Editors Ryuichi Egashira (Tokyo Institute of Technology) Jun Fukai (Kyushu University) Choji Fukuhara (Shizuoka University) Toshitaka Funazukuri (Chuo University) Takayuki Hirai (Osaka University) Jun-ichi Horiuchi (Kitami Institute of Technology) Eiji Iritani (Nagoya University) Yoshinori Itaya (Gifu University) Noriho Kamiya (Kyushu University) In-Beum Lee (Pohang University of Science and Technology (POSTEC)) Kouji Maeda (University of Hyogo) Hideyuki Matsumoto (Tokyo Institute of Technology) Masaru Noda (Fukuoka University) Hiroyasu Ogino (Osaka Prefecture University) Mitsuhiro Ohta (The University of Tokushima) Eika (W. Qian Tokyo University of Agriculture and Technology) Yuji Sakai (Kogakuin University) Noriaki Sano (Kyoto University) Naomi Shibasaki-Kitakawa (Tohoku University) Ken-Ichiro Sotowa (The University of Tokushima) Hiroshi Suzuki (Kobe University) Nobuhide Takahashi (Shinshu University) Shigeki Takishima (Hiroshima University) Yoshifumi Tsuge (Kyushu University) Tomoya Tsuji (Nihon University) Da-Ming Wang (National Taiwan University) Takuji Yamamoto (National Institute of Advanced Industrial Science and Technology (AIST)) Yoshiyuki Yamashita (Tokyo University of Agriculture and Technology) Miki Yoshimune (National Institute of Advanced Industrial Science and Technology (AIST))
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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
Power numbers of several large two-blade paddle impellers in stirred vessels with dished bottoms were measured for a wide range of Reynolds numbers. Mixing patterns of these impellers with dished bottoms were observed for a wide range of Reynolds numbers by using a decolorization method based on the reaction between sodium thiosulfate and iodine. The power numbers of these impellers can be correlated with the modified correlation of Kamei et al. A relationship was established between the power number diagram (Np–Re diagram) and the shape of the isolated zone. At low Reynolds numbers, complicated isolated zones were observed, while a cylindrically rotating isolated zone was not observed.
The separation of 2-adamantanone from 1-adamantanol and 2-adamantanol by simulated moving bed (SMB) chromatography is reported. Among several combinations of adsorbents and solvents, NaY-type zeolite and 2-methyl-2-butanol were selected as the optimal combination of stationary and mobile phases by batch experiments. SMB operation conditions were determined by using the free software ‘Wsmb’ for SMB simulation based on experimentally determined thermodynamic and kinetic model parameters. The simulation results were validated under the optimized experimental conditions, and in the experiment 2-adamantanone was recovered in 99.6% purity and 86.6% yield, showing good agreement with the simulation results. In addition, the variable cost of the SMB process was optimized on a commercial scale with the simulation software. The results show that the SMB process was economically viable under the assumptions of this study.
The present study was classified into two sections. In the first, a kinetic analysis of the oxidation of phenol in aqueous solution over a supported (0.7% Pt)/Al2O3 catalyst was investigated at atmospheric pressure in a batch operating system. The kinetic analysis proved that the reaction consists of two mechanisms, and that the initial rate and steady state activity regimes which exhibited first order behavior with respect to phenol concentration. The reaction rates show an unusual dependence on catalyst loading which suggested a heterogeneous–homogenous free radical mechanism. Phenol removal can be increased by increasing the amount of oxygen gas but at higher flow rates of oxygen a retarding effect of oxygen on phenol oxidation was observed. In the second section, a comparative study of the catalytical wet oxidation (CWO) of phenol in two different types of flow reactors (i.e., falling film and back mixing reactors) was carried out and design parameters such as inlet temperatures, residence time of reactants and catalyst loading in the reactors were used to establish similarity reaction conditions in the two reactors. The study supports the following conclusions: The oxidation rate of phenol was low because of the solubility of oxygen under atmospheric conditions. At low flow rates of liquid reactant the falling film reactor showed a better performance as a result of its lower resistance to mass and heat transfer while the result is completely different at higher liquid flow rates. Non-isothermal operation showed that water evaporation has a strong impact on phenol conversion and must be taken into account in scale up and adiabatic CWO reactor design. Neglecting evaporation can lead to erroneous calculation of the exit stream phenol conversion and temperature. The power law technique has been utilized to correlate the phenol conversion with the operating parameters in the two reactors.
A simplified decoupling method is compactly extended for general n×n multivariable processes by introducing coefficient matching to obtain a stable, proper, and causal simplified decoupler. This simplified decoupling technique allows transfer functions of decoupled apparent processes to be expressed as a set of n equivalent independent processes and then derived as a ratio of the original open-loop transfer function to the diagonal element of the dynamic relative gain array. The advanced design of proportional-integral/proportional-integral derivative (PI/PID) controllers is then directly employed to enhance the overall performance of the decoupling control system while avoiding difficulties arising from properties inherent to simplified decoupling. The structured singular value theory is considered to ensure robust stability of decoupling control systems under multiplicative output uncertainty. Some industrial processes are considered to demonstrate the simplicity and effectiveness of the proposed method.
In the process of rolling of Quenched and Tempered (Q&T) reinforcement bars, it is required for bars to obtain both good strength and elongation properties. Many parameters associated with the raw material and process affect the final properties of bars. In industry, destructive tests cannot be performed frequently to measure the final properties of bars. This study is an attempt to investigate the usefulness of various computational methods in the design of data based quality prediction models for Q&T reinforcement bars. To work with the problem, twelve parameters related to the raw material and process were selected as inputs and three features as outputs. Then, multiple linear regression, principal components regression, partial least squares regression, artificial neural networks and locally weighted regression were sequentially implemented to construct prediction models. In advance, to increase the prediction quality, we have proposed a selective approach which has three different modules. Two of the three select the proper models through pre-screening the process in terms of the similarity of the query to the pre-determined clusters. The third approach tries to incorporate the local correction from the value predicted by global linear model. For the collected data from two real industries, the proposed selective approach outperformed the five individual prediction models in overall comparison.
Glucose oxidase (GO) is encapsulated in phosphatidylcholine vesicles (PC liposomes) for controlling the oxidation rate of glucose at 40°C. The liposome membrane is composed of DEPC (1,2-dierucoyl-sn-glycero-3-phosphocholine), POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) or DLPC (1,2-dilauroyl-sn-glycero-3-phosphocholine). These lipids are different in the length and degree of unsaturation of acyl chains. In the static liquid system, the permeation of glucose through the membrane controls the oxidation rate. The GO in the DEPC liposome shows the highest activity, while that in the POPC liposome exhibit significantly low activity. In an external loop airlift bubble column, the oxidation reaction in the DEPC liposome system is markedly accelerated because of gas–liquid flow-induced membrane permeabilization to glucose. On the other hand, the oxidation rate obtained with the POPC liposome is still strongly controlled by the membrane permeation process and the rate is dependent on the superficial gas velocity in the airlift. The above results clearly demonstrate that the rate of liposomal GO reaction is controllable on the basis of the properties of acyl chains of lipids in combination with the gas-liquid flow of the liposome suspension.
We developed an effective microreactor for photoreactions by using a black aluminum oxide channel substrate with low reflectance and good heat conductance. The performance of this microreactor was tested by carrying out a photoreactive synthesis of benzopinacol and acetone from benzophenone and 2-propanol. In the microreactor made of quartz glass, the channels were blocked at smaller flow rates, because of precipitation from the product solution owing to the vaporized liquid components such as 2-propanol and acetone. However, in the microreactor that used the black aluminum oxide channel substrate, the channels remained unblocked and clear at the identical flow rates. The yield reached 36% with an irradiation time of 469.2 s and was improved by more than 30% when compared to the values obtained by the batch method. Furthermore, the temperature of the light emitting diode (LED) source remained at about 303 K with the microreactor that used the black aluminum oxide channel substrate with low reflectance, while the temperature of the LED source increased to 313–323 K when the microreactors made of quartz glass were used. Therefore, the microreactor that used the black aluminum oxide channel substrate was found to be effective for improving the yields of photoreactions.
We developed a microreactor for water separation through a T-type zeolite membrane by pervaporation. The microreactor was applied to an equilibrium esterification reaction of oleic acid, and the experimental rate constants were obtained in order to clarify the reaction mechanisms. The reaction processes were optimized for achieving an improved yield by water separation using microreactors. The addition of water separation to the batch method only improved the yield by 3.1% points from the equilibrium point at a longer reaction time of 180 min. On the other hand, in the microreactor system with water separation, the yield reached 62.6% and was improved by 10.3% points over the equilibrium point after a reaction time of 85.1 min. The experimental reaction rate constant for the forward esterification reaction, k1, for the microreactor system was approximately 5 times larger than that for the batch method. Furthermore, the rate constant for water separation, k2, for microreactors was around 108 times larger than that for the batch method. It was verified that water was effectively separated from the reaction mixture using the microreactor system, providing an improved product.
Biomass-derived chemical products are regarded as alternative materials because they substitute fossil resources for renewable resources. In this regard, the environmental impact originating from the production and consumption of the biomass-derived products should be assessed through life-cycle analysis, including biomass cultivation. In 2010, a commercial plant producing ethylene from sugarcane ethanol was constructed in Brazil and production of biomass-derived polyethylene (bio-PE) was started. In this study, we aim to reveal the environmental performance of bio-PE using life-cycle assessment by investigating scenarios in which bio-PE is produced in Brazil, shipped to Japan, used in containers and packages, and finally incinerated. The results demonstrate that bio-PE gives rise to a reduction in greenhouse gas (GHG) emission during its life cycle as compared to that of fossil-derived PE (fossil-PE). It is furthermore revealed that neither the transport of bio-PE from Brazil to Japan, the nonuse of surplus biomass, or land use transformation upends the dominance of bio-PE over fossil-PE. Based on these results, we conclude that the adoption of bio-PE can reduce GHG emissions originating from polyethylene production.
The cost of carbon dioxide (CO2) sequestration by an aqueous mineral carbonation process using waste concrete was estimated. We considered scenarios where the amount of waste concrete used and the conversion ratio of calcium to calcium carbonate (CaCO3) varied in the range of 30–300 kt/y/plant and 50–80 wt%, respectively. Installation of CaCO3 recrystallization equipment, which produces greater revenue, was also examined. The costs of CO2 sequestration and waste concrete treatment decreased with increasing waste concrete throughput and the conversion ratio of calcium to CaCO3. The lowest estimated cost of CO2 sequestration by the described process was −232 USD/t-CO2, and the process could sequester approximately 1.4 million t of CO2 annually, in Japan. The process can also be applied to recycling waste concrete; recycling becomes economically feasible when more than 90,000 t of waste concrete is treated by the plant annually. The proposed aqueous mineral carbonation process is highly competitive with other sequestration methods, but optimum efficiencies of scale are limited by the availability of waste concrete.