JOURNAL OF CHEMICAL ENGINEERING OF JAPAN
Print ISSN : 0021-9592
Volume 39 , Issue 12
Showing 1-11 articles out of 11 articles from the selected issue
Physical Properties and Physical Chemistry
Transport Phenomena and Fluid Engineering
  • Akanksha , Kamal Kishore Pant, Pulak Mohan Pandey, Vinod Kumar Srivast ...
    Type: Research Paper
    2006 Volume 39 Issue 12 Pages 1229-1236
    Published: 2006
    Released: December 20, 2006
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    A mathematical model was developed for the absorption of gas in liquid considering diffusion and a reaction of a gas through a non-isothermal, exothermic, irreversible first order reaction. The model consists of a set of coupled partial differential equations for heat and mass transfer, which were solved using a finite-difference backward implicit scheme. Parameters like the Thiele modulus, the Arrhenius factor and the Biot number for mass transfer of different kinetic mechanisms were optimized using a genetic algorithm. The utility of this model is illustrated by applying it to the absorption of chlorine gas into n-decane solution. A comparison of this model with literature has also been done.
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  • Stoyan Nedeltchev, Uwe Jordan, Adrian Schumpe
    Type: Research Paper
    2006 Volume 39 Issue 12 Pages 1237-1242
    Published: 2006
    Released: December 20, 2006
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    The volumetric liquid-side mass transfer coefficients kLa in 1-butanol, toluene, ethanol and tap water were used in order to show that, when the classical penetration theory is applied to ellipsoidal bubbles, it needs to be corrected. The kLa data were obtained in a 0.102 m diameter bubble column operated in the homogeneous flow regime at pressures varied from 0.1 to 1.0 MPa. The new correction factor (lower than unity) was correlated with the dimensionless Eötvös number, Eo (gravitational force to surface tension force ratio). The kLa data (32 points) are fitted with a mean error of 8.2%.
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  • Chii-Dong Ho, Jiun-Jiau Fu, Jr-Wei Tu
    Type: Research Paper
    2006 Volume 39 Issue 12 Pages 1243-1254
    Published: 2006
    Released: December 20, 2006
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    A permeable barrier was inserted to divide an open duct into two subchannels of uniform wall fluxes for conducting double-pass laminar countercurrent operations. The mass transfer rate of such a double-pass device was substantially improved and has been investigated theoretically by using an eigenfunction expansion in power series.
    The theoretical predictions of mass-transfer efficiency enhancement in double-pass parallel-plate mass exchangers were represented graphically and compared with those in an open duct of single-pass operation (without a permeable barrier inserted). The results show that the double-pass operation can effectively enhance the mass transfer efficiency and especially when the permeable-barrier position is appropriately adjusted.
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  • Masaya Shigeta, Nobuhiko Atsuchi, Takayuki Watanabe
    Type: Research Paper
    2006 Volume 39 Issue 12 Pages 1255-1264
    Published: 2006
    Released: December 20, 2006
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    Effective generation of chemical reactive species in thermal plasmas has been required in the field of material processing and waste treatment. The effect of oxygen injection into argon induction plasmas was investigated by numerical analysis without chemical equilibrium assumptions. Reaction kinetics rates of the dissociation and recombination of oxygen as well as the ionization were taken into account. The transport properties were estimated using higher-order approximation of the Chapman–Enskog method for required accuracy. Oxygen dissociation and heat flux to a torch wall can be controlled by oxygen injection location. Therefore, suitable oxygen injection needs to be chosen according to the application requirement. The present modeling would give more precise information and provide the guidance for the rational design of new material processing with effective reactive gas injection into plasmas.
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Separation Engineering
  • Aynur Senol
    Type: Research Paper
    2006 Volume 39 Issue 12 Pages 1265-1275
    Published: 2006
    Released: December 20, 2006
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    This study deals with the performance of a randomly packed distillation column depending on the effective vapor–liquid interfacial area (ae) and the flood ratio (Fl). Optimum conditions have been interpreted analytically using the proposed ae model for random packings and the flood ratio (Fl) from the Eckert model. Capacity and efficiency data obtained for a Raschig-type ceramic ring are used to establish the basis to the model reliability in terms of a statistical log-ratio objective function. An example of scaling-up of a pilot plant with respect to the resulting statistical factors is elucidated. Some aspects of selection of an appropriate packed column design algorithm are discussed.
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  • Hideya Kamikawa, Keita Hibi, Kensaku Mizoguchi, Shigetoshi Matsui, Ken ...
    Type: Research Paper
    2006 Volume 39 Issue 12 Pages 1276-1282
    Published: 2006
    Released: December 20, 2006
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    The purpose of this study was to improve the adsorption ability of activated carbon for removal of trihalomethanes (THMs) to design a small and efficient water purifier. The phenol activated carbon with the high adsorption ability to THMs was used in the experiment. To improve the adsorption ability of the activated carbon, the effect of heat treatment temperature under the nitrogen atmosphere was investigated. The effect of the heat treatment temperature was evaluated from the chloroform adsorption isotherm, and the amount of purified water containing THMs. First of all, phenol resin was carbonized at 600°C for 3 h, and was activated by steaming at 900°C. Activation time was 0.5, 1.0, and 2.5 h. Next, the heat treatment was carried out for the sample of 1.0 h activation with the highest adsorption ability. The heat treatment temperature was 450, 600, 750, and 900°C. The heat treatment time was fixed at 3 h for all samples. As a result, it was found that the adsorption ability of the phenol activated carbon to THMs raised by about 1.6 times with the heat treatment at 750°C following the activation. On the other hand, the influence of the heat treatment on the structure of the phenol activated carbon was investigated. The structure was analyzed with pore size distribution measurement, X-ray photoelectron spectroscopy (XPS), temperature programmed desorption mass spectrometry (TPD-MS), and field emission-type scanning electron microscope (FE-SEM). The elimination of functional groups were observed clearly with the heat treatment, which means increased hydrophobicity of pore surface in the phenol activated carbon. Moreover, enlargement of the pore entrance were confirmed. Therefore, we concluded that THMs were efficiently led into pores due to the enlarged pore entrance, and was adsorbed strongly due to the increased hydrophobicity.
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  • Che-Chia Hu, Shih-Yu Wang, Chia-Ling Li, Ching-Jung Chuang, Kuo-Lun Tu ...
    Type: Research Paper
    2006 Volume 39 Issue 12 Pages 1283-1290
    Published: 2006
    Released: December 20, 2006
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    Adsorption crossflow filtration is a technique that combines the advantages of membrane filtration and chromatography, both widely used to separate and purify the protein mixture in bioseparation processes. Ion exchange adsorption coupled with crossflow filtration for enhancing bovine serum albumin (BSA), ovalbumin (OV) and lysozyme (LY) separation were conducted experimentally in this study. The DEAE Sepharose, diethylaminoethyl weak anion exchange gel particle, was used to examine adsorption behavior under different solution conditions. Protein recovery, purity and transmission during the adsorption crossflow filtration process were analyzed based on the condition of an optimal pH value and ionic strength obtained in the adsorption test. The experimental results reveal that the hydrophilicity difference between BSA and OV leads to different adsorption behaviors at optimal separation conditions of phosphate buffer of pH 9.0 and the ionic concentration 20 mM. As ionic strength in the solution increases, compression of an electrical double layer and electrostatic shielding result in decreasing BSA and OV adsorption capacity. Adsorption operation consistently shows a lower LY capacity since LY and the gel particle have the same charged polarity at the optimal value of the pH 9.0. A two-stage adsorption crossflow filtration process is proposed and examined for protein purification under optimal conditions obtained in the purification of a binary protein mixture solution. Comparison of the experimental results obtained in the two-stage adsorption crossflow filtration in our previous work by crossflow ultrafiltration indicated that adsorption crossflow filtration provides higher efficiency and recovery for protein purification.
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Chemical Reaction Engineering
  • Jin-Mok Hur, Sun-Seok Hong, Chung-Seok Seo
    Type: Research Paper
    2006 Volume 39 Issue 12 Pages 1291-1295
    Published: 2006
    Released: December 20, 2006
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    The electrochemical reduction of spent nuclear fuel in LiCl–Li2O molten salt for the conditioning of spent nuclear fuel requires the separation of the residual salts from a reduced metal product after the reduction process. Considering the behavior of spent nuclear fuel during the electrochemical reduction process, a surrogate material matrix was constructed and inactive tests on a salt separation were carried out to produce the data required for active tests. Fresh uranium metal prepared from the electrochemical reduction of U3O8 powder was used as the surrogates of the spent nuclear fuel components which might be metallized by the electrochemical reduction process. LiCl, Li2O, Y2O3 and SrCl2 were selected as the components of the residual salts. Interactions between the salts and their influence on the separation of the residual salts were analyzed by differential scanning calorimetry (DSC) and thermogravimetry (TG). Eutectic melting of LiCl–Li2O and LiCl–SrCl2 led to a melting point which was lower than that of the LiCl molten salt was observed. Residual salts were separated by a vaporization method. Co-vaporization of LiCl–Li2O and LiCl–SrCl2 was achieved below the temperatures which could make the uranium metal oxidation by Li2O possible. The salt vaporization rates at 950°C were measured as follows: LiCl–8 wt% Li2O > LiCl > LiCl–8 wt% SrCl2 > SrCl2.
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Biochemical, Food and Medical Engineering
  • Hiroshi Ito, Kentaro Takayanagi, Mina Okochi, Mitsuhiro Shikida, Kazuo ...
    Type: Short Communication
    2006 Volume 39 Issue 12 Pages 1296-1299
    Published: 2006
    Released: December 20, 2006
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    A miniaturized chemical-analysis system based on magnetic beads-droplet-handling mechanism without pumps and valves was developed for analysis. The analysis system has possibility for the development of a portable analysis device since there is no complicated mechanical component. In this report, we constructed an analysis system with 8 wells connected by channels. Magnetic beads with a diameter of 22.0 μm were used as a mobile phase. We demonstrated the detection of biotin-labeled DNA oligomers using this system. The result showed that this detection system has specificity and dependence of the signal on the target DNA concentration.
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Energy
  • Yukihiko Matsumura, Daisuke Shigenobu, Yoshito Oshima
    Type: Short Communication
    2006 Volume 39 Issue 12 Pages 1300-1302
    Published: 2006
    Released: December 20, 2006
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    To determine the capability of formic acid as a hydrogenating agent in supercritical water, we conducted hydrogenation of acetone using formic acid. It was found that the formic acid enabled hydrogenation of acetone to produce 2-propanol. We varied the concentration of formic acid available for hydrogenation by changing the retention time in the formic-acid preheater, prior to mixing with acetone. The highest yield of 2-propanol occurred when the concentration of formic acid was a maximum. The yield decreased with thermal decomposition of the formic acid, as the retention time in the preheater was increased. However, an unexpected and rapid increase in the 2-propanol yield was observed when the retention time in the preheater was further increased. We theorize that the hydrogenating agent responsible for this phenomenon is closely related with the presence of carbon monoxide although further work is required to elucidate the mechanism.
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