JOURNAL OF CHEMICAL ENGINEERING OF JAPAN
Online ISSN : 1881-1299
Print ISSN : 0021-9592
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Volume 31, Issue 3
Displaying 1-28 of 28 articles from this issue
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Thermodynamics, Physical Properties and Molecular Simulation
  • Measurements of Henry’s Constants for Hydrocarbon Vapors in Polystyrene and Poly(Phenylene Sulfide) Powders by Gas Chromatography
    Iwao Akiba, Hirokatsu Masuoka
    1998 Volume 31 Issue 3 Pages 313-319
    Published: 1998
    Released on J-STAGE: April 26, 2004
    DOIhttps://doi.org/10.1252/jcej.31.313
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    Henry’s constants have been obtained for ethylbenzene in polystyrene in the region from 373.2 to 523.2 K, and for ten nonpolar hydrocarbon vapors in molten poly(phenylene sulfide) in the region of 563.2 to 593.2 K under atmospheric pressure by using a gas chromatography method. Columns were packed with physical mixtures of GC support and polymer powders. As the particle size increased, the flow rate effect was diminished and experimental results coincided with those obtained by the coating method. For the case of poly(phenylene sulfide) with an average particle size of 30 μm, values of specific retention volume for all substances were independent of the flow rate at the temperatures above the polymer melting point and good results could be obtained. Experimental Henry’s constants of nonpolar hydrocarbons in molten poly(phenylene sulfide) could be correlated with a relationship for molten polyethylene and polyisobutylene.
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Transport Phenomena, Fluid Mechanics and Mixing
  • The Effects of Surfactant on the Mass Transfer in Extraction Column
    Yuh-Lang Lee, Jer-Ru Maa, Yu-Min Yang
    1998 Volume 31 Issue 3 Pages 340-346
    Published: 1998
    Released on J-STAGE: April 26, 2004
    DOIhttps://doi.org/10.1252/jcej.31.340
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    A single-drop extraction apparatus was used to investigate the dependency of mass transfer coefficient on the amount of surfactant added. The mass transfer rate during drop formation and falling period, as well as the overall mass transfer coefficient were studied. The theory of dynamic surface effect was used to explain these phenomena. The results show that the mass transfer resistance increases with the added amount of SLS when the surfactant concentration is below 20 ppm. If the concentration is higher than this value, the resistance becomes constant. The mass transfer during drop formation plays an important part on the overall mass transfer efficiency and will be significantly affected by the presence of surfactant. According to this study, it is more appropriate to explain the mass transfer resistance induced by the surfactant from the viewpoint of hydrodynamics, rather than from the model of barrier layer.
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  • Estimation of Surface Diffusion Coefficient in Reversed-Phase Liquid Chromatography Using Methanol/Water Mobile Phases
    Kanji Miyabe, Shigeya Takeuchi, Yoshisato Tezuka
    1998 Volume 31 Issue 3 Pages 347-354
    Published: 1998
    Released on J-STAGE: April 26, 2004
    DOIhttps://doi.org/10.1252/jcej.31.347
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    An estimation procedure for the surface diffusion coefficient (Ds) is proposed for a reversed-phase liquid chromatographic system using an octadecylsilyl-silica gel and methanol/water mixtures. The procedure is based on a restricted molecular diffusion model for surface diffusion, in which Ds is correlated with molecular diffusivity by introducing restriction energy (Er) due to an adsorptive interaction between adsorbates and adsorbents. The ratio of Er to isosteric heat of adsorption (Qst) is linearly correlated with 1/(–Qst). It is indicated that the linear correlation between γ (=Er/(–Qst)) and 1/(–Qst) can be observed when a linear free-energy relation and an enthalpy-entropy compensation effect in adsorption equilibrium are established. Though both Er and γ are empirical parameters, Ds at given temperatures and mobile phase compositions can be consistently calculated with an error less than about 20% from only one datum of adsorption equilibrium constant.
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  • Development and Evaluation of Large-Scale Impeller Generating Strong Circulation Flow Suitable for Wide Viscosity Range in Reactor with Cooling Coil
    Kazumi Yamamoto, Katumi Abe, Atushi Tarumoto, Kazuhiko Nishi, Meguru K ...
    1998 Volume 31 Issue 3 Pages 355-365
    Published: 1998
    Released on J-STAGE: April 26, 2004
    DOIhttps://doi.org/10.1252/jcej.31.355
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    For radical addition polymerization, the viscosity of the fluid rapidly increases with increasing conversion. In such a polymerization, one of the most important characteristics is to mix the entire fluid in the reactor and rapidly remove the reaction heat. For this purpose, we made a large-scale impeller (called an experimental impeller hereafter) which is a combination of a paddle impeller for low viscosity and a half ellipse impeller for high viscosity with the purpose of using it for the wide viscosity range that occurs during polymerization. The effectiveness of the experimental impeller is compared with a multistage pitched blade turbine, anchor impeller, helical screw impeller and helical ribbon impeller based on circulation time, power characteristics, mixing time and mixing efficiency. Actual radical addition polymerization was performed using these impellers. Each impeller is evaluated by comparing the uneven temperature distribution generated in the reactor equipped with the coil and the physical properties of the produced polymer. Furthermore, the change in the heat transfer coefficient of the cooling coil, which is related to the fluid flow, was measured during polymerization using the experimental impeller, a helical screw impeller and a multistage pitched paddle turbine.
    As a result, it is clarified that this experimental impeller generates strong axial circulation in the polymerization field, so that even with a large change in the viscosity range, polymerization is steadily performed.
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  • A Method for Measuring Bubble Diameter Distribution in Gas-Liquid Agitated Vessel under High Gas Hold-Up Using Real-Time High-Speed Image Processing System
    Mitsuo Kamiwano, Meguru Kaminoyama, Kazihiko Nishi, Daigo Shirota
    1998 Volume 31 Issue 3 Pages 366-373
    Published: 1998
    Released on J-STAGE: April 26, 2004
    DOIhttps://doi.org/10.1252/jcej.31.366
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    For an improved understanding of the gas-liquid contact system in an agitated vessel, it is very important to accumulate data about the bubble size distribution and interfacial area at all locations in the vessel. In this study, an advanced method is proposed for measuring the bubble volume and diameter equivalent to a sphere under high gas hold-up conditions based on the suction probe technique. This technique withdraws liquid containing bubbles from the vessel to the outside. It has already been elucidated in past studies by Greaves et al. The real-time high-speed image processing system, which was originally developed by the authors, is utilized as the measuring technique. It enables visualizing the entire image of a bubble distributed from about 30 μm to 10 mm. Because this method can use a sampling tube with a diameter larger than that in conventional methods, it can be applied to viscous liquids and allows selection of sampling conditions without breaking the bubble during its flow in the tube, in contrast to conventional methods. The measured bubble diameter distribution data, specific surface area in various liquids, and examples of the relation between the conditions of agitation and the characteristics of the bubbles are presented. Using this method, quantitative information on bubbles in an aerated vessel with agitation is very accurate and is obtained in a very short time.
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  • Maximum Spreading of Liquid Droplets Colliding with Flat Surfaces
    Jun Fukai, Mitsuru Tanaka, Osamu Miyatake
    1998 Volume 31 Issue 3 Pages 456-461
    Published: 1998
    Released on J-STAGE: April 26, 2004
    DOIhttps://doi.org/10.1252/jcej.31.456
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    The deformation of a spherical liquid droplet colliding with a flat surface is numerically simulated in the range of Weber numbers from 10 to 103 and Reynolds numbers from 102 to 104. The maximum spreading diameter and the time required for the droplet to reach the maximum are correlated with the dimensionless groups and the dynamic contact angle. From a comparison between the developed models and experiments where the values of the dynamic contact angles are known, the models predict well the experimental results with respect to the dynamic contact angle. The models predict the experimental results from several published reports within 13% over the wide ranges of 5 < We < 2720 and 20 < Re < 2900. The prediction error of the present model for the maximum spreading diameter is smaller than those of previous models.
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Catalysis, Kinetics and Reactor Design
  • Characteristics of Chemical Heat Pump through Kinetic Analysis of Paraldehyde Depolymerization
    Haruo Kawasaki, Atsushi Kanzawa, Takayuki Watanabe
    1998 Volume 31 Issue 3 Pages 374-380
    Published: 1998
    Released on J-STAGE: April 26, 2004
    DOIhttps://doi.org/10.1252/jcej.31.374
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    The paraldehyde/acetaldehyde (Pa/A) chemical heat pump is used as a cooling system. The present study investigates depolymerization of paraldehyde for a chemical heat pump cycle. The depolymerization rate of paraldehyde was measured in a range from 286 K to 303 K on an acid resin catalyst (Amberlyst 15E). The rate determining step of the depolymerization is the paraldehyde ring-opening step on the catalyt. The depolymerization rate equation on the solid catalyst is described by the Langmuir-Hinshelwood kinetic model. The cooling rate of the Pa/A system at 286 K is estimated from the reaction rate equation. The cooling rate is 10 kW per unit catalyst-weight and higher than other CHPs. The coefficient of performance of the Pa/A system is 6.3.
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  • Dehydrogenation of 2-Propanol in Reactive Distillation Column for Chemical Heat Pump
    Pag-Asa D. Gaspillo, Leonila C. Abella, Shigeo Goto
    1998 Volume 31 Issue 3 Pages 440-444
    Published: 1998
    Released on J-STAGE: April 26, 2004
    DOIhttps://doi.org/10.1252/jcej.31.440
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    The system of 2-propanol-acetone-hydrogen can be effectively utilized as a chemical heat pump cycle. This research focuses on an important part of the cycle, specifically the liquid-phase dehydrogenation of 2-propanol to produce acetone and hydrogen at low temperatures under boiling conditions. As preliminary experiments, the reaction rate in the vapor phase was measured in a fixed-bed reactor filled with Ru-Pd/C catalyst which had high selectivity and activity for dehydrogenation. The conversion was limited by the equilibrium (0.108 at 90°C). Next, since the product acetone is known to be a strong inhibitor in the dehydrogenation, a reactive distillation column was used to separate acetone from the reaction field. Acetone (b.p. 56.3°C) is vaporized as the top product ahead of 2-propanol (b.p. 82.4°C). The hydrogen produced remains in the gas phase throughout the operation. The use of reactive distillation, which is a pioneering idea for this chemical heat pump, can facilitate complete conversion of the dehydrogenation. Pure acetone can be obtained for the specified conditions (less than 0.04 mmol/s of feed flow rate). The conversion was greatly affected by the feed flow rate, the temperature of the heat source, and the reflux ratio. The reaction rate is independent of the mole fraction of acetone in the feed. The proposed reactive distillation may be promising for a chemical heat pump.
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Materials and Devices
  • Thiol-Mediated Immobilization of Photocatalytic Metal Sulfide Ultrafine Particles Formed in Reverse Micellar Systems in Polythiourethane
    Susumu Shiojiri, Masanori Miyamoto, Takayuki Hirai, Isao Komasawa
    1998 Volume 31 Issue 3 Pages 425-433
    Published: 1998
    Released on J-STAGE: April 26, 2004
    DOIhttps://doi.org/10.1252/jcej.31.425
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    A method for immobilization of metal sulfide ultrafine particles formed in reverse micellar systems in polythiourethane via bonding of the thiol groups to a metal sulfide surface is investigated. CdS or CdS-ZnS coprecipitated ultrafine particles-polythiourethane composites (CdS-PTU and CdZnS-PTU) were prepared by polymerization (polyaddition) of xylene-α, α′-dithiols and hexamethylene diisocyanate in the presence of the metal sulfide ultrafine particles formed in a reverse micellar system and then surface-modified with thiophenol. The immobilized metal sulfide particles in the PTU composites are able to be characterized spectrophotometrically by measuring the scattered light from dispersions of the composites and found to show a quantum size effect. The particle exposed fraction, F, is defined as the ratio of the quantity of Cd or Zn dissolved from the composites by HCl to the quantity of the metal dissolved by concentrated H2SO4 (total analysis). The value of F can be controlled by the quantities of the monomers, and also by the value of Wo (=[H2O]/[AOT]) of the original reverse micellar system. The PTU composites were applied to photocatalytic H2 generation from aqueous solution of 2-propanol. They showed improved stability against photodegradation compared with the thiophenol-modified CdS particles before immobilization. The value of F seems to show the fraction of the metal sulfide particles effective for the photocatalytic reaction, and the photocatalytic activities of the PTU composites are possibly evaluated by using the quantity of H2 generated per unit quantity of the exposed metal sulfide particles.
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  • Preparation of Rare Earth Oxalate Ultrafine Particles in Emulsion Liquid Membrane System Using Carboxylic Acid as Cation Carrier
    Takayuki Hirai, Norihiko Okamoto, Isao Komasawa
    1998 Volume 31 Issue 3 Pages 474-477
    Published: 1998
    Released on J-STAGE: April 26, 2004
    DOIhttps://doi.org/10.1252/jcej.31.474
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    The preparation of oxalate particles of Y and Pr is carried out by using an emulsion liquid membrane (ELM, W/O/W emulsion) system, consisting of Span 83 (sorbitan sesquioleate) as a surfactant and VA-10 (2-methyl-2-ethyl heptanoic acid) as an extractant (cation carrier). The rare earth ions are extracted from the external water phase and are stripped into the internal water phase to precipitate by the reaction with oxalic acid. Oxalate particles, 20–60 nm in size, are obtained for both rare earth elements, together with a smaller amount of submicron-sized spherical aggregates. This result is rather different from that obtained in the ELM system employing EHPNA (2-ethylhexylphosphonic acid mono-2-ethylhexyl ester) as an extractant, where oxalate particles of heavier rare earths such as Y are hardly obtained. Calcination of the resulting particles easily gives Y2O3 particles of about 50 nm in size and Pr6O11 particles of submicron-size.
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Separations
  • Copper Removal from Dilute Aqueous Solution by Extraction with Counter-Current Multi-Stage Column
    Koji Tani, Tomoaki Ohta, Susumu Nii, Katsuroku Takahashi
    1998 Volume 31 Issue 3 Pages 398-406
    Published: 1998
    Released on J-STAGE: April 26, 2004
    DOIhttps://doi.org/10.1252/jcej.31.398
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    Copper was extracted by LIX84I-Shellsol 71 solution from a dilute aqueous solution with a five-stage mixer-settler extraction column. The effective removal of copper could be achieved by extraction with the multi-stage extraction column. The reaction rate of copper extraction by LIX84I was measured with a flat interface stirred vessel, and the rate is found to increase significantly by purification of the extractant. Simulation of the multi-stage counter-current extraction was carried out using the specific interfacial area determined from the dispersed phase holdup and the dispersed drop size. The mass transfer coefficients in the continuous and dispersed phases are estimated on the basis of the mass transfer around and within the rigid sphere. The simulated results agree with the observed ones when the reaction rate with the purified extractant is used. This indicates that the effect of surface active impurities on the extraction reaction rate might be reduced with an increase in the specific interfacial area. The simulation suggests that extraction with a high concentration of the extractant is effective for copper removal, but the effect of mass transfer resistance within the aqueous phase cannot be neglected with the increase in extractant concentration.
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  • Hydrodynamics in a Flat-Plate Crossflow Filter and Particle Trajectory with Electric Fields Imposed on the Filter
    Ching-Jung Chuang, Chuan-Wei Hsu
    1998 Volume 31 Issue 3 Pages 407-416
    Published: 1998
    Released on J-STAGE: April 26, 2004
    DOIhttps://doi.org/10.1252/jcej.31.407
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    The hydrodynamic behavior of a Newtonian-fluid flow in a parallel-plate channel with one porous wall having uniform permeation rate is studied theoretically. The Navier-Stokes equations were solved numerically under laminar flow conditions for a wide range of wall Reynolds number. Distributions of shear stress acting on the permeable wall are also evaluated.
    Based on the results of the fluid flow analysis, a method for the prediction of particle trajectories in a filter chamber with imposed electric fields is outlined in the present report. Furthermore, the flux of particles transported onto the filter medium is estimated and also compared with experimental data, which show favorable agreement.
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  • A New Reversed Micellar System from Di(2-Ethylhexyl)Phosphorothioic Acid: Its Application to Extraction of Hemoglobin
    Long Rong, Takashi Yamane, Hiroshi Takeuchi
    1998 Volume 31 Issue 3 Pages 434-439
    Published: 1998
    Released on J-STAGE: April 26, 2004
    DOIhttps://doi.org/10.1252/jcej.31.434
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    From a series of solubilization experiments for various surfactants with two alkyl chains, di(2-ethylhexyl)phosphorothioic acid (DEPTA) is found to be effective for the formation of reverse micelles (RMs). The DEPTA/isooctane/water system can extract and concentrate hemoglobin as a comparatively large molecular weight protein. The size and shape of the RM were determined by small angle X-ray scattering (SAXS) method; it has been demonstrated that DEPTA assumes a spherical shape just like the conventional Aerosol-OT. Furthermore, desolubilization of the protein entrapped in the RMs by weak alkaline solution can be realized with the addition of a small amount of n-octanol, and then the micellar solution after stripping can be regenerated by bringing it into contact with dilute hydrochloric acid. It is illustrated in the recovery of hemoglobin that the present RM system can possibly be used in the extraction process in cascade operation.
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  • Numerical Simulation of Dynamic Layer Solidification for a Eutectic Binary System
    Keisuke Fukui, Kouji Maeda
    1998 Volume 31 Issue 3 Pages 445-450
    Published: 1998
    Released on J-STAGE: April 26, 2004
    DOIhttps://doi.org/10.1252/jcej.31.445
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    Direct numerical simulations of layer solidification for unsteady condition have been carried out for a eutectic binary fluid of lauric acid and myristic acid, which exhibits a laminar flow between two parallel walls of different temperatures. Two-dimensional differential equations for momentum, heat and mass transfer are solved simultaneously using non-orthogonal coordinate systems. The boundary-fit grid is generated according to the time-changed shape of the solid-liquid interface. The predictions are discussed with reference to the time-changes of the shape of the solid-liquid (S-L) interface, the growth rate, the concentration at the S-L interface, the super-cooled layer adjacent to the S-L interface, and the concentration in the solid.
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  • Performance of Thermal Swing Honeycomb VOC Concentrators
    Yoichi Mitsuma, Yasutaka Ota, Tsutomu Hirose
    1998 Volume 31 Issue 3 Pages 482-484
    Published: 1998
    Released on J-STAGE: April 26, 2004
    DOIhttps://doi.org/10.1252/jcej.31.482
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    A honeycomb laminate was formed with ceramic fiber paper and was then heat-treated. It was impregnated with a dispersion of high silica zeolite, inorganic binder and silica sol, and was dried to get a honeycomb rotor of adsorbent for the VOC concentrating rotor.
    The removal efficiency of the rotors, which were installed in a testing unit and user’s actual units, was examined for several variables, such as the rotation speed, the face velocity of desorption air, the effect of VOC concentration ratio, f, on the fractional removal of the rotors etc. The result showed that the optimal rotation speed of the VOC concentrating rotor was expressed by a nondimensional number, UR(f•noptL = 450, and that the rotor removed more than 90% of the VOCs laden in the process gas stream with its concentration ratio of 10 times in the desorption gas stream with the suitable combinations of the variables mentioned above.
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  • Pervaporation Separation of Methanol from Methanol—t-Amyl Methyl Ether Mixture by Polyion Complex Membrane
    Phan Do Hung, Teruyuki Masawaki, Setsuji Tone
    1998 Volume 31 Issue 3 Pages 484-487
    Published: 1998
    Released on J-STAGE: April 26, 2004
    DOIhttps://doi.org/10.1252/jcej.31.484
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    Pervaporation separation of methanol (MeOH) from methanol-t-amyl methyl ether (TAME) mixtures is carried out using polyion complex (PIC) hollow fiber membrane. The sorption experiment is performed to observe the equilibrium relations between solute concentrations in the solution and in the membrane phase. With increasing MeOH weight fraction in the feed solution, the permeation flux of MeOH increases, but that of TAME remains almost constant. Considering the swelling effect by MeOH component, the flux model is described using diffusion coefficients dependent on MeOH concentration in the membrane and it can be successfully fitted to experimental data. The separation factor of MeOH ranges from 12 to 73, and decreases with increasing MeOH weight fraction in the feed solution.
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Particle Technology and Fluidization
Process Systems Engineering
  • New Tuning Method for IMC Controller
    Kang Liu, Tadaaki Shimizu, Makoto Inagaki, Akira Ohkawa
    1998 Volume 31 Issue 3 Pages 320-324
    Published: 1998
    Released on J-STAGE: April 26, 2004
    DOIhttps://doi.org/10.1252/jcej.31.320
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    For a complex control process, ordinary control such as PID cannot usually realize a desirable response and robustness for the system. Therefore, we tried to apply IMC (Internal Model Control) to a heat exchanger model which describes the dynamic behavior of the distributed parameter systems. Also, to facilitate IMC controller design, we proposed a new method of determining the low-pass filter parameter. In conclusion, we discussed the results of the simulation and compared the IMC to the PID control.
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  • Synthesis of Heat Exchanger Networks Considering Location of Process Stream Sources
    Niniek Fajar Puspita, Tetsuo Fuchino, Masaaki Muraki
    1998 Volume 31 Issue 3 Pages 330-339
    Published: 1998
    Released on J-STAGE: April 26, 2004
    DOIhttps://doi.org/10.1252/jcej.31.330
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    The synthesis of a heat exchanger network (HEN) is an active field of interest in process engineering in order to develop a systematic procedure for finding an optimal network and individual heat transfer areas to meet the target temperatures at minimum total cost, which consists of energy and capital costs. Previous methods have given priority to identifying the minimum energy cost at a given minimum approach temperature (ΔTmin) common to all heat matches between the heat sources and sinks beforehand. However, ΔTmin for each match depends on the physical properties, the temperature levels and the locations of the process stream sources, which are strongly related to the total cost effect.
    The purpose of this study is to develop a HEN synthesis method considering the energy and capital costs simultaneously, and an evolutionary approach is found to be suitable for the nature of this problem. In adopting this approach, generating an initial network and searching for the neighboring ones becomes important. In this study, an algorithm of selection criterion is developed to generate an initial network based on the thermodynamic and economic consideration. Moreover, three evolutionary rules: changing the neighboring heat match; adding heat match; and varying heat transfer area have been proposed. These rules enable evolutionary searching without missing a better network. Finally, the effect of the developed evolutionary method is demonstrated through an illustrative example problem.
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  • Control of Axial Temperature Distribution in a Packed-Bed Reactor
    Masatoshi Yoshida, Shigeru Matsumoto
    1998 Volume 31 Issue 3 Pages 381-390
    Published: 1998
    Released on J-STAGE: April 26, 2004
    DOIhttps://doi.org/10.1252/jcej.31.381
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    Control of temperature profiles of a tubular packed-bed reactor with our proposed design method for a parabolic distributed parameter system is investigated. The oxidation reactor of carbon monoxide over a platinum-catalyst is used as a controlled process. The reactor dynamics are modeled by a simple parabolic partial differential equation in one-dimensional space, on the assumption that temperature distribution in the radial direction of the reactor is negligible. A state feedback controller was designed by use of a reduced order lumped parameter system, which was obtained by applying the finite integral transform technique to the phenomenological model of the process. It is demonstrated that hot-spot temperatures can be eliminated and the axial temperature profile of the reactor can be made to agree well with a specified target profile.
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  • Constrained Nonlinear Control of a Binary Distillation Column
    Young Han Kim, Jung Soo Kim
    1998 Volume 31 Issue 3 Pages 417-424
    Published: 1998
    Released on J-STAGE: April 26, 2004
    DOIhttps://doi.org/10.1252/jcej.31.417
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    A multivariable nonlinear control procedure is formulated for the control of a binary distillation column, and its set-point tracking and regulatory performances are examined and compared with those of the quadratic dynamic matrix control (QDMC) through simulation study. Direct integration of material balances at all trays is carried out to find the predicted outputs for the different values of input in the optimization process using the successive quadratic programming.
    The outcome indicates that the proposed control of this study leads to better set-point tracking and regulatory performances than those of the QDMC because the nonlinear model gives better output prediction than the step response model of the QDMC for nonlinear process. It is also proved that the complex nonlinear process model can be implemented for the real time control of multivariable systems without model simplification. In addition, a tuning guideline of the nonlinear control is suggested through stability analysis.
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Biochemical, Food and Medical
  • Influence of Protein on Phase Transition of Amorphous Sugar
    Koreyoshi Imamura, Tetsuo Suzuki, Shinya Kirii, Takayuki Tatsumichi, M ...
    1998 Volume 31 Issue 3 Pages 325-329
    Published: 1998
    Released on J-STAGE: April 26, 2004
    DOIhttps://doi.org/10.1252/jcej.31.325
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    In order to investigate the influence of protein on the phase transitions of amorphous structure of sugar, we carried out differential scanning calorimetry (DSC) analysis of freeze-dried sucrose containing various contents of water and bovine serum albumin (BSA). Glass transition temperature Tg, crystallization temperature Tcr, and melting temperature Tm were measured. Tg, Tcr, and Tm decreased with increasing water activity. Addition of BSA raised Tg except the case that water activity was low (up to about 0.1). Tcr increased linearly with BSA content, and Tm did not depend on BSA content. The increase in Tg and Tcr with BSA suggests that protein contributes to stabilizing amorphous structure of sugar.
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  • Numerical Analysis of Slowest Heating or Cooling Point in a Canned Food in Oil
    Tamotsu Hanzawa, Qiz Hi Wang, Minoru Suzuki, Noboru Sakai
    1998 Volume 31 Issue 3 Pages 451-455
    Published: 1998
    Released on J-STAGE: April 26, 2004
    DOIhttps://doi.org/10.1252/jcej.31.451
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    In the sterilizing process of canned food in oil for a fish meat such as tunny, the slowest heating or cooling point is very important for the thermal process determination of the can. To obtain the slowest point, the temperature profiles in solid food are estimated by numerical calculation from the fundamental equations at unsteady state in consideration of a free convection in the space occupied by the oil.
    The positions of the slowest heating or cooling point in the canned food in oil are obtained accurately, and a correlative equation for the position is obtained numerically under various operating conditions. The calculated temperature profiles and the position of both slowest points are in sufficiently good approximation to the experimental ones.
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  • A Phase-Segregated Model for Plant Cell Culture: The Effect of Cell Volume Fraction
    Wei Zhang, Shintaro Furusaki, Anton P. J. Middelberg
    1998 Volume 31 Issue 3 Pages 469-474
    Published: 1998
    Released on J-STAGE: April 26, 2004
    DOIhttps://doi.org/10.1252/jcej.31.469
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    Plant cells are characterized by low water content, so the fraction of cell volume (volume fraction) in a vessel is large compared with other cell systems, even if the cell concentrations are the same. Therefore, concentration of plant cells should preferably be expressed by the liquid volume basis rather than by the total vessel volume basis. In this paper, a new model is proposed to analyze behavior of a plant cell culture by dividing the cell suspension into the biotic- and abiotic-phases. Using this model, we analyzed the cell-growth and the alkaloid production by Catharanthus roseus. Large errors in the simulated results were observed if the phase-segregation was not considered.
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Safety, Environment and Energy
  • Role of Organic Chemical Additives in Pulsed Corona Discharge Process for Conversion of NO
    Young-Sun Mok, In-Sik Nam
    1998 Volume 31 Issue 3 Pages 391-397
    Published: 1998
    Released on J-STAGE: April 26, 2004
    DOIhttps://doi.org/10.1252/jcej.31.391
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    We have applied the pulsed corona discharge process to the removal of NO from a simulated gas stream. The effect of alcoholic and aliphatic hydrocarbon additives on the oxidation of NO to NO2 was investigated, and some possible reaction schemes for the role of the additives in enhancement of NO conversion were suggested on the basis of their cracking patterns. The conversion of NO increased with the chain length of the alcohol used. In the presence of aliphatic hydrocarbon, the conversion of NO was also greatly enhanced. Comparison between alkyl alcohol or alkane and its isomer showed that alkyl alcohol or alkane gave better removal performance than its isomer. By using the alcoholic and aliphatic hydrocarbons, large reduction in energy requirement for NO removal was achieved.
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  • Effect of Aluminum Ion on Silica Removal from Geothermal Brine by Seeding Method Using Silica Gel
    Hajime Sugita, Rui Suzuki, Yoshiyuki Bando, Masaaki Nakamura
    1998 Volume 31 Issue 3 Pages 462-464
    Published: 1998
    Released on J-STAGE: April 26, 2004
    DOIhttps://doi.org/10.1252/jcej.31.462
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    The seeding method using silica gel has been suggested as a way to inhibit silica scale formation. In order to improve the silica removal performance, the effect of coaddition of aluminum ion on the silica removal was experimentally examined. When only aluminum ion solution is added in the supersaturated silica solution, the decrease in silica concentration increases with time. This is because aluminum ion produces aluminosilicate deposits. The decrease in silica concentration becomes larger with increasing aluminum ion concentration or with increasing initial pH. When initial pH is 9, the decrease in silica concentration in the coaddition is larger than three times that in the silica gel addition. The coaddition of aluminum ion is found to improve the performance of silica removal when the initial pH is higher than 8.
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  • Hydrogen Production from Cellulose in Hot Compressed Water Using Reduced Nickel Catalyst: Product Distribution at Different Reaction Temperatures
    Tomoaki Minowa, Zhen Fang
    1998 Volume 31 Issue 3 Pages 488-491
    Published: 1998
    Released on J-STAGE: April 26, 2004
    DOIhttps://doi.org/10.1252/jcej.31.488
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    Cellulose, a major component of woody biomass, was gasified in hot-compressed water using reduced nickel catalyst at reaction temperatures from 200 to 350°C. The product distribution was analyzed at different temperatures and reaction times. Cellulose decomposed to water-soluble products at first, and then, the water-soluble products reacted to form hydrogen and carbon dioxide. The obtained hydrogen was consumed by a methanation reaction to form methane. A reaction model for catalytic and noncatalytic cellulose decomposition is proposed.
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General Research
  • Solvent Extraction of Titanium(IV) with 2-Ethyl Hexyl Phosphonic Acid Mono 2-Ethyl Hexyl Ester (HEHEHP)
    J. Jayachandran, P. M. Dhadke
    1998 Volume 31 Issue 3 Pages 465-468
    Published: 1998
    Released on J-STAGE: April 26, 2004
    DOIhttps://doi.org/10.1252/jcej.31.465
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    Liquid-liquid extraction of titanium(IV) from sulfuric acid solution using 2-ethyl hexyl phosphonic acid mono 2-ethyl hexyl ester (PC-88A) in toluene has been studied. The extraction of titanium(IV) was found to be quantitative with 0.03 M PC-88A in toluene in the acidic range of 0.01–0.3 M and 12.0–14.0 M H2SO4. Titanium(IV) extracted in the organic phase was stripped with the mixture of 2.0–3.5 M H2SO4 and 3% H2O2. Effect of reagent concentration on the extraction of titanium(IV) was studied.
    The stoichiometry of the extracted species of titanium(IV) was determined on the basis of slope analysis method. The extraction reaction proceeds with cation exchange mechanism in the range of 0.01 M–0.3 M H2SO4 and the extracted species is in the TiOR2·2HR form and at higher acidty (12.0 M–14.0 M H2SO4) it proceeds by solvation, the extracted species is Ti(OH)3HSO4·4HR. Temperature dependence of the extraction equilibrium constants was examined to estimate the apparent thermodynamic functions (ΔH, ΔS and ΔG) for extraction reaction.
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