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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A nanoparticle dispersion process was designed on the basis of a simulation-based in-depth evaluation of the bead–fluid interactions in a stirred media mill. Volume-averaged four-way coupling equations were used to simulate the bead motion and turbulent flow. A distinct element method (DEM) was studying for bead motion and a large eddy simulation (LES) was used for investigation turbulence flow. Methods for calculating the power of the fluid shear, bead collision, and friction are presented in this paper. A high power area that developed in the mill was visually represented and quantified. In addition, the effect of the fluid shear, bead collision, and friction power on the dispersion of aggregates was evaluated in detail by varying the operational parameters. Under the conditions that promote dispersion of the aggregates (high bead filling ratio, high stirring rate, and small bead diameter), the fluid shear power was the only force generated in the mill that consistently increased. The frequency of bead–bead contact, which is thought to be an important factor influencing dispersion, was also calculated. This parameter remained unchanged when the stirring rate was increased; in contrast, the frequency of bead–bead contact increased for a high bead filling ratio and smaller bead diameter. The correlation of the average size of the aggregated particles attained in the dispersion experiment after 30 min with each factor (fluid shear, bead collision, and friction) and with the frequency of bead–bead contact was examined, and strong correlation of the average size of the aggregated particles with the fluid shear power and the frequency of bead–bead contact was observed. Therefore, for effective dispersion of the aggregates into the primary particle size, an increase in both the fluid shear power and the frequency of bead–bead contact is critical. In addition, these correlations facilitated the optimum design of a dispersion process in the wet stirred media mill.

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The batch cooling crystallization of an organic compound, p-acetanisidide, was carried out using methanol as a solvent and no seed crystal. The crystallization needed an induction period of 10–200 min before nucleation, and the size distribution of the product crystals was broad with sizes ranging from 10 to 270 µm determined as the diameter of a circle with equal projection area. In order to control the nucleation process and obtain microcrystals with a narrow size distribution, the dissolution of crystals obtained by cooling crystallization, followed by recrystallization was adopted. Thus, the crystals once obtained by cooling crystallization were completely dissolved by heating the slurry to a temperature 17°C that was higher than the saturation temperature by 1.5°C. After the solution was maintained at that temperature for a given time, it was cooled again. In the case of repeated crystallization, the induction period observed in the first crystallization disappeared, and small crystals with a mean diameter of 40 µm and a narrow size distribution were obtained. However, the effect of the complete dissolution of crystals on the production of microcrystals with a narrow size distribution disappeared when the solution was incubated at 17°C over 90 min. These results were explained on the basis of the history of the solution structure.

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To expand the knowledge of the extraction for metal ions with an amino acid derivative, a new extraction agent having proline as a functional moiety, 1-{2-[di-(2-ethylhexyl)carbamoyl)ethyl}pyrrolidine-2-carboxylic acid (D2EHCEP), has been synthesized in this study. In addition, a polymer inclusion membrane (PIM) has been prepared using D2EHCEP as a carrier and cellulose triacetate (CTA) as a polymer matrix to examine the solid–liquid extraction and membrane transport of metal ions. The PIM containing D2EHCEP exhibited an active transport of copper(II) against the concentration gradient and no transport of indium(III). This observation may be due to the difference in the structures of their extracted complexes, that is, indium(III) is only complexed with carboxyl groups through electrostatic interaction, whereas copper(II) forms chelate-complexes with amino and carboxyl groups of D2EHCEP. The influences of the aqueous and membrane components on the permeability of copper(II) were studied to elucidate the transport mechanism of metal ions across the PIM. Their results suggest that the rate-determining step for the permeability rate at high pH is the mass transfer of a metal complex across the membrane phase. The mass transfer coefficients in the aqueous boundary layer (k_f) and in the membrane phase (k_m) were determined based on the diffusion model. The mass transfer coefficients obtained were k_f=3.7×10⁻⁶ m s⁻¹ and k_m=4.3×10⁻¹⁰ m s⁻¹.

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When an accidental gas explosion occurs, a flame propagates spherically from the ignition point through the mixture of a combustible gas and air; the flame radius may reach 10 m or greater. Such a large-scale flame has a fractal structure induced by hydrodynamic effects, and the flame area, to which the flame speed is proportional, can be expressed in terms of the flame fractal dimension. Because the damage caused by an explosion is significantly influenced by the flame speed, knowledge of the fractal dimension can be used to estimate the consequences of the explosion. This paper discusses methods to predict the flame fractal dimension by computationally simulating the planar flame propagation. Three methods are tested and the results are compared. The first method, proposed in an earlier work, computes the fractal dimension from the dependence of the flame speed on the domain size; the second method is a Fourier analysis of the flame shape; and the third method is the widely used box-counting method. It is confirmed that these different methods yield consistent results.

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A new concept-sensitive factor and a modified factor analysis (FA) modeling approach called process monitoring based on sensitive factor analysis (SFA) are proposed to improve process monitoring performance. The aim of the present study is to solve the factors selection problem, which is a key step in process monitoring based on FA and can directly affect the monitoring result. Process monitoring based on FA usually employs the first several factors that represent the maximum information of normal operating sample, and the determination of factors is rather subjective. Generally, because the GT² statistic measures the variation along each of the loading vectors directly, it is possible to find some factors that reflect the dominant variation of abnormal observations, which are termed as sensitive factors in this paper. Additionally, the change rate of the GT² of each factor is defined to determine the sensitive factors. Then, a new fault diagnosis approach based on sensitive factors is proposed. Furthermore, a case study on the TE process demonstrates the performance of the SFA model on online monitoring. Results show that the performance based on SFA is improved signally, compared with the classical FA model.

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An energy-efficient distillation column using internal heat integration is proposed, and its energy saving performance and thermodynamic efficiency are compared with those of a conventional distillation column. The proposed column has three identical columns, with each handling one-third of the feed for a conventional binary distillation column, and two heat integrations are installed among them for the heat recovery. Applying different operating pressures, the heat integration among the columns is possible without vapor compression, of which the utilization is a main obstacle for the practical implementation of the existing internally heat-integrated distillation column (HIDiC). The performance comparison between the proposed and conventional systems indicates that the former requires 35.2% less reboiler duty and 36.8% less condenser duty compared with the latter for the benzene–toluene process and 29.2% less heating duty and 29.8% less cooling duty for the methanol–ethanol process. The thermodynamic efficiencies of the proposed and conventional systems are close for the benzene–toluene process. However, the efficiency of the proposed system in the methanol–ethanol process is lower than the conventional system due to the large enthalpies of the feed and products. Because the proposed system does not utilize a compressor, the difficulties accompanying the field application of the existing internal heat-integrated distillation system are eliminated. The operation and control of the proposed system are similar to those of the conventional binary column due to the separate reboiler and condenser attached to each of the three distillation columns.

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The transesterification of food oils to biodiesel under various ratios of magnesium slag to MeOH was investigated in terms of fatty acid methyl ester (FAME) yield. The use of slag as a heterogeneous catalyst enabled the conversion of used cooking oil into biodiesel. The optimal conditions for transesterification using untreated magnesium slag were studied, and it was found that maximum conversion was 96% after 12 h of reaction. The maximum achievable FAME yield was observed at a ratio of untreated magnesium slag to oil of 15 to 20% and a methanol (MeOH) to oil ratio of 20%. To investigate the mechanism of the transesterification reaction, the heterogeneous solid catalyst MgO–CaO/Al₂O₃, derived from magnesium slag was also tested. Maximum FAME conversion (98%) was achieved in 30 min, and it was noted that the MgO–CaO/Al₂O₃ catalyst showed increased performance in the presence of CO₂. The experimental work indicated that temperature is the main driving force for the transesterification reaction, leading to a FAME conversion efficiency of 98–99% within 1 min in the temperature range of 350 to 500°C. In summary, the use of the environmentally benign magnesium slag is a potential substitute for the commercially used homogeneous acid/base catalyst.

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Proteome analysis using two-dimensional electrophoresis (2-DE) was applied to characterize the physiological states of Brevibacterium flavum during threonine-limited lysine fermentation. Cell samples taken from batch culture under different physiological states were analyzed by 2-DE, and protein spots were identified by peptide mass fingerprinting. On differential analysis of 2-DE maps, the differences in physiological states of microorganisms were recognized at the protein level. The proteomic information obtained by 2-DE of culture samples provided a global and dynamic view of changes in the physiological state of B. flavum in response to environmental conditions.

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The effects of the bed temperature, gas flow rate, bed material and static bed height on the fast pyrolysis of Jatropha curcas L. seedshell cake (JSC) and palm shell in a bubbling fluidized bed reactor have been determined. Without catalysis, the maximum pyrolysis liquid yields of 49 and 56 wt% from JSC and palm shell are obtained at bed temperatures of 743 and 762 K, respectively. The effect of the FCC catalyst on the fast pyrolysis of palm shell has also been studied. The use of a fresh FCC catalyst (FC) and spent FCC catalyst (SC) increased the yields of gas and water, while the oil fraction decreased when compared with the non-catalytic pyrolysis. Elemental analysis shows that the oxygen content of the pyrolysis liquid decreased to 17% with the FC and to 23% in the presence of the SC, resulting in increased higher heating values (HHV) of the catalytic pyrolysis liquids compared with the non-catalytic pyrolysis liquid. Simulated distillation (SIMDIS) analysis of the JSC pyrolysis liquids show that the pyrolysis liquid obtained at a bed temperature of 744 K had the highest content of middle distillate.

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Crystal growth phenomena were investigated in the suspension melt crystallization of an organic acid. Methacrylic acid was used as the target material, a certain amount of methanol was used as the solvent, and the effect of a small amount of the maleic acid byproduct formed during the methacrylic acid synthesis was focused on. Batch crystallizations were carried out on a laboratory scale using various concentrations of maleic acid. In the presence of maleic acid, it was observed that the mother liquor compositions did not attain equilibrium. Moreover, the quantity of crystal deposition in the presence of maleic acid was smaller than in the absence of maleic acid; nevertheless, the final temperature in the crystallizer was the same. It was suggested that the amount of saturated deposition decreased in the presence of maleic acid. Furthermore, it was observed that the ratio of the growth rate of the minor axis to the growth rate of the major axis varied; the average aspect ratio of the obtained crystal particles gradually decreased over time concurrently with crystal growth. The variation of this growth rate ratio depended on the concentration of maleic acid and it was observed that the crystal size obtained was smaller in the presence of maleic acid than in the absence of maleic acid; maleic acid seemed to suppress the growth rate of the crystals. In addition, the relationship between the aspect ratio and crystal length suggested that aspect ratios of crystals deposited under lower supersaturation conditions will be small and this allows for the potential to decrease the surface washing load of the crystal particles.

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By-product hydrogen generated in chemical complexes has been used as feedstock for other chemical and refinery processes, as a product for sale, and as fuel for boilers. The value of by-product hydrogen has increased along with concerns about the depletion of fossil fuels and environmental problems. Therefore, utilization of high-grade by-product hydrogen is required under these circumstances. Fuel cells, for which the technology has grown to nearly the level of commercialization, are a high-value way hydrogen can be used. In this study, a fuel cell power plant was modeled using certain assumptions and was assessed to demonstrate its economic feasibility as a potential method for using by-product hydrogen. An economic profitability standard was calculated for the base case and sensitivity and break-even analyses were done for key variables. Some cases considered future plans about support systems and variations in prices. Feed-in tariffs and the continuing development of fuel cell technologies were important to guarantee the profitability of the system. The trend toward higher prices was not favorable under the situation in which a feed-in tariff was applied but had an advantage under a no feed-in tariff condition. The results of a comparison among various hydrogen sources indicate that by-product hydrogen from chemical complexes has an economic advantage.

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