CIESC Journal

MEASUREMENT OF SOLUBILITIES OF CO₂ IN POLYMERS BY QUARTZ CRYSTAL MICROBALANCE

WANG Shaolei, PENG Changjun, LI Kun, WANG Jichao, SHI Jibin, LIU Honglai

2003, 54(2): 141-146.

Abstract ( 637 )

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A new apparatus based on quartz crystal microbalance has been established to measure the solubilities of gas in polymer. The measured solubilities of CO₂ in Nylon 66,nature rubber and polyvinyl chloride are in good agreement with literature data. The solubilities of CO₂ in 3 homopolymers including polystyrene, poly(methyl methacrylate)and poly(n-butyl methacrylate), and in 8 block copolymers including poly(styrene-co-methyl methacrylate), poly(styrene-co-butadiene-co-styrene), poly(n-butyl methacrylate-co-N,N-dimethylaminoethyl methacrylate), poly(n-butyl methacrylate-co-perfluoroalkylethyl acrylate) are measured. The equation of state for chain fluids developed by Peng et al.is used to correlate the experimental data.Satisfactory results are obtained.

NUMERICAL SIMULATION OF ENTRAINED FLOW FIELD IN CIRCULARLY LOBED NOZZLE

LIU Youhong, LIU Xi, LI Liguo

2003, 54(2): 147-152.

Abstract ( 573 )

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In this paper, a numerical procedure to study the mixing flow in a circularly lobed nozzle is presented.The predictions are obtained by using SIMPLEC and complete pressure corrections algorithm to solve the incompressible Navier-Stokes equations.Turbulence is characterized by the standard k-ε eddy viscosity model.To fit the irregular boundaries of the flow field,curvilinear greatly nonorthogonal coordinates are used.The robustness of the computational procedure is enhanced by making use of nonstaggered grids. Results show that the thermal mixing efficiency of primary and secondary flow varies with the axial length of the mixer, and the streamwise vortex development.In the whole, the thermal mixing efficiency is not high, and the maximum value is 0.874.Good agreement between the numerical and experimental results is obtained for the axial velocity and temperature profiles in the outer section of the mixer, and the pressure coefficient on the wall of the mixer along the axial line.

EFFECTS OF DIFFERENT DISTRIBUTOR CONFIGURATION PARAMETERS ON FLUID FLOW DISTRIBUTION IN PLATE-FIN HEAT EXCHANGER

JIAO Anjun, LI Yanzhong, ZHANG Rui , CHEN Chunzheng

2003, 54(2): 153-158.

Abstract ( 714 )

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Flow maldistrbution exists in plate-fin heat exchanger due to its complicated interior structure and it would cause the deterioration of heat exchanger’s efficiency.Many factors could cause fluid flow nonuniformity in the plate-fin heat exchanger.The objective of this paper is to investigate the effects of different distributor configuration parameter(h/H) on the fluid flow distribution in plate-fin heat exchanger.It is found that the effect of different distributor’s(h/H) on flow maldistribution in plate-fin heat exchanger mainly exists in the parallel direction of gross flow passage.A change in the distributor’s h/H can make the flow distribution more uniform in the parallel direction of gross flow passage.To optimize the configuration of distributor can effectively improve the flow distribution in plate-fin heat exchanger.The conclusions of this paper are of great significance in the optimum design of plate-fin heat exchanger.

CFD SIMULATION OF DISTILLATION TRAY BASED ON THREE DIMENSIONAL TWO-LAYER MODEL

LI Rui, XU Chunjian, ZENG Aiwu, ZHOU Ming

2003, 54(2): 159-163.

Abstract ( 602 )

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Distillation is the most widely used for unit operation separation in chemical and petrochemical industries but the prediction of tray efficiency remains a difficult task because of the complexity of hydrodynamics on the tray.In this paper,a three dimensional computational fluid dynamics(CFD)model is developed for describing the hydrodynamics on a sieve tray——Two-Layer Model,in which essential features of sieve tray are fully considered.On a sieve tray working under the foaming condition,two layers of liquid considered are jetting layer which is near the tray bottom resulting from high velocity gas phase emerging from the gas holes,and bubble layer——the upper layer in which gas exists in the form of gas bubbles resulting from the break-up of gas column due to much loss of gas energy.The two-equation k-ε turbulent model is used respectively to the two layers in modeling process considering the different types of interaction between phases.A sieve tray of 1.2 m in diameter is simulated,the results of calculation are reasonable.The calculation is carried out with commercial software Fluent 5.4 of Fluent Inc.

MASS TRANSPORT ANALYSIS OF SEPARATION OF METHANOL/MTBE MIXTURES BY PERVAPORATION——DIFFUSION OF SINGLE COMPONENT IN MEMBRANE

ZHU Lifang, CAI Bangxiao, GAO Congjie, WANG Shaolei

2003, 54(2): 164-169.

Abstract ( 631 )

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The equilibrium solubility and sorption curves for methanol(MeOH) and methly ter-butyl ether(MTBE) in cellulose acetate (CA) membrane at 298.15K，305.75K and 312.95K were measured by quartz crystal microbalance method. The results showed that mass transport processes of MeOH and MTBE in CA membrane belonged to Fickion diffusion .Both the equilibrium solubility and sorption rate of MeOH were much higher than that of MTBE, which meant that CA membrane had excellent separation performance for MeOH/MTBE mixtures. At the same sorption temperature, the equilibrium solubility and sorption rate increased with increasing sorption vapor pressure. The diffusion of MeOH and MTBE in CA membrane could be explained by Eyring’s “hole” theory of diffusion.

ABSORBING REFLECTED SHOCK WAVE IN THERMAL SEPARATOR

LI Xuelai, HUANG Qifei, ZHU Che

2003, 54(2): 170-175.

Abstract ( 599 )

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In the present paper, the reflected shock wave absorbing effect and its influence on the performance of thermal separator are investigated by means of a single-tube set-up.In the experiments, the shock wave absorber is a short tube whose relative diameter D/d is 5.7 and relative length l/d is 9.0, the relative length of the oscillatory L/d is from 107 to 730. The expansion ratio is from 2.0 to 6.0 and the exciting frequency is from 30 to 200 Hz. The experimental results show that the reflected shock wave is eliminated effectively as L/d＜400 while the absorber is mounted at the closed end of the tube, but when L/d＞400, it makes no difference to mount the absorber anywhere because the energy of the reflected shock wave is exhausted by the viscosity and friction of the gas inside the tube. Absorbing the reflected shock wave has great effect on the performance of thermal separator, e.g. the refrigeration efficiency is increased significantly, the optimal exciting frequency is decreased, the tube length can be shortened, the varying operating mode of the thermal separator can be improved, etc. When the tube is relatively short, the refrigeration efficiency is increased with the tube length, but when the tube length is increased to some value, the result is just the contrary. The recommended optimal tube length L/d is 200—350 for the tube without absorber and 150—250 for the tube with absorber. There exists a number of peak values of refrigeration efficiency when the exciting frequency is increased and the optimal exciting frequency is equal to the first, the second, and the third peak oscillatory frequency respectively when the tube length is L/d≤267， 267＜L/d≤502, L/d＞502. An optimal parameter matching relationship, which can be used to predict the value of the optimal exciting frequency, is derived in this paper.

PROCESS AND NUMERICAL SIMULATION IN FILLING STAGE OF GAS-ASSISTED INJECTION MOLDING

WANG Lixia, SHEN Changyu, CHEN Jingbo, LI Qian

2003, 54(2): 176-181.

Abstract ( 546 )

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The gas-assisted injection molding(GAIM)process, as an innovative technology, is being increasingly used in the plastics industry. It is derived from the conventional injection molding process. GAIM provides benefits in material saving and improved processing capabilities, but it is a more complex manufacturing process than conventional injection molding of plastic because it involves a greater number of manufacturing stages and process variables. The flow is also made more complex by the combination of low and high viscosity fluids. So CAE（computer-aided engineering）simulation software is expected to become an important and required tool to assist in parts design, mold design, and process evaluation in the coming age.

This paper presents the process of gas-assisted injection molding and a mathematical model to describe the mold filling and the gas penetration during the gas-assisted injection molding. A hybrid Finite element/finite difference/control volume method is used to calculate the pressure field, to trace the moving boundaries, one for melt front, the other for gas/melt interface. A typical part is simulated to demonstrate the applicability of the model.

ANALYSIS OF FLOW STRUCTURE IN LARGE-SCALE CIRCULATING FLUIDIZED BEDS

ZHANG Minghui, QIAN Zhen, YU Hao, WEI Fei, JIN Yong

2003, 54(2): 182-187.

Abstract ( 649 )

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Local transient solids fraction and particle velocity signals were measured in a 0.418m×18m large-scale circulating fluidized bed(CFB) by a dual-optical fiber density probe and a Laser Doppler Velocimeter(LDV) system. The probability density distribution(PDD) of both transient solids fraction and particle velocity was obtained. The bimodal distribution of PDD for both solids fraction and particle velocity can be clearly seen in the riser.While in the downer, the PDD curves only exhibit single peak distribution.The results indicate that two phases, i.e., the cluster phase with solids fraction near 1-ε_mf and the void phase with solids fraction about 0.01—0.02,exists in the riser. Meanwhile, only single void phase exists in the downer. Although there exist particle clusters in the downer, they cannot form a stable cluster phase with solids fraction near 1-ε_mf.The dissimilarity of solids flow structure reveal the significant difference in gas-solids flow structure and mechanism between the along-gravity gas-solids flow in the downer and the against-gravity flow in the riser.

NUMERICAL SIMULATION OF DRAG FORCE ON NON-SPHERICAL PARTICLE IN GAS-PARTICLE TWO-PHASE FLOW

You ChangFu, QI Haiying, XU Xuchang

2003, 54(2): 188-191.

Abstract ( 665 )

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Study of the effect of non-spherical particle on drag force was carried out by using numerical simulation. At Re＜100, the flow over three different non-spherical particles (cube, cylinder and frustum) was calculated with N-S equations. In particular,three promising correlations for the drag coefficient of non-spherical particle were critically examined with the computational results. The best method appeared to be that of Ganser which used the equal volume sphere diameter and the sphericity of particle. Comparing the results obtained by two different cylinders arrangements, the axis of cylinder perpendicular to the coming flow direction and parallel to that, the divergence between these two cases was very obvious.

MEASUREMENT OF SLUG VELOCITY AND LENGTH IN HORIZONTAL PIPELINE BY MEANS OF DIFFERENTIAL PRESSURE FLUCTUATION ANALYSIS

HE Limin, GUO Liejin, CHEN Xuejun

2003, 54(2): 192-198.

Abstract ( 663 )

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An experimental and theoretical investigation on slug velocity measurement method in horizontal pipe was conducted.By analysis of the differential pressure signal, the low to high leading edge in differential pressure signal curve was found to correspond to liquid slug’s arriving at the upstream location of differential pressure transducer and the high to low leading edge correspond to liquid slug’s leaving from the downstream location of differential pressure transducer.The pulse width of differential pressure signal was the time in which a liquid slug moved from upstream location to downstream location of pressure transducer, and the product of slug velocity and pulse width was the sum of slug length and the distance of between two differential pressure transducers.By analysis of correlation velocity,it was found that the result obtained from conductance probe signal was the average of the slug velocity and interface wave velocity in liquid film section, the result obtained from differential pressure was the slug velocity and the result obtained from pressure signal was random.A good agreement was obtained between the experimental data of air-water, air-diesel oil, air-lubricating oil and the data of other authors.

SELECTIVE CATALYTIC REDUCTION OF NITROGEN OXIDE BY PROPYLENE

ZHOU Liming, CHEN Guangwen, WANG Shudong , WU Diyong

2003, 54(2): 199-203.

Abstract ( 584 )

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The reaction of selective catalytic reduction (SCR) of nitrogen oxide (NO) in lean-burning engine exhaust with propylene was studied on Pt/γ-Al₂O₃ supported by monolith honeycomb. A one-dimensional heterogeneous model was set up to simulate the process behavior of reactions, and the effects of factors, such as reaction temperature, reactant concentration, dimension of channel of monolith catalyst, were discussed in detail both by experiment and theory. The results predicted by the model were tested through experiments. With this model, the effects of inter- and intra-phase diffusion and other factors are discussed. The model shows that the NO conversion rate will rise when higher concentration C₃H₆ is used; the influence of hydraulic diameter is small; the reaction is controlled by the kinetics under low temperature and after the light off of C₃H₆ the internal diffusion becomes serious.

ONLINE OBSERVATION FOR UNMEASURABLE INPUTS IN FCCU RISER

JIANG Qingyin , CAO Zhikai, CHEN Ziluan, CHEN Xiliang, DENG Mingbo, WANG Chenglin

2003, 54(2): 204-208.

Abstract ( 719 )

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On-line optimizing control of FCCU has been considered as a very important work.Although there have been so many studies on this topic but the practical application results are not so ideal.This is due to essentially that the process is very complicated so there exist some key input variables which affect the reaction and cannot be measured on-line.This is the bottleneck of optimization.

This paper discusses the problem of on-line observation of unmeasurable variables in nonlinear systems such as FCCU.Based on the theory of nonlinear observers, a simplified sufficient conditon under certain conditons is presented to confirm the observability of the unmeasurable inputs in these systems.Based on it, the observable condition for the unmeasurable inputs in the riser of FCCU is discussed and a more available on-line observation method for these variables is put forward.Simulation results and industrial running results are also given.

PREPARATION AND ANTITUMOR EFFECT OF DRUG DELIVERY SYSTEM OF TAXOL CONJUGATED TO POLYETHYLENE GLYCOL

FENG Xia, LIANG Shile, LI Xiaofeng, YUAN Yingjin

2003, 54(2): 209-214.

Abstract ( 816 )

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A novel drug delivery system (DDS) of taxol was developed by linking taxol to a water-soluble polymer——polyethylene glycol (PEG) through amino acid spacer. Solubility of the DDS and content of taxol in them were determined. Their antitumor activity were evaluated against two human tumor cell lines: MCF-7 and PG. It was found that the DDS were more soluble in water than taxol and had similar cytotoxicity compared with the latter.In this way, a new kind of DDS of taxol with improved water-solubility and potential antitumor activity was well established.

EFFECT OF ADSORPTION DENSITY ON PORE DIFFUSIVITY OF PROTEINS IN ION EXCHANGER

CHEN Weidong, SUN Yan

2003, 54(2): 215-220.

Abstract ( 659 )

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The ion-exchange adsorption kinetics of bovine serum albumin (BSA) and γ-globulin into an anion exchanger,DEAE-Spherodex M, has been studied by batch adsorption experiments.The pore diffusion model was used to predict pore diffusivity.The effect of initial protein concentration and average adsorption density on pore diffusivity was investigated.The results showed that pore diffusivity decreased exponentially with increasing initial protein concentration and average adsorption density. Moreover, the larger the dimension of the protein, the greater the decline of pore diffusivity was observed.

OXIDATION AND ADSORPTION OF CATECHOL WITH POLYPHENOL OXIDASE-CELITE COUPLED SYSTEM IN AQUEOUS MEDIA

LIU Lin, SHI Zhengce, WANG Quan, JIN Jiangnan, FAN Yun

2003, 54(2): 221-225.

Abstract ( 846 )

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The oxidation/adsorption properties of polyphenol oxidase（PPO）-celite coupled system in the separation of catechol from aqueous media containing anisole were studied.The enzyme showed exclusive substrate selectivity for catechol oxidation.Celite adsorbed the enzyme-generated products subsequently.The coexisting anisole presented no undesirable influence on the reaction.This phenomenon indicated that the coupled system enhanced the elimiation process of catechol.PPO can be easily separated from aqueous media.The half-life of the enzyme increased about 2.4 folds and the corresponding adsorption efficience could be as high as 98.76 %.

FLUORIDE EMISSION CONTROL BY BLENDING AND INJECTING CaO AND CALCIUM-BASED SORBENTS DURING COAL COMBUSTION

QI Qingjie, LIU Jianzhong, ZHOU Junhu, CAO Xinyu, CHENG Jun, ZHANG Shuxin, CEN Kefa

2003, 54(2): 226-231.

Abstract ( 654 )

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The experimental and theoretical analysis about toxic fluoride removal during coal combustion are reported in this paper.It has been identified that CaO can restrain the emission of fluoride and fluoride retention ratios are between 12.2% and 61.0%, with mean value 39.5% by blending CaO with coal during coal combustion in tubular furnace at 900 ℃. Influence factors on fluoride retention by blending CaO with coal are studied such as type of coals, combustion temperature,retention time and Ca/S molar ratio.The optimum conditions for fluoride retention by blending CaO with coal are that combustion temperature in the range 800 to 1000 ℃,retention time between 5—10 min and Ca/S ratio in the range 2.5 to 3.0. In chain-grate furnace combustion of coal, fluoride retention ratios are about 54.0%—64.8% with mean value 59.3% by blending calcium-based sorbents with coal and are about 72.5%—80.5% with mean value 75.5% by blending calcium-based sorbents with coal accompanied by injection of calcium-based sorbents.

GAS SENSOR OF FUEL CELL TYPE BASED ON PROTON CONDUCTOR

CHEN Aifan, CUI Meisheng, BAI Shouli, ZHANG Maihong, LUO Ruixian, WANG Dao, LIU Chungchiun

2003, 54(2): 232-236.

Abstract ( 540 )

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In recent years, considerable attention has been paid to the research and development of chemical sensors based on solid proton conductor electrolytes.Some proton conductors such as solid polymer membrane,zirconium phosphate, antimonic acid and so on, kept relatively high ionic conductivity even at room temperature. In this paper,this type proton conductor sensors for detecting combustible gases of H₂,CO and C₂H₄ at room temperature were fabricated and studied. We here described their structures, sensing mechanisms and performances. The effects of the temperature, humidity, catalytic electrode materials and preparation method of composite electrode on the sensor response were also discussed.These sensors will be extensively applied to the petrochemical industry,environmental protection and daily life.

HEAT RESISTANCE AND HIGH-TEMPERATURE OXIDATION RESISTANCE OF Ni-W GRADIENT DEPOSIT WITH NANOSTRUCTURE

WANG Hongzhi, YAO Suwei, ZHANG Weiguo

2003, 54(2): 237-240.

Abstract ( 635 )

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This paper studied the heat resistance and high-temperature oxidation resistance of Ni-W gradient deposit with nanostructure. Experiments results indicated that the Ni-W gradient deposit still kept original structure after heat treatment at 400℃, and the hardness of the deposit was as high as Hv 1300,better than the hard Chromium deposit. XRD test shows that the structure of the Ni-W gradient deposit has changed from a displacement solid solution made up of solvent Ni and solute W to a polycrystal structure made up of Ni and W after heat treatment at 600℃. Also, the W content remained the gradient distribution in the deposit. Furthermore, the Ni-W gradient deposit had good high-temperature oxidation resistance, suitable for the high-temperature oxidation circumstances.

DEVELOPMENT AND APPLICATION ON FIBER-OPTIC OXYGEN SENSOR

SHEN Huifang, ZHANG Mingquan, ZHANG Yanhong, CHEN Huanqin

2003, 54(2): 241-245.

Abstract ( 683 )

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Some metallorganic complexes can emit fluorescence or phosphorescence when excited by light with suitable wavelength. Usually, the fluorescence and phosphorescence can be quenched by oxygen. 13 kinds of metallorganic complexes were synthesized. Two kinds of them, namely ［Ru(bathophen)₃］(ClO₄)₂ and Pt(TFPP) were selected as oxygen-sensing indicators for excellent characters.Optimal technology for preparation of oxygen-sensing films with high sensitivity, rapid response and excellent photostability was developed.The influence factors of the sensor are discussed. A non-contact fiber-optic oxygen sensor was developed by using ［Ru(bathophen)₃］(ClO₄)₂-Cab-O-Sil-silicone film. The non-contact design makes it possible to monitor a number of samples by scanning in a short time under the control of computer.Furthermore, the sensor was applied in biological toxicity tests.The effects of some heavy metal ions on activated sludge and E.coli were tested with the oxygen sensor. It is feasible to conduct the toxicity test by empolying the oxygen sensor. It has unique advantages in sensitivity and efficiency.

NEW UNIFAC GROUP-INTERACTION PARAMETERS OF N-FORMYLMORPHOLINE

ZHAO Quanyu, ZHENG Ying’e , ZHAO Weipeng

2003, 54(2): 246-249.

Abstract ( 879 )

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There are limited Vapor-Liquid Equilibrium(VLE) data including N-formylmorpholine(NFM) for the design of the extractive distillation process using NFM as solvent.The new interaction parameters of UNIFAC model were fitted with experimental data between CH₂，ACH and NFM which was regarded as a main group.Comparison of the prediction results of VLE data and infinite dilution activity coefficients with other published methods of group division for NFM, indicated more satisfying results with the interaction parameters of this paper. The four methods of group division for NFM were discussed based on the group division for ring molecule and group charge distribution. The group charge distribution at the minimum energy state was calculated by the AM1 method in Chem3D Pro. The good theoretical basis was presented for the group division of NFM.

DPIV EXPERIMENTAL STUDY OF SQUARE JET INTO CROSSFLOW

WU Hailing, CHEN Tingkuan, LUO Yushan, GONG Wuqi

2003, 54(2): 250-254.

Abstract ( 654 )

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Digital particle imaging velocimetry (DPIV) was used to measure the transient and time-averaged flow field in the mixing region and the wake of a square jet into crossflow at jet-to-crossflow velocity ratio (VR) of 0.5 and 2. The phenomenon of vortex instantaneously shedding from the jet hole was investigated, and the flow turbulence intensity was estimated. The complex vortical structures encountered at VR of 2 were analyzed. Compulsively oppressed by the main flow, the jet attached to the wall at VR of 0.5, and lifted off the wall to develope into the main flow at VR of 2. The twisted vortices in the leeward of jet contributed to the transportation of the crossflow boundary-layer fluid into the near wake, causing intensive turbulence. Strong vortices formed near the jet hole soon broke down and dissipated, yet the weak counter-vortex pair still held in the far wake.

SELECTIVE REMOVAL OF NITROGEN-CONTAINING COMPOUNDS FROM LUBE OIL BASE STOCKS USING HETEROPOLY ACID

XIE Ying, BAO Xiaojun, LIU Hongtao, WEI Weisheng, SHI Gang

2003, 54(2): 255-258.

Abstract ( 759 )

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By using heteropoly acid/acetone system as chemical extractant, a novel process was developed to selectively remove nitrogen-containing compounds from lubricating oil base stocks. The results showed that the process could effectively reduce the content of nitrogen-containing compounds and thus greatly increase the anti-oxidative stability of the lubricating oil base stocks, without significantly lowering sulfur content and affecting other physical and chemical properties of the refined base stocks. This work may provide an alternative way for denitrification of lubricating oil base stocks.

GLYCEROL PRODUCTION BY BATCH AND CONTINUOUS FERMENTATION WITH NaCl AS OSMO-REGULATOR

LIU Yongqiang, LIU Dehua, SU Qiong

2003, 54(2): 259-263.

Abstract ( 881 )

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Adding sodium chloride into a medium containing 140g·L^-1 glucose could promote the glycerol accumulation efficiently, but the glycerol productivity would decrease when sodium chloride concentration was above 40g·L^-1.Experimental results in shake flask showed that sodium chloride concentration of 40g·L^-1 was favorable.Moreover, the feasibility of multi-stage cascade continuous fermentation was tested and the results indicated that multi-stage continuous system was superior to single-stage continuous fermentation.Compared with batch fermentation,the glycerol concentration and the glycerol yield in multi-stage cascade continuous system decreased by only 9.83 % and 5.71 % respectively, but the glycerol productivity increased by 18.54% even the preparing time between two batch fermentation was not considered.

L-ASPARAGINASE RELEASE FROM Escherichia coli CELLS WITH AQUEOUS TWO-PHASE SYSTEM

YU Jiaye, ZHAO Fengsheng

2003, 54(2): 264-268.

Abstract ( 629 )

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A method to release L-asparaginase(EC3.5.1.1) from Escherichia coli ATCC 11303 cells using an aqueous two-phase system was proposed. The system was composed of K₂HPO₄ and polyoxyethylene octyl phenyl ether (POOPE). This method combined enzyme release with enzyme purification.The influences of POOPE concentration, K₂HPO₄ concentration,E. coli cell concentration,pH and treatment time on the release of L-asparaginase were investigated.Under suitable conditions,over 90% of L-asparaginase in cells was released into surrounding medium.Electron micrography indicated that the chemical treatment altered the inner structure of E.coli cells significantly.

RELATIONSHIP BETWEEN VOLATILE YIELD AND PETROGRAPHIC ANALYSIS DURING PYROLYSIS OF SHENMU MACERALS

SUN Qinglei, LI Wen, LI Baoqing

2003, 54(2): 269-272.

Abstract ( 582 )

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The mass loss in pyrolysis of macerals from Shenmu coal was systematically investigated by using TG-151 pressurized thermobalance at different final temperatures and heating rates.The volatile yield was related to petrographic composition.The results of ΔW,the difference of coal volatile yields between experimental and theoretical ones, indicated that vitrinite and inertinite had significant synergistic effect during pyrolysis. With increasing temperature, the synergism of vitrinite and inertinite during pyrolysis increased.The heating rate had different effect on the synergism which depended on the final temperature.

MICROSTRUCTURAL CHARACTERISTICS OF SHELL AND LIMESTONE AS BURNING COAL SULFUR SORBENT

LU Chunmei, ZHAO Jianli, HAN Kuihua

2003, 54(2): 273-276.

Abstract ( 593 )

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The microstructure of the raw,calcined,and desulfurized samples of shell and limestone was detected and analyzed by SEM.Their ability of capturing SO₂ was verified by using LCT-2 thermobalance and the high temperature tube reactor.The results showed that the better pore structure and smaller gas diffusion resistance of shell were in favor of the inner reaction for SO₂ gas.Shell had higher calcium utilization ratio than that of limestone especially under the conditions of high reaction temperature and the increased reaction time.The bigger difference of the inner structure was found in the reaction of sulfation after calcination and direct sulfation.In direct sulfation, the reaction was restrained because of the bad pore connectivity, while the former reaction took place with good pore connectivity.

RELATIONSHIP BETWEEN QUANTITATIVE STRUCTURE AND BIODEGRADABILITY OF QUATERNARY CATIONICS

CHEN Shenghui, JIN Xiaohong, LI Suyue

2003, 54(2): 277-279.

Abstract ( 550 )

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A remarkable relationship between the biodegradability and their quantitative structure of quaternary cationic surfactants was found using the term of topologic index.A model equation related the degradability and molecular connection index was established by the regression analysis,which showed excellent complex related coefficient (R>0.97), standard deviation (E₀=13.7910) and average standard deviation (D=0.0432).

The values calculated by using above equation were in good agree with the values reported in literature for biodegradability of quaternary cationic surfactants.It indicated that the equation was reliable and was a new method for evaluation of biodegradability of quaternary cationic surfactants.