Editor-in-Chief: Yoshiyuki Yamashita (Tokyo University of Agriculture and Technology) Associate Editors-in-Chiefs: Hiroyuki Honda (Nagoya University) Takao Tsukada (Tohoku University)
Editors Tomohiro Akiyama (Hokkaido University) Georges Belfort (Rensselaer Polytechnic Institute) Jun Fukai (Kyushu University) Yutaka Genchi (National Institute of Advanced Industrial Science and Technology (AIST)) Takayuki Hirai (Osaka University) Masahiko Hirao (The University of Tokyo) In-Beum Lee (Pohang University of Science and Technology (POSTEC)) Eiji Iritani (Nagoya University) Hideo Kameyama (Tokyo University of Agriculture and Technology) Masahiro Kino-oka (Osaka University) Toshinori Kojima (Seikei University) Shin Mukai (Hokkaido University) Akinori Muto (Okayama University) Nobuyoshi Nakagawa (Gunma University) Satoru Nishiyama (Kobe University) Hiroyasu Ogino (Osaka Prefecture University) Naoto Ohmura (Kobe University) Mitsuhiro Ohta (Muroran Institute of Technology) Hiroshi Ooshima (Osaka City University) Noriaki Sano (Kyoto University) Manabu Shimada (Hiroshima University) Masahiro Shishido (Yamagata University) Shigeki Takishima (Hiroshima University) Richard Lee Smith, Jr. (Tohoku University) Yoshifumi Tsuge (Kyushu University) Da-Ming Wang (National Taiwan University)
Editorial office: The Society of Chemical Engineers, Japan Kyoritsu Building, 4-6-19, Kohinata, Bunkyo-ku Tokyo 112-0006, Japan firstname.lastname@example.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
Ice growth depression and drag reduction of ice slurries treated with a combination additive of cetyl dimethyl betaine (surfactant) and poly(vinyl alcohol) (PVA) have been investigated. From the results, it is found that the particle size becomes smaller when treated by the present surfactants compared with the corresponding result of each concentration of PVA. Additionally, particle growth depression can be observed due to a cooperative effect of surfactants, even in the case when PVA concentration was reduced to 4 g/l from 8.7 g/l, which was required in the case without surfactants. The present combination additives also cause drag reduction phenomena on the solution. Thus, the combination of surfactants and of PVA could be a promising candidate as additives for improvement of ice slurry fluidity.
The swelling processes of polymer gels are described by the diffusion equation for the displacement of a stretched polymer chain. This diffusion equation and its boundary condition are mathematically obtained from the stress-diffusion coupling model, which is a system of constitutive equations for polymer gels. Numerical analysis of the free swelling of a spherical and cylindrical polymer gels is carried out to show the change of the displacement of particles inside and the change in the radius of the gels with time, and the results of our calculation are compared with experimental data. The calculated results are in good agreement with experimental data.
A method for direct silica-coating of fluorescent semiconductor nanoparticles is proposed. The fluorescent semiconductor nanoparticles used are quantum dots (Q-dots), which are CdSexTe1−x nanoparticles coated with ZnS and succeedingly surface-modified with amino groups. The silica-coating was performed in the presence of the Q-dots in 1–15 M H2O, 0.4×10−4–40×10−4 M NaOH and 0.5×10−4–50×10−4 M tetraethyl orthosilicate (TEOS). Silica shells were formed at 5 M H2O and 4×10−4 M NaOH. Under these concentrations of H2O and NaOH, the particle size of silica-coated Q-dots could be varied from 15.8 to 31.7 nm as the TEOS concentration was increased from 2.5×10−4 to 50×10−4 M. The silica-coated Q-dots showed fluorescence as well as the uncoated Q-dots.
The cross contamination of Na form resins from the regeneration step in a mix-bed ion exchange column for pure water production processing will affect the quality of the effluent. For the prediction of the effect of the contamination on performance of a regenerated column, the breakthrough curve of the column packed with Na form, NH4 form and H form cationic resins is studied. The ion exchange equilibria in the H–Na–NH4 system is explained by a simple form derived from selectivity coefficients of KHNa and KHNH4. The packing conditions of H form, Na form, and NH4 form cationic resins in a laboratory scale column were studied by stacking in layers and mixing in random order. The breakthrough curve depended on the packing conditions and was analyzed with a mathematical model in order to understand the local ion exchange behaviors. The effect of the packing conditions could be well simulated by using adequate initial conditions representing the packing conditions of resins in the column. It is shown that the homogeneous initial conditions of the mixing ratio of Na form resin is useful for the prediction of the effluent quality in an industrial scale column.
In this paper, an integrated energy-saving process module based on self-heat recuperation for distillation processes is proposed; the energy saving in this module occurs via heat circulation. The proposed integrated process module consists of a heat circulation module and a distillation module in which the heating and cooling loads are balanced by exergy analysis. The self-heat recuperation technology proposed in our previous studies is adopted, and thus, the heat of condensation and the cooling heat are recuperated by compressors and exchanged with the heat of vaporization and the heating heat by employing heat exchangers in both the heat circulation and distillation modules. The proposed technology helps to achieve a drastic energy saving of more than 80% in comparison with a benchmark process involving the use of an external heat source and a reboiler for heating. This shows that the proposed modularity of the heat circulation based on heat recuperation for a distillation process is a very promising feature for drastically reducing the energy consumption for distillation.
The hydrolysis of chloropentafluoroethane (CFC-115) is investigated using alumina–zirconia catalysts prepared from boemite and γ-alumina composed of various different alumina contents. In the case of alumina–zirconia (alumina–zirconia(B)) catalysts prepared from boemite, a catalyst with an alumina content of 90 wt% exhibited the highest rate of hydrolysis. The acidity of these catalysts is found to correlate to the rate of hydrolysis, however, the hydrolysis rate increases linearly with an increase in acidity. On the other hand, in the case of alumina–zirconia (alumina–zirconia(A)) catalysts prepared from γ-alumina, the hydrolysis rate and acidity increase with an increase in alumina content. The hydrolysis rate increases linearly with an increase in acidity. The hydrolysis rate and acidity over alumina–zirconia(A) are removed from the hydrolysis rate and amount of acidity over alumina–zirconia(B), respectively. The residual hydrolysis rate increases linearly with the residual acidity. Thus, alumina–zirconia(B) catalysts have been determined to bear two types of acidity.
According to previous reports, the oxidative dehydrogenation of lactic acid to pyruvic acid in an aqueous phase does not proceed with Pd/C, while Pd/C doped with Te or Pb has catalytic activity at atmospheric pressure and 363 K in an aqueous NaOH solution at a pH of 8. Since use of heavy metals, such as Te or Pb, is inconsistent with green chemistry, a heavy-metal-free Pd/C catalyst is employed in the present study. The oxidative dehydrogenation of sodium lactate to sodium pyruvate in an aqueous phase at 358 K under pressurized oxygen at 1 MPa proceeded favorably using Pd/C with no adjustment of solution pH. Under pressurized oxygen, the catalytic activity of Pd/C was similar to that of Pd/C doped with either Te or Pb. This result suggests that a heavy-metal-free Pd/C catalytst might also be applied to other catalytic reactions. As an alternative to doping Pd/C with Te or Pb, the dissolution of gaseous oxygen into the reaction solution significantly enhanced the catalytic activity of Pd/C. To show the contribution of the dissolution of gaseous oxygen, the effects of the volume of oxygen in the reactor (stainless autoclave) on the reaction rate and the activity were examined. The activation parameters thus obtained reveal that the volume of oxygen in the reactor is a more important determinant of catalytic activity than the activation of the reaction itself.
The aim of this study is to perform ultrafiltration experiments in vitro with several commercial hemofilters for continuous renal replacement therapy (CRRT) in aqueous albumin solution and in various modifications of bovine blood in order to discuss separation characteristics of albumin. In aqueous solution system, 2000 mL of a single component albumin solution (2.552 g/L) was used. Flow rates of the albumin solution and ultrafiltration were 100 and 10 mL/min, respectively, and the experiment was performed for 720 min at 310 K. Adsorption of albumin was evaluated from the time courses of the concentration profile and sieving coefficient (s.c.). We investigate two polymethylmethacrylate (PMMA), two polysulfone (PS) and one polyacrylonitrile (PAN) hemofilters with four kinds of bovine blood test solutions as well as the aqueous solution. PMMA that has strong adsorption characteristics showed relatively low s.c. for albumin (0.01–0.03) in aqueous albumin solution. PMMA membrane with enlarged pore size showed two times higher s.c. for albumin than that with normal pore size. Albumin concentration in the reservoir in aqueous experiments decreased approximately by 20% and 50% in 630 min using the PMMA membranes with normal and enlarged pores, respectively. On the other hand, albumin concentration decreased by only 5.0% and 4.4 to 5.5% using PAN and PS hemofilters, respectively. The discrepancy may be explained by the physical structures of the membrane, i.e. albumin molecules may have been occlusively trapped by the entirely dense structure of PMMA. In the PS membrane, s.c. for albumin in the aqueous system was not significantly different from those found in various bovine serum systems which implied that a very small amount of albumin was adsorbed by the PS membrane due to reduced hydrophobicity caused by the use of a large amount of hydrophilic agent.
The purpose of this study is to create a dehalogenation material made of wood powder cheaply. The dehalogenation material consists of an inorganic and organic compound. The sodium was adsorbed to the surface of the wood powder by ionic-bonding using low-temperature plasma irradiation. For the wood powder material, unwanted lumber from thinning trees in forests and scrap wood could effectively be utilized. This dehalogenation material, which consists of wood powder and sodium, can easily be used for an environmental cleanup business, because this material is biodegradable. When the sodium wood powder was put in water, highly-dense sodium ion concentration of 80 mg/L was released. The sodium wood powder was left in a hydrogen chloride gas atmosphere to examine the dehalogenation characteristics. As a result, it was verified that the chlorine was able to be removed from the hydrogen chloride. The sodium wood powder created in this experiment can be utilized as an adsorption material for contaminated soil with dioxins and PCB, also from vehicle emissions and for hydrogen chloride gas that would have been rejected by incineration facilities.
The destructive adsorption of dichloromethane (DCM), trichloroethylene (TCE), and perchloroethylene (PCE) on CaO powder under air flow was investigated. CaO pretreated at 823 K showed high activity (100% DCM conversion for 2 h) at 823 K under DCM (1 mol%)/air flow; 0.1 mol of CaO was used in this case. This amount was decided from the calculation data, according to which the amount of Ca2+ ions was equal to the total feed amount of Cl atoms in the reactant (DCM) during a 5-h reaction; CaCl2 was assumed to form in this reaction. During 100% DCM conversion, the main gaseous products formed were CO2, H2O, and CO, and no chlorinated product was formed. This implied that all the Cl atoms were captured in the CaO matrix to form CaCl2, as confirmed from XRD and XRF measurements. On the other hand, CaO was not useful for the destructive adsorption of PCE, and 100% PCE conversion was observed only for 5 min at 873 K under PCE (1 mol%)/air flow when 0.1 mol of CaO was used. When the amount of the reactant fed during a 10-h reaction was maintained at 0.2 mol, which corresponded to the CaO loading amount, the order of reactivity of the abovementioned chlorinated volatile organic compounds over CaO was TCE > DCM > PCE. This order could be explained on the basis of the H/Cl molar ratio in the reactant and the ease of thermal decomposition of the reactant because the destructive adsoption reaction proceeded via the reaction between the produced HCl and CaO.