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
Outstanding Paper Awards Subcommittee of Journal of Chemical Engineering of Japan has assessed the 168 papers published in volume 42 into 2009, and the editorial board finally selected the three papers for JCEJ Paper Awards of 2009; those are the papers on “Promotional Effect of Titanium on the Catalytic Performance of Anodic Alumina Supported Silver Catalyst for the Selective Reduction of NO with Propene,” “Preparation of L929 Cell Array by Magnetic Pin Holder Device for Single Cell Function Analysis,” and “Modeling for PEFC MEAs Based on Reaction Rate on Pt Surface and Microstructures of Catalyst Layers.”
The purpose of this study is to examine the possibility of establishing innovative chemical-wise CO2 recovery system with a lithium silicate slurry bubble column, which could collect hot CO2 from massive emission sources. This is realized by using the composite of lithium and silica, called lithium orthosilicate, Li4SiO4, which can reversibly absorb and strip CO2 gas at high temperatures, i.e. ca. 700°C and 850°C, respectively. Therefore, continuous recovery of CO2 is feasible simply by thermal swing. The fundamental chemical reaction is expressed as follows: Li4SiO4+CO2 ⇄ Li2SiO3+Li2CO3. The reaction under high temperature conditions is possible by preparing molten salt as a reaction field. The lithium silicate is suspended in molten salt, and 20% CO2 containing gas is distributed to achieve absorption, both physically and chemically. To confirm the feasibility of the proposed system, two experiments were conducted to demonstrate CO2 capture ability: 1) physical absorption to Li-K-CO3 molten salt, and 2) chemical absorption to a Li4SiO4 suspended slurry. CO2 solubility and its level of mass transfer to Li-K-CO3 are investigated based on the results. Moreover, the performance of the CO2 recovery is investigated from the effects of gas feed rate, quantity of absorbent, and suspension concentration. Overall, the proposed system enables CO2 recovery under hot conditions, resulting in high efficiency recovery. This study establishes a lithium silicate suspended slurry system as an effective instrument for recovering CO2.
Mechano-chemical processing for the solid-state polymorphic transition of theophylline from Form I to Form II has been investigated. Contrarily to the same transition without mechanical energy, the transition was found to proceed without humidity and completed in about 24 h. The effect of additives on the transition was examined by co-grinding with purine derivatives. Except for uric acid, they delayed the transition to Form II, and the presence of paraxanthine resulted in going through a Form III of theophylline. In conclusion, additive selection has an important role for controlling the polymorphic transition and the appearance of polymorphs by mechano-chemical processing.
Numerical computations on vapor flow and non-absorbable gas diffusion in the evaporator/absorber are performed in order to research the extraction method of non-absorbable gas. Non-absorbable gas behavior was tried to control by using an immersed plate and an extraction. From the results, it was found that both the immersed plate and the extraction can prevent from the performance decrease of the absorber. Non-absorbable gas tended to stay in the low vapor velocity region, because non-absorbable gas is rolled up into the low velocity region. Non-absorbable gas diffused from the low velocity region, when the vapor velocity entirely becomes lower because of the absorber performance decreases. In order to extract non-absorbable gas effectively, the extraction vent should be mounted near the position where non-absorbable gas was concentrated.
In this work, the effect of water content on biofilter performance is discussed. The inlet air humidity and media water content are two important parameters that affect biofilter performance. Using a laboratory scale biofilter unit, the effect of water content on toluene removal is studied. Water content of the packing media (peat) is varied and its effect on the removal efficiency was observed. Experimental data show that the biofilter media performed efficiently when the water content was around 50%. A good agreement between the model predictions and the experimental data was observed when experimentally obtained toluene removal efficiencies at various water contents were compared with the theoretical model predictions. Using the experimental data, correlations for biofilm surface area as a function of water content and porosity have been developed. These correlations can be useful in designing large-scale biofilter systems.
A microreactor was employed for the oxidative dehydrogenation of propane to propylene in order to suppress a deep oxidation of the resultant propylene to CO and CO2. Magnesium ortho-vanadate, doped and undoped with palladium, and calcium hydroxyapatite, were used as catalysts while the reaction temperature was controlled by steady- and unsteady-state conditions. The enhancement of the selectivity to propylene was the most advantageous effect from using the microreactor, and it occurred when calcium hydroxyapatite was used under an unsteady-state. For example, the selectivity to propylene was 0 and 73.0% using a fixed-bed continuous-flow reactor and the microreactor, respectively, under almost identical propane conversion of 3.1 and 3.2%, respectively. The advantageous effect was also achieved, although to a lesser degree, when magnesium ortho-vanadate was used undoped with palladium under both steady- and unsteady-state conditions. However these advantageous effects of the microreactor were not observed with magnesium ortho-vanadate doped with palladium. With regard to the selectivity to propylene, the redox nature of the catalysts seemed to influence the performance of the microreactor.
The production of high-density polyethylene involves frequent grade transitions due to increased diversity among the products demanded by consumers. In this study, staged property models are developed to predict the changes in polymer properties during continuous, discontinuous, and semi-continuous grade transitions. At the outset, the operation states of the reactors are divided into three stages according to their distinct dynamics. Polymer property models are subsequently formulated for each stage based on empirical models. Model parameters are updated on a real-time basis according to the change of the partial properties of polymers in the reactors. The effectiveness of the proposed model is demonstrated via application to an industrial slurry high-density polyethylene process.
Mesocellular siliceous foams (MCFs) functionalized with different groups were used in the trypsin immobilization process. Macromolecular reagents were co-assembled with trypsin in the MCFs to create a microenvironment resembling that in living cells. The catalytic characteristics and stability of trypsin preparations were investigated. The relative activity of immobilized trypsin was 122.9% when the enzyme was immobilized adsorptively in the MCFs. Trypsin assembled with BSA in the MCFs attained maximum specific activity, 1.33 times that of the unmodified immobilized trypsin. The Km value of the BSA derivative of trypsin was reduced to 15.9% and 16.6% relative to the valve for native and solely immobilized trypsin, respectively, while the Kcat/Km value of trypsin assembled with BSA was enhanced to 148%. The residual activity of trypsin assembled with BSA was 48.5% and 29.4% at 50°C and 60°C, respectively, after incubation for 60 min.
Recombinant human (rh)-prorenin expressed using the baculovirus expression vector system (BEVS) is processed in situ to produce active rh-renin. However, rh-renin is significantly degraded during very late stage of the infection. This study aims at preventing excess degradation of recombinant proteins in the BEVS. Culture media of baculovirus-infected Sf9 insect cells are supplemented with either protease inhibitors or bovine serum albumin (BSA) at various time points postinfection. Although the degradation of active rh-renin is suppressed by cysteine protease inhibitors, proteolytic activation of rh-prorenin into active rh-renin is also inhibited concurrently, and the yield of active rh-renin is decreased. On the contrary, BSA supplementation during late stages of the infection is useful for preventing the degradation of active rh-renin without affecting the proteolytic activation. This indicates that addition of proteins to culture media at specific time points postinfection is a simple and effective method for suppressing the degradation of recombinant proteins expressed by the BEVS.
We have developed an electrochemical antibiofouling system for plate heat exchangers that employs heat exchange plates as the electrodes. A field experiment was performed using plates made of titanium or Pt/IrO2-coated titanium. Iron bar and silver–silver chloride electrode were set inside of the heat exchanger, and used as a counter and reference electrode, respectively. The reactive current reached equilibrium above seawater flow at 1.0 m3 h−1, and a uniform potential distribution was observed. Electrochemical antibiofouling experiments were performed using seawater as the secondary cooling water, which was pumped through a strainer into the plate heat exchanger at a flow rate of 1.66 m3 h−1. Organism's attachment on the heat exchange plates was prevented for over 1.5 years by the electrochemical treatment.
Recent demands for cheaper and more compact devices require electronic devices to have more added in printed circuit boards. To meet these demands, smooth copper foils that enable finer copper wiring has need to be fabricated. For achieving such wiring, the effect that the initial deposition of copper on a titanium cathode has on the smoothness of the resultant foil and the effect of physical polishing and chemical etching of the cathode surface on the initial deposition of copper were investigated. The morphology of the titanium surface was modified by chemical etching using dilute sulfuric acid and by physical polishing with emery paper. We confirmed that the initial deposition of copper considerably affects the smoothness of the copper foil and that smooth foil can be obtained by the etching and polishing processes. In cathode samples where physical and chemical treatments were performed on the surface, the amount of deposition on the cathode was found to be high. We also confirmed the possibility of fabricating fine copper foil with minimal surface roughness. Irregularities with a depth of approximately 0.1 µm and line defects were observed on the surface of the treated titanium cathode, and the atomic ratio of metallic titanium on the surface by a factor of increased 3 to 4 as compared to those without treatment. The surface of titanium is covered by oxides and can be exposed by chemical etching and physical polishing. It is thought that the exposed areas of metallic titanium, which has a low electrical resistivity, act as nucleation points for the initial copper deposits and are useful for obtaining smooth copper foil through uniform copper deposition.
Specific behaviors of polymer solution droplets evaporating on a lyophilic surface are reported. Polystyrene (solute) is dissolved in acetophenone, anisole and mesitylene (solvent). The single solvents and acetophenone/mesitylene solvents are stationary during drying and form ring-like polymer films. On the other hand, mesitylene/anisole droplets move around on the surface at low solute concentrations. This movement results from solutal Marangoni flow, whose direction is the opposite to the direction of the acetophenone/mesitylene solvents. The movement is almost inhibited at low temperatures. At low temperatures, the droplets comprise a core film surrounded by a ring structure. The morphology of the core film depends on the mixing ratio of the components of the solvent.
We report achieving a very high voltage of 1.17 V, corresponding to an energy-conversion efficiency greater than 90%, for the first time in a polymer electrolyte fuel cell (PEFC) below 10 nA/cm2. We achieved this high efficiency by optimizing various parameters, such as humidity, catalyst and electrolyte membranes, so as to reduce the amount of adsorbed oxygen-containing species that originate from water on Pt.
Barren grounds (ground devoid of seaweed beds) in coastal areas present serious environmental problems in Japan and around the world. To restore seaweed beds on barren ground, a mixture of steel slag (hereafter referred to as slag) and compost, which included humic substances (HSs), was applied in a coastal area in Mashike (Hokkaido, Japan). Three plots on barren ground were considered. One was treated with slag, another was treated with a combination of slag and compost, and the third plot was left untreated (control plot). The types of seaweed and their fresh weights were recorded in the three subsequent years. Restoration of a seaweed bed was confirmed at the locations treated with a mixture of slag and compost, and that treated with only slag. Specifically, the amount of restored seaweed and the restored area at the former site were significantly larger than those at the latter site and control site. The concentrations of iron at the site with slag-compost mixture was significantly greater than those at the other sites. Because the pH values of seawater are known to be around 8.1, ionic species of iron are deposited due to the formation of hydroxides. Laboratory experiments showed that the elution of iron from slag is dramatically enhanced in the presence of HSs. This result was attributed to the complexation between iron on the surfaces of slag and HSs. Complex of iron with HSs can stably exist in solution. Therefore, applying a mixture of slag and compost is an effective technique to supply dissolved iron to barren grounds in a coastal area.