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 (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))
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
In this study, the heat and mass transfer processes in direct contact membrane distillation (DCMD) are compared with the heat transfer process in the traditional surface-type heat exchanger. A hollow fiber membrane heat exchanger is proposed for the heat transfer on the basis of the principle of DCMD. Unlike in DCMD, both the heat conduction and the latent heat transfer across the membrane wall are beneficial to the membrane heat exchanger. The heat conduction across the membrane wall is the basic heat transfer mode, while the transfer of latent heat of water vapor across the membrane is a new mode of heat transfer enhancement. A mathematical model of the heat and mass transfer processes is established for the hollow fiber membrane heat exchanger by using the distributed parameter method. The membrane heat exchanger is more compact and has a lower volume capacity than the traditional surface-type heat exchanger. Further, because of its large heat transfer contact area and the latent heat transfer enhancement mode, the membrane heat exchanger is more suitable for working conditions wherein the flow rate and the temperature difference between the hot and cold feeds in a heat transfer process are small.
The application of the recycle-effect concept to a double-pass parallel-plate mass exchanger under asymmetric uniform wall concentrations is proposed to enhance device performance. An analytical analysis of the Sherwood number and mass-transfer efficiency improvement is developed, and the theoretical predictions are represented graphically and compared with those in single-pass devices without inserting a permeable membrane. A considerable mass-transfer efficiency improvement is obtained by employing such a recyclic design with a suitable adjustment of the permeable-membrane location and recycle ratio, instead of using the single-pass device without external recycle. The results show that the recyclic double-pass operation can effectively improve the mass transfer efficiency, especially as the device is operated in the larger mass-transfer Graetz number.
An epoxy-group-containing vinyl monomer, i.e., glycidyl methacrylate, was graft-polymerized onto polyethylene particles with an average diameter of 35 µm at various reaction temperatures within 278–333 K. The produced epoxy group was converted into a diethylamino group as an anion-exchange group. From the equilibrium binding capacity of the resultant particle-packed bed for bovine serum albumin (BSA) and the pressure loss required for a protein solution to flow through the bed, the formation of graft chains that were sufficiently long to hold BSA in multilayers and allow convective flow among them was predicted. The achieved ideal adsorption characteristics enabled a higher flow rate of the protein solution, which leads to a higher overall adsorption rate of the protein because of convective flow among the graft chains.
Upward dead-end filtration tests accompanied with a sudden reduction in the cake surface during the course of filtration are proposed in order to determine the properties of the filter cake formed during microfiltration of oil-in-water (O/W) emulsion. Both upward and downward dead-end filtration tests were conducted under constant pressure conditions by using a filter having a sudden reduction in its filtration area, and the filtration characteristics between the two were compared. Consequently, it was found that the filtration rate in downward filtration was much higher than that in upward filtration as a result of cake exfoliation which occurred in downward filtration, leading to lower specific cake resistance. Moreover, when the average cake porosity was evaluated on the basis of an overall mass balance of dead-end filtration on the assumption that the cake was not exfoliated, the cake porosity in downward filtration became much lower than that in upward filtration for a similar reason. It was revealed that the correct values of cake properties were obtained from the data of upward dead-end filtration in which the exfoliation of the cake did not occur. It was necessary to consider the influence of the cake porosity in the calculation of the average specific cake resistance when an O/W emulsion was not dilute. On the basis of upward dead-end filtration tests, the power law relationship was applicable in order to represent the effects of the applied pressure on both the average volume fraction of oil droplets and the average specific resistance of the cake comprised of oil droplets. It was found that the cake formed during filtration of O/W emulsion was highly compressible due to the deformability of oil droplets. Moreover, the average volume fraction of oil droplets and the average specific resistance were kept constant throughout the course of filtration.
Potassium iron(III) hexacyanoferrate(II) (K/Fe–Fe(CN)6) supported on wood chips (WC) was prepared and its Cs uptake in seawater was measured under batch agitation. The Cs-uptake behavior of this adsorbent was compared with that of K/Fe–Fe(CN)6 supported on activated carbon (AC), which had already been published. Applying the Elovich equation, both the WC and AC adsorbents showed a similar time-dependence for Cs adsorption reaction, suggesting the same size of K/Fe–Fe(CN)6 particles for Cs diffusion. From the Cs-adsorption isotherm (298 K), the maximum Cs uptake per unit mole of Fe(CN)6 supported on WC (0.423 mol/mol-Fe(CN)6–1) was 7-fold larger than that on AC (0.060 mol/mol-Fe(CN)6−1): this difference in the Cs uptake should be ascribed to that K/Fe–Fe(CN)6 particles being partially filled into rather large macropores of WC, whereas narrow macropores in AC were blocked by the K/Fe–Fe(CN)6. The Cs-distribution coefficient, Kd for K/Fe–Fe(CN)6-on-WC is larger than that for K/Fe–Fe(CN)6-on-AC when the equilibrium Cs concentration in solution is high.
Separation of coker gas oil (CGO) by solvent extraction was studied for the recovery of aromatic hydrocarbons and upgrade of the oil to diesel fuel oil. CGO was analyzed by gas chromatograph to identify 17 kinds of aromatics, 16 kinds of alkanes and 6 kinds of alkenes, respectively. The liquid–liquid equilibrium extraction was conducted with furfural, sulfolane and methanol solvents. In all cases, the aromatic components in CGO were selectively extracted with the employed solvents. In the case of furfural without water, the distribution ratios of aromatics were larger than other solvents. With the solvent of sulfolane, the separation selectivities of aromatic components relative to nonaromatic components were larger than those with other solvents, although the distribution ratios of aromatics with sulfolane were approximately the same as those with other solvents. Methanol solvent without water could dissolve both aromatics and nonaromatics, thereby exhibiting low separation selectivity. However, the addition of water could improve the separation selectivities of aromatic components as much as those with furfural without water, and the distribution coefficient of methanol was the largest among the solvents used. When the aqueous solutions of sulfolane and methanol were used, di-cyclic aromatic components were selectively extracted among aromatic components. These kinds of solvents can be expected not only for the recovery of aromatic components, but also for the separation of aromatic components.
The present study investigates a monolithic silica microhoneycomb including ammonium molybdophosphate (AMP-SMH) that was synthesized for cesium separation in a continuous flow system. The honeycomb structure of the AMP-SMH causes significantly less hydraulic resistance to a liquid flow than a conventional bed of particles as demonstrated by pressure-drop measurements using water. AMP particles were dispersed as small particles ≈10 µm in diameter on or within the microchannels of the silica microhoneycomb as characterized by SEM. These AMP particles function as effective sorbents to remove ppm-level cesium ions effectively from a solution, as shown by the breakthrough curve. These data suggest the potential features of the AMP-SMH for processing a large volume of a solution containing radioactive cesium.
The catalytic conversion of 1,2-propandiol to propanal is examined using FSM-16 particles (0.85–1.70 mm) molded by wet-treatment and pressurization. When FSM-16 was molded with 0.6 g of pressurization and supplied to the catalytic conversion of 1,2-propandiol at 673 K, this system resulted in a 94.8% conversion of 1,2-propandiol and 90.5% selectivity to propanal at 0.25 h on-stream, which was the maximum amount of activity. However, at 4.50 h on-stream, the activity decreased extremely to deactivation 19.9% conversion of 1,2-propandiol and 84.7% selectivity to propanal. In contrast, when FSM-16 molded with wet-treatment (0.15 g) was used for the conversion at 573 K, activity was greatly increased and stable 98.6% conversion of 1,2-propandiol and 56.2% selectivity to propanal at 0.25 h on-stream followed by 91.9% and 52.5%, respectively, at 4.50 h on-stream. The hexagonal structure of FSM-16 was suggested to have contributed to the suitable conversion of 1,2-propandiol to propanal.
A control-oriented multivariable Hammerstein model is used to identify the strongly nonlinear dynamics of fuel cell systems that are described by nonlinear differential or differential-algebraic equations. Within the Hammerstein model framework, the static nonlinear part is constructed by a wavelet network, and the linear dynamic part is described by a discrete-time transfer function of the state-space model. For prescribed input-output patterns for high-order fuel cell systems, simulations demonstrate the accuracy of system identification using wavelet networks in the Hammerstein structure that is better than that in the neural network structure.
Production of endoxylanase and β-xylosidase by Aspergillus niger in solid state fermentation (SSF), submerged fermentation (SmF), and liquid surface fermentation (LSF) was studied. The production of endoxylanase and β-xylanase by LSF resulted in the highest enzyme activity among the 3 fermentation modes. The maximum endoxylanase and β-xylosidase activity in LSF was about 4.7 and 8.5 times that in SSF, respectively. The production of biomass and biomass yield in LSF was about 1.5 times higher than that in SmF. LSF was limited in the production of enzyme and biomass when the liquid film thickness is relatively high or is too low. The appropriate liquid level for LSF was found to be 0.5–1 mm.
The transient behavior of hybrid system composed of a photo-catalytic reactor and a biofilter was observed at the height of each sampling port to treat waste-air containing hydrogen sulfide highly concentrated up to 1000 ppmv with high loading. The biofilter packed with mixed media (of granular activated carbon and compost) was inoculated with a pure culture of Thiobacillus sp. IW, while the photo-catalytic reactor was composed of 15 W UV-A lamps and annular pyrex tubes packed with glass beads coated with TiO2 sol before calcination. The maximum elimination capacity of a biofilter-only process was 95 g/m3/h. On the other hand, the maximum elimination capacity of a hybrid system was observed to be 140 g/m3/h. The contribution of the photo-catalytic process to the increment of the elimination capacity of the applied hybrid system was composed of the direct contribution of photo-catalytic process and its indirect contribution to the increment of the elimination capacity of subsequent process, a biofilter. The contributions of the photo-catalytic process to the hybrid system-elimination capacity turned out to consist of a direct (37–55%) one and an indirect (45–63%) one for the removal of highly concentrated hydrogen sulfide with high loading of 232 g/m3/h. However, the indirect contribution of the photocatalytic process could not be estimated for the stages of lowly-loaded hybrid system run. Consequently, the percent-fraction of the indirect contribution of photo-catalytic process for the removal of hydrogen sulfide is reported to be smaller than that for the removal of VOCs.