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Volume 35 (2009)
- Issue 6 Pages 573-
- Issue 5 Pages 417-
- Issue 4 Pages 337-
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- Issue 2 Pages 195-
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Predecessor
Volume 35, Issue 4
Displaying 1-13 of 13 articles from this issue
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Hitoshi Kosuge, Naoto Ohmura2009 Volume 35 Issue 4 Pages 337-338
Published: July 20, 2009
Released on J-STAGE: July 30, 2009
JOURNAL RESTRICTED ACCESSOutstanding Paper Award Subcommittee of Kagaku Kogaku Ronbunshu has assessed the 93 papers published in volume 34 into 2008, and the editorial board finally selected the three papers for Kagaku Kogaku Ronbunshu Paper Awards of 2008; those are the papers on “Magnetic Field Influence on the Crystal Structure of 2,2′:6′,2″-Terpyridine,” “Pressure Distribution on the Blade Surface and Form Drag of Impeller in a Gas–Liquid Stirred Vessel with a Disc Turbine,” and “Dynamic Observation of the Behavior of the Surface of Liquid Films of Polymer–Organic Solvent System by Ripplon Surface Laser-Light Scattering Method.”View full abstractDownload PDF (173K)
Transport Phenomena and Fluid Engineering
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Naoki Shimada, Rina Saiki, Akio TomiyamaArticle type: Research Paper
Subject area: Transport Phenomena and Fluid Engineering
2009 Volume 35 Issue 4 Pages 339-344
Published: July 20, 2009
Released on J-STAGE: July 30, 2009
JOURNAL RESTRICTED ACCESSA computational fluid dynamics-based method proposed in our previous study was used to investigate the effects of flow on the yield in a reactor. First, selectivities in a plug flow reactor and a continuous stirred reactor were calculated to confirm that the proposed method can calculate reactions in ideal flows. The predictions agreed well with exact solutions.
Next, three columns with the same volume were used to evaluate selectivity in a consecutive reaction. In addition, marker particles were used to evaluate the mixing behavior. The effects of column geometry on the relation between selectivity of product and conversion of reactant were then discussed. The predictions indicated that selectivity is affected by locations of gas spargers, the direction of liquid injection, and the presence of baffle plates. It was also demonstrated that the proposed method can evaluate the effects of column geometries on flow patterns and reactions.View full abstractDownload PDF (858K) -
Toshiro Miyahara, Naoki NagataniArticle type: Research Paper
Subject area: Transport Phenomena and Fluid Engineering
2009 Volume 35 Issue 4 Pages 345-350
Published: July 20, 2009
Released on J-STAGE: July 30, 2009
JOURNAL RESTRICTED ACCESSIn our previous paper (Miyahara et al., 2007), the splitting of single bubbles by the liquid flow through a Raschig ring packed bed was investigated for the production of fine bubbles, including micro-bubbles, which are effective for chemical reactors and for water purification in rivers, lakes, marshes and dam lakes or fishery cultivation because of the good liquid mixing and the increase in mass transfer rate. In the present study, experiments were performed to produce fine bubbles, including micro-bubbles, using a Raschig ring packed bed under a variety of gas flow rates and six kinds of liquids. As a result, micro-bubbles less than 1 mm in diameter were confirmed with increasing liquid velocity and liquid viscosity and decreasing surface tension of liquid. Correlation equations for volumetric mean bubble diameter of split bubbles were presented as a function of gas Reynolds number, liquid Reynolds number, size of Raschig ring and Morton number. Furthermore, the measured bubble size distribution was found to be well represented by an upper limit log-normal probability function with two constants and only one variable, the maximum stable bubble diameter, as described in our previous paper (Miyahara et al., 2007).View full abstractDownload PDF (2552K) -
Yoshinao Harada, Meguru Kaminoyama, Kazuhiko Nishi, Ryuta Misumi, Kiyo ...Article type: Research Paper
Subject area: Transport Phenomena and Fluid Engineering
2009 Volume 35 Issue 4 Pages 351-356
Published: July 20, 2009
Released on J-STAGE: July 30, 2009
JOURNAL RESTRICTED ACCESSThe validity of 2,3-dichloro-1,3-butadiene (DC) suspension polymerization as an alternative evaluation method to poly(vinyl chloride) (PVC) suspension polymerization was investigated. The correlation of experimental data between PVC suspension polymerization and DC suspension polymerization was examined using two types of suspending agents.
It was found that the particle properties can be expressed with a power function of the power consumption per unit volume.View full abstractDownload PDF (398K) -
Sunho You, Yuusuke Sugikawa, Toshihisa UedaArticle type: Research Paper
Subject area: Transport Phenomena and Fluid Engineering
2009 Volume 35 Issue 4 Pages 357-363
Published: July 20, 2009
Released on J-STAGE: July 30, 2009
JOURNAL RESTRICTED ACCESSCross-sectional visualization of the mixing pattern in a non-element mixer was carried out using laser induced fluorescence (LIF) to evaluate characteristics of a mixer consisting of the main flow pipe and branch flow pipes. The branch flows were injected periodically with the period Tp normal to the main flow, and rhodamine B was mixed into the most upstream branch flow to visualize mixing pattern in the main flow pipe by LIF. The length of boundary line L of the LIF image, where molecular diffusion takes place, was measured. When the number of branch flows is increased, the mixing pattern became complicated and was supposed to become chaotic. The mean value of length of boundary line L increased exponentially with an increase in the number of branch flows, which indicates that L increases nonlinearly in the same way as in a Kenics type static mixer.View full abstractDownload PDF (970K)
Separation Engineering
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A Method for Removing Ions from Aqueous Solution by Electric Double Layer Formed Using Active CarbonSeiji Tanahashi, Masakazu TanahashiArticle type: Research Paper
Subject area: Separation Engineering
2009 Volume 35 Issue 4 Pages 364-369
Published: July 20, 2009
Released on J-STAGE: July 30, 2009
JOURNAL RESTRICTED ACCESSA batch method to remove ions rapidly from aqueous solution by applying a high voltage was investigated. In this method, activated carbon cloth, which forms an electric double layer in aqueous solution, was employed as the ion-absorbing electrodes. Two electrodes were set in parallel with a wide inter-electrode spacing in an ion-containing aqueous solution. The current density was set from 0.3 to 13 mA/cm2 and a voltage of 1 to 60 V was applied between the electrodes.
As a result, a high voltage could be easily applied using the IR drop in the aqueous solution, so ions were removed from the aqueous solution at a high rate. The activated carbon surface was used effectively because ions stay inside the electrodes until the deionization process ends in the batch method.
This method is promising as a new ion removal method that is simple to operate and easily self-recycling.View full abstractDownload PDF (378K) -
Takumi Shibukawa, Yuichi Ohira, Eiji ObataArticle type: Research Paper
Subject area: Separation Engineering
2009 Volume 35 Issue 4 Pages 370-374
Published: July 20, 2009
Released on J-STAGE: July 30, 2009
JOURNAL RESTRICTED ACCESSThe temperature dependence of the absorption rate, absorption efficiency, and selectivity of NO2 in solutions of sodium sulfite or magnesium sulfite and in water were experimentally investigated. At lower temperature, the absorption rate and absorption efficiency of NO2 in water increased. At higher temperatures, less nitrite was generated and the absorption rate and absorption efficiency of NO2 decreased. Similarly, use of a sulfite solution at higher temperatures generated less nitrate even though the absorption rate and absorption efficiency of NO2 decreased.View full abstractDownload PDF (328K)
Process Systems Engineering and Safety
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Masayasu Kamikozuru, Michio Miyahara, Koki Suruga, Kazuyuki Shigehisa, ...Article type: Research Paper
Subject area: Process Systems Engineering and Safety
2009 Volume 35 Issue 4 Pages 375-381
Published: July 20, 2009
Released on J-STAGE: July 30, 2009
JOURNAL RESTRICTED ACCESSPA-13 A (Propane-Air 13 A gas), which is made by diluting propane gas with air to give a calorific value of 62.8 MJ/m3, is very useful as town gas in medium-sized cities. This paper reports a newly developed, streamlined production process of PA-13 A which requires less energy and labor input than the conventional production process. An indispensable component in the new plant is the mixer used to dilute LPG with air. The mixer selected was a Venturi tube type mixer which did not require any power. The characteristics of the mixer were determined by testing a 1/2 scale prototype. Test results showed stable mixing characteristics that met or exceeded the specifications desired, and sufficient pressure to feed the production tank was maintained. These results indicated that it was possible to use the mixer in the production process of PA-13 A. Based on the present findings and those of previous work, the authors developed, built, and commenced operation of a new PA-13 A production plant consisting of an LPG storage tank, an LPG vaporizer heated by the wind, a Venturi tube type mixer, and a PA-13 A storage tank. This plant, having the capacity to supply gas to around 10,000 households, consists of fewer main and incidental facilities. It was verified that the facility and operation costs were much lower than the former PA-13 A plant and LNG-13 A plants supplying LNG.View full abstractDownload PDF (546K) -
Hiromasa Kaneko, Masamoto Arakawa, Kimito FunatsuArticle type: Research Paper
Subject area: Process Systems Engineering and Safety
2009 Volume 35 Issue 4 Pages 382-389
Published: July 20, 2009
Released on J-STAGE: July 30, 2009
JOURNAL RESTRICTED ACCESSSoft sensors are widely used to estimate a process variable which is difficult to measure online. One of the crucial difficulties of soft sensors is that predictive accuracy drops due to changes of state of chemical plants. In order to cope with this problem, a regression model can be updated. However, if the model is updated with abnormal data, the predictive ability can deteriorate. In this paper, we propose a new fault detection and classification method using independent component analysis (ICA) and support vector machine (SVM). This method, named ICA-SVM, was applied to the soft sensor in order to increase fault detection ability and predictive accuracy. It is conceivable that we could comprehend the state of a plant by using the ICA-SVM model and estimate the objective variable by the regression model, updating it appropriately. We analyzed real industrial data to confirm the fault detection ability and predictive accuracy of the proposed method. First, we verified the fault detection ability, and then showed that the proposed method achieved higher predictive accuracy than the traditional one.View full abstractDownload PDF (570K)
Energy
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Masahiro Haguro, Yasuhiro Shibata, Yasufumi Otsubo, Hironao OguraArticle type: Research Paper
Subject area: Energy
2009 Volume 35 Issue 4 Pages 390-395
Published: July 20, 2009
Released on J-STAGE: July 30, 2009
JOURNAL RESTRICTED ACCESSWe previously proposed chemical heat storage and chemical heat pump using a reversible calcium sulphate/water reaction system. Calcium sulphate has possibility of storing thermal energy at the temperature level of around 373 K and releasing hot heat at the same level and cold heat at the 273 K level. Although we proposed reaction equilibrium and reaction rate equations for an open system, more reaction rate studies are necessary for this reaction system, especially for reaction rate in semi-closed and closed systems. In this study, we considered three conditions to decide the reaction rate equations: (1) the difference of diffusion rate in the material core, (2) the difference of material temperature based on convection heat transfer solved by the unsteady heat transfer equations, and (3) the adsorption rate of saturated water vapor at high pressure range. As a result, it was found that calculated data by the proposed reaction rate equations could reproduce the experimental data. Furthermore, the possible operating temperature range and the reaction rates were shown by the simulation.View full abstractDownload PDF (454K) -
Koki Terui, Toshiyuki Hirosawa, Yutaka Sangu, Yohsuke Matsushita, Hide ...Article type: Research Paper
Subject area: Energy
2009 Volume 35 Issue 4 Pages 396-402
Published: July 20, 2009
Released on J-STAGE: July 30, 2009
JOURNAL RESTRICTED ACCESSThe effects of long-term absorption-desorption testing with hydrogen containing water vapor and of reactivation on the hydrogen absorption-desorption properties of hydrogen-absorbing alloys were experimentally investigated. With absorption times, the hydrogen-absorbing alloys degraded in the first several cycles. In subsequent cycles, the degraded alloys recovered and degraded again due to the pulverization. On reactivation with pure hydrogen, the hydrogen absorbing-desorbing capacity and rate of hydrogen absorption-desorption recovered, but the hydrogen-absorbing capacity did not recover completely to that before degradation, due to the extrinsic degradation.View full abstractDownload PDF (723K)
Environment
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Risehiro Nonaka, Hitoshi Funayama, Katsuyasu SugawaraArticle type: Research Paper
Subject area: Environment
2009 Volume 35 Issue 4 Pages 403-410
Published: July 20, 2009
Released on J-STAGE: July 30, 2009
JOURNAL RESTRICTED ACCESSIn order to develop a selective recovery process of tantalum and niobium from tungsten and cobalt extracted residue (WCR), the release of rare metals during chlorination in a chlorine stream in a fixed bed reactor was investigated. The chemical forms of niobium in the sample were estimated to be CrNbO4 and (Ti, Nb, Fe, Ta) O2. During chlorination at 573–1273 K, release of tantalum reached 15–46%, and that of niobium 74–97%. In the presence of added carbon, niobium originating from CrNbO4 was released in the temperature range of 273–773 K, and niobium and tantalum originating from (Ti, Nb, Fe, Ta) O2 were rapidly released into the gas phase at above 773 K. The carbochlorination enabled all niobium and tantalum in the solid phase to be released at the temperature of 873 K by changing their chemical forms to chlorides via oxychlorides.
Two-step chlorination consisting of chlorination and carbochlorination was carried out for selective separation of niobium and tantalum from coexisting elements. During chlorination in the first step, 96% of niobium and 26% of tantalum were recovered from WCR. All of the tantalum in the residue of the first step could be released into the gas phase by addition of carbon, and a volatile composed of 80% of tantalum was obtained in the second step.View full abstractDownload PDF (1380K) -
Shinya Hayashi, Wataru Minami, Tatsuo Oguchi, Hee-Joon KimArticle type: Data
Subject area: Environment
2009 Volume 35 Issue 4 Pages 411-415
Published: July 20, 2009
Released on J-STAGE: July 30, 2009
JOURNAL RESTRICTED ACCESSTo develop SF6 decomposition technology which will contribute to the prevention of global warming, we investigated the decomposition of dilute SF6 in N2, O2 and Ar+H2O. Reaction parameters such as rate constants and activation energies of SF6 decomposition were evaluated.
SF6 decomposition was found to be a first-order reaction in N2, O2 and Ar+H2O bath gas. Apparent activation energies of SF6 decomposition were 386 and 446 kJ·mol−1 for N2 and O2 bath gas respectively. When H2O was added to Ar from 50 to 1000 ppm, the activation energies were 310±10 kJ·mol−1. Mass spectrum analysis of the decomposition components in SF6+O2 gas mixture at 1373 K revealed the presence of SO, SO2, SOF, SO2F, SOF2 and SO2F2.View full abstractDownload PDF (390K)
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