The third-phase behavior in extraction oxalic acid by trioctylamine (TOA) was investigated through measuring the solubility of oxalic acid in organic solvent.The result showed that n-octanol affected the dissolution of oxalic acid in the organic solvent apparently, and the solubility of oxalic acid, the complex of oxalic acid with TOA in the organic solvent and the extractability of oxalic acid with TOA increased with n-octanol concentration in the organic solvent. An obvious shift of the solubility of oxalic acid appeared when the oxalic acid concentration was larger than the saturated concentration of oxalic acid for TOA, which depended on the formation of complex dimer. Comparatively, the solubility of oxalic acid in organic phase for the experiment of extraction equilibrium was more than that of the organic solvent without water, and the water in the organic solvent was good for the dissolution of oxalic acid. Meanwhile, mathematical models were established to describe the solubility of oxalic acid and the complex, and the model parameters were obtained by fitting the experimental data.

Hydrodynamics and particle attrition and entrainment measurements for the spouting of fine particles were carried out in a conical-based cylindrical bed of diameter 0.186 m, inlet orifice diameters of 6 mm to 14 mm, and included cone angles of 45 to 80 degrees.Four different types of fine particles with diameter ranging from 0.241 mm to 0.874 mm were investigated. Four different flow regimes-fixed bed, stable spouting, unstable spouting and slugging were identified and mapped. Stable spouting could be achieved when the ratio of the orifice diameter to particle diameter was less than 19. The minimum spouting velocities measured were in agreement with those predicted by the Mathur-Gishler equation within ±15%. The solid density measurements obtained by a gamma ray densitometer showed that the solid density in the spout increased with bed height and that in the annulus was 3%—10% higher than in a loosely packed bed. It was observed that both particle attrition and entrainment increased with the increasing gas velocity and became smallest when stable and well-organized spouting was established.

An experimental study of heat transfer between gas and solid particles in the centrifugal fluidized bed(CFB) was carried out.Influences of bed thickness, rotating speed of the bed and particle diameter on gas-solid two-phase heat transfer coefficient were examined. Based on the field synergy principle, the mechanism of convection heat transfer enhancement in CFB was analyzed and discussed. The experimental results indicated that when the flow direction coincided with the direction of heat flux at a given rotating speed in the centrifugal fluidized bed, the gas-solid heat transfer would be enhanced and heat transfer equation was in the form of Nu＝CRePr. The ranges of Pe(=RePr) number satisfying a linear relationship between Nu and Pe at different rotating speeds were obtained. It showed that when Pe number was larger than the critical Pe number the relationship between Nu and Pe in the CFB would depart from the linear region.

Distillation experiments for methanol-ethanol-water system in a tray column were carried out.A mathematics model that takes the effects of concentration on mass transfer coefficients into account is set up for simulation calculation of concentration profiles in the column. The predicted values agree well with the experimental values. Both of experimental and predicted values show that ethanol appears complex concentration profiles in some concentration range.

The permeating flux and annular gap pressure profile in a tubular micro-filtration membrane separator with rotary cross-flow were measured and analyzed by a self-developed on-line pressure measuring system.This test was done under different entrance pressures, different suspension liquid consistency, and different membrane separator annular gap dimensions.A comparison of the results with annular gap pressure distribution and permeation flux in membrane separator with traditional cross-flow was also made.The results showed that for rotary cross-flow the pressure value and pressure variation in the annular gap were greater, and its permeating flux was higher than traditional cross-flow by about 1.5 times. Enhancement effect of rotary cross-flow membrane micro-filtration was clear. The results can provide the experimental basis for further research on enhancement mechanism and the method of reducing or solving polarization and pollution in membrane micro-filtration.

Stirred mixing vessels are widely used in chemical industry for processes involving the mixing or/and chemical reactions of liquids,gases or solids.The ability to numerically simulate the whole flow field is vital to optimal design.Previous attempts have adopted a steady-state semi-empirical analysis requiring experimentally-based inputs of some form.In the present work, the CFD code CFX-4 is used for the full field computation for both the fluid within the impeller passages and the fluid outside.The model solves the unsteady ensemble-averaged continuity and momentum equations(Reynolds equations)with turbulence effects accounted for by k-ε model, RNG k-ε model,and algebraic stress model.The equations are discretised by the finite-volume approach.The mesh is divided into two parts which are fixed to their respective frames of reference, one being stationary and the other rotating with the impeller. At the interface between these two parts the rotating mesh slides over the fixed one at each time interval.The computation proceeds simultaneously over the whole flow field and the solutions in both rotating and stationery domains are coupled at all times.Comparisons between the predictions and the experimental data measured by particle imaging velocimetry(PIV)show that all the major flow patterns are well reproduced. The quantitative comparisons show encouraging agreement.

The multifractal analysis for pressure fluctuation signal in bottom region and upper region of circulating fluidized bed(CFB) was performed by using the wavelet transform modulus maxima method.The intermittence index of the signals can be calculated with this method.Results show that the gas-solid flow in CFB is shown to possess a multifractal character.A new method is also proposed to identify the regime transition in CFB.The lower turning point of intermittence index curve can be used to determine the transition of flow regimes from fast fluidization to dense pneumatic conveying.The transition of flow regime in CFB is not homogeneous along the axis of riser, the transtion in bottom region may be later than in upper region, and the transport velocity based on this method is also compared with that calculated by some empirical equations.

The behavior, kinetics and model for oxidation of CaS at 730—970℃ under pressure of 0.1 MPa and 1 MPa were investigated using TG technique. The oxidation product was analyzed by XRD spectra. The results showed that CaSO₄ was the only product of oxidation of CaS. The conversion of CaS was enhanced by increasing pressure or temperature.The solid-solid reaction between CaS and CaSO₄ was suppressed under pressure. The activation energy for chemical control and diffusion control was 73.08 kJ·mol^-1 and 137.3 kJ·mol^-1 and the pre-exponential factor for them was 3.905×10^-5 and 0.1298 respectively. The oxidation rate of CaS was controlled by diffusion process.

The transport-reaction process characteristics during product layer formation in flue gas desulfurization was studied theoretically and experimentally.The transport-reaction process could be described by Thiele number incorporating the influences of chemical reaction resistance and diffusion resistance.It was found that the conversion rate at the end of the process decreased with increasing Thiele number.The conversion rate increased with increasing temperature and porosity, and also depended upon pore geometry and distribution.

A pilot set-up was built to test a novel four-bed pressure swing adsorption (PSA) process with a hydrogen-separation operation.The new PSA process features intermediate surge tanks, through which depressurization and re-pressurization of columns are accomplished. As consequence, the coupling between columns via pressure-equalization is disconnected, and the possibility of operating the process at lower pressure is provided. A new cycle sequence was suggested for the new PSA process. Operations of separating hydrogen from a mixture of H₂/N₂/CH₄ of molar ratio 60/10/30, which simulated the dry gas of refineries, were performed on such process at pressures lower than 1.0 MPa. Process performance was studied with columns packed consecutively with adsorbents composed of ordinary activated carbon (OAC) with ZMS-5A, and that of superactivated carbon(SAC) with ZMS-5A for the pressure range 0.4—1.0 MPa. It was proven that a relatively high recovery and as high as 99.99% of purity of the product could be realized at low pressures with the new PSA technology.

By treating an element of structured packing as a three-dimensional node net and analyzing the flow patterns of 2 kinds of liquid stream in the net,i.e. net line flow and node flow, the liquid distribution model for an element of structured packing was eslablished.By transforming the liquid exchange between packing and column wall into that between the node net of packing and the node net of column wall,the liquid distribution model for the column wall zone around a packing element was presented.The boundary conditions for the liquid distribution problem of structured packed columns were proposed. The liquid distribution model for corrugated sheet structured packed columns was thus composed of the above two models and relevant boundary conditions. Three model parameters were estimated by using the simplex method. The calculated results agreed very well with the experimental data, that is to say, the mathematical model could describe the liquid flow behavior in corrugated sheet structured packed column correctly.

Genetic algorithms(GA)are used more and more wide in the optimization of complicated, non-linear questions in the chemical industries. In the paper,a multi-Agent system which includes two kinds of Agents:O-Agent and A-Agent is built.There are a number of O-Agents in the system，and their function is equal to the seeds of evolution，but there is only one A-Agent.The A-Agent is in charge of the work of evolution.It monitors and controls the GA evolution procedure. These two kinds of Agents can exchange the useful information which can represent the current situation of evolution. By means of the limit of life of these two kinds of Agents，the system can avoid prematureness and at the same time can speed up convergence.The genetic algorithms based on Intelligent Agent (M-Agent-GA) improves greatly the feature of standard GA（SGA）, especially in the optimization of complicated questions. It was used in the optimization of the equipment of xylene isomerization and the result was good.

Traditional studies on long-range planning and process debottlenecking mainly focus on the net present value of production process only,by using the MILP/MINLP approaches.However, MILP/MINLP approaches are lack of flexibility to solve multi-objective problems with sustainability being considered. Moreover, process debottlenecking and investment evaluation are executed as two separate processes.In this paper,a supply chain long range planning and investment decision making system is proposed for supply chain debottlenecking and investment decision making simultaneously with sustainability being considered.At first, a hierarchical structure of investment evaluation and decision making system is set up under three strategic objectives-enterprise benefits, social benefits and customer benefits. Secondly,the relative weights of various qualitative and quantitative elements in the hierarchical structure are evaluated by using the analytical hierarchy process (AHP).Thirdly, a multi-objective multi-period mixed integer nonlinear programming model is formulated to streamline the operations and suggest design modifications that will improve the efficiency and sustainability of the supply chain. It can be utilized to anticipate the impact of market changes and introducing new unit process, thus supply chain bottlenecks can be identified and debottlenecking actions can be recommended.Finally, goal programming is utilized to solve the multi-objective multi-period mixed integer nonlinear programming model and optimized investment project or coupled projects are selected. The application of this integrated system is illustrated by a practical example.

Sodium PVA sulfate(SPS) was prepared through the sulfonation of the hydroxyl groups of PVA by using chlorosulfonic acid as sulfonating agent. Industrial grade acrylic acid and SPS were used as raw materials of static solution polymerization to synthesize acrylic acid-based superabsorbents inter-penetrated with sodium PVA sulfate (SA-IP-SPS) which have higher water and saline absorbency.Characterization results with IR,TG and sulfur content measurement proved the formation of inter-penetrating network structure in SA-IP-SPS superabsorbents. The effects of SPS content and PVA relative molecular mass on the absorbency of the superabsorbents were studied and the optimized SPS content and the PVA relative molecular mass were 3% and 90000—124000 respectively. Under the optimized reaction conditions, the water absorbency was about 900g·g^-1,and the 0.9% NaCl solution absorbency is 97 g·g^-1.

Polyethylene glycol-400(PEG-400)grafted in polystyrene-divinyl benzene(PS) supporter as macromolecule ligand was synthesized.The effects of such factors as temperature，time and solvent etc are also studied, and the structure of the ligand was characterized by IR spectrum.Polystyrene-supported PEG-400 molybdenum(Ⅵ) dioxo(2,4-pentanedione)［PS-PEG-MoO₂(acac)］ used as epoxidation catalysis species,was for the first time synthesized by the phase transfer catalysis method,and was characterized by infrared spectrum technique.The affecting factors on the synthesis process of PS-PEG-MoO₂(acac)were also discussed.Epoxycyclohexane synthesized by the reaction of cyclohexene and t-butyl hydroperoxide(t-BuOOH)with PS-PEG-MoO₂(acac) as catalyst was investigated in the presence of nitrogen.The analysis method of Mo in the catalyst and the gas chromatogram (GC) method of epoxycyclohexane analysis were set up.The optimum reaction condition was obtained by orthogonal experiment design, that is,according to n(t-BuOOH)=0.1mol,n(cyclohexene)∶n(t-BuOOH)=3∶1, volume of solvent is about 5ml, reaction temperature～80℃,time～60min，and mass of molybdenum in the catalyst is～0.0198g.Under this condition, the yield of epoxycyclohexane calculated by the amount of t-BuOOH is more than 99.5%,the purity of epoxycyclohexan is about 99.5% by GC analysis.

A macroporous copolymer GET to be used as the matrix for expanded bed adsorption(EBA)was synthesized by suspension polymerization in the presence of porogenic agents from glycidyl methacrylate(GMA)and ethylene dimethacrylate (EDMA) with surface-modified superfine TiO₂ embedded.In this paper, the effects of the amount of TiO₂, the crosslinking degree, the amount of porogenic agent and their proportion on the copolymer wet true density and its porous structure，such as specific surface area, average pore diameter and pore volume were investigated.

Equilibrium gas solubility and volumetric mass transfer coefficient of hydrogen in turpentine were measured at various pressures(2.0～8.0MPa),temperatures(353～473K), and 600 r·min^-1 stirrer speeds in a high-pressure agitated autoclave (type FYX-2G).The result showed that equilibrium gas solubility and volumetric mass transfer coefficient of hydrogen increased with increasing temperature and pressure at a temperature range from 353K to 443K,and the solubility of hydrogen accorded with Henry Law,but at temperature 473K the solubility of hydrogen decreased.Based on the equation of solubility coefficient suggested by Vuuren, the relationship of gas equilibrium solubility with temperature and dissolution heat of hydrogen in turpentine were obtained.The model for volumetric mass transfer coefficient was also established.

Based on the results obtained in the investigation for cyclohexane recovery by extractive distillation with single solvent,and the Wsy-1 mixed solvent was experimentally studied.The effects of cyclohexanol concentration in solvent,cyclohexane concentration in feed and solvent-to-feed ratio on relative volatility were investigated. The relative volatility of n-heptane/cyclohexane was increased from 0.661 to 1.11, and that of 2,3-dimethylpentane/cyclohexane increased from 0.84 to 1.21 at the Wsy-1 solvent-to-feed ratio of 7∶1. The cyclohexane purity and recovery were 98.5% and 80%, respectively, when a feed stream consisting of 85% cyclohexane was introduced to the experimental extractive distillation column operating at the reflux ratio of 10.

This paper proposes a stochastic optimal technique based on Genetic Algorithm (GA) for the calculation of multiphase and multicomponent chemical equilibrium by minimization of Gibbs free energy. Three aspects are improved based on the drawbacks of the conventional GA.An alternative decimal encoding strategy is adopted to enhance the precision of calculation.A dynamic encoding method that can limit the bounds of optimized variables within their feasible regions is developed to cope with the complex constraints of the problem.Finally,sequential search technique is applied to improve GA to approach global optima.It is shown through the calculation of complex chemical systems,in which non-ideal,multireaction and multiphase coexistence are simultaneously involved,that the presented GA is general and efficient for the addressed problem.

A new wet flue gas desulfurization method by reaction across the falling liquid film on the outside surface of axial finned-tube bundle and its principles of removal of SO₂ are presented in this paper.The effects of different styles of tube bundle,and the pitch of tubes,flue gas velocity,gas-liquid ratio and flue gas temperature on desulphurization efficiency and the moisture content of flue gas are studied.The experiment results show that desulphurization effect is better for flue gas at 65℃,4.0m·s^-1 against the tube bundle of 10 rows with relative pitch of staggered rows S₁/d=2.1,S₂/d=1.8.

A series of well-designed deflectors were used to regulate the liquid flow behaviour on the 95-Ⅱ tray. A multiple-plug flow pattern was observed in each liquid flow channel between two deflectors on the tray.On a test rig with a diameter of 1000mm, the liquid layer temperature profiles in the vertical and horizontal directions were measured by resistivity thermal detectors(RTDs).An oxygen desorption experiment was carried out and the oxygen concentration in the inlet liquid and the outlet liquid were determined by iodimetry,through which the liquid phrase Murphree tray efficiency(E_ML) was calculated. The results show that the well-designed and placed deflectors on the tray can obviously increase the tray efficiency by almost 30% under the same operating conditions.

A novel Pd/Al₂O₃ catalyst prepared by glow discharge plasma technology is reported.The results of H₂-chemisorption indicate that palladium dispersion of the plasma-prepared Pd/Al₂O₃ reaches 29.7%,which is about 5 times higher than Pd/Al₂O₃ prepared by conventional preparation.Meanwhile,the particle diameter of the plasma-prepared catalyst is 3.8 nm, but the particle diameter of the conventional catalyst is 20.4 nm.Such plasma-prepared Pd/Al₂O₃ catalyst shows a higher activity for catalytic combustion of methane than the conventional catalyst.Methane conversion reaches 90% at 400 ℃, but it is only near 30% for the conventional catalyst at the same temperature.

The paper chiefly compares the catalytic activity and stability of nano-sized nickel and Raney nickel in the catalytic hydrogenation of p-nitrophenol.The experimental results show that the catalytic activity and stability of nano-sized nickel are superior to those of Raney nickel under the same reaction conditions. The fresh and used nickel samples are characterized by nitrogen sorption and particle analyzer. The results suggest that particle size,surface structure,etc. may play a key role in determining the catalytic activity of nickel samples.The aggregation of nano-particles would lead to the deactivation of nano-sized nickel,while the jamming of pores would be one of the reasons for the deactivation of Raney nickel.