Editors: Ryuichi Egashira (Tokyo Institute of Technology) Jun Fukai (Kyushu University) Choji Fukuhara (Shizuoka University) Takayuki Hirai (Osaka University) Masahiko Hirao (The University of Tokyo) Jun-ichi Horiuchi (Kitami Institute of Technology) Eiji Iritani (Nagoya University) Yoshinori Itaya (Gifu University) Hideo Kameyama (Tokyo University of Agriculture and Technology) Masahiro Kino-oka (Osaka University) Toshinori Kojima (Seikei University) In-Beum Lee (Pohang University of Science and Technology (POSTEC)) Kouji Maeda (University of Hyogo) Shin Mukai (Hokkaido University) Akinori Muto (Osaka Prefecture University) Nobuyoshi Nakagawa (Gunma University) Hiroyasu Ogino (Osaka Prefecture University) Naoto Ohmura (Kobe University) Mitsuhiro Ohta (The University of Tokushima) Yuji Sakai (Kogakuin University) Noriaki Sano (Kyoto University) Masahiro Shishido (Yamagata University) Richard Lee Smith, Jr. (Tohoku University) Hiroshi Suzuki (Kobe University) Shigeki Takishima (Hiroshima University) Yoshifumi Tsuge (Kyushu University) Tomoya Tsuji (Nihon University) Da-Ming Wang (National Taiwan University) Yoshiyuki Yamashita (Tokyo University of Agriculture and Technology) Miki Yoshimune (National Institute of Advanced Industrial Science and Technology (AIST))
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AIMS AND SCOPE:
Journal of Chemical Engineering of Japan, an official publication of the Society of Chemical Engineers, Japan, is dedicated to providing timely original research results in the broad field of chemical engineering ranging from fundamental principles to practical applications. Subject areas of this journal are listed below. Research works presented in the journal are considered to have significant and lasting value in chemical engineering.
Physical Properties and Physical Chemistry Transport Phenomena and Fluid Engineering Particle Engineering Separation Engineering Thermal Engineering Chemical Reaction Engineering Process Systems Engineering and Safety Biochemical Food and Medical Engineering Micro and Nano Systems Materials Engineering and Interfacial Phenomena Energy Environment Engineering Education
The adsorption behavior of toluene on activated carbon in the presence of carbon dioxide was measured from 313 to 353 K at 10.0 and 15.0 MPa. The amount of toluene adsorbed increased with increasing temperature and decreasing pressure, which indicates that the density of carbon dioxide has a significant impact. The Langmuir model was applied to investigate the amount of adsorbed toluene at various mole fractions at each isothermal and isobaric condition: The Langmuir constants decreased with increasing carbon dioxide density. A mathematical model was applied to describe the adsorption kinetics with consideration of the equilibrium, diffusion in the solids, axial dispersion, and mass transfer from the bulk of the fluid phase to the surface of the solid. The model provides a good representation of the experimental data with one fitting parameter: the effective diffusion coefficient of toluene in the pores. Additionally, the effective diffusion coefficient strongly depends on the density of carbon dioxide, which implies that the breakthrough curves could potentially be predicted at various conditions.
The diffusion coefficients of aqueous mixtures of two deep eutectic solvents (DESs) and their densities and viscosities have been measured at different concentrations and temperatures (303.15 to 323.15) K and normal atmospheric pressure. The DESs were choline chloride/ethylene glycol and choline chloride/malonic acid. The diffusion coefficients were measured using Taylor dispersion technique and the data were used to adjust the parameters of such empirical and semi-theoretical models as the equation by Snijder et al., UNIDIF equation, and an equation based on the rough hard-sphere theory. The density and viscosity of the aqueous DES systems have also been measured and the data used to determine the parameters of a Vogel–Tamman–Fulcher-type equation, and to express the properties’ dependence on temperature and composition. The data and the corresponding values calculated from such equations and correlations agree well.
A specially designed high-density downward gas–solids flow fluidized bed, consisting of a solids reservoir tank, a solid distributor, an acrylic downer (3.0 m high), a gas–solid separator and a solid receiver tank, has been developed to study the fundamentals of high-density downward gas–solids flow characteristics in the downer reactor. Experiments have been carried out using two types of sand particles (ρp=2600 kg/m3, dp=80 and 320 µm) as bed materials with superficial downward gas velocities (Ugd) ranging from 0 to 5 m/s. Particle diameter has a great effect on the solids mass flux (Gs) and solids hold-up (εs) in the downer. It is found that Gs in a 50 mm diameter downer reached up to 1876 and 815 kg/m2·s, with average εs up to 0.16 and 0.07 in the developed region, for 80 and 320 µm sand, respectively. The solids hold-up decreased with increasing Ugd at a fixed solids mass flux in the developed region. By considering the effects of downer diameters, operating conditions, and solids properties, a correlation for the prediction of dense solids hold-up (εs*>0.07) in the developed region of the downer is proposed based on experimental data from the literature and this study.
To synthesize polymer-grade propylene from bioethanol containing an organosulfur compound such as dimethylsulfide (DMS) or dimethylsulfoxide (DMSO), we examined the adsorptive desulfurization of propylene by employing commercial activated alumina. It was found that both DMS and DMSO were converted predominantly to hydrogen sulfide during the catalytic conversion of ethanol to propylene over HZSM-5 zeolite. The performance of the adsorbent was evaluated by measuring a packed-bed breakthrough curve for the adsorption of hydrogen sulfide in gaseous propylene. Because of the adsorptive desulfurization, the concentration of hydrogen sulfide in propylene could be reduced to less than 10 ppb.
Transparent TiO2–SiO2 thin films doped with single dopants, such as a metal (Fe3+ ions), a non-metal (N-S), or a sensitizing dye (polyaniline, PANI), were synthesized by a modified sol–gel method combined with the peroxo titanic acid (PTA) approach at low temperature (∼100°C). These samples were characterized by X-ray diffraction, wavelength-dispersive X-ray fluorescence spectrometry, Fourier-transform infrared spectroscopy, nitrogen adsorption–desorption isotherm measurements, and UV-Vis spectroscopy. The photocatalytic activities of the films were assessed by the degradation of methylene blue and formaldehyde. The results indicated that the crystallite size of anatase TiO2 was 15 nm. The photocatalytic activities toward gaseous formaldehyde degradation were similar, about 90% and 87% under UV and visible light irradiation, respectively, in the case of all the samples. These results suggested that the doped TiO2–SiO2 thin films exhibited high photoactivities.
Type: Research Paper
Subject area: Process Systems Engineering and Safety
2012 Volume 45 Issue 12 Pages
Published: December 20, 2012
Released: December 20, 2012 [Advance publication] Released: July 24, 2012
The tuning of PID controllers is of great importance for process industries because it directly affects productivity, operability, and operating cost. Performance monitoring and maintenance of PID controllers are also serious issues for anyone seeking to maintain profitable plant operation. This paper presents a novel PID tuning methodology using a reference trajectory and a simple optimization-based algorithm. In particular, the proposed methodology is readily able to handle process constraints and to obtain PID tuning parameters using optimization directly. An application of this tuning method to a liquid level controller in a drum is shown, which has a constraint to avoid flooding of the liquid level. Furthermore, the method was implemented in DCSs of two kinds and was demonstrated successfully by simulation of a Crude Distillation Unit preflash drum.
Estimation algorithms to measure the actual performance of a lithium-ion battery are presented for real-time online monitoring. Capacity was selected as the representative variable indicating the performance of the battery. Three algorithms were suggested to estimate the degree of capacity fading: principal algorithm, supplementary algorithm, and hybridized algorithm. The principal algorithm was based on a simplified equivalent circuit model and a soft sensor technique. The soft sensor technique was based on a system identification methodology with moving horizon estimation. The supplementary algorithm was developed to compensate for the problem of computational load. Finally, both the algorithms were combined to develop a complementary hybridized algorithm. The suitability of the algorithms was demonstrated with real-time online monitoring of fresh and aged cells using cyclic experiments.
In this study, the effect of polymer decomposition temperature on the preparation of boron carbon oxynitride (BCNO) phosphors is investigated with the aim of obtaining materials with enhanced photoluminescence properties. Three types of polymers, including polyethyleneimine (PEI), polyallylamine (PAA), and tetraethylene glycol (TEG) are used as carbon sources for the formation of BCNO phosphors. PEI is found to have the highest internal quantum efficiency (IQE) of the three polymers because of its optimum thermal decomposition temperature and high exothermic energy during BCNO formation. The IQE of the BCNO phosphors prepared with PEI is 50%, representing a 130% increase over the value observed when TEG was used as the carbon source. In addition, the emission band of the BCNO phosphors can be tuned from 380 to 490 nm by varying the reaction temperature and polymer concentrations.