The flow patterns and their transitions of oil-water two-phase flow in horizontal pipes
were studied. The experiments were conducted in two kinds of horizontal tubes, made of
plexiglas pipe and stainless steel pipe with 40 mm ID respectively. No. 46 mechanical oil
and tap water were used as working fluids. The superficial velocity ranges of oil and water
were: 0.04-1.2 m.s-1 and 0.04-2.2 m.s-1, respectively. The flow patterns were identified by
visualization and by transient fluctuation signals of differential pressure drop. The flow
patterns were defined according to the relative distribution of oil and water phases in the
pipes. Flow pattern maps were obtained for both pipelines. In addition, semi-theoretical
transition criteria for the flow patterns were proposed, and the proposed transitional
criteria are in reasonable agreement with available data in liquid-liquid systems.

A mathematical model of two-dimensional turbulent gas-particle two-phase flow based on the
modified diffusion flux model (DFM) and a numerical simulation method to analyze the gas-
particle flow structures are developed. The modified diffusion flux model, in which the
acceleration due to various forces is taken into account for the calculation of the
diffusion velocity of particles, is applicable to the analysis of multi-dimensional gas-
particle two-phase turbulent flow. In order to verify its accuracy and efficiency, the
numerical simulation by DFM is compared with experimental studies and the prediction by κ-
ε-κp two-fluid model, which shows a reasonable agreement. It is confirmed that the
modified diffusion flux model is suitable for simulating the multi-dimensional gas-particle
two-phase flow.

An experimental study of the extent of axial backmixing in both gas and liquid phases was
conducted in a 150 mm ID column packed with Mellapak 250Y corrugated structured packing.
The column was operated at pressures ranging from 0.3 MPa to 2.0 MPa with nitrogen and
water flowing countercurrently through the packing.The amount of axial backmixing was
experimentally evaluated by the pulse response techniques using hydrogen in gas phase and
an aqueous solution of NaCl in liquid phase as inert tracers. The response of the tracer
was monitored by means of thermal conductivity in the gas phase and electrical conductance
in the liquid phase. The experimentally determined residence time distribution (RTD) curves
were interpreted in terms of the diffusion-type model. The results indicated that the axial
backmixing in the gas increased notably with gas flowrate and slightly with operating
pressure and liquid flowrate. The liquid-phase axial backmixing was an increasing function
of both gas and liquid flowrates and insensitive to pressure. Various correlations were
developed for reproducing the experimental mixing data. The agreement between experimental
and correlated data appeared to be acceptable and within +20% of difference.

The prediction of slug frequency has important significance on gas-liquid two-phase flow. A
hydrodynamic model was put forward to evaluate slug frequency for horizontal two-phase
flow, based on the dependence of slug frequency on the frequency of unstable interfacial
wave. Using air and water, experimental verification of the model was carried out in a
large range of flow parameters. Six electrical probes were installed at different positions
of a horizontal plexiglass pipe to detect slug frequency development. The pipe is 30 m long
and its inner diameter is 24 mm. It is observed experimentally that the interfacial wave
frequency at the inlet is about 1 to 3 times the frequency of stable slug. The slug
frequencies predicted by the model fit well with Tronconi (1990) model and the experimental
data. The combination of the hydrodynamic model and the experimental data results in a
conclusion that the frequency of equilibrium liquid slug is approximately half the minimum
frequency of interfacial wave.

A new separation method, reactive extractive distillation, was put forward for separating
water and acetic acid. The separation mechanism was analyzed through infrared spectra
technique. Isobaric vapor-liquid equilibrium (VLE) data at 101.33 kPa for the binary or
ternary systems consisting of water, acetic acid and tributylamine were measured. The
activity coefficients were correlated by using Wilson, NRTL, and UNIQUAC Equations.The VLE
experiment showed that tributylamine could enhance the relative volatility of water to
acetic acid. An extractive distillation experiment was carried out and proved that
tributylamine was a good extractive solvent.

Suspension catalytic distillation (SCD) has been developed recently as an innovative
technology in catalytic distillation. In this paper, a brief introduction to SCD is given
and an equilibrium stage (EQ) model is developed to simulate this new process for synthesis
of linear alkylbenzene (LAB) from benzene, and 1-dodecene.Since non-ideality of this
reaction system is not strong, EQ model developed could be applied to it
successfully.Simulation results agree well with experimental data, and indicate some
characteristics of SCD process as an advanced technology for the production of LAB: 100%
conversion of olefins, low temperature (90-100℃) and low benzene/olefin mole ratio.

Pd/LaxPbyMnOz, Pd/C, Pd/molecular sieve and Pd-heteropoly acid catalysts for direct
synthesis of diphenyl carbonate (DPC) by heterogeneous catalytic reaction were compared and
the results of DPC synthesis indicated that the catalyst Pd/LaxPbyMnOz had higher activity.
The Pd/LaxPbyMnOz catalyst and the support was characterized by XRD, SEM and TEM, the main
phase was La0.62Pb0.38MnO3 and the average diameter could be about 25.4nm. The optimum
conditions for synthesis of DPC with Pd/LaxPbyMnOz were determined by orthogonal
experiments and the experimental results showed that reaction temperature was the first
factor of effect on the selectivity and yield of DPC, and the concentration of O2 in gas
phase also had significant effect on selectivity of DPC. The optimum reaction conditions
were catalyst/phenol mass ratio 1 to 50, pressure 4.5 MPa,volume concentration of O2 25%,
reaction temperature 60℃ and reaction time 4 h. The maximum yield and average selectivity
could reach 13% and 97% respectively in the batch operation.

Mechanism analysis on simultaneous oxidation of NO and SO2 with additives was presented and
numerical simulation was developed to investigate the performances of three additives on
oxidation of NO and SO2. The simulation result showed that reaction temperature, residence
time, additive dose and NO concentration influence the oxidation process significantly.
There exists an optimum reaction condition for each additive. n-C4H10 has the strongest
ability to oxidize NO and SO2.

Multi-objective optimization of a purified terephthalic acid (PTA) oxidation unit is
carried out in this paper by using a process model that has been proved to describe
industrial process quite well. The model is a semiempirical structured into two series
ideal continuously stirred tank reactor (CSTR) models. The optimal objectives include
maximizing the yield or inlet rate and minimizing the concentration of 4-carboxy-
benzaldhyde, which is the main undesirable intermediate product in the reaction process.
The multi-objective optimization algorithm applied in this study is non-dominated sorting
genetic algorithm Ⅱ (NSGA-Ⅱ). The performance of NSGA-Ⅱ is further illustrated by
application to the title process.

Study on pinching liquid filament in literature was reviewed. The breakup of liquid
filaments under surface tension is governed by incompressible, two-dimensional (2-D),
Navier-Stokes Equations. Surface tension was expressed via a CSF (continuous surface force)
model that ensures robustness and accuracy. A new surface reconstruction scheme,
alternative phase integration (API) scheme was proposed to solve the kinematic equation,and
was compared with other three referential schemes. A general-purpose computer program has
been developed for simulating transient, 2-D, incompressible fluid flows with free surface
of complex topology. The transient behavior of breaking Newtonian liquid filaments under
surface tension was simulated successfully using the developed program.The initial wave
growth predicted using API-VOF (volume of fluid) scheme was in good agreement with
Rayleigh’s linear theory and one-dimensional (1-D) long-wave theory. Both long wave theory
and two-dimensional (2-D) APIVOF model on fine meshes show that as time goes on, these
waves pinch off large droplets separated by smaller satellite ones that decrease in size
with decreasing wavelength. Self-similar structure during the breakup was found using 1-D
and 2-D models, and three breakups were predicted for a typical case. The criterion of
filament breaking predicted by the 2-D model is that the wavelength is longer than the
circumference of a filament. The predicted sizes of main and satellite droplets were
compared with published experimental measurements.

The maximum effective hole-diameter mathematical model describing the flow of slightly
compressible fluid through a commingled reservoir was solved rigorously with consideration
of wellbore storage and different skin factors. The exact solutions for wellbore pressure
and the production rate obtained from layer j for a well production at a constant rate from
a radial drainage area with infinite and constant pressure and no flow outer boundary
condition were expressed in terms of ordinary Bessel functions. These solutions were
computed numerically by the Crump’s numerical inversion method and the behavior of systems
was studied as a function of various reservoir parameters. The model was compared with the
real wellbore radii model. The new model is numerically stable when the skin factor is
positive and negative, but the real wellbore radii model is numerically stable only when
the skin factor is positive.

A microscopic diffusion-reaction model was developed to simulate in-situ ozonation for the
remediation of contaminated soil, i.e., to predict the temporal and spatial distribution of
target contaminant in the subsurface.The sequential strategy was employed to obtain the
numerical solution of the model using finite difference method. A non-uniform grid of
discretization points was employed to increase the accuracy of the numerical solution by
means of coordinate transformation. One-dimensional column tests were conducted to verify
the model. The column was packed with simulated soils that were spiked with 2-chlorophenol.
Ozone gas passed through the column at a flow time intervals. Compared the experimental
data with the simulated values, it was found that the mathematical model fitted data well
during most time of the experiment.

The paper presents a procedure to design water network. First of all, water reuse system,
water regeneration reuse system (including regeneration recycle) and wastewater treatment
system are designed separately.But the interaction between different parts demands that
each part is designed iteratively to optimize the whole water network. Therefore, on the
basis of the separated design a water network superstructure including reuse,regeneration
and wastewater treatment is established from the system engineering point of view. And a
multiobjective adaptive simulated annealing genetic algorithm is adopted to simultaneously
integrate the overall water network to balance the economic and environmental effects. The
algorithm overcomes the defect of local optimum of simulated annealing (SA), avoids the
pre-maturation of genetic algorithm (GA) and finds a set of solutions (pareto front) in
acceptable computer time. From the pareto front, a point with minimum fresh water
consumption will be extended to zero discharge as our ultimate goal.

Mixed-weight least-squares (MWLS) predictive control algorithm, compared with quadratic
programming (QP) method, has the advantages of reducing the computer burden, quick
calculation speed and dealing with the case in which the optimization is infeasible. But it
can only deal with soft constraints. In order to deal with hard constraints and guarantee
feasibility, an improved algorithm is proposed by recalculating the setpoint according to
the hard constraints before calculating the manipulated variable and MWLS algorithm is used
to satisfy the requirement of soft constraints for the system with the input constraints
and output constraints. The algorithm can not only guarantee stability of the system and
zero steady state error, but also satisfy the hard constraints of input and output
variables. The simulation results show the improved algorithm is feasible and effective.

The kinetics of liquid-phase hydrogenation of benzene in misch metal nickel-five (MlNi5)
and benzene slurry system was studied by investigating the influences of the reaction
temperature, pressure, alloy concentration and stirring speed on the mass transfer-reaction
processes inside the slurry. The results show that the whole process is controlled by the
reaction at the surface of the catalyst. The mass transfer resistance at gas-liquid
interface and that from the bulk liquid phase to the surface of the catalyst particles are
negligible. The apparent reaction rate is zero order for benzene concentration and first
order for hydrogen concentration in the liquid phase. The kinetic model obtained fits the
experimental data very well. The apparent activation energy of the hydrogen absorption
reaction of MlNi5-C6H6 slurry system is 42.16 kJ.mol-1.

Contrast degradation experiments between ethanol and polyvinyl alcohol (PVA) were conducted
during H2O2, UV/H2O2, Fenton, and Photo-Fenton processes in this study. UV/VIS spectra
showed. that complexes between Fe(Ⅲ) and organics were easily formed and degraded within
reaction time. Compared with the degradation of complex, hydroxyl radicals acted weakly in
Fenton or Photo-Fenton process. Hydroxyl radicals involved in Photo-Fenton process were
deemed to be generated from the split decomposition of H2O2, photolysis of Fe3+/aq, and
degradation of hydrated Fe(Ⅳ)-complex but not traditional Fenton reaction. Experimental
evidence to support this point was presented in this paper.

Nanofiltration separation has become a popular technique for removing large organic
molecules and inorganic substances from water. It is achieved by a combination of three
mechanisms: electrostatic repulsion,sieving and diffusion. In the present work, a model
based on irreversible thermodynamics is extended and used to estimate rejection of
inorganic salts and organic substances. Binary systems are modeled, where the feed contains
an ion that is much less permeable to the membrane as compared with the other ion. The two
model parameters are estimated by fitting the model to the experimental data. Variation of
these parameters with the composition of the feed is described by an empirical correlation.
This work attempts to describe transport through the nanofiltration membranes by a simple
model.

Cubic shaped CaCO3 particles with mean size of 30-40 nm were prepared by intermittent
carbonation process without any additives. It was found that the flow rate of CO2 has no
distinct influence on the particle size larger size.

A high yield xylanase producing strain, A. usamii L336-23, was screened out from its parent
strain A.usamii L336 after microwave irradiation. Its productivity of xylanase activity
increased by 35.7% from The mechanism of microwave mutation was also discussed.

The thermodynamic properties of different geometric structures of 1,2-cyclohexanediol which
were rarely reported in literature, such as combustion enthalpy, formation enthalpy,
melting enthalpy and heat capacities, were determined by NETZSCH DSC 204 Scanning
Calorimeter. The relationship between the melting point and the composition for the mixture
system of cis-1,2-cyclohexanediol and trans-1,2-cyclohexanediol was investigated and
corresponding phase diagram was obtained. The melting enthMpies of both cis-1,2-
cyclohexanediol and trans-1,2-cyclohexanediol are 20.265 kJ·mol-1 and 16.368 kJ·mol-1
respectively. The standard combustion enthalpies of cis- and trans-1,2-cyclohexaneddiol
were determined by calorimeter. They are respectively -3507.043 kJ·mol-1 and -3497.8 k J·
mol-1 at 298.15 K.The standard formation enthalpies are respectively 568.997kJ·mol-1and
578.240kJ·mol-1 for cis- and trans-1,2-cyclohexaneddiol.

The surfactant-coated Candida rugosa lipase was used as catalyst for hydrolysis of olive
oil in two-phase system consisting of olive oil and phosphate buffer without organic
solvent. For both the coated and native lipases,the optimal buffer/oil volume ratio of 1.0,
aqueous pH 6.8 and reaction temperature 30℃ were determined. The maximum activity of the
coated lipase was ca 1.3 times than that of the native lipase. The half-life of the coated
lipase in olive oil and the native lipase in phosphate buffer was ca 9 h and 12 h, and the
final residual activity was 27% and 20% of their initial values, respectively. The final
substrate conversion by the coated lipase was ca 20% higher than that of the native lipase.

In order to reduce the production cost of imidacloprid, the preparation technology for the
direct combination of 2-chloro-5-chloromethylpyridine and 2-nitryliminoglyoxaline has been
optimized in a 10 L stirred tank reactor with a new solvent, butanone, and a new catalyst,
benzyl triethyl-ammonium chloride (BTEAC), which was proved to be more profitable for the
production of imidacloprid. Three main affecting factors (the reaction temperature, the
molar ratio of BTEAC to 2-nitryliminoglyoxaline and the concentration of 2-
nitryliminoglyoxaline) for the production of imidacloprid were investigated and the optimum
operating conditions were found. Based on the above technological optimization, an
industrial process for imidacloprid with a production capacity of 50 tons per year was put
in operation using a 2500 L stirred tank reactor under the same operating conditions. Good
yield and purity of imidacloprid was also obtained in the industrial production.

A new process for the direct chlorination of 2-chloro-5-methylpyridine to yield 2-chloro-5
-chloromethylpyridine in an airlift loop reactor (ALR) has been studied. Five main reaction
conditions including TR,na/ns, cp, Qg and dD/dR were optimized. The average molar yield and
purity of 2-chloro-5-chloromethylpyridine obtained were 79% and 98.5% respectively under
the optimum operating conditions. Finally, the efficiency for the preparation of 2-chloro-
5-chloromethylpyridine with ALR and stirred tank reactor (STR) respectively was compared.

A methodology is presented to identify environmental impact minimization alternatives for
reaction processes and assess their environmental performance. The potential environmental
impact (PEI) scheme can be used to visibly display the transformation relationships among
different types of PEI, identify the sources of environmental impacts, and propose
alternatives for eliminating or minimizing the impacts. To evaluate the environmental
performance of the alternatives effectively, some new indices, such as PEI input rate of
non-products, PEI output rate of non-products per profit and the PEI conversion efficiency
are proposed. Finally, the application of the methodology is illustrated using an
industrial case study.