JOURNAL OF CHEMICAL ENGINEERING OF JAPAN
Online ISSN : 1881-1299
Print ISSN : 0021-9592
Volume 39, Issue 9
Displaying 1-16 of 16 articles from this issue
Editorial Note
  • Yutaka Tada, Hiroshi Ooshima
    Article type: Editorial Note
    2006 Volume 39 Issue 9 Pages 905-906
    Published: 2006
    Released on J-STAGE: September 20, 2006
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    Outstanding Paper Awards Subcommittee of Journal of Chemical Engineering of Japan has assessed the 147 papers published in 2005, corresponding to volume 38, and selected the candidates of the award. As a result, the editorial board finally selected the four papers for JCEJ Paper Awards of 2005; those are the papers on “the micro-filtration of the colloidal particles”, “the prediction of the dynamic behavior of nonlinear chemical processes”, “the molecular simulation of adsorption process” and “the design of the computer-aided monitoring system dealing with incomplete process data”.
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Physical Properties and Physical Chemistry
  • Tohru Saito, Yoshio Iwai, Yasuhiko Arai, Futoshi Nakadai, Daisuke Tani ...
    Article type: Research Paper
    2006 Volume 39 Issue 9 Pages 907-914
    Published: 2006
    Released on J-STAGE: September 20, 2006
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    An apparatus has been developed for the measurement of mutual miscibility temperatures of binary liquid mixtures coexisting with a high pressure gas to examine to what extent the phase behavior changes. Methanol + hydrocarbon (cyclohexane, hexane, octane, and decane) binary mixtures were selected as typical polar and non-polar mixtures. And their mutual miscibility temperatures were measured at temperatures from 275.4 to 363.9 K and pressures up to 2.2 MPa with pressurized carbon dioxide (CO2). The experimental results were correlated with the NRTL equation by adopting a pseudo-binary mixture treatment. The NRTL interaction parameters between methanol and hydrocarbons were assumed to vary due to the presence of CO2. A good agreement between the experimental and the correlated mutual miscibility temperatures is obtained.
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Transport Phenomena and Fluid Engineering
  • Hiroshi Suzuki, Sayaka Yamada, Hiromoto Usui
    Article type: Research Paper
    2006 Volume 39 Issue 9 Pages 915-923
    Published: 2006
    Released on J-STAGE: September 20, 2006
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    A two dimensional numerical study on flow and heat transfer of viscoelastic fluid in a cavity has been performed in order to investigate how effective the heat transfer augmentation technology is by using the Barus effect in the region of low Reynolds and Weissenberg numbers on the bottom wall of the cavity between ribs mounted in the parallel plates. In this paper, the heat transfer characteristics on the bottom of the cavity were focused on. The cavity length and the rib height were changed in three steps, respectively, while the wide flow path width and the solid wall temperature were kept constant. The solvent Reynolds number based on the rib height was set at 100. From the results, it is found that the flow penetration into the cavity effectively occurs just at the inlet of the cavity in the cases of viscoelastic fluids, while a large recirculating region is formed there for the cases of water. The local Nusslt number takes peaks at the position corresponding to the peak positions of velocity gradients on the bottom wall. It is also found that the mean Nusselt number increases with rib height and cavity length. However, the increase rate on the cavity length becomes smaller in a large cavity length region. This indicates there exists the optimum geometric condition and that the present technology has an advantage for making the heat exchanger compact in comparison with that using a water flow.
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Particle Engineering
  • Hyun Tae Jang, Sang Bum Kim, Wang Seog Cha
    Article type: Research Paper
    2006 Volume 39 Issue 9 Pages 924-931
    Published: 2006
    Released on J-STAGE: September 20, 2006
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    The pressure fluctuation properties and mixing degree were investigated with a binary mixture of different density particles using polymethyl methacrylate (PMMA) and sand (or natural manganese ore (NMO)) in a gas fluidized bed. This study was restricted to systems of 50% by volume jetsam, i.e. flotsam rich system. Mixing-segregation phenomena were analyzed by pressure fluctuation properties, and the results were confirmed with the mixing degree using a sieve test. It was found that take-over velocities were obtained from the value of the specific gas velocity which was observed by transition of the slope of the standard deviation of pressure fluctuations. The mixing degree was related to the variation of the bed pressure difference by measuring the height of the axial position according to gas velocity. In addition, take-over velocities could likewise be obtained from a pressure difference profile.
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  • Nenad Kuzmanic, Marija Akrap, Antonija Kovacevic
    Article type: Research Paper
    2006 Volume 39 Issue 9 Pages 932-939
    Published: 2006
    Released on J-STAGE: September 20, 2006
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    Experimental work is reported on the drawdown of floating solids by a mechanically agitated vessel with multiple impellers. The main aim of this work was to study the effect of different types of dual-impeller systems on the achievement of the complete suspension state of floating solids. Previous investigations on this topic have been limited to single-impeller systems only. In the present work three types of impellers were employed: a three-bladed 30° pitched turbine down-flow (3-PTD), a four-bladed 45° pitched turbine down-flow (4-PTD), and a straight blade turbine (SBT). Tap water and polyethylene particles (PEHD) were used as liquid and solid phases, respectively. The effects of physical properties of suspension as well as the impacts of a number of geometrical variables of the systems on the critical impeller speed and power consumption were studied in detail. The results indicate that the appropriate location of the second impeller on the same shaft can improve the performance of the agitation system for the process of floating solids suspension. This improvement is noted through the decrease of FrJS and (P/m)JS values. For all dual-impeller systems examined, the correlations for the estimation of the minimum impeller speed to attain the just dispersed state of floating solid particles has been developed.
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Separation Engineering
  • José Marcos F. Silva, Carlos E. Lopes, Antonio J. A. Meirelles, ...
    Article type: Research Paper
    2006 Volume 39 Issue 9 Pages 940-947
    Published: 2006
    Released on J-STAGE: September 20, 2006
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    A one-dimensional model for the crystallization of a binary or pseudo-binary solution was developed. Usually, the Stefan’s problem is associated with the crystallization of melted solids, in which the energy transfer (heat diffusion) dominates the process. In the present work, the Stefan’s problem was solved for the crystallization from solutions, i.e., a situation in which mass transfer is the most important phenomenon. An analytical solution was obtained for the equation describing the process. From this solution, a mathematical expression for the crystal growth was obtained as a function of time, degree of supersaturation, liquid diffusivity and solution molar concentration. It was also observed that the expression for the crystal growth agrees qualitatively well with experimental data reported in the literature.
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  • Hiroshi Fukuoka, Naoya Shigemoto, Hitoshi Inomo, Wataru Shiraki
    Article type: Research Paper
    2006 Volume 39 Issue 9 Pages 948-955
    Published: 2006
    Released on J-STAGE: September 20, 2006
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    In order to evaluate a potential adsorbent to remove arsenic in soil, the asenite/arsenate adsorption properties in soil were examined by employing three different crystalline types of iron oxyhydroxides, α-FeOOH (goethite), β-FeOOH (akaganeite) and γ-FeOOH (lepidocrocite). A weathered granite soil (Masatsuchi) and a clay were used in the experiment. These soils showed a rather lower arsenic uptake than FeOOH. The arsenite/arsenate uptakes by the FeOOHs strongly depended on the pH of the equilibrium solution. The arsenic uptakes at pH = 7 with or without the soils were well-fitted by Freundlich’s equation. The arsenite/arsenate uptakes by α-FeOOH and the arsenate uptake by γ-FeOOH were negatively affected by coexistence of the soils, presumably due to leaching components such as sulfate ions from the soils, though the similar arsenite/arsenate uptakes around several mg-As/g were observed by these three types of FeOOHs.
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  • Hideki Yamamoto, Chika Nagano, Fumiko Takeuchi, Junji Shibata, Motoyuk ...
    Article type: Research Paper
    2006 Volume 39 Issue 9 Pages 956-962
    Published: 2006
    Released on J-STAGE: September 20, 2006
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    Wastes discharged from beer breweries are mainly composed of malt and hop. The nutritional value of malt is quite high and, consequently, it is recycled as feed for domestic animals; however, the nutritional value of hop as feed is not so high. A new utilization method for hop waste is therefore required. In this experiment, it is found that Procyanidin, a polymer composed of catechins, is abundantly contained in hop bract part and hop itself. This research deals with the extraction of total polyphenols, catechin, and procyanidin from hop bract part under various extraction conditions. When ethanol was used as the extract solvent, about 30% of the total extracted polyphenols was procyanidin, showing that ethanol has the highest selectivity for procyanidin. The extraction of all polyphenols, catechin, and procyanidin was conducted in about 10 min at a temperature of 293–333 K and with horizontal shaking at 130 rpm. The amount of each polyphenol extracted increased with increasing temperature. The total amount of catechin extracted reached a maximum at an extraction temperature of 333 K. Compared with tea, more polyphenols were shown to be contained in the hop bract part. A continuous extraction process for collection of the polyphenols contained in the hop bract part using a modified mixer-settler extractor device is described and the fundamental performance of the presented extractor was examined.
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  • Kejin Huang, Keigo Matsuda, Koichi Iwakabe, Takeichiro Takamatsu, Masa ...
    Article type: Research Paper
    2006 Volume 39 Issue 9 Pages 963-970
    Published: 2006
    Released on J-STAGE: September 20, 2006
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    Exergy analysis of an ideal heat-integrated distillation column is conducted in this paper. It is found that the process is most favourable to the separation of binary close-boiling mixtures. Pressure elevation from stripping section to rectifying section appears to be a critical design variable that can affect the thermodynamic efficiency of the process. Feed composition presents almost no effect upon internal heat integration between the rectifying section and the stripping section. Although an implicit limitation has been imposed on the process throughput, it can be obviated through a careful trade-off between capital investment and operating cost during process development. Comparison against a conventional distillation column is also conducted, which shows the great potential of internal heat integration between the rectifying section and the stripping section.
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Chemical Reaction Engineering
  • Hong Li, Yoshito Oshima
    Article type: Research Paper
    2006 Volume 39 Issue 9 Pages 971-979
    Published: 2006
    Released on J-STAGE: September 20, 2006
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    Supercritical water oxidation (SCWO) of dimethylamine (DMA) and trimethylamine (TMA) was conducted at 400–450°C and 25 MPa in the presence of excess O2. An apparent induction time was experimentally observed only in the oxidation of DMA. Monomethylamine (MMA) was the common major product in both oxidations of DMA and TMA in spite of the different numbers of substituted methyl groups, suggesting that the oxidations of two amines were via different reaction mechanisms. The SCWO of DMA was considered as a radical chain reaction that proceeded via such a peroxyl radical as CH3NHCH2O2, leading to the appearance of the induction time. In contrast, the SCWO of TMA mainly proceed via formation of N-methyl methanimine (CH2=NCH3) followed by its hydrolysis to form MMA and formaldehyde. We proposed global reaction mechanisms that can reasonably explain the experimental observations in DMA and TMA oxidation in supercritical water.
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  • Akihiko Shimada, Teruyuki Hakoda, Takuji Kojima
    Article type: Research Paper
    2006 Volume 39 Issue 9 Pages 980-986
    Published: 2006
    Released on J-STAGE: September 20, 2006
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    An electron beam (EB) suitable for decomposition of dilute organic pollutants in high-flow rate air was applied to the treatment of a formaldehyde (HCHO)/air mixture for purification in a clean room after sterilization. Air mixtures containing 90–1230 ppmv of HCHO with and without 30–340 ppmv of methanol (CH3OH), which are commonly used for sterilization, were irradiated by EB to the absorbed doses of 5–80 kGy (=kJ/kg). The dose required for decreasing the initial HCHO concentration to 10 ppmv was examined as a function of the initial HCHO concentration (ppmv) in the air mixture ([HCHO]0) with and without CH3OH. The following relations were obtained: D = –4.2 × 10–5[HCHO]02 + 1.2 × 10–1[HCHO]0 – 1.2 and D = –3.8 × 10–5[HCHO]02 + 1.0 × 10–1[HCHO]0 – 1.0, respectively, where D [kGy] is the dose. According to these results, the treatment completion time of the HCHO/air mixture with CH3OH using EB was simulated considering the conceptual processing. This EB processing can be applicable, to the clean rooms at food packaging factories, for example, and contributes to improve the operation efficiency of the factories.
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Process Systems Engineering and Safety
  • Hiroyuki Nakabayashi, Hiroshi Inomata, Toru Nagasaka, Shigeru Tsuchiya
    Article type: Research Paper
    2006 Volume 39 Issue 9 Pages 987-993
    Published: 2006
    Released on J-STAGE: September 20, 2006
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    Serious fire accidents have occurred in oxygen supplying systems in which an adiabatic compression of oxygen has been identified as an ignition source. For exploring the ignition mechanism of oxygen compression, a fluid flow in a tube having a closed end has been studied by experimental and CFD approaches. The simulation results on gas pressure history are in good agreement with the experimental results; whereas the simulated gas temperature history was not in agreement with the experimental results. Ignition tests for a small sample piece placed at the end of the tube were conducted under the same adiabatic compression conditions. Nylon 6,6 and PTFE are used as the polymeric samples. The ignitions for Nylon 6,6 samples have been observed more frequently with higher initial pressures. It should be also noted that the maximum temperature simulated by CFD at the initial pressure of 25 MPa is close to the autogenous ignition temperature of Nylon 6,6, suggesting that the gas temperature simulated by CFD would be more realistic than that in experimental results because of the difficulty in keeping the adiabatic condition in experiments.
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Materials Engineering and Interfacial Phenomena
  • Kiyomi Fuchigami, Yoshinari Taguchi, Masato Tanaka
    Article type: Research Paper
    2006 Volume 39 Issue 9 Pages 994-999
    Published: 2006
    Released on J-STAGE: September 20, 2006
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    Benzoyl peroxide (BPO) was microencapsulated with polyethyl methacrylate (PEMA) by the drying-in-liquid method to apply to a liquid type adhesive. In the experiment, two kinds of calcium carbonate with different shape and size were used as stabilizers. Microencapsulation efficiency over 90% was obtained under the experimental conditions adopted here. Microcapsules prepared were characterized for medical applications. It was found that adhesive biomaterials prepared using microcapsules had sufficient ability for initiating radical polymerization even after two-month storage at 40°C and a relative humidity of 75%.
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  • Junseo Choi, Bumsang Kim, Jinsoo Kim
    Article type: Short Communication
    2006 Volume 39 Issue 9 Pages 1000-1003
    Published: 2006
    Released on J-STAGE: September 20, 2006
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    Stable 2 M [mol/L] boehmite sol was prepared by modifying the Yoldas process, followed by a granulation process in which paraffin oil and ammonia solution were used as the media to facilitate shape forming and consolidation of the gel structure, respectively. The product granules were always spherical with large surface area and narrow pore size distribution. A systematic investigation of the effect of calcination temperature on the pore structures of the granules was carried out. When the calcination temperature was increased, the product granules exhibited larger pore size with reduced porosity. The pore structure can be precisely controlled by the calcination temperature.
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Environment
  • Sea Cheon Oh, Hyun Kwak, Seong-Youl Bae
    Article type: Short Communication
    2006 Volume 39 Issue 9 Pages 1004-1009
    Published: 2006
    Released on J-STAGE: September 20, 2006
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    A kinetic analysis method for the degradation of polymer in supercritical fluid was proposed in this work. The method was applied to predict the degradation of polystyrene (PS) in supercritical acetone by nonisothermal weight loss technique with heating rates of 3, 5, and 7°C/min. To verify the effectiveness of the kinetic analysis method proposed in this work, the experimental values were compared with those of the numerical integration results using kinetic parameters obtained in this work. It was found that the kinetic analysis method proposed in this work gave a reliable value of kinetic parameter for PS degradation in supercritical acetone. The kinetic parameters were also compared with the values of thermal degradation of PS in the nitrogen atmosphere reported in the literature.
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Engineering Education
  • Steven B. Kraines, Michihisa Koyama, Rafael Batres
    Article type: Research Paper
    2006 Volume 39 Issue 9 Pages 1010-1027
    Published: 2006
    Released on J-STAGE: September 20, 2006
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    A system-based approach is effective in conducting simulation modeling of complex chemical systems. However, traditional centralized or monolithic modeling approaches are restricted to the knowledge domain of the modeler, and therefore these approaches cannot lead to the discovery of potentially important knowledge from other areas. Furthermore, knowledge of important phenomena, which are unfamiliar to the researcher who is designing the chemical system but may be well-known in other domains, are often overlooked in the conventional modeling process, leading to incorrect predictions of the modeled chemical system characteristics. An emergent simulation modeling approach for knowledge discovery (emergent simulation approach) is proposed to evaluate phenomenological behavior in chemical systems. In this emergent simulation approach, knowledge experts who have developed computational models that simulate the phenomena occurring under different design and operation conditions make those models available to a software system. Other engineers and scientists can access the software system to search for models simulating phenomena that match certain conditions and specifications describing a particular chemical system. In order to support the search and match process, an ontological markup language for chemical systems is proposed. Researchers can use this markup language to create a specification of the chemical system that they are investigating. That specification is used to discover which computational models can simulate phenomena that could occur in the given specification. This paper presents 1) the concept of the emergent simulation approach, 2) an ontological markup language developed for the emergent simulation of phenomena in chemical systems, and 3) a design for a software system that supports the proposed emergent simulation approach.
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