Numerical simulation of transient mass transfer to a single drop controlled by the internal
resistance or by the resistance in both phases was mathematically formulated and simulated
in a boundary-fitted orthogonal coordinate system. The simulated results on the transient
mass transfer dominated by the internal resistance are in good agreement with the Newman
and Kronig-Brink models for drops with low Reynolds number. When the drop Reynolds number
is up to 200, the mass transfer coefficient from numerical simulation is very low as
compared with the Handlos-Baron model. The cases with mass transfer resistance residing in
both the continuous and drop phases were simulated successfully and compared with the
experimental data in three extraction systems recommended by European Confederation of
Chemical Engineering (EFCE). For single drops with Re ＜ 200, the numerically predicted
values of the extraction fraction and overall mass transfer coefficient are in reasonable
coincidence with the experimental data. It is concluded that the numerical simulation can
be resorted in some cases of solvent extraction for conducting numerical experiments and
parametric study. Nevertheless, for better resolution as higher Reynolds number drops are
simulated, more sophisticated techniques should be developed and incorporated to deal with
the large deformation and transient shape oscillation as well as possible Marangoni effect.

In accordance to the anisotropic feature of turbulent flow, an anisotropic algebraic stress
model is adopted to predict the turbulent flow field and turbulent characteristics
generated by a Rushton disc turbine with the improved inner-outer iterative procedure. The
predicted turbulent flow is compared with experimental data and the simulation by the
standard κ-ε turbulence model. The anisotropic algebraic stress model is found to give
better prediction than the standard κ-e turbulence model. The predicted turbulent flow
field is in accordance to experimental data and the trend of the turbulence intensity can
be effectively reflected in the simulation. The distribution of turbulent shear rate in the
stirred tanks was simulated with the established numerical procedure.

Solvent extraction equilibria of four main alkaline earth metals (magnesium, calcium,
strontium and barium) with di(2-ethylhexyl) phosphoric acid (DEHPA), 2-ethylhexyl
phosphonic acid mono-(2-ethylhexyl) ester,di(2,4,4-tri-methylpentyl) phosphinic acid and IR
spectra of the extracts have been studied. The selectivity order is dependent on the e/r
value and hydration energy of the metal ions. The minor shift of the P-O in IR absorption
of the alkaline earth metal extracts indicates that the interaction between the metal ions
and P-O is much weaker for alkaline earth metals than for transitional metals. The
distribution of the four alkaline earth elements between aqueous solutions and solutions of
DEHPA and neutral organophosphorus compounds, tri-n-butyl phosphate (TBP) or tri-octyl
phosphine oxide (TOPO) in kerosene have been determined at varying ratio of TBP or TOPO to
DEHPA and the positive synergism is observed. The synergic effect is explained by using IR
spectra of the loaded organic phase.

The solvent extraction of KAu(CN)2 from alkaline solution by quaternary ammonium salts
(trialkylmethylammonium chloride or cetyltrimethylammonium bromide) was investigated by
means of 198Au radioactive tracer method. Various parameters, such as the gold (Ⅰ)
concentration in aqueous phase, the modifier, emulsification at the interface of two
phases, and phase ratio used in the extraction of gold (Ⅰ) were studied. The results
demonstrate that almost all gold (Ⅰ) in the aqueous phase was practically extracted into
the organic phase. The water content in the organic phase decreased significantly with
increase of gold (Ⅰ) concentration using long chain alcohol as modifier, in contrast with
the system with tributyl phosphate (TBP) as modifier. Emulsification at the interface of
two phases decreases with an increase of modifier concentration in the organic phase or
with the addition of a small amount of lysozyme into the aqueous phase. The method with
198Au tracer can be directly used to determine the Au(Ⅰ) concentration both in aqueous and
organic phases, which is especially suitable for the low concentration of Au(Ⅰ).

A novel surface aeration configuration featured with a self-rotating and floating baffle
(SRFB) and a Rnshton disk turbine (DT) with a perforated disk has been developed. The SRFB,
consisted of 12 fan blades twisted by an angle of 30° to the horizontal plane, is
incorporated onto the impeller shaft to improve gas entrainment, bubble breakup, mixing in
a φ154 mm agitated vessel. This new configuration is compared to the conventional DT
surface aeration experimentally. The results suggest that the critical impeller speed for
onset of gas entrainment is lower for the new configuration and it demands greater power
consumption. Moreover, the SRFB system produces 30%-68% higher volumetric mass transfer
coefficient per unit power input than that obtained in the conventional DT surface aerator
under the same operation conditions.

Hydroformylation of 1-dodecene was studied in a biphasic system using water-soluble rhodium
complex [RhCl(CO)(TPPTS)2] as catalyst in the presence of cetyl trimethyl ammonium bromide
as surfactant to enhance the reaction rate. Efforts were devoted to improve the performance
of hydroformylation by exploring reactor configuration which enhanced the mixing,
dispersion and interphase mass transfer. Experiments were carried out in a 0.5 L autoclave
at the total pressure of 1.1 MPa and temperature from 363 K to 373 K. Several surface
aeration configurations were tested, and higher hydroformylation rate with higher
normal/branched aldehyde ratio produced were achieved. The experiences suggest that
improved reactor configuration by taking reaction engineering measures is beneficial to
better process economy in alkene hydroformylation.

A digitally controlled three-dimensional gamma-scanning apparatus was developed and used to
troubleshoot distillation column in the present investigation. In a 140 mm (ID) model
column, various malfunctional phenomena, both rate and process related conditions and
structural problems, which may be frequently encountered in the operation of tray and
packing columns, were experimentally simulated and tested with the developed scanning
system. The experimental results showed that the scanning spectra can fairly reflect the
simulated phenomena.The salient feature of the scanning apparatus lies in that it
integrates the so called grid scan and computer-assisted tomography scan in a single
system. It was confirmed that the gamma-scanning technique can serve as an important on-
line troubleshooting and maintenance tool.

The catalytic partial oxidation of methane to syngas (CO+H2) has been simulated
thermodynamically with the advanced process simulator PRO/Ⅱ. The influences of
temperature, pressure, CH4/O2 ratio and steam addition in feed gas on the conversion of CH4
selectively to syngas and heat duty required were investigated, and their effects on carbon
formation were also discussed. The simulation results were in good agreement with the
literature data taken from a spouted bed reactor.

The effects of reduction procedure, reaction temperature and composition of feed gas on the
activity of a CuO-ZnO-Al2O3 catalyst for liquid phase methanol synthesis were studied. An
optimized procedure different from conventional ones was developed to obtain higher
activity and better stability of the catalyst. Both CO and CO2 in the feed gas were found
to be necessary to maintain the activity of catalyst in the synthesis process.Reaction
temperature was limited up to 523 K, otherwise the catalyst will be deactivated rapidly.
Experimental results show that the catalyst deactivation is caused by sintering and
fouling, and the effects of CO and CO2 on the catalyst activity are also investigated. The
experimental results indicate that the formation of water in the methanol synthesis is
negligible when the feed gas contains both CO and CO2. The mechanism for liquid-phase
methanol synthesis was discussed and it differed slightly from that for gas-phase
synthesis.

This study is devoted to gas-solid mass transfer behavior in heterogeneous two-phase flow.
Experiments were carried out in a cold circulating fluidized bed of 3.0 m in height and 72
mm in diameter with naphthalene particles. Axial and radial distributions of sublimated
naphthalene concentration in air were measured with an online concentration monitoring
system HP GC-MS. Mass transfer coefficients were obtained under various operating
conditions, showing that heterogeneous flow structure strongly influences the axial and
radial profiles of mass transfer coefficients. In the bottom dense region, mass transfer
rate is high due to intensive dynamic behavior and higher relative slip velocity between
gas and clusters. In the middle transition region and the upper dilute region, as a result
of low mass transfer driving force and the influence of flow structure, mass transfer rate
distribution becomes non-uniform. In conclusion, among the operating parameters influencing
mass transfer coefficients, the superficial gas velocity is the most important factor and
the solid circulation rate should be also taken into account.

The kinetic theory of granular flow (KTGF) is modified to fit the Einstein’s equation for
effective viscosity of dilute flow. A pseudo-fluid approach based on this modified KTGF is
used to simulate the dynamic formation and dissipation of clusters in a circulating
fluidized bed riser. The agglomeration of particles reduces slip velocity within particle
clusters, and hence results in two reverse trends: discrete particles are lifted by air
while particle clusters fall down along the wall. The dynamic equilibrium of these two
types of motion leads to the characteristic sigmoid profile of solid concentration along
the longitudinal direction. The predicted solid velocity,lateral and longitudinal profiles
of solid volume fraction and annulus thickness are in reasonable agreement with
experimental results.

Continuous hydrolysis of chitosan was performed in a convoluted fibrous bed bioreactor
(CFBB) with immobilized T. reesei. At dilution rate of 0.4 d-1 and substrate concentration
of 2%(mass vs. volume), the average degree of polymerization of hydrolysate can be kept at
1.25-1.35, which can be easily regulated by changing dilution rate or inlet chitosan
concentration.

The stoichiometric matrix of a simplified metabolic network in Bacillus Subtillis was
constructed from the flux balance equations, which were used for reconciliation of the
measured rates and determination of the inner metabolic rates. Thus more reliable results
of the true and empirical maintenance coefficients were obtained. The true maintenance
coefficient is linearly related to the specific growth rate and changes with the P/O ratio.
The measured biomass yield of adenosine triphosphate(ATP) is also linearly related to the
P/O ratio.

The present paper intends to introduce a new method for reducing bends erosion from
particles impacts:the ribbed bend erosion protection method. Ribs are evenly fixed in the
range of 20°-80° on the inner-wall of inside 90° bend and the bend (including ribs) is
made of medium carbon steel. Three-dimensional numerical work is performed and the result
shows satisfactory agreement with the experimental measurement. Numerical simulation
studies the characteristics of axial gas flow along the bend and secondary flow at cross
section. Detailed analyses involving the impact velocity and incidence angle of particle-
metal (either particle-rib or particle-duct) impact unveil the mechanism of the anti-
erosion effect. As a result, predications achieve that the average erosion rate of the
ribbed bends is only a third of the bare bend under test conditions and rectangle ribs
possess higher anti-erosion effect than square ribs, while the wear distribution pattern
remains unchanged after adding ribs onto the bend. All results confirm that the ribbed bend
erosion protection method is a simple and effective method for reducing bends erosion from
particles impacts.

The sorption behavior of acid dyes onto cetyltrimethylammonium bromide (CTAB)- modified
silica as a function of pH in the aqueous medium was studied. Single- and multi-solute
sorption equilibria of orange Ⅱ(OR),phenol red (PR) and Eriochrome Black T (EBT) were
studied at pH 3, unbuffered water pH and pH 11. Sorption behavior of EBT could not be
conducted at pH 3 due to its aggregation in acidic medium. All the reaction
conditions,experimental protocols and techniques remained the same throughout the sorption
process. Sorption isotherms for single-solute system were fitted by the Langmuir model,
while Langmuir competitive model (LCM) and the ideal adsorbed solution theory (IAST)
coupled with Langmuir model (IAST/Langmuir) were used for the prediction of multisolute
competitive sorption. Sorption affinities influenced by the factors like physical
interactive forces between the molecules of CTA on silica and sorbate, structural
limitations of the dyes based on their geometrical arrangement were investigated. Sorption
affinity of OR was found to be higher than that of EBT and PR at all the pH values
investigated. Magnitude of the sorption capacities was observed to be higher in acidic
medium but lower in alkaline medium. Trends of the sorption affinities in multisolute
system were similar to those in single-solute system but magnitude of the sorption
capacities was significantly reduced due to the prevailing competition among the sorbates.

The effects of surfactant on the solvent extraction in leaching sphalerite were
investigated. It is found that sodium dodecyl sulfonate is the effective surfactant in
improving the zinc recovery from sphalerite in the aqueous FeCla-HCl-tetrachloroethylene
system. Through the measurements of surface tension and viscosity of the sphalerite slurry
modified with different surfactants, it is concluded that sodium dodecyl sulfonate in the
concentration range of 0.05 to 0.2g@L-1 can improve the viscosity of sphalerite slurry in
the water, decrease the surface tension of leaching solution, prevent the aggregation of
ore particles, and give very high zinc extraction .

A novel extractant mixture, di-2-ethylhexyl phosphate (DEHPA) plus HX, was proposed and
tested for recovering gallium from sulfate solution. It was found that the extraction
capacity of DEPHA for gallium from sulfate solution could be enhanced significantly due to
the synergistic effect of acidic extractant HX. Gallium extraction is negligible below pH 0
and highly sensitive to pH of aqueous phase in the range from 0 to 1, and satisfactory
extraction can be gained at pH＞1. More than 96% Ga extraction was obtained using 15% DEHPA
plus 2% HX. Although Fe (Ⅲ) was found to be extracted preferentially to Ga (Ⅲ), effective
extraction of Ga (Ⅲ) was possible by reducing ferric to the ferrous state prior to
extraction. A loaded organic phase containing 0.48g. L-1 Ga could be produced from solution
of 0.12g@L-1 Ga at A/O ratio of 4: 1 via three mixer-settler operation stages.Gallium was
stripped quantitatively from the loaded organic phase with 1.5 mol@L-1 of sulfuric acid.

A novel operation of batch distillation-ombination of varying column pressure and total
reflux-total efflux is studied experimentally. In the operation, the product is accumulated
at the top of the column under total reflux and then drained off completely, and the column
pressure is varying in the whole process. This process has been industrialized successfully
with large profits. The conventional mode of batch distillation is improved by this method
effectively: the separation efficiency and the yield of product are increased greatly, the
operation time is shortened and the production cost is cut down. Moreover, the amount of
condensation water is decreased and the over-high reboiler temperature is lowered.

The local gas-phase flow characteristics such as local gas holdup (εs), local bubble
velocity (Vb) and local bubble mean diameter (db) at a specified point in a gas-liquid-
solid three-phase reversed flow jet loop reactor was experimentally investigated by a five
-point conductivity probe. The effects of gas jet flow rate, liquid jet flow rate, solid
loading, nozzle dianeter and axial position on the local εg, Vb and db profiles were
discussed. The presence of solids at low solid concentrations not only increased the local
eg and Vb, but also decreased the local db. The optimum solid loading for the maximum local
εg and Vb together with the minimum local db was 0.16 × 10-3 m3,corresponding to a solid
volume fraction, εs = 2.5%.

The gold sorption from thiosulphate solutions on carbon sorbents and on anion exchangers
was studied.It was shown that the anion exchangers AV-17-10P and AP-100 are the most
effective and selective at pH=5-8.These anion exchangers can be recommended for the gold
recovery from the industrial solutions.

Central composite design (CCD), the most popular design of response surface methodology
(RSM),was employed to investigate the effect of total organic carbon(TOC) ratio of high
molecular weight organic matter (HMW) to low molecular weight organic matter (LMW), the LMW
strength and molar ratio of hydrogen peroxide to ferrous ion on landfill leachate treatment
by Fenton process. Based on the experimental data, a response surface quadratic model in
terms of actual factors was obtained through analysis of variance (ANOVA). The model showed
that TOC removal increased with the increase of HMW to LMW ratio and the decrease of LMW
strength. There existed an optimal hydrogen peroxide to ferrous ion molar ratio for TOC
removal.

The pH dependence of the extrapolated shear yield stress for Alcoa A16 α-Al2O3 suspensions
at the powder volume fraction of 0.27 with and without addition of both polyvinyl alcohol
(PVA) and polyethylene glycol (PEG) each at fixed 0.18% of the powder mass was studied.
With the polymer added, the full deflocculation of the suspension shifts from about pH=-4
to around pH=1.5, at which the minimum value of shear yield stress is higher than that at
pH=4. The addition of both PVA and PEG was found to prevent the filter cake from cracking.