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) Nobuyoshi Nakagawa (Gunma University) 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 (University of Hyogo) 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
The batch cooling crystallization of the organic compound, ibuprofen, was carried out under 2.45 GHz microwave irradiation. n-Hexane containing a small amount of acetone (5 mol%) and Fluorinert™, which did not absorb microwave, were selected as the solvent and coolant circulating through the jacket of crystallizer, respectively. The ibuprofen-hexane solution was cooled from 40 to −1°C under microwave irradiation and no irradiation. When the solution was not irradiated to the solution, ibuprofen crystals appeared at 35°C. On the other hand, when irradiation with 300 W microwave was carried out, nucleation did not occur even when the solution temperature reached to −1°C. At that time, the supersaturation ratio was 9.5. Thus, crystal nucleation of ibuprofen was inhibited by the microwave irradiation. The effect of microwave irradiation continued for at least 100 min after the irradiation was stopped at −1°C. By adding a small amount of crystals to the highly supersaturated solution, small crystals with a narrow size distribution were produced.
The purpose of this research is the development of a hybrid volatile organic compounds (VOCs) treatment process, which consists of adsorptive separation and catalytic oxidation. This process greatly reduces energy consumption compared with conventional thermal or catalytic combustion processes. Low concentrations of VOCs in polluted air are initially separated and concentrated into a small stream in the adsorptive step, and the concentrated VOCs are oxidized on an electrically heated alumite catalyst. Numerical system evaluation was carried out to estimate the effect of the concentration of VOCs in the air on the material and energy balances. Experimental and theoretical studies were performed on the adsorption of toluene in nitrogen gas, and desorption and concentration by hot nitrogen purging, in fixed-beds charged with activated carbon. A linear driving force mass-transfer model with an averaged overall mass-transfer coefficient was found to provide an acceptable fit to the measured desorption data. The experimental and modeling results were used to assess the influence of the purge gas flow rate and regeneration temperature on the bed length and cyclic steady-state convergence times using cyclic dynamic simulation of thermal swing adsorption. The evaluation results showed that a large amount of energy could be saved, and the unit cost lowered, by combining the adsorption step with electrically heated catalytic oxidation in the treatment of gases with low VOCs concentrations.
Adsorption is an effective method for removing carbon dioxide (CO2) from natural gas. Herein, an adsorption/desorption experimental apparatus was designed and constructed to examine the performances and adsorption capacities of three typical 13X-type molecular sieves, 13X-PG, 13X-HP, and APG-II, for removing CO2 from a methane (CH4)/CO2 mixture. The effects of varying initial CO2 contents and adsorption pressures on the adsorption performance were investigated and discussed, and it was found that increasing the adsorption pressure could increase the adsorption capacity of the three molecular sieves. However, the breakthrough time for each molecular sieve was shortened at increased initial CO2 contents in the gas mixture. Moreover, the effects of varying the nitrogen-heating temperatures and flow rates on the desorption performance were investigated, and it was found that increasing the nitrogen-heating temperature and flow rate shortened the desorption times. Thus, a high nitrogen-heating temperature and a large nitrogen-flow rate are beneficial for improving the desorption performance of the molecular sieves.
Catalytic hydrothermal oxidation of p-chlorophenol has been examined using two types of reactor systems, i.e., a flow-type reactor system in which the catalyst powder was suspended in the reaction mixtures and a fixed-bed reactor system in which the sintered catalyst was packed in the reactor. Cu- or Fe-grafted TiO2 was employed as a catalyst and hydrogen peroxide was used as an oxidizing reagent. The decomposition efficiency of p-chlorophenol treated by the flow-type reactor system is considerably enhanced with the help of Cu-grafted TiO2 at reaction temperatures around 200°C; whereas, little effect is observed at any temperature for Fe-grafted TiO2. It is suggested that the Fenton-type reaction catalyzed by Cu ions contained in the Cu-grafted TiO2 and/or dissolved out in the solution undergoes substantial acceleration at high temperatures, leading to the increased generation of OH· radicals that can effectively oxidize p-chlorophenol. On the other hand, it appears that the Fe-ion-catalyzed Fenton reaction is suppressed in the hydrothermal environment. The prolonged treatment of p-chlorophenol using the fixed-bed reactor system, that is more suitable for practical use than the flow-type one, has also been performed with Cu-grafted TiO2 catalyst at a reaction temperature of 200°C. The result demonstrates that it is possible to treat p-chlorophenol continuously for up to 36 h without significant loss of the catalytic activity.
A pH-stat method for measuring the dissolution rates of calcium-based alkaline industrial wastes (CAIW) in flue gas desulfurization is applied in this paper. The dissolution characteristics of two kinds of CAIW including carbide slag (CS) and magnesium slag (MS) were studied in a stirred tank at 30, 40 and 50°C, pH values of 4.3, 5.4, 6.0 and 7.5, particle sizes of 0.000–0.097, 0.097–0.105 and 0.105–0.3 mm and stirring speed of 300 rpm. The dissolution rate control step of CAIW was analyzed by using a modified shrinking core model. It was found that CS dissolution kinetics followed the film diffusion accompanied by surface reaction control, and the activation energies of the two steps were 7.89±1.0 kJ mol−1 and 14.41±1.0 kJ mol−1, respectively. The MS dissolution obeyed the surface reaction model and the activation energy was 14.51±0.5 kJ mol−1.