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))
Shin Mukai (Hokkaido University)
Akinori Muto (Osaka Prefecture University)
Nobuyoshi Nakagawa (Gunma University)
Hiroyasu Ogino (Osaka Prefecture University)
Naoto Ohmura (Kobe University)
Mitsuhiro Ohta (Muroran Institute of Technology)
Hiroshi Ooshima (Osaka City University)
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)
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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In a previous paper, we extended the Tao and Mason equation of state (TM EOS) to refrigerant fluids using speed of sound data. Herein, we employ the TM EOS to predict volumetric properties of multi-component mixtures of liquefied natural gas (LNG). The second virial coefficient, B₂(T), necessary for the mixture version of the TM EOS, in the absence of sufficient experimental data on B₂(T), were calculated from the corresponding state correlation. Analysis of our predicted results shows that the TM EOS is capable of accurately predicting the densities of multi-component liquefied natural gas mixtures over wide range of temperatures and pressures. The overall average absolute deviation (AAD) of the calculated densities from the literature ones for 222 data points was found to be 2.37%. Furthermore, the densities of LNG mixtures obtained from the TM EOS have been compared with those calculated from Peng–Robinson (PR) and Ihm–Song–Mason (ISM) equations of state. Generally, our results show that the TM EOS is favorable over the two other equations of state. The overall average absolute deviation for the 222 data points calculated by ISM and PR equations of state were of the order of 2.90% and 4.85%, respectively.

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ASOG is one of the group contribution methods for predicting activity coefficients. This article deals with the determination of ASOG group interaction parameters for 20 group pairs in order to extend and revise the existing parameter matrix. In particular, all group interaction parameters relating to the NMP group have been revised and extended. The group interaction parameters relating to the C≡C (C–C triple bond group) have also been revised. The data base used for determining the parameters are the vapor–liquid equilibria (VLE) and infinite-dilution activity coefficients (γ^∞) stored in the Dortmund Data Bank.

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The application of ionic liquids as alternatives to conventional organic solvents in extraction processes has been actively investigated. A crucial step towards the practical use of ionic liquids is the development of extractants that work effectively within these new media. In the present study, the extraction separation of rare earth metals into ionic liquids, 1-butyl, 1-octyl, and 1-dodecyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C_nmim][Tf₂N], n = 4, 8, 12), was performed using a novel extractant, N,N-dioctyldiglycol amic acid (DODGAA). Quantitative extraction of metal ions such as Y³⁺ and Eu³⁺ was selectively achieved in the presence of the base metal ion Zn²⁺, which was not extracted at all under the present experimental conditions. The extraction efficiency was enhanced for the shorter-alkyl-chain imidazolium ionic liquid [C₄mim][Tf₂N] compared to that for a conventional organic solvent system. Extraction mechanism studies elucidated that the metal extraction proceeds via proton exchange reactions between DODGAA and the metal ions in the ionic liquid (the same mechanism as in the conventional organic solvent). The stripping reaction, or recovery, of the metal ions from the extracting phase was readily accomplished with an acid solution such as nitric acid.

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A simplified solvent extraction process based on U, Pu and Np co-recovery using tri-n-butylphosphate (TBP) as an extractant has been developed for advanced aqueous reprocessing of fast neutron reactor fuel. The influence of the HNO₃ concentration in the feed and scrubbing solutions on the behavior of Np is evaluated experimentally and found to be co-extracted into the TBP with U and Pu. Moreover, the leakage ratio of Np to the raffinate is calculated from the changes in HNO₂ concentration in the feed solution. 9.89% of the Np leaked to the raffinate in low HNO₃ concentration feed and high HNO₃ concentration scrubbing solutions. Almost all the Np in a 4.9 mol/dm³ HNO₃ feed solution is recovered with U and Pu, based on the experimental flow sheet with double scrubbing solutions of 9 and 1 mol/dm³ HNO₃. The experimental results show a large contribution from the HNO₃ concentration in the feed solution and at the extraction section to Np(V) oxidation. On the other hand, the calculation results show that high HNO₂ concentrations in the feed solution tended to leak Np into the raffinate. The DF of Cs for U, Pu and Np product achieves 10⁵ in all runs.

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In order to quantitatively investigate the effect of convection in an electromagnetically levitated molten iron droplet on the thermal conductivity of the droplet measured by the electromagnetic levitation (EML) technique in the presence of a static magnetic field, numerical simulations of the melt convection in the droplet and measurements of the thermal conductivity with the periodic laser heating method were carried out. In addition, the thermal conductivity of molten iron was measured by the EML technique, and then compared with values obtained numerically. It was found that the numerical simulations could sufficiently explain the measurement of thermal conductivity by the EML technique in a static magnetic field. It is suggested that a static magnetic field of 10 T is enough to measure the real thermal conductivity of molten iron by the EML technique. Moreover, the correlation between the static magnetic field and the contribution of melt convection to the measured thermal conductivity was investigated by using a nondimensional parameter, which is the ratio of the electromagnetic force operated by the static magnetic field to that produced by the alternating current in the RF coils.

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Carbon dioxide reforming of methane to synthesis gas over an alumina-supported 1% Ni-based catalyst has been investigated at atmospheric pressure. The reforming reactions were carried out at reaction temperatures of 500–800°C. The catalyst activity and stability, carbon deposition, and synthesis gas H₂/CO ratio were determined. XRD, SEM, TGA and TPD techniques were employed to characterize the spent and fresh catalysts calcined at 900°C. Further experiments were performed at 600°C to reduce catalyst deactivation by coking. It was observed that, although increasing reaction temperatures from 500 to 600°C increased the formation of carbon, a further increase in reaction temperature to 800°C decreased the formation of carbon. The highest CH₄ and CO₂ conversion drops were recorded at 600°C. Experiments at 600°C revealed that addition of Ca promoter decreased coke formation and, therefore, enhanced the stability of the catalyst. Also, the combined partial oxidation increased the activity and reduced carbon formation. The optimum catalyst performance with respect to O₂ addition was obtained with a feed containing 20% O₂. On other hand, when the CO₂/CH₄ feed ratio was increased from 0.65 to 1.50, the drop in CH₄ conversion with time-on-stream was reduced from 65 to 15%. The best catalytic performance was achieved with a space velocity of 33 mL/min · g_cat.

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A modified kinetic model for the synthesis of dichloropropanol (DCP) from glycerin and anhydrous HCl has been proposed for high-pressure reactions with a fixed weight ratio of glycerin to acetic acid by considering the volume change arising from the generation of water during the reaction. The yield of DCP was found to be maximized at 130°C and 6 bar. The modified kinetic parameters and high-pressure reaction model were evaluated by high-accuracy fitting to experimental data. The results allowed the creation of a kinetic model suitable for application to DCP synthesis from glycerin and anhydrous HCl at high pressures.

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Constrained optimal control using an industrial three term controller is remarkably challenging to achieve, even for processes with simple dynamics. In this paper, an optimization based practical approach for the design of an industrial PI controller is developed for optimal servo control of integrating processes with operational constraints. The constrained optimal servo problem is formulated and converted into a simple analytical form, which allows for graphical analysis to be used to find the global optimum, by using a clever parameterization. The Lagrangian multiplier method is then applied to analytically find the optimal PI parameters by solving the equivalent unconstrained optimization problem. The developed method minimizes the optimal performance measure and also explicitly deals with the important control constraints, such as the maximum allowable limits in the controlled variable, the manipulated variable, and the rate of change of the manipulated variable. The proposed method is demonstrated through the example of a CSTR level control system.

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We investigate the adsorption of D₂/H₂ and HD/H₂ binary mixtures in carbon slit pores and carbon cylindrical pores using equilibrium molecular simulations, and determine the optimum pore size and topology for the quantum sieving of hydrogen isotopes at 77 K. We show that the grand canonical Monte Carlo method with the Feynman–Hibbs variational approach (FH-GCMC) can be used as an alternative to that with the rigorous Feynman path-integral formalism (PI-GCMC) for exploring quantum H₂ adsorption at 77 K. Further, we employ FH-GCMC to investigate the adsorption of D₂/H₂ and HD/H₂ binary mixtures at 77 K. We show that, under the separation conditions of adsorption/desorption cycling between 0.1 and 1 MPa at 77 K, the optimum pore topology for quantum sieving of hydrogen isotopes is a cylindrical pore, and the pore sizes that yield the largest recoverable adsorption amounts with high selectivity are 0.623 nm for D₂ and 0.625 nm for HD. We also demonstrate, by comparing the results with those from the binary-mixture FH-GCMC simulations, that the ideal adsorbed solution theory can effectively predict the selectivity of D₂ and HD over H₂ in nanopores at 77 K (below 1 MPa).

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