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) 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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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 linear blending rule (LBR) is the simplest mixing rule linking physical properties with mixture composition. It is just a composition-weighted arithmetic mean over the pure component property values. Unfortunately, the composition dependence of most mixture properties shows nonlinear deviations from the LBR. The conventional approach is to use higher-order Scheffé polynomials. However, this introduces cross-parameters that characterize nonlinear blending effects and that require extensive mixture data for their evaluation. Instead, we propose new parameter-sparse mixing rules that feature pure component parameters only. The new mixing rules were constructed by (i) employing composition-weighted power means, (ii) transforming the composition variables via Wohl’s q-fraction concept, and (iii) combinations of these two approaches.
Blending operations are widely employed in the petroleum and chemical process industries in order to maintain products within specifications. It is often impractical to analyze stream compositions when the number of components present is very large (e.g., gasoline blends). In such cases, there is a need for mixing rules that will allow prediction of the final blend properties from knowledge of constituent stream properties and the ratios in which they are blended. It is shown that this can be done if the q-fractions (r, s) mixture rule applies and the composition descriptors can be expressed in terms of a second, known mixture property. This principle is illustrated for the surface tension of the system benzene+n-hexane + cyclohexane with the refractive index chosen as the pure component composition descriptor. In essence, the q-fractions (r, s) model is a composition-adjusted weighted double power mean. It is a general form that includes several simpler models as special cases. The prediction accuracy of this family of models is demonstrated using surface tension, viscosity and refractive index data for the ternary system benzene + cyclohexane + hexane. Parameter confidence intervals were determined using the bootstrap.
In order to evaluate the potential of surface-discharge microplasma devices (SMDs) as ion sources for high-efficiency electrical charging of nanoparticles, a long SMD was installed in a surface-discharge microplasma aerosol charger (SMAC), and the charging performance of the SMD for aerosol nanoparticles was measured. The intrinsic charging efficiency for 5-nm-diameter particles was approximately 60%, and that for 10-nm-diameter particles was 90% at an aerosol flow rate of 1.5 L · min−1 because a long SMD is capable of generating a uniform concentration of ions over a wide area. The size-dependent charging efficiencies for these aerosol nanoparticles with diameters ranging between 3 nm and 30 nm were in good agreement with those predicted using the diffusion charging theory. The product of ion concentration (N) and charging time (t), estimated via the diffusion charging theory, was 3.0×1013 s · m−3, which is one order of magnitude higher than that for previously reported chargers. These results confirm the high potential of SMDs as ion sources for charging aerosol nanoparticles.
A mL-scale continuous crystallizer has been newly developed to produce small crystals with a narrow size distribution. The crystallizer is used for the poor solvent crystallization of glycine and L-alanine. The crystallizer is composed of a stainless-steel mixing vessel with an inner volume of 0.9 mL and a high-speed agitator that can agitate the crystallization solution up to 24,000 rpm. Glycine or L-alanine aqueous solution and poor solvent (methanol) are supplied into the vessel at a constant flow rate and intensely mixed by the agitator. The average residence time was set at 0.33, 3.3 and 33 s by changing the flow rate of an amino acid solution and poor solvent. The crystals obtained by the crystallizer are small and uniform in size, comparing with those obtained by a conventional beaker-scale semi-batch and continuous MSMPR type crystallizers. For example, glycine crystals having the 1/38 of the size of crystals obtained by a semi batch crystallizer were obtained. The short residence time that can be attained by the present mL-scale crystallizer is advantageous for the production of small crystals with a narrow size distribution. The size distribution can be further controlled by changing the mixing ratio of poor solvent.
The present study investigates the degradation of soy sauce cake, which is the waste obtained during soy sauce manufacturing, in subcritical water (170–300°C, 10 MPa). In the experiments performed at a constant temperature, the yields of the identified saccharides were lower than the total sugar yield. This suggested that saccharides were recovered mainly as oligomers. We performed a two-step experiment in which the holding temperature was 200°C and 260°C in the first and second steps, respectively. Most of the hemicellulose-derived saccharides were detected in the fraction treated at 200°C, while glucose was detected in the fraction treated at both of the abovementioned temperatures. The total sugar yield in the aforementioned experiment was higher than that obtained in other experiments performed at a constant holding temperature, suggesting that stepwise elevation of the holding temperature facilitates the recovery of valuable compounds from biomass.
In this study, the effects of the pretreatment time on the properties of Ni/TiO2 catalysts are examined. The optimum time has been determined to be below 3 h with regard to the catalytic activity. The difference between the CH4 conversion and CO2 conversion drastically increased for a catalyst pretreated for 4 h. The activity tests of the reverse water gas shift reaction (RWGS), temperature-programmed hydrogenation, and elementary reaction of dry reforming over the catalysts showed that the difference between the two conversions was attributed to the high RWGS reaction rate.
The deactivation rate equation for a commercial Cu/ZnO water–gas shift catalyst was derived on the basis of a high-order power-law equation for sintering rate. The parameters for the equation were then calculated from experimental data obtained over a short period during which the deactivation conditions were severe (250–350°C). The values calculated from an 11th-order deactivation rate equation were in good agreement with the experimental values over a long period (1000 h) under practical conditions (200°C).
To obtain a near optimal solution for operating procedure synthesis under safety constraint, in this paper, we aim at applying a meta-heuristic method termed differential evolution (DE). Compared with the approaches reported previously, we have shown DE’s ability to derive such an operating sequence that is adaptive to various practical requirements. Since the algorithm is straightforward and flexible to manage various conditions appearing in real-world applications, we can claim that the proposed approach has great promise. In a case study, we applied the proposed method to safety mixing operation of acrylic acid synthesis process and validated its adaptability under various significant practical conditions.
Lithium chloride (LiCl)-modified magnesium hydroxide (Mg(OH)2) is a material used for chemical heat pumps. LiCl-modified Mg(OH)2 is able to store thermal energy at around 250°C. LiCl-modified Mg(OH)2 was examined using 1, 7, and 105 runs of a cyclic dehydration and hydration operation. The sample was dehydrated at 250°C and hydrated at 110°C. It was found that the hydration conversion, which corresponds to the heat output performance, decreased from 81.1 to 65.7%. There were no LiCl needle-like crystals on the sample before the cyclic operation. On the other hand, after 105 runs of the cyclic operation, the sample showed LiCl needle-like crystals. The reason for the decrease in the reactivity of the LiCl-modified Mg(OH)2 could be a change in the surface state.