Editor-in-Chief:
Hiroyuki Honda (Nagoya University)

Associate Editors-in-Chiefs:
Manabu Shimada (Hiroshima University)
Takao Tsukada (Tohoku University)

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))

Editorial office:
The Society of Chemical Engineers, Japan
Kyoritsu Building, 4-6-19, Kohinata, Bunkyo-ku
Tokyo 112-0006, Japan
journal@scej.org

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

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The solubilities of the system LiCl–Li₂SO₄–Li₂B₄O₇–H₂O at 298.15 K were calculated based on the Pitzer model and its HW extended model. The values of the parameters were derived from literature or through fitting with the solubility data of the respective ternary system in literature. By comparing the experimental values with the calculated solubilities, it is shown that the model can be used to successfully predict the solubilities of the system under investigation. The parameters and equilibrium constants obtained in this study can furthermore be used for solubility calculations of more complicated systems that contain Li₂B₄O₇, and the results can provide a theoretical basis for the extraction of lithium borate from salt lake brine sources.

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Membrane fouling phenomena, which can be certainly promoted by the adsorption of biomolecules such as proteins and polysaccharides, have been one of the major challenges in membrane separation. Surface modification has recently become a promising approach to suppressing such fouling. In this study, to conduct a computational design of an optimal surface modifier, a simple strategy has been applied, where the local affinities between an amino acid residue and a repeating unit of a candidate material are evaluated, by calculating free energy profiles for a residue approaching a repeating unit in explicit water molecules from a molecular dynamics simulation. We show that the predicted profiles for a 2-methoxyethylacrylate monomer have almost no energetically stable points. On the other hand, the profile for a conventional isophthalamide shows an energetically remarkable minimum. These results show the possibility for drastically simplifying the screening procedures of an optimal surface modifier.

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A previous numerical model has been expanded to predict the impurity concentration profiles during purification of bibenzyl by zone refining after several zone passes. It proves that the model is efficient through comparison of theoretical and experimental impurity concentration profiles within 10 passes. For all impurities in bibenzyl, 30 zone passes are sufficient for zone refining by theoretical computation under the experimental conditions. Through optimization of zone length for two typical impurities in theory, it shows that refining efficiency with varied zone length, adopting a longer zone length for the early zone passes, and a shorter zone length for the later passes, is higher than that with constant zone lengths in all passes. It provides a guide for purification of bibenzyl during processes of zone refining, theoretically.

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Dielectrophoresis can be applied to capture specific particles from particle mixture dispersed in a liquid. In this study, the motion of graphite particles mixed with TiO₂ particles dispersed in ethanol is observed in a dielectrophoretic condition. It has been found that a particle chain of graphite is first formed, and TiO₂ particles are attracted to the graphite particle chain afterward. The electric field profile has been calculated around a modeled graphite particle chain which is a conductive needle to observe the influence of the particle chain length on the DEP force qualitatively. This calculation reveals that the gradient of square of the electric filed strength at the particle chain can become significantly larger when the particle chain is longer. This result suggests that TiO₂ particles are attracted to the well-grown graphite particle chain even when TiO₂ particles are hardly attracted to the pristine electrodes. Namely, to keep high selectivity in the collection of target particles, the duration time for the dielectrophoretic separation should not be excessively long in order to interrupt particle chain growth to avoid the attachment of impurity particles.

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The properties of humic acid fouling in cellulose acetate microfiltration membranes and the response of the zeta potential, ζ_obs, of the membrane to the fouling were studied with two dead-end filtration modules connected in series. ζ_obs was monitored during the filtration by streaming potential measurement by pulse pressure mode. The fouling was caused by particulate humic acid at membrane surface and dissolved humic acid did not cause fouling. The fouling observed in the membrane having pore size of 0.22 µm was the cake filtration and those in the membranes having pore size of 0.45 and 0.8 µm were the pore blocking filtration followed by the cake filtration. The ζ_obs changed during the filtration responding to the increase in the filtration resistance. The responses of ζ_obs to the fouling can be elucidated in terms of the location of pressure drop and the local zeta potential.

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In this study, transition-metal-oxide bulk catalysts were prepared with the precipitation method to investigate their activity for the catalytic oxidation of volatile organic compounds (VOCs) (model VOCs: toluene and ethyl acetate), with an aim to develop a low-cost, safe, and highly effective substitute catalyst for noble-metal-based catalysts. A synergistic effect of copper and cobalt was observed over the Cu–Co oxide catalysts, which showed higher activity than either copper oxide or cobalt oxide alone. It is considered that in the Cu–Co catalyst, the fine dispersion of CuO particles on the surface of Co₃O₄, especially the formation of a Cu–Co spinel, probably causes an increase in the BET surface area and eventually enhances the VOC oxidation activity. When the 31 wt%Cu–44 wt%Co catalyst was subjected to toluene catalytic oxidation, it gave a complete oxidation temperature of 200°C, similar to that for a commercial 0.5 wt%Pt/Al₂O₃ catalyst. In ethyl acetate catalytic oxidation, dramatic activity was exhibited and the complete conversion temperature of 175°C obtained over the 31 wt%Cu–44 wt%Co catalyst was far lower than that for 0.5 wt%Pt/Al₂O₃ (ca. 300°C).

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Modern supply chains are expanding globally and are subject to a wide range of risks, such as demand uncertainty, natural disasters, and terrorist attacks. This study investigates a huge multi-stage logistics network design problem with facility disruption that could be caused by various risks. Discussing prospects for risk management against facility disruption, we have formulated a probabilistic programming problem. To find a solution for this design issue, we have proposed an effective hybrid method composed of the metaheuristic method and graph algorithms to offset potential losses from the network disruptions. Finally, the effectiveness of the proposed method is validated through numerical experiments.

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The intracellular NADH level in Escherichia coli cells harboring alanine dehydrogenase was regulated by introducing formate dehydrogenase from Mycobacterium vaccae. The cells were grown under aerobic culture conditions, with formate feeding to enhance alanine production. In cultures using media supplemented with 89 mM formate, alanine and pyruvate were produced at 49±3 and 73±2 mM, respectively, while 108 mM glucose was consumed within a culture time of t=24 h. The accumulation of alanine (94±2 mM) was further enhanced by supplementing the culture with additional formate at 89 mM and elevating the oxygenation level during the course of culture at t=12 h, which also suppressed the accumulation of pyruvate and lactate as by-products.

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The effects of freezing treatments on the activity of the lactobacilli-aggregating peptide QRCVNLQA were studied. The aggregation activity of the peptide solution was enhanced by rapid deep freezing in liquid nitrogen followed by storage for at least 1 d below －10°C. The treated peptide strongly induced the aggregation of suspended cells of Lactobacillus rhamnosus GG to provide a clear supernatant after 1.5 h. The peptide was activated by oxidation of thiol groups, probably through dimerization of the peptide molecules to form disulfide bonds. Addition of the freeze-oxidized peptide to a suspension of lactobacilli promoted the adhesion of the lactobacilli to a monolayer of Caco-2 intestinal epithelial cells.

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Cobalt nanoparticles were synthesized in mesoporous silica via a supercritical CO₂ impregnation technique using methanol as an entrainer at temperatures from 313 to 353 K, pressures from 20 to 25 MPa, and methanol concentrations from 5 to 20 mol%. The loading of cobalt particles in the materials, as quantified by energy-dispersive X-ray spectroscopy, was found to depend strongly on methanol concentration and slightly on temperature, and was revealed to reach a maximum of 3.8 wt% after calcination at 333 K, 20 MPa, a methanol concentration of 10 mol%, and a fixed reaction time of 5 h. Repeated treatment under the optimized conditions improved the Co loading up to 6.6 wt%, where the Co particles were observed by transmission electron microscopy (TEM) to be in the silica mesopores.

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The effects of mixed solvent on polymer film morphologies formed from droplets of solution dried on a substrate with circular hydrophilic surfaces patterned on a hydrophobic surface were investigated. Several solvent mixtures were used, with polystyrene as a solute at various concentrations. Droplets formed a thin film after shrinking on the hydrophobic surface to the boundary between the two surfaces. The results from the chosen binary solvent pair combination showed that ring films tend to shift to flat films at each mixing ratio as the initial solute concentration increases. Marangoni flow arising from the concentration profiles of the solvents and solute was discussed. However, no evidence was found for Marangoni effects changing the experimental film morphologies when considering the effect of solute. Instead, the viscosity and contact angle at self-pinning was found to affect film morphology.

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