The separation efficiency of a representative sheet metal structured packing (Mellapak 350Y) in experimental columns (0.15m i.d.) is presented at high-pressure and total reflux distillation conditions. N -butane and n-pentane is used as the testing system.Pressures span the range of 0.7-1.9MPa.With the increase of F -factor,the HETP values decrease slightly in the loading area at all test pressure but increase before flooding point.By comparing the experiment data with the predictions of SRP model,it is found that SRP model performance deteriorates at a high pressure.

Exergy analysis has been extended from general energy analysis to thermoeconomic analysis and environmental analysis,i.e.,sustainability analysis.Some fundamental studies of exergy analysis become more important.This research emphasizes the importance of the strict concept of standard state and the new values of standard thermodynamic properties.Based on the concept from the ISO 13600 series standards of the technical energy system,the IUPAC’s rule about thermochemical standard properties,and the up-to-date and authoritative data of the Gibbs free energy of standard formation,the model of environmental-reference-state by Kameyama et al is modified,which consists of selected standard compounds at 298.15K and 1bar in the atmosphere, hydrosphere or geosphere.A new data system of the element standard exergy involving 80 kinds of ordinary elements is proposed.In addition,the example of a homogenous liquid mixture of ammonia and water given in the paper suggests that standard exergy is the principal value of exergy function of the mixture.

Wall function, k-ε turbulence model are used in the present study.The numerical hydrodynamics models and mass transfer models in flow loop system are defined in accordance with the basic theory of hydrodynamics and conservation of mass,momentum or energy.Flow-induced corrosion kinetics model of carbon steel in flowing 3.5% NaCl solution is set up on the basis of determining main controlling factors and analyzing their degree of influence in flow-induced corrosion by some electrochemical experiments. The numerical method used in this study is based on the control volume approach for discretization of partial differential equations that express the characteristics of fluid flow and mass transfer.The power law scheme is also used in discretization of convection-diffusion equations.In this manner,the resulting discretization equations express the conservation principle for mass,momentum and energy over the finite control volume,just as the differential equations express the same principle for the infinitesimal volume.In this way,the formulation is straightforward.The user program is compiled.In accordance with flow-induced corrosion kinetics models,flow-induced corrosion rates are numerically calculated with SIMPLE algorithm.The flow-induced corrosion rates calculated by numerical method are compared with the ones measured by weight loss.The numerically computed flow-induced corrosion rates are mostly equal to the ones measured by weight loss experiments.If proves that the flow-induced corrosion kinetics models are correct and accurate,and that the user program is reasonable.The models are founded on the basis of some electrochemical experiments and reasonable hypothesis.Corrosion electrochemical factor plays a dominant role in flow-induced corrosion of carbon steel in flowing 3.5% NaCl solution.

As a large equipment used in flue gas desulfuration,Plural Tray,which operates in the spray regime and consists of large-holed sieve tray and structured packing,has been developed.Hydrodynamics of such new sieve tray is studied in this paper.The experiments are accomplished in a cold model column with diameter of 400mm.The effect of hole diameter and free area of Plural Tray on the hydrodynamic properties is studied.The larger the hole diameter is,the more the wet tray pressure drop is;the more the free area is,the worse the operating flexibility is.As a result,Plural Tray has the characteristics of lower resistence,little entrainment and big upper limit velocity of operation.

As a large equipment used in flue gas desulfuration trechnique,Plural Tray,which operates in the spray regime and consists of large-holed sieve tray and structured packing,has been developed.Hydrodynamics of such new sieve tray is studied in this paper.The experiments are accomplished in a cold model column with diameter of 400mm.On the basis of the first part,this part investigated on the effect of operating variable and liquid physical property on sieve tray hydrodynamics.With the increase of liquid density,weeping and the tray wet pressure drop increase;with increase of liquid viscosity,pressure drop decrease;with decrease of surface tension,weeping and flooding velocity decrease,while entrainment increases.Results of this study provide theoretical basis for designing and operating commercial columns with large-holed Plural Tray.This Plural Tray was used successfully in a project of flue gas desulfuration,which treats flue gas of 100000m ³·h ^-1 .

A novel hybrid solid adsorption-steam ejection refrigeration cycle is presented and thermodynamically analyzed.The refrigerant steam with high temperature and high pressure desorbed from the adsorbent bed is led into an ejector before it enters the condenser.Therefore the hybrid refrigeration system may produce cold not only in the adsorption course but also desorption course,and refrigeration capacity is increased.The influences of some operating parameters,such as desorption temperature and ejecting pressure,on the hybrid refrigeration cycle are discussed.The coefficient of performance of the hybrid system is comparable to that of adsorption cycle with heat recovery when operated with high desorption temperature,and the hybrid adsorption-ejection refrigeration cycle with heat recovery will greatly improve the performance of the system.Simulated results show that the hybrid refrigeration system is attractive when it is powered by high-temperature exhaust heat.

Based on the overview on 3-D pin-fin tubes,the experimental results obtained by the authors are presented and compared with the results of 14 types of pin-fin tubes from Q.Liao et al .The influences of different parameters on heat transfer and pressure drop are also discussed.

In this paper,molten aluminum flow with heat transfer though SiC porous media in a centrifugal force field is described with a mathematical and physical model.The implicit TDMA Algorithm and first kind of first-order upwind difference were used to solve the conservation equation associated with appropriate boundary conditions.The distribution of molten aluminum velocity and pressure,the temperature field of flow and porous media in a centrifugal force field are examined for different conditions.The results show that local temperature of fluid phase is higher than that of solid phase.The temperature difference between fluid and solid decreases with the moving of infiltrated distance.The infiltration of molten aluminum through SiC porous media in the centrifugal force field depends greatly on the angular velocity and the temperature of preheated SiC porous media.SiC volume fraction has a strong effect on velocity and pressure drop of molten aluminum.

This paper presents a simulation model of a thermofluid system,which is based on combined neural network and process mechanism characteristics.It is an artificial neural network model,the ideal simulation speed thus is ensured.During design of the network model,the physical fundamental with which the system between input and output is considered.This network model is a "grey box" rather than a conventional "black box" to a certain degree.Besides the conventional learning function of numerical mapping between input and output,training of the network reflects the learning of physical mechanism between input and output,thereby associative ability,extending inference ability and recurrent ability of the network model are ensured.

Experiments were carried out in cylindrical Plexiglass tanks of 0.8m and 1.6m diameter agitated by single down pumping propeller (CBY).A new type of bi-electrode probe was used to measure local,three-dimensional liquid velocities in the solid-liquid system with solid volumetric concentration ( C _v) from 5.4% to 19.8%.The effects of solid volumetric concentration and scaling-up on liquid velocity distribution were studied.The down-flow outside a propeller was accelerated and the up-flow near the wall of tank was resisted by particles.The resultant liquid velocities just above the bottom of the tank are also resisted by particles.Outside the agitator radius (2 r/T>D/T ) the mean resultant liquid velocity along radius in jet region ( h/T =0.3) increases about 12% in the small tank and by 45% in the large one with solid volumetric concentration ( C _v) of 5.4%.The flow numbers were calculated for a homogeneous fluid and a suspension in the two stirred tanks.

The solubilities of styrene in supercritical carbon dioxide under different supercritical conditions are determined.The range of temperature covered is 323.15-33.15K and pressure 3.0-24.0MPa.A model representing solubility behavior is derived from the solvation concept, the equilibrium constant of high-pressure reaction and the rules of phase equilibrium. It is tested by experimental results with good agreement. Also, some experimental results from the literature are reproduced by means of this model.

The extraction process based on chemical complexation is of higher capacities and selectivities for dilute polar organic solution.In this work,phase equilibrium governing the reactive extraction of maleic acid from aqueous solution into solutions of TOA in the diluents chloroform,4-methyl-2-pentanone (MIBK), n -hexane and n -octanol was investigated.The results showed that the influence of the diluents on extraction depended on the concentration of maleic acid.Protonation diluent was more effective than others in low equilibrium concentration of maleic acid.In high equilibrium concentration of maleic acid,the sequence of extraction capacity was MIBK> n -octanol> n -hexane>chloroform.Overloading existed and the sequence was MIBK> n -octanol> n -hexane>chloroform.FT-IR spectroscopic analysis of organic samples loaded with maleic acid was carried out,the results showed that amine formed 1∶1 complexation with maleic acid.

The extraction features of maleic acid by trioctylamine (TOA) were investigated further to study the extraction mechanism.Based on the first part (Ⅰ) of this paper,we proposed an assumption of four kinds of dissolution existing during extraction of maleic acid with TOA,i.e.physical dissolution of maleic in diluent,hydrogen bond action of TOA on maleic acid,ion pair association of maleic acid with TOA,and physical dissolution of maleic acid in complex.A model containing these four kinds of dissolution was set up using Mass Action Law.The results showed that the calculated concentration of maleic acid in organic phase approached the experimental data.The overall distribution coefficient of physical dissolution of solvent was not always equal to the sum of the diluent and complex,where the experimental distribution coefficient was larger than the sum value for MIBK system,smaller than the sum value for chloroform system and equivalent to the sum value for n -octanol system.

Globular Al ₂O ₃ powders with diameter ( d ₅₀ ) of 5.82μm were prepared by spray-drying the solution of ammonium alum combined with pyrolysis process.SEM,XRD,DTA-TG,and Energy Spectrum were used to analyze the morphology and composition changes of powders obtained at different preparation stages.The results showed that the particles prepared by spray-drying were relatively coherent,then were dried,separated,dehydrated and shrunk after drying and pyrolysis processes.As a result,the diameter of powders decreased gradually,and the proportion of bigger particles significantly decreased.The sequence of the phase transition of ammonium alum was found to be NH ₄Al(SO ₄) ₂·12H ₂O→NH ₄Al(SO ₄) ₂→Al ₂(SO ₄) 3→ θ -Al ₂O ₃→ α -Al ₂O ₃ according to DTA-TG and XRD results.Sintered at 1370℃ for 2h, α -Al ₂O ₃ powders of high purity was obtained.

VG1(pTU14) is a novel recombinant Escherichia coli for Poly- β -hydroxybutyrate (PHB) production,which contains Vitreoscilla hemoglobin gene ( vgb ),lytic genes of phage λ( S -RRz ) and PHB biosynthetic genes ( phb CAB) in the cell.During the process of fed-batch culture of VG1 (pTU14),it was found that the level of dissolved oxygen (DO),the concentration ratio (C/N) and the range of carbon and nitrogen source were all important parameters affecting cell growth and PHB accumulation.DO and pH could be used to decide the time for the nutrition feeding.When C/N,carbon and nitrogen concentration were in the range of 10-20,10-40g·L ^-1 ,1.0-2.0g·L ^-1 respectively and DO was higher than 5%,the cell growth was enhanced.Otherwise,PHB accumulation would be enhanced too early to attain the high cell density culture.Finally,the optimal feeding strategy,by which the cell growth was emphasized in early process and the PHB accumulation was promoted in late process,was carried out.After 60h fed-batch culture under the optimal conditions,cell concentration,PHB concentration and PHB content were reached up to 215.9g·L -1 ,193.7?g·L -1 and 89.7%,respectively.

Aspergillus oryzae (3042)mycelium pellets cultured in liquid were immobilized by cross-linking with gelatin and formaldehyde.Based on orthogonal design L ₁₆ (4 ⁵),a four-layer artificial neural network (ANN) model with back-propagation of error (BP) was used to optimize the immobilization conditions.The optimal condition was obtained.The conditions were:1g wet pellets were added into 8ml immobilization solution,both the concentration of gelatin and formaldehyde were 5g·L ^-1 ,and the immobilization time was 1.5h.The relative activity of immobilized preparation under the optimal condition was assayed.The relative activity was 83%,which was in good agreement with that predicted by ANN.Finally,the stabilization of immobilized preparation was studied.It illustrated that the optimum reaction condition differed from that of free pellet.Compared with free pellet,the optimum pH of reaction system changed from 7.0 to 8.0,temperature changed from 52℃ to 63℃,and the proper reaction condition range was increased.When the immobilized pellet preparation was used for L-alanine continuous production in a φ10mm×100mm packed bed reactor,operational stabilization was markedly increased,and the half-life period was 77d.The immobilized preparation had high stability,and artificial neural network can find the better conditions.

Several technical parameters were studied during the fermentation of recombinant E.coli for the production of collagen-like biopolymer.The effects of dissolved oxygen as well as glucose concentration on fermentation were observed.The OD 600 value could reach 98 when dissolved oxygen was controlled at 50% and glucose around 1%.The production of human-like collagen with a yield of 29.4% was obtained.

Studies of two-phase flow patterns and their transitions during condensation have gained increasing interest because heat transfer characteristics are strongly dependent on flow patterns.Therefore,it is very important to know flow pattern inside a condenser at certain flow conditions and hence to develop heat transfer correlations consistent with the prevailing heat transfer mechanism in each flow pattern. The condensation heat transfer for R134a in two kinds of in-tube three-dimensional (3-D) microfin tubes with different geometries is investigated experimentally.In the range of experimental conditions,six distinguishable flow patterns (annular flow,semi-annular flow,stratified flow,wavy flow,slug flow and plug flow) are recorded by a video camera.The obtained results show that the flow regime transition criterion between annular flow and stratified-wavy flow decreases from Fr equal to 7 to Fr equal to 2 in the Soliman flow regime map.In stratified-wavy flow regime,the average heat transfer coefficients h of the two kinds of in-tube 3-D microfin tubes increase as mass flux increases and the number of microfins in 3-D microfin tube is not the controlling factor of condensation heat transfer performance.The regressed condensation heat transfer correlation from the experimental data of stratified-wavy flow regime is obtained.The disparity of the experimental data is within the limits of ±22%.Combined with the criteria of flow pattern transitions,the correlations can be used for the design of condenser of 3-D microfin tubes.

Seven typical components in municipal solid wastes (MSWs)--paper,food,textile,wood,straw,plastic and rubber were chosen as the thermogravimetric analysis samples in this paper to study the pyrolysis characteristics. By the thermogravimetry and differential scanning calorimetry (TG-DSC) analysis,pyrolysis characteristics of MSWs’ components and pyrolysis endothermal enthalpy were obtained.The kinetic parameters of pyrolysis were determined with the Doyle method and a multi-stage first order pyrolysis model was proposed.The simulated results by this model showed good agreement with the TG experimental data.The pyrolysis characteristics provide significant parameters to a new concept of circulating fluidized bed incinerator,which can simultaneously restrain the high-temperature HCl corrosion and emission of dioxins.

A new equation of self-diffusion coefficients for real fluids is proposed over wide temperature and density ranges.The new equation is derived from the molecular dynamics simulation data of LJ model fluid in literature,which could be applied to gas,liquid and supercritical fluid (0≤ ρ * ≤1.0,0.8≤ T *≤4.0) with AAD 4.95% .With a generalized expression for the LJ parameters of pure real fluids according to the corresponding state principle and critical properties,the proposed equation is extended to pure real substances with the prediction accuracy 18.83%.Correlated LJ parameters are also used for comparison and the total AAD is 3.43% for 19 pure substances and 1299 data points.The new self-diffusion equation could be used in process design and development.

Cationic ion-exchange Separation process of L-phenylalanine with high salt concentration was investigated.One cationic exchange resin HD-1 with high adsorbance on L-phenylalanine was selected for the separation.The adsorbance of resin was near to 0.09g L-phenylalanine per milliliter resin.At the same time,the effects of concentration,velocity of flow and inorganic salt on L-phenylalanine adsorption were studied.The yield of separation process was close to 96.7%.