In spite of the fact that the first patent on transient operation of chemical reactor was applied in 1938,the forced unsteady state operation of chemical reactors as an attractive novel technology and its associated profound theory are a new area of study in chemical reaction engineering.This paper briefly reviews its research history,the present situation and perspectives.Basic scientific questions and important experimental technics used and relevant to this area are primarily discussed.Some suggestions are made to promote more systematic and deeper studies on the unsteady state catalysis and forced period operation of chemical reaction systems with different scales.

A mathematical model of double sublimation fronts was developed for microwave freeze-drying for a cylindrical porous media with cylindrical dielectric cores.The set of transient governing equations describing the drying process were solved numerically with the variable time-step finite volume method.The numerical results showed that two sublimation fronts did exist within the porous media.Proper usage of cylindrical dielectric cores could dramatically reduce the drying time.The impact of cylindrical dielectric cores on drying could not be ignored even though the initial saturation was low(S₀=0.2).

The optimal design for multi-stream plate-fin heat exchanger with differential model was investigated. An effective method for the passage arrangement was presented, together with the corresponding calculation program. With this program, many conditions with different initial lengths and slice thicknesses were calculated. From the calculation results,the initial length almost had no effect on the final divergent length, but the slice thickness had great influence on the final result. A numerical example shows the feasibility and effectiveness of the proposed method.

Micromixing in the rotating packed bed(RPB) is extensively used and is a novel reactor for fast reactions such as reactive precipitation to synthesize nanoparticles. The study on micromixing in RPB is crucial in understanding the mixing-diffusion mechanism and the behavior of tiny liquid elements in the packing of RPB,which are the theoretical basis for synthesizing nanoparticles by precipitation in RPB.In this paper, on the basis of prior studies,a model describing the turbulent micromixing phenomena and reaction process in RPB is presented in accordance with the flow pattern in RPB. By sufficiently taking into account the unique characteristics of tiny liquid elements in RPB, the concentration distribution outside the packing is simulated by modifying the method proposed by the authors.The computational X_s values with the model are in reasonable agreement with the experimental results.

A modular prototype apparatus was designed and built up to investigate the efficiency of the enhanced heat transfer tubes in the lithium bromide absorption refrigerator. Experimental studies approximate to industrial condition were carried out to investigate the heat and mass transfer performance of the three types of developed enhanced tubes and the effect of adding surfactant.Furthermore, the empirical equations given in this paper can be used for engineering design.Marangoni convection was observed in the experiments.The results of the experimental studies reveal that in order to achieve higher effectiveness of the enhanced tubes, the technical parameters involved, such as spray density and velocity in tube-side, have to be adjusted accordingly.It is necessary to add surfactant properly for the best heat and mass transfer enhancement when constant curvature surface is used in the absorber.With the enhanced tubes in this paper, the copper needed in 1160 kW lithium bromide absorption refrigerator may be reduced by 1700 kg to 2000 kg and the mass of the machinery may be reduced by 30% to 40 %.

This paper presents an experimental study on the axial pressure, voidage and gas flow of gas-solids two-phase flow in a φ150 mm×11500 mm standpipe under negative pressure gradient.The outlet of standpipe is submerged in a dense fluidized bed and the maximum mass flux of solids is about 1200 kg•m^-2•s^-1.The axial pressures, voidage and gas flow in the standpipe are affected by mass flux of solids, inlet velocity of cyclone, fluidizing velocity, mainly determined by mass flux of solids.When mass flux of solids is less than 200～250 kg•m^-2•s^-1, there are two fluidization regimes coexisting in the standpipe,a dilute-phase flow and a bottom dense-phase flow. The pressure is low and changes little in the dilute regime.Gas flows upward, which is fluidizing gas from the standpipe bottom.When mass flux of solids is more than 200～250 kg•m^-2•s^-1, there is only one dense phase conveying regime in the standpipe.The pressure increases progressively from top to bottom and pressure profiles are smooth. Gas flows downward, and is carried by particles. The axial voidage distribution in the standpipe changes from Z-shaped profile to S-shaped as mass flux of solids increases.

Based on the two-regime theory of Davis, a complete motion differential equation for a single oscillating microparticle in an electrodynamic balance (EDB) has been put forward by introducing Oseen’s formula and inhomogeneous term and solved numerically by using the classic Runge-Kutta method in this paper. The fact that there exists a transitional regime, in which the charged particle can be in steady damped oscillation, has firstly been demonstrated by theoretical method. By virtue of the simulated trajectories, a three-regime state curve (δ-β), which is different from Davis theory, has been delineated and the theoretical foundation of EDB research on microparticle oscillation has further been built up.And the above-mentioned theoretical results have been verified experimentally hereby.

An experimental investigation on oil-air two-phase flow through a straight horizontal plexiglass pipe within 40mm inner diameter was conducted.The superficial velocity ranges of oil and air were 0.05—0.612m•s^-1 and 0.024—50.64m•s^-1, respectively.The ambient temperature was maintained throughout the experiments.The frictional pressure drop multiplier of two-phase flow was expressed using the Lockhart-Martinelli parameter correlation in accordance with typical flow pattern, but the modification factor C in the correlations was defined afresh according to flow conditions.New predict correlations for pressure gradient in accordance with typical flow patterns were proposed and the mechanisms of pressure drop production were analyzed for each flow pattern.The proposed models gave good agreement with the experimental data.

The effects of pH value and steam pressure of treating solvent on the acidity of β zeolite were investigated.The results showed that the acidity density of zeolite decreased after treating with steam.The higher the steam pressure,the lower the acidity density.When treated with basic solvent, the acidity density of the sample almost remained unchanged;while acidity density decreased with reducing pH value when treated with acidic solvent.The relative content of Bronsted acid reduced after treating with steam or acid/base solvent.Bronsted acid of zeolite surface could convert into Lewis acid in the modification process.

In this paper,the two-stage riser fluidized catalytic cracking technology (TSRFCC) is proposed aiming at improving the performance and overcoming the disadvantages of the ordinary one-stage riser FCC technology (OSRFCC).The distinct features of TSRFCC are attributed to catalyst relay and sub-section reaction. Daqing VGO mixed by 65% VR as feedstock and ZC-7300 catalyst were used to test the feasibility and superiority of the TSRFCC technology.A series of experiments were carried out in a pilot unit.By analyzing the abundant experimental data,the following conclusions can be reached: compared to OSRFCC technology, in the condition of similar conversion of heavy oil feedstock, TSRFCC can increase diesel oil yield by 6—8 percentage point, and light oil yield by 1—2 percentage point.Gasoline octane number also increases. TSRFCC shows the great potential and superiority in increasing diesel oil yield and improving product distribution and quality.

A kind of soluble planar binuclear metal-phthalocyanine was synthesized and was characterized by element analysis and FT-IR spectra. The effects of pH, concentration of catalytic agent and the various ratios of both binuclear phthalocyanineiron(Ⅲ) and phthalocyaninecobalt(Ⅱ) in mixtures on the catalytic oxidation of 2-mercaptoethanol were studied.The results showed that the catalytic activity of binuclear metal-phthalocyanine was the highest at pH=11 and the catalytic activity of binuclear phthalocyaninecobalt(Ⅱ) was higher than that of binuclear phthalocyanineiron(Ⅲ).Moreover, it was found that catalytic activity of binuclear phthalocyanineiron(Ⅲ) and phthalocyaninecobalt(Ⅱ) mixture was higher and even the best at the ratio of 1∶1, whose reaction mechanism was deeply discussed.

Polyhalite is a kind of resource of potassium.The key problem of extracting potassium from polyhalite is dissolution of potassium in lixiviant. This paper presents the fundamental study of a new method of exploiting-leaching potassium from polyhalite deeply underground in Sichuan Nongle using CaCl₂ solution as solvent.The kinetic process of dissolving potassium from polyhalite was studied by investigating the influence of the leaching conditions such as concentrations of solvent (CaCl2), mineral particle size,and temperature on the process of lixiviation through analysing potassium concentration in the lixiviation solution.The possible lixiviation process of polyhalite was discussed.The recovery of K increased with decreasing mineral particle size and could be higher than 80% under the experimental conditions(mineral particle size:0.42—1mm,initial concentration of CaCl₂:5%, solid to liquid ratio=1/10,tempreture:288—373K).The experimental results showed that the dissolution reaction order was first-order.Apparent activation energy of the reaction calculated was 8.34kJ•mol^-1.The paper establishes that the process controlled the dissolution process is diffusion through the ash layer, and the leaching behaviour can be modelled as a shrinking un-reacted core. This paper introduces the fundamental theoretical and laboratory studies which shows the possibility for extracting potassium from polyhalite underground by leaching.

The three-component alcohol batch distillation process was simulated by the Thomas method based on ASOG phase equilibrium theory.The distortion of the simulation results was effectively avoided by using an accurate verifying method.Experimental results showed that the mathematical model is accurate and the numerical method is reliable.The objective function for economic benefits per time unit was proposed，and the effects of reflux ratio and theoretical plate number on economic benefits per time unit were discussed.In conclusion the optimal reflux ratio and the optimal theoretical plate number were 5.5 and 20 respectively under the given condition.

To overcome the shortcoming of the traditional PLS algorithm, a discounted-measurement recursive PLS (DRPLS) algorithm is proposed to build prediction model of the Mooney-viscosity of rubber mixture. This improved RPLS model could be on-line updated with new data, and more adjustable parameters are available. On the other hand, the rubber-mixing process is a typical non-linear batch process with very short operation time, and the rigorous mixing mechanism is not well developed. The Mooney-viscosity of the mixture is the key factor that has great effect on the quality of rubber products. By this developed DRPLS algorithm, a highly precise and flexible Mooney-viscosity model could be built. Application results confirm superior predictive precision of the developed approach.

In this paper, a Fe-C alloy corrosion sensing film of the Fiber Optical Corrosion Sensor (FOCS)was fabricated by PVD on the fiber core.The thickness of this film is about 1 μm and the optical signal can respond to the film[DK]’s corrosive information.Furthermore, on the basis of the comparability between the planar wave-guide and column wave-guide，a method of PVD and its incorporation with electroplating was used to fabricate the Fe-C alloy film onto quartz in order to increase the film thickness. The surface morphology of electroplating the Fe-C alloy film was investigated by metallographic microscopy. The structure of film was studied by X-ray diffraction and an electrochemical method was used to evaluate the corrosion resistance of the Fe-C alloy film in NaCl (sodium chloride) solution of different concentration. The initial results showed that the structure and corrosion resistance of the Fe-C alloy film were close to that of carbon steel,and the response between the optical signal and corrosion information of film could be detected. These data have formed the basis of a FOCS.

Different kinds of amphiphilic block copolymers, PEG-PCL-PEG(PECL), mPEG-PLLA(PELLA) and mPEG-PDLLA(PEDLLA)，were used to encapsulate paclitaxel to prepare nano-micelle formulation. The nano-micelles had a core-shell structure,in which paclitaxel was enveloped in the core, and the PEG shell made the micelles loaded with paclitaxel lyotropic in water. The kinetics of paclitaxel release from the micelles in phosphate buffer solution(PBS) was studied.The results showed that the diameter of the micelles affected apparently drug release rate, and micelles with low drug loaded content(DLC) would release more paclitaxel; enhancing the refresh volume of PBS facilitated drug[DK]’s release; both PECL micelle and PELLA micelle released paclitaxel in PBS under the rule of first order equation; PEDLLA micelles loaded with paclitaxel prepared by solid dispersion technology obeyed zero-order release in two stage.

A new sorbent of heavy metal ion, surface molecular imprinting chitosan（CTS） resin on the surface of mycelium, was prepared by using Ni²⁺ as the molecule imprinting agent and epichlorohydrin(EPH) as the crosslinking agent. The resin produced has a good adsorption capacity and mechanical strength.The ratio of chitosan, mycelium and EPH was 1g∶20g∶0.5ml. The ratio of the EPH used to crosslink mycelium, crosslink CTS and mix the crosslinked mycelium and crosslinked CTS was 2∶2∶1. The adsorption capacity of the resin was 55 mg•g^-1 at initial Ni²⁺ concentration 200mg•kg-1 in the solution and the adsorption capacity increased by 3 times as compared with that of mycelium.Moreover, it had a fast adsorption rate and was less affected by salt concentration in the solution.Its stability was also better than that of mycelium and crosslinked mycelium in the acidic solution.

Neutrase AS1.398 could be used to separate soybean protein and oil from soybean powder in reverse micelles.Revealing the enzyme catalysis mechanism could help to optimize the extraction technology.The reaction mechanism of the enzyme in AOT/iso-octane reverse micelles was investigated with soybean protein isolated as the substrate.Since the dispersion of substrate molecule showed Poisson distribution in the reverse micelles, then through calculating the ratio of the number of substrate molecule to that of the enzyme, it was deduced that the probability of single substrate molecular reaction was predominant.Single substrate molecular enzyme catalysis reaction considering molecular exchange effects in reverse micelles was proposed with aqueous system reaction as reference, the Michaelis-Menten constant in aqueous system was about ten times greater than that in the reverse micelles from the model.The experimental values of the constants were 3.2×10^-3g•ml^-1 and 4.2×10^-4g•ml^-1,respectively.The experimental results were in good agreement with those calculated by the model.It showed that the model can express the enzyme catalysis reaction in the reverse micelles.

The two dimensional， two-phase mathematical model was developed for the cathode of proton exchange membrane fuel cell with conventional flow field operated with air. The governing equations included conductive equation, continuity equation in porous media, the convection-diffusion equations for O₂ and water vapor, and the transfer equation for liquid water.The concentration of O₂ and water vapor, the current density and liquid water saturation in the diffuser were calculated.The mechanism of H₂O transport in the cathode diffuser and the gaseous species concentration distribution in the diffuser were studied.

The adsorption of hydrogen in square and triangular single-walled carbon nanotube arrays was studied with grand canonical ensemble Monte Carlo method. The adsorption isotherm was simulated at 77 K, 133 K and 298 K, and the ability of hydrogen adsorption storage in two different structural SWNTA was compared. The reason for the difference in adsorption ability of the two SWNTA was analyzed according to potential field distribution, and the potential field distribution of different tube diameters and different inter-tube spacings and the effect of potential field distribution on adsorption ability were discussed.The inter-tube spacing is the key factor inducing the difference of potential field distribution and adsorption ability of different structural nanotube arrays.

Removal of NO by nonthermal plasma combined with in situ absorption was experimentally investigated with a wire-in-tube pulsed corona reactor. High pulse voltage was applied to the wire of the reactor and the tube was grounded. For the reactor combined with in situ absorption, the grounded electrode was covered by a Ca(OH)₂ layer as the sorbent for in situ capture of the NO oxidation products. It was found that NO removal was much higher by the reactor combined with in situ absorption than by the reactor without Ca(OH)₂ sorbent, and meanwhile the outlet NO2 concentration from the reactor was also suppressed to less than 12 mg•m^-3.It was indicated that in situ absorption of the NO₂ or NO₃ by Ca(OH)₂ was responsible for the promotion of NO removal. The existence of O₂ and water vapor in the gas stream was beneficial for gas-solid absorption reaction, therefore resulting in the increase of NO removal.

The effects of rubber content, initiation methods and rubber types on the kinetics of bulk graft copolymerization of styrene onto rubber were studied.It is concluded that the low concentration and the cage effect of initiator and the occlusion effect of rubber radical are the main factors on polymerization rate decrease after low-cis-polybutadiene rubber addition by chemical initiation. With the increase of the content of styrene unit of rubber, the influence of rubber addition on polymerization decreased.When the viscosity of rubber was very high, the polymerization would accelerate due to the gel effect. Compared with thermal initiation, the contents of grafted polystyrene and occluded polystyrene were higher with chemical initiation, which resulted in the evident decrease of polymerization rate and an apparent turning point at phase inversion.

Monte Carlo method was applied to bulk ring-opening copolymerization of octamethylcycl-otetrasiloxane with N-β-aminoethyl-γ-aminopropylmethyldimethyoxysilane.With consideration to the cost of computation as well as the precision of simulation results,a new computational model was established to simulate copolymerization system based on the free volume theory used to indicate diffusion influence and chemical reaction kinetic theory.The reaction rate constants were obtained by simulating main elemental reactions of the copolymerization.Based on the optimum rate constants, Monte Carlo simulation indicates:(1)the stationary state assumption of total amount of living groups is proved to be correct;(2)the average molecular mass and its distribution coefficient have a sudden change during the copolymerization process.

Coupling agent plays an important role in increasing the dispersivity and compatibility between ultrafine Fe₃Al powder and polymer matrix.The single molecular layer saturated adsorption of two coupling agents:stearic acid and A-172 on Fe₃Al powder surface was determined by TG analysis(stearic acid 1.24%,A-172 1.8%）.The reaction mechanism between powder surface and coupling agent was studied with IR spectra.With SEM photography the effects of two coupling agents on the dispersivity of Fe₃Al powder into polymer matrix were compared at this adsorption amount.Coupling agent A-172 is the better choice because it can make ultrafine Fe₃Al powder effectively disperse in polymer matrix.

A continuous cycle unit to extract water from air was built, in which a new composite adsorbent SiO₂•xCaCl₂•yH₂O(CaCl₂ mass content is 38.4%)prepared by the authors was used.Each adsorber contains 1.5kg adsorbent.The operating characteristics of the unit were measured in the condition of Februany and March in east China.When adsorption and desorption time was two hours, 0.27kg fresh water was obtained on night-time operation(air average temperature 10.4℃ and relative humidity 77%), and 0.15kg fresh water was obtained on day-time operation(air average temperature 22.2℃ and relative humidity 44%).When macro-porous silica gel is taken as adsorbent,1.0kg adsorbent could be filled in each adsorber, and 0.06kg fresh water was obtained in the condition of air average temperature 17.8℃ and relative humidity 55% with the same operation time.

To evaluate the effect of two liquid phase on the separation of musks mixture, the phase equilibria of musk ketone + musk xylene + dimethyl sulfoxide + heptane system were studied for the first time. The whole and every part of the phase equilibrium for the quaternary system were shown by three-dimensional phase diagrams, the liquid-liquid equilibria, solid-liquid equilibria and solid-liquid-liquid equilibria of the quaternary system were also shown. As a result, the compositions of musks in the equilibrium liquid phases were different from those in the feed, that is, musk ketone was enriched in dimethyl sulfoxide phase while musk xylene was enriched in heptane phase. So these equilibrium liquid phases were useful in separating musk ketone and musk xylene. On the basis of these results, a new process“two liquid phase extractive crystallization”was proposed to separate the eutectics of musk ketone and musk xylene.

The drying mechanism is important to the drying technology of sewage sludge.Using dynamic electronic balance and image acquisition technique, the paper studies the change of surface configuration and characteristics of moisture transference for three kinds of sewage sludge during drying.In the meantime，the paper also analyses the influence of sludge shape on moisture transference and the change of sludge apparent volume and porosity in the course of drying.

A series of pH-responsive gating membranes, with a wide range of grafting yields, were prepared by grafting poly(acrylic acid) (PAAC) onto porous polyvinylidene fluoride (PVDF) membrane substrates with a plasma-induced pore-filling polymerization method. The effect of grafting yields on gating characteristics of pH-responsive gating membranes was investigated systematically.The results showed that the grafting yield heavily affected water flux, pH-responsiveness coefficient and pH-responsive gating factor of membrane pore size. When the grafting yield was smaller than 1.01%, both flux responsiveness coefficient and pH-responsive gating factor of pore size increased with increasing grafting yield.When the grafting yield was in the range from 1.01% to 6.44%, both flux responsiveness coefficient and pH-responsive gating factor of pore size decreased with increasing grafting yield;however, when the grafting yield was higher than 6.44%, both flux responsiveness coefficient and pH-responsive gating factor of membrane pore size approached to 1, i.e., little gating characteristics existed.In order to obtain a satisfactory pH-responsive gating property of the membrane, the grafting yield must be kept in a proper range.

A bioreactor system with a total working volume of 4.8 L，composed of four airlift suspended-bed bioreactors, one of which was designated for seed cultivation and the others in series for ethanol fermentation, was established and continuously operated for 40 days. A self-flocculating fusant from Saccharomyces cerevisiae and Schizosaccharomyces pombe (SPSC01) was used and ethanol and yeast were co-produced from corn dry milling, two-stage enzymatic hydrolysis (raw material residues were separated after saccharification).The results showed that average levels of 98 g•L^-1 for ethanol, 4 g•L-1 for residual reduced sugar and 6—9 g•L^-1 for residual total sugar were achieved when the medium containing total sugar of 220 g•L^-1 was fed at a dilution rate of 0.05 h-1.Pure yeast, equivalent to 5% (mass) of ethanol and containing protein as high as 48.6%(mass), was co-produced. Ethanol production is expected to be more economically competitive as this high quality yeast potentially can be further processed as value-added by-products.