that the adsorption process matches the pseudo-second-order model and Elovich kinetic model. Thermodynamic data suggest that the adsorption process is endothermic spontaneous reaction.

The study was designed to investigate the use of two sorbents namely (i) Fe₃O₄ nanoparticles immobilized in sodiumalginate matrix (FNPSA) and (ii) Fe₃O₄ nanoparticles and saponified orange peel residue immobilized in sodium alginate matrix (FNPSOPR) as sorbents for fluoride removal from contaminated water. The synthesized nanoparticles were analyzed and characterized by dynamic light scattering, X-ray diffraction, vibrating sample magnetometry, and scanning electron microscopy with energy dispersive X-ray spectroscopy and Fourier transform-infrared spectrometry. The sorbentmatriceswere prepared in the formof beads and surface functionalized to enable enhanced sorption of fluoride ions. Batch sorption studieswere carried out and the sorption isotherm and reaction kinetics were analyzed. Both the sorbents followed Langmuir model of isotherm and fitted well with Pseudo first order reaction. The maximum sorption capacity exhibited by FNPSA and FNPSOPR was 58.24 mg·g^-1 and 80.33 mg·g^-1 respectively. Five sorption-desorption cycles exhibited 100%, 97.56%, 94.53%, 83.21%, and 76.53% of regeneration of FNPSOPR. Accordingly, it is demonstrated that FNSOPR could be used as a promising sorbent for easy and efficient removal of fluoride from contaminated water with good reusability. The current work suggests a simple and effective method to remove fluoride from contaminated water.

The energy-conserving performance of dividing wall column (DWC) is discussed in this paper. The heat transfer through the dividing wall is considered and the results are compared with that of common heat insulation dividing wall column (HIDWC). Based on the thermodynamic analysis of heat transfer dividing wall column (HTDWC) and HIDWC, both computer simulation and experiments are employed to analyze the energyconserving situation. Mixtures of n-hexane, n-heptane and n-octane are chosen as the example for separation. The results show that the energy consumption of HTDWC is 50.3% less than that of conventional distillation column, while it is 46.4% less than that of HIDWC. It indicates that DWC is efficient on separating threecomponent mixtures and HTDWC can save more energy than HIDWC. Thus it is necessary to consider the heat transfer while applying DWC to industry.

Currently, thermal decomposition of hydrocarbons for the production of basic petrochemicals (ethylene, propylene) is carried out in steam-cracking processes. Aside from the conventional method, under consideration are alternative ways purposed for process intensification. In the context of these activities, the method of hightemperature pyrolysis of hydrocarbons in a heat-carrier flow is studied, which differs from previous ones and is based on the ability of an ultra-short time of feedstock/heat-carrier mixing. This enables to study the pyrolysis process at high temperature (up to 1500 K) at the reactor inlet. A set of model experiments is conducted on the lab scale facility. Liquefied petroleumgas (LPG) and naphtha are used as a feedstock. The detailed data are obtained on temperature and product distributions within a wide range of the residence time. A theoretical model based on the detailed kinetics of the process is developed, too. The effect of governing parameters on the pyrolysis process is analyzed by the results of the simulation and experiments. In particular, the optimal temperature is detected which corresponds to the maximum ethylene yield. Product yields in our experiments are compared with the similar ones in the conventional pyrolysis method. In both cases (LPG and naphtha), ethylene selectivity in the fast-mixing reactor is substantially higher than in current technology.

Methylphenyldichlorosilane (MPDS, CH₃C₆H₅SiCl₂) is an important silicone monomer for the synthesis of highperformance polymethylphenylsiloxane polymers. In this work, the mechanism of the synthesis of MPDS from methyldichlorosilane and chlorobenzene by gas phase condensation was studied, and a kinetic model with 35 species and 58 elementary reactions was established. Experiments were carried out in a tubular reactor under a wide range of reaction conditions. The calculated mole fractions of the reactants and products were in a good agreement with the experimental results. A mechanism of the insertion of chloromethylsilylene into the C\Cl bond of chlorobenzene was proposed, which was proved to be the main pathway of MPDS production. The established kinetic model can be used in design and optimization of the industrial reactor for MPDS synthesis.

Efficiency and selectivity of hydrogenating depolymerization of the coal extract benzene-insoluble part over the heterogeneous Co-Mo/Al₂O₃ catalystwere assessed using a mathematical model. The analytical equations of the mathematical modelwere generated based onmaterial balance incorporating the physico-chemical phenomena (reaction and diffusion) both in the autoclave and the catalyst grain. The equations offer the possibility for predicting changes of the reactants in the autoclave during the process and for determining the distribution of reactant concentrations in the grain as a function of its radius. The analytical equations of the model serve as the basis of the algorithm for assessing the influence of restrictive diffusion on the effectiveness and selectivity of the catalyst, and also for defining the optimal radii of the catalyst's pores to enable free transport of reactants in the grain interior.

The intrinsic kinetics of iron oxide reduced by carbon monoxide is evaluated by a method of online measuring concentration of off-gas in an isothermal differential micro-packed bed. Under the condition of getting away from the influence of gas diffusion and gas-solid heat transfer and mass transfer, the reaction of Fe₂O₃ to Fe₃O₄, Fe₃O₄ to FeO and FeO to Fe in the process of single reaction can be clearly distinguished from each other, and the relevant activation energy is characterized to be 75.4, 74.4, and 84.0 kJ·mol^-1, respectively. Therefore, the change of surface area in the reaction process due to losing oxygen could be easily calculated by combining it with pre-exponential parameters of Arrhenius equations. In conclusion, these kinetic parameters are verified by the experimental data for the process of ore reduced by carbon monoxide in a packed bed.

In chemical process, a large number of measured andmanipulated variables are highly correlated. Principal component analysis (PCA) iswidely applied as a dimension reduction technique for capturing strong correlation underlying in the process measurements. However, it is difficult for PCA based fault detection results to be interpreted physically and to provide support for isolation. Some approaches incorporating process knowledge are developed, but the information is always shortage and deficient in practice. Therefore, this work proposes an adaptive partitioning PCA algorithm entirely based on operation data. The process feature space is partitioned into several sub-feature spaces. Constructed sub-block models can not only reflect the local behavior of process change, namely to grasp the intrinsic local information underlying the process changes, but also improve the fault detection and isolation through the combination of local fault detection results and reduction of smearing effect. The method is demonstrated in TE process, and the results show that the new method is much better in fault detection and isolation compared to conventional PCA method.

Total site heat integration (TSHI) providesmore opportunities for energy saving in industry clusters. Some design methods including direct integration using process streams and indirect integration using intermediate-fluid circuits, i.e., steam, dowtherms and hotwater, have been proposed during last fewdecades. Indirect heat integration is preferredwhen the heat sources and sinks are separated in independent plants with rather long distance. This improves energy efficiency by adaption of intermediate fluid circle which acts as a utility provider for plants in a symbiotic network. However, there are some significant factors ignored in conventional TSHI, i.e. the investment of pipeline, cost of pumping and heat loss. These factors simultaneously determine the possibility and performance of heat integration. This work presents a new methodology for indirect heat integration in low temperature range using hot water circuit as intermediate-fluidmedium. The new methodology enables the targeting of indirect heat integration across plants considering the factorsmentioned earlier. AnMINLPmodelwith economic objective is established and solved. The optimization results give themass flow rate of intermediate-fluid, diameter of pipeline, the temperature of the circuits and the matches of heat exchanger networks (HENS) automatically. Finally, the application of this proposed methodology is illustrated with a case study.

Liquefied natural gas (LNG) is the most economicalway of transporting natural gas (NG) over long distances. Liquefaction of NG using vapor compression refrigeration system requires high operating and capital cost. Due to lack of systematic design methods for multistage refrigeration cycles, conventional approaches to determine optimal cycle are largely trial-and-error. In this paper a novel mixed integer non-linear programming (MINLP) model is introduced to select optimal synthesis of refrigeration systems to reduce both operating and capital costs of an LNG plant. Better conceptual understanding of design improvement is illustrated on composite curve (CC) and exergetic grand composite curve (EGCC) of pinch analysis diagrams. In this method a superstructure representation of complex refrigeration system is developed to select and optimize key decision variables in refrigeration cycles (i.e. partition temperature, compression configuration, refrigeration features, refrigerant flow rate and economic trade-off). Based on this method a program (LNG-Pro) is developed which integrates VBA, Refprop and Excel MINLP Solver to automate the methodology. Design procedure is applied on a sample LNG plant to illustrate advantages of using this method which shows a 3.3% reduction in total shaft work consumption.

Fermentative production of chlortetracycline is a complex fed-batch bioprocess. It generally takes over 90 h for cultivation and is often contaminated by undesired microorganisms. Once the fermentation system is contaminated to certain extent, the product quality and yieldwill be seriously affected, leading to a substantial economic loss. Using information fusion based on the Dezer-Smarandache theory, self-recursive wavelet neural network and unscented kalman filter, a novel method for online prediction of contamination is developed. All state variables of culture process involving easy-to-measure and difficult-to-measure variables commonly obtained with soft-sensors present their contamination symptoms. By extracting and fusing latent information fromthe changing trend of each variable, integral and accurate prediction results for contamination can be achieved. Thismakes preventive and correctivemeasures be taken promptly. The field experimental results showthat themethod can be used to detect the contamination in time, reducing production loss and enhancing economic efficiency.

A new method of nonlinear analysis is established by combining phase space reconstruction and data reduction sub-frequency band wavelet. This method is applied to two types of chaotic dynamic systems (Lorenz and Rössler) to examine the anti-noise ability for complex systems. Results show that the nonlinear dynamic system analysis method resists noise and reveals the internal dynamics of a weak signal from noise pollution. On this basis, the vertical upward gas-liquid two-phase flow in a 2 mm× 0.81mmsmall rectangular channel is investigated. The frequency and energy distributions of the main oscillation mode are revealed by analyzing the time- frequency spectra of the pressure signals of different flow patterns. The positive power spectral density of singular-value frequency entropy and the damping ratio are extracted to characterize the evolution of flow patterns and achieve accurate recognition of different vertical upward gas-liquid flow patterns (bubbly flow: 100%, slug flow: 92%, churn flow: 96%, annular flow: 100%). The proposed analysis method will enrich the dynamics theory of multi-phase flow in small channel.

A pilot-scale modified carbon source division anaerobic anoxic oxic (AAO) process with pre-concentration of returned activated sludge (RAS) was proposed in this study for the enhanced biological nutrient removal (BNR) of municipal wastewater with limited carbon source. The influent carbon source was fed in step while a novel RAS pre-concentration tank was adopted to improve BNR efficiency, and the effects of an influent carbon source distribution ratio and a RAS pre-concentration ratiowere investigated. The results showthat the removal efficiency of TN is mainly influenced by the carbon source distribution ratio while the TP removal relies on the RAS pre-concentration ratio. The optimum carbon source distribution ratio and RAS pre-concentration ratio are 60% and 50%, respectively, with an inner recycling ratio of 100% under the optimum steady operation of pilot test, reaching an average effluent TN concentration of 9.8 mg·L^-1 with a removal efficiency of 63% and an average TP removal efficiency of 94%. The mechanism of nutrient removal is discussed and the kinetics is analyzed. The results reveal that the optimal carbon source distribution ratio provides sufficient denitrifying carbon source to each anoxic phase, reducing nitrate accumulation while the RAS pre-concentration ratio improves the condition of anaerobic zone to ensure the phosphorus release due to less nitrate in the returned sludge. Therefore, nitrifying bacteria, denitrifying bacteria and phosphorus accumulation organisms play an important role under the optimum condition, enhancing the performance of nutrient removal in this test.

In situ surface synthesis of Ca-Mg-Al hydrotalcite (HT) on inorganic ceramic membrane (CM) was investigated with urea as precipitator. The effects of molar ratio of raw materials, crystallization time, and temperature on surface synthesis of HT were examined. The as-prepared HT/CM samples were characterized by XRD and SEM and an in sit growth mechanismof HT on CMwas proposed. KF/HT/CMobtained by loading potassium fluoride (KF) on the HT layer by impregnation and calcination method was used as catalyst for transesterification between palm oil and methanol. The comparison of KF/HT/CMand pure KF/HT powder under identical reaction conditions shows that the production of fatty acid methyl ester is equivalent, which means that the use of inorganic catalytic membrane in the transesterification is a viable alternative.

Coagulationmechanisms of polyaluminumchloride (PACl) at various dosageswere studied using a conventional jar test at different final and initial pH values during treating kaolin suspension. The optimal final pH and dosages for PACl were obtained based on residual turbidity and zeta potential of flocs. The coagulation zones at various PACl dosages and solution pH values were developed and compared with those of alum. It is found that the optimal mechanism under acidic condition is charge neutralization, while alkaline condition will facilitate the coagulation of PACl. Both charge neutralization coagulation and sweep coagulation can achieve high coagulation efficiency under the alkaline condition ranging from final pH 7.0 to 10.0. Stabilization, charge neutralization destabilization, restabilization and sweep zones occur successively with increasing PACl dosages with the final pH values fixed at 7.0 and 8.0, but restabilization zone disappears at final pH 10.0. When the final pH is not controlled and consequently decreases with increasing PACl dosage, no typical sweep zone can be observed and the coagulant efficiency decreases at high PACl dosage. It seems that the final pH is more meaningful than the initial pH for coagulation. Charge neutralization coagulation efficiency is dominated by zeta potential of flocs and PACl precipitates. The charge neutralization and sweep coagulation zones of PACl are broader in the ranges of coagulant dosage and pH than those of alum. The results are helpful for us to treat water andwastewater using PACl and to understand the coagulation process of PACl.

A novel system coupling an up-flow anaerobic sludge blanket (UASB) and sequencing batch reactor (SBR) was introduced to achieve advanced removal of organic and nitrogen from ammonium-rich landfill leachate. UASB could remove 88.1% of the influent COD at a volumetric loading rate of 6.8 kg COD·m^-3·d^-1. Nitritation- denitritation was responsible for removing 99.8% of NH₄⁺-N and 25% of total nitrogen in the SBR under alternating aerobic/anoxic modes. Simultaneous denitritation and methanogenesis in the UASB enhanced COD and TN removal, and replenished alkalinity consumed in nitritation. For the activated sludge of SBR, ammonia oxidizing bacteria were preponderant in nitrifying population, indicated by fluorescence in sit hybridization (FISH) analysis. The Monod equation is appropriate to describe the kinetic behavior of heterotrophic denitrifying bacteria, with its kinetic parameters determined from batch experiments.

Dynamic characteristics of UV enhanced gas-solid PVC chlorination process were revealed by a UV-Vis spectral online analysis method. Experimental results showed an instantaneous increase of the chlorination rate as soon as UV lightwas affiliated, which demonstrated the intensified effect of UV radiation on PVC chlorination directly. Different affiliationmethods of UV light were then studied, proving that continuous UV radiation could enhance the chlorination process significantly while intermittent UV radiation was able to initiate the chlorination reaction once it was conducted. Besides, experiments were carried out to study the influences of parameters on the chlorination process such as UV wavelength, chlorination temperature, partial pressure of chlorine gas and PVC raw materials. Among all the parameters, chlorination temperature and partial pressure of chlorine gas were testified as two key factors to determine the chlorination performance. Thermal analysis of CPVC products showed that their corresponding properties such as the glass transition temperature (T_g) and the homogeneity of chlorine distribution in polymer phase were improved with the increase of chlorine content.

A simple and fast plasma reduction method is developed for synthesis of Au and Pd metal nanoparticles. The scanning electron microscopy (SEM) analysis indicates a formation of aggregates of Au and Pd nanoparticles with branched structure. The transmission electron microscopy (TEM) image shows that the inclusive nanoparticles are all about 5 nm in size. Compared to conventional hydrogen reduction method, plasmamethod inhibits the agglomeration of metal particles. The room temperature operation is very helpful to limit the nanoparticle size. Most interestingly, plasma reduction produces more flattened metal particles. This plasma reduction does not require the use of any hazardous reducing chemicals, showing the great potential for the fabrication of noble metal nanoparticles.