巻号一覧
42 巻, 2 号
選択された号の論文の11件中1～11を表示しています
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Transport Phenomena and Fluid Engineering
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Yoshio Masuda, Takafumi Aizawa, Akira Suzuki原稿種別: Research Paper
2009 年 42 巻 2 号 p. 64-70
発行日: 2009/02/20
公開日: 2009/02/20
ジャーナル 認証ありFluid flow at the T-junction of a model of a supercritical water microreactor is studied experimentally and numerically. Experimental cells are fabricated from three pieces of sapphire; the flow path width is 2 mm while the depth is 2.5 mm. SC/Tetra is used as the computational fluid dynamics software and three-dimensional calculation is performed. Experimental results and numerical results are compared for the condition where the temperature and pressure of hot water are 389 K and 45 MPa, respectively. Natural convection is found to be dominant even in such a small flow area.抄録全体を表示PDF形式でダウンロード (3899K)
Particle Engineering
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Takashi Ueda, Masatsugu Fukui, Yoshiuki Komoda, Hiroshi Suzuki, Hiromo ...原稿種別: Research Paper
2009 年 42 巻 2 号 p. 71-77
発行日: 2009/02/20
公開日: 2009/02/20
ジャーナル 認証ありA model for predicting the latex agglomerate size during the coagulation process, when the growth and breakup of the latex agglomerates proceed simultaneously in a turbulent flow, is proposed in this paper. In this model, the size of the agglomerate was expressed as a function of the external shear force, the strength of the agglomerate, and the volume fraction of the slurry. The strength of the latex agglomerate was determined by a measurement of the slurry rheology in accordance with Usui’s approach, where an inter-particle bonding energy between primary particles was calculated from the viscosity data. With this model, it was possible to predict the absolute size of the cluster in the turbulent flow. To confirm the validity of this model, the latex was agglomerated in various agitation conditions in the stirring vessel, while the dependence on volume fraction was also examined. The relation between the experimentally determined latex agglomerate sizes and the calculated agglomerate sizes from the proposed model was evaluated.抄録全体を表示PDF形式でダウンロード (1137K)
Separation Engineering
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Meisam Torab-Mostaedi, Jaber Safdari, Mohammad Ghannadi-Maragheh, Moha ...原稿種別: Research Paper
2009 年 42 巻 2 号 p. 78-85
発行日: 2009/02/20
公開日: 2009/02/20
ジャーナル 認証ありThe volumetric overall mass transfer coefficients of a pilot scale Hanson mixer-settler extraction column with seven stages have been measured using toluene/acetone/water and n-butyl acetate/acetone/water systems. The effects of operational variables such as agitation speed, phase ratio, and throughput on volumetric overall mass transfer coefficient have been investigated and found to be significant. By using the interfacial area, the dispersed phase overall mass transfer coefficients are determined from the volumetric coefficients. Comparison between theoretical models and experimental results of overall mass transfer coefficient shows that these models do not have enough accuracy for design. In the present work, effective diffusivity is substituted for molecular diffusivity in the Gröber equation for prediction of dispersed phase overall mass transfer coefficients. The enhancement factor is determined experimentally and therefrom an empirical correlation is proposed for prediction of effective diffusivity as a function of the Reynolds number, Eötvös number and dispersed phase holdup. Dispersed phase overall mass transfer coefficients predicted by the presented model are in good agreement with experimental results.抄録全体を表示PDF形式でダウンロード (833K) -
Hidenori Ohashi, Taichi Ito, Takeo Yamaguchi原稿種別: Research Paper
2009 年 42 巻 2 号 p. 86-94
発行日: 2009/02/20
公開日: 2009/02/20
ジャーナル 認証ありA new free volume theory, which we named “shell-like free volume” theory, is developed for penetrant diffusivity in polymers by introducing microscopic concept of molecular collisions. Shell-like free volume is defined as the ambient free space of the penetrant molecule; it is consistent with the notion of molecular collisions, which is the microscopic origin of molecular diffusion. The microscopic notion can give physical meaning to all the parameters in the theory, and the parameters can be evaluated using the only pure-component parameters: the experimental viscosity of the solvent, the viscoelasticity of the polymer, and the molecular surface area estimated from the chemical structure using the semiempirical quantum chemical calculation. The predictive ability of the shell-like free volume theory is good for self-diffusivities of molecules with shapes from spherical to chain-like in polymer solutions over wide ranges of temperature and concentration.抄録全体を表示PDF形式でダウンロード (1087K) -
Yuya Sato, Toshinori Tsuru, Shin-ichi Nakao原稿種別: Research Paper
2009 年 42 巻 2 号 p. 95-106
発行日: 2009/02/20
公開日: 2009/02/20
ジャーナル 認証ありThree types of membranes have been studied: ES10 (reverse osmosis membrane), LES90 (nanofiltration membrane), and improved LES90 for the analysis of the improvement of membranes by tannic acid. We assumed that ES10 had a uniform structure without any pores, LES90 had a normal section and a defective section, and that in improved LES90, most defects were improved by tannic acid. We calculated the membrane transport parameters for a normal section using a best-fit method based on the Spiegler–Kedem equation, and for a defective section using the Steric Hindrance–Pore model for neutral solutes and the Teorell–Meyer–Sievers model for sodium chloride. We carried out various permeation experiments using four types of neutral solutes: ethanol, 2-propanol, t-butanol, and glucose, as well as sodium chloride. We analyzed the relationship between the volumetric flux and real rejection, and compared the experimental results with the model calculations. There was good agreement between the experiments and calculations.抄録全体を表示PDF形式でダウンロード (3032K) -
Radia Zaamouche, Abdellah Beicha, Nik Meriam Sulaiman原稿種別: Short Communication
2009 年 42 巻 2 号 p. 107-110
発行日: 2009/02/20
公開日: 2009/02/20
ジャーナル 認証ありA cross-flow ultrafiltration model which couples the formation of a cake layer and the existence of a polarized layer above the cake has been developed. The model contains three constants and the specific cake resistance to be evaluated from experiments. The model gave an excellent prediction on the performance of the cross-flow ultrafiltration of polyethylene glycol solutions. Experimental observations on the effects of transmembrane pressure, solute concentration and cross-flow velocity agreed well with the predicted permeate fluxes.抄録全体を表示PDF形式でダウンロード (439K)
Process Systems Engineering and Safety
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Ru-Qiang Wang, Chu-Fu Li, Xiao-Rong He, Bing-Zhen Chen, Ping Wang, Hen ...原稿種別: Research Paper
2009 年 42 巻 2 号 p. 111-116
発行日: 2009/02/20
公開日: 2009/02/20
ジャーナル 認証ありAn optimization model for chemical production planning with optimal management of purchase and inventory was developed in this paper, based on the characteristics of the chemical industry. The objective of the model was to maximize the gross profit of a chemical enterprise while considering several constraints, such as material balance, chemical reaction balance, production capacity, product demand, raw material supply, inventory balance and inventory capacity. In the optimization model, a novel inventory management model was proposed to implement optimal management of purchase and inventory of raw and intermediate materials. In order for the above planning model to be applied in chemical enterprises to improve management level, a Graphic I/O Chemical Industry Modeling System (GIOCIMS) was developed. The proposed chemical production planning optimization model with optimal management of purchase and inventory was validated by two cases in which GIOCIMS was applied in a real world chemical enterprise. Results indicated that the proposed model was efficient for production planning optimization in the chemical industry.抄録全体を表示PDF形式でダウンロード (433K)
Materials Engineering and Interfacial Phenomena
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Yuntao Song, Yanzhao Yang, Hui Liang原稿種別: Research Paper
2009 年 42 巻 2 号 p. 117-125
発行日: 2009/02/20
公開日: 2009/02/20
ジャーナル 認証ありZnO wurtzite nanoparticles (crystallite sizes ca. 15 nm) were prepared via thermal decomposition of batch supercritical antisolvent (SAS) processed zinc acetate precursor. Batch SAS could produce nanoscale zinc acetate particles (average sizes ca. 35 nm) at 4°C and 15 MPa when choosing the optimum flow of the supercritical fluid. ZnO nanoparticles were formed by decomposing nanoparticles of zinc acetate at 150, 300 and 450°C, respectively. The Zinc acetate and ZnO nanoparticles were characterized based on TEM, FTIR spectroscopy and X-ray powder diffraction. TGA and FTIR spectra were used to the thermal decomposition course of the zinc acetate particles. ZnO nanoparticles were ultrapure and have no residual organic group. Calcination temperatures of zinc acetate particles have no significantly negative influence on the size of final ZnO particle. The ZnO crystalline agglomeration, particle size and size distribution are determined by the quality of the SAS processed precursors. The present work is helpful to develop a clean, size controllable nanoparticle preparation method.抄録全体を表示PDF形式でダウンロード (2566K) -
Xiaoyan Sun, Jianwei Li, Chunyan Hang, Yingxia Li, Biaohua Chen原稿種別: Research Paper
2009 年 42 巻 2 号 p. 126-133
発行日: 2009/02/20
公開日: 2009/02/20
ジャーナル 認証ありMCM-22 zeolites with various morphology properties including BET surface area, pore volume and platelet size were synthesized using glycerin as the auxiliary chemical (AC) under dynamic hydrothermal conditions. The products had been characterized by means of XRD, BET, TG-DSC, FT-IR and SEM techniques. Depending on the amount of the auxiliary chemical, the BET specific surface area of MCM-22 could be controlled up to 483 m2·g–1. Moreover, the alkylation of benzene with propylene was carried out under liquid-phase reaction over the prepared MCM-22 zeolite. The results showed that, in the alkylation catalyzed by the MCM-22 obtained using glycerin as the AC with the molar ratio of AC/SiO2 = 1.0, the selectivity of cumene was improved to 80.8%, which was about 5.0% higher than that in the alkylation catalyzed by the material obtained without using auxiliary chemical. Finally, a conceivable mechanism of catalytic performance improvement in the presence of glycerin as the auxiliary chemical is discussed.抄録全体を表示PDF形式でダウンロード (2139K) -
Hiroaki Wakayama, Yoshiaki Fukushima原稿種別: Research Paper
2009 年 42 巻 2 号 p. 134-138
発行日: 2009/02/20
公開日: 2009/02/20
ジャーナル 認証ありSupercritical fluids (SCFs) are used for the preparation of size-controlled nanoparticles in micro- and meso-porous silicas with different pore sizes, CnFSM-16 (n = 8, 10, 12 and 16; pore diameter = 1.6–3.5 nm), where the value n denotes the carbon number in the alkyl chain of the surfactant template. Precursors, M(acac)n (M = Pd, Rh, Ru and Fe; acac = acetylacetonate), dissolved in supercritical CO2 with acetone were loaded on the FSM-16, followed by reduction in a flow of H2 at 673 K or oxidation in a flow of O2 at 673 K. Nanoparticles of Pd, Rh, Ru and Fe2O3 can be impregnated on nanoporous silica with a uniform pore size, i.e. FSM-16. The particles are highly dispersed and have a small size distribution. Metal/metal oxide nanoparticles were impregnated inside the pores. For the impregnation of Pd nanoparticles, size-controlled Pd nanoparticles can be prepared in the FSM-16 nanoporous silica with a uniform pore size. The particle size linearly increased with the increase in the pore size of the FSM-16.抄録全体を表示PDF形式でダウンロード (798K)
Environment
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Photodegradation of Toluene and Xylene by Fluidized Bed Gaseous System with TiO2/SiO2 PhotocatalystsJae-Hyoung Park, Yong-Soo Seo, Jea-Keun Lee, Il-Kyu Kim原稿種別: Research Paper
2009 年 42 巻 2 号 p. 139-146
発行日: 2009/02/20
公開日: 2009/02/20
ジャーナル 認証ありToluene and xylene are typical volatile organic compounds (VOCs) found in contaminated sites. The photodegradation of toluene and xylene in a photocatalytic fluidized bed system with TiO2/SiO2 have been investigated. TiO2 film was prepared by the sol–gel method and coated on the silica–gel particles. The UV lamp is installed in the center of the reactor, and the toluene and xylene are analyzed by GC/FID/MSD. The effects of different photocatalyst sizes, superficial gas velocity, and sole UV light on the photodegradation of toluene and xylene (m,p-xylene and o-xylene) have been examined in the fluidized bed reactor. At steady-state, operation about 80.1, 99.8, and 99.9% of removal efficiencies have been achieved for toluene, m,p-xylene and o-xylene, respectively, in the optimal conditions (2.0 Umf of superficial gas velocity and 1.43 of height/diameter ratio). Benzene, acetaldehyde, formic acid, and malonic acid were identified as reaction intermediates of toluene. It has been proposed that toluene was oxidized by OH radicals and sequentially led to formation of benzene, acetaldehyde, formic acid, and malonic acid. In addition, benzene, toluene, acetaldehyde, formic acid, and malonic acid were identified as photodegradation intermediates of xylene. It has been proposed that xylene was oxidized by OH radicals and sequentially led to formation of benzene, acetaldehyde, formic acid and malonic acid. In this study, the development of an effective decomposition system to utilize solar energy and TiO2/SiO2 photocatalyst has been investigated for the removal of gaseous contaminants.抄録全体を表示PDF形式でダウンロード (2900K)
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