All issues
Volume 42, Issue 6
Displaying 1-12 of 12 articles from this issue
- |<
- <
- 1
- >
- >|
Physical Properties and Physical Chemistry
-
Katsumi Tochigi, Jürgen Rarey, Jürgen GmehlingArticle type: Research Paper
2009 Volume 42 Issue 6 Pages 376-380
Published: June 20, 2009
Released on J-STAGE: June 20, 2009
JOURNAL RESTRICTED ACCESSThis paper deals with the determination of recommended temperature dependent NRTL parameters by simultaneous correlation of VLE-, γ ∞-, and hE data from the Dortmund Data Bank (DDB) using an interactive program package. Correlation results for selected mixtures are discussed in detail. The program package RECVAL is directly interfaced to the Dortmund Data Bank, makes extensive use of graphics for data representation and may be extended for the correlation and prediction of further mixture or pure component data. To ensure rapid conversion in case of a large amount of data, simultaneous convergence of the outer parameter fitting loop and the inner phase equilibrium iterations is employed. Recommended temperature dependent NRTL parameters have been determined for 133 binary systems. These parameters have been obtained by a simultaneous fit to VLE-, γ ∞-, and hE-data stored in DDB.View full abstractDownload PDF (1026K)
Particle Engineering
-
Naoki Noguchi, Akira Ohno, Shinji Aramaki, Haruki Asatani, Masakuni Ma ...Article type: Research Paper
2009 Volume 42 Issue 6 Pages 381-385
Published: June 20, 2009
Released on J-STAGE: June 20, 2009
JOURNAL RESTRICTED ACCESSA small molecule organic semiconductor CuTBP (copper tetrabenzoporphyrin) was formed from a precursor CuCP (Copper tetrabicycloporphyrin) using a solution process. In this study, the solid-state crystallization process of CuTBP on a substrate surface was observed and evaluated. To obtain good semiconductor performance, it is very important to understand and control the crystallization process, which was found to consist of three steps during annealing. These steps were clearly observed with XRD-DSC. Although the starting temperatures of the first and second CuTBP crystallization steps did not show distinct changes, the starting temperature of the third step changed significantly with the heating rate, requiring a temperature higher than 145°C. The grain morphology also changed depending on the crystallization temperature. At lower crystallization temperatures, the growth of homogeneously colored grains having diamond shapes was promoted, while at higher temperatures heterogeneously colored grains of petal shapes were formed.View full abstractDownload PDF (4095K)
Separation Engineering
-
Keigo Hanaki, Izumi HirasawaArticle type: Research Paper
2009 Volume 42 Issue 6 Pages 386-392
Published: June 20, 2009
Released on J-STAGE: June 20, 2009
JOURNAL RESTRICTED ACCESSThe nucleation behavior of an active pharmaceutical ingredient (API) is investigated in semi-batch drowning-out crystallization. A methanol solution of the API was fed in a short period into a well-mixed anti-solvent at low temperature. The effect on nucleation behavior of the amount of seed crystals and concentration of API methanol solution to be fed was investigated using in-line particle monitoring technique (FBRM). Despite the presence of seed crystals in anti-solvent into which the API solution was fed, nucleation took place after an induction period from feeding in some experiments, and it was found that the addition of seed crystals is effective to control the induction period and to enhance nucleation after the induction period. As for feed concentration, at high feed concentration, generation of nuclei during feeding was observed and then a supersaturated slurry of fine particles was obtained; however, at low feed concentration, anti-solvent became clouded locally during feeding and then clear supersaturated solution was obtained. At high feed concentration, it was also observed from time courses of FBRM chord count for several size classes that fine particles generated during feeding grew very slowly during the induction period, and rapid nucleation took place accompanied with agglomeration of fine particles and subsequent dispersion with generating nuclei.View full abstractDownload PDF (1212K) -
Masakuni Matsuoka, Kohei DanzukaArticle type: Research Paper
2009 Volume 42 Issue 6 Pages 393-399
Published: June 20, 2009
Released on J-STAGE: June 20, 2009
JOURNAL RESTRICTED ACCESSTo demonstrate the effect of mechanochemical processing on solid-state recrystallization, four inorganic salts of NaCl, KCl, NaBr and KBr were selected on the basis of a literature survey and crystallographic data, and their binary mixtures were ground with a planetary ball mill. X-ray powder diffraction patterns of the ground particles were analyzed, showing either formation of solid solutions and exchange reactions as well as no changes occurring due to grinding. The binary systems of NaCl–NaBr and KCl–KBr resulted in the formation of complete solid solutions, while the NaBr–KCl system exhibited the exchange reaction so that the final XRD patterns were exactly the same as those of NaCl–KBr. Additional experiments with salt mixtures containing NaBr and KCl showed the occurrence of the exchange reactions and simultaneous formation of solid solutions. From these observations, mechanochemical processing was found to be effective to cause several types of solid-state recrystallization at the atomic level.View full abstractDownload PDF (4303K)
Chemical Reaction Engineering
-
Salah Aljbour, Tomohiko Tagawa, Hiroshi YamadaArticle type: Research Paper
2009 Volume 42 Issue 6 Pages 400-406
Published: June 20, 2009
Released on J-STAGE: June 20, 2009
JOURNAL RESTRICTED ACCESSA capillary-microreactor assisted by ultrasound irradiation was designed and demonstrated to carry out aqueous–organic chemical reactions. The hydrolysis of benzyl chloride in a two-phase slug flow system was investigated. The capillary-microreactor was irradiated by 28 kHz ultrasound at different temperatures, capillary lengths and phase flow rates. It was found that the combination of microreactor technology and the ultrasound irradiation provides a promising protocol for process intensification. Under sonication conditions, higher mass transfer rates were obtained compared to silent conditions. The presence of ultrasound has affected the multiphase slug size and promoted better internal circulation within these slugs. Similar hydrodynamics behavior was noticed at higher temperatures for both sonication and silent conditions.View full abstractDownload PDF (860K) -
Makoto Takahashi, Takashi Aida, Akira Igarashi, Kazuhisa OhtaguchiArticle type: Research Paper
2009 Volume 42 Issue 6 Pages 407-416
Published: June 20, 2009
Released on J-STAGE: June 20, 2009
JOURNAL RESTRICTED ACCESSThe transient state of adsorbed species during the CO–NO reaction on Pt/γ-Al2O3 catalyst was monitored using in situ FT-IR. Experiments were performed at the low temperature region for elevating adsorption rate. The amount of adsorbed species on the surface was calculated from band-area of absorbance. The change in the CO consumption rate in the CO–O2 reaction was viewed by relating to that in the relative area of linear-CO on the catalyst. The experiments where catalyst was exposed to gaseous NO showed that the increase in the concentration of NO in the feed stream resulted in the increase in the relative area of nitrate species as bridge-NO and in a concomitant decrease in that of linear-NO. An argument is made in that bridge-NO was formed by binding gas phase NO onto the chemisorbed atomic oxygen that was formed in the dissociation of linear-NO. The participation of chemisorbed atomic oxygen in CO oxidation by NO over Pt/γ-Al2O3 at low temperature was viewed in the results of experiment where the catalyst was exposed to gases containing a fixed amount of CO and varied amount of NO.View full abstractDownload PDF (556K) -
Koichi Hirao, Kazunari Masutani, Hitomi OharaArticle type: Short Communication
2009 Volume 42 Issue 6 Pages 417-419
Published: June 20, 2009
Released on J-STAGE: June 20, 2009
JOURNAL RESTRICTED ACCESSNoncatalytic polycondensation of L-lactic acid under microwave irradiation is compared with that under conventional heating. Under microwave irradiation, higher molecular weights of poly(L-lactic acid) can be obtained comparing with under conventional heating. Though the racemization of L-lactate was induced, it can be lowered at higher vacuum. As a result, higher molecular weight poly(L-lactic acid), comparing with conventional heating without increasing racemization, was synthesized with microwave irradiation.View full abstractDownload PDF (363K)
Process Systems Engineering and Safety
-
Daim-Yuang Sun, Tzu-Chen HuangArticle type: Research Paper
2009 Volume 42 Issue 6 Pages 420-432
Published: June 20, 2009
Released on J-STAGE: June 20, 2009
JOURNAL RESTRICTED ACCESSIn this study, line-up computational algorithm (LCA) is applied to estimate the parameters of nonlinear chemical systems under the framework of the integration approach. Four benchmark problems are provided in this paper to demonstrate the robustness and efficiency of LCA. The strategy for improving unsatisfactory convergence of LCA in some problem is also proposed. Additionally, the differences in convergence between LCA and differential evolution are also discussed.View full abstractDownload PDF (480K) -
Chu-Fu Li, Lai-Xi Zou, Bing-Zhen Chen, Xiao-Rong He, Chun-Jian Dong, G ...Article type: Research Paper
2009 Volume 42 Issue 6 Pages 433-440
Published: June 20, 2009
Released on J-STAGE: June 20, 2009
JOURNAL RESTRICTED ACCESSMost models for chemical production planning are based on deterministic programming approaches without considering uncertainty. This paper presents a two-stage stochastic programming model for chemical production planning optimization with management of purchase and inventory under economic uncertainties including prices of raw materials, product prices and demands, and uses the Monte Carlo sampling method to solve it. The expected profit is maximized taking into account raw materials costs, inventory costs, operating costs and costs of lost demand under economic uncertainties, while the production planning and purchase scheme are optimized simultaneously. The proposed model is validated by a real chemical enterprise based on GIOCIMS (Graphical I/O Chemical Industry Modeling System). The results indicate that the two-stage stochastic programming model can suggest a solution with higher expected profit and lower risk than the one suggested by deterministic programming model.View full abstractDownload PDF (606K)
Biochemical, Food and Medical Engineering
-
Zhiqiang Du, Anming Wang, Cheng Zhou, Shemin Zhu, Shubao ShenArticle type: Research Paper
2009 Volume 42 Issue 6 Pages 441-446
Published: June 20, 2009
Released on J-STAGE: June 20, 2009
JOURNAL RESTRICTED ACCESSMicrowave irradiation technology is used to covalently immobilize lipase at low temperature to improve enzyme properties. The specific activity of lipase immobilized under microwave irradiation was 114.4 U·mg–1, 1.23 times of that for a traditional method without microwave irradiation. The Km and Kcat/Km of microwave immobilized lipase was 0.12 and 1.26 folds that of free lipase. Moreover, alcohols were used to quench the excessive activated groups on MCFs surface to improve thermal stability of immobilized lipase. Residual activity of immobilized lipase quenched by ethanol, retained 60.64% after incubation at 50°C for 5 h, 2.36 and 1.99 times higher than those of free lipase and immobilized lipase which was not quenched by alcohols, respectively. The results showed that microwave irradiation could improve lipase covalent immobilization and quenching remaining groups could enhance thermal stability of immobilized lipase.View full abstractDownload PDF (503K)
Energy
-
Hiroshi Suzuki, Kosuke Nakayama, Yoshiyuki Komoda, Hiromoto Usui, Kazu ...Article type: Research Paper
2009 Volume 42 Issue 6 Pages 447-451
Published: June 20, 2009
Released on J-STAGE: June 20, 2009
JOURNAL RESTRICTED ACCESSThis report describes the particle distribution characteristics of an ice slurry treated with surfactants and brines generated by a vacuum production system. Ice particle size in slurries with surfactants was measured by an image-processing method at different concentrations of surfactant and brine. The results indicate that the effect of the ice fraction is very small on ice particle size obtained by the present vacuum production system. It was also found that the influence of brine concentration on particle size was very small. The effect of surfactant concentration on particle distributions was also very small. In addition, a small amount of surfactant reduced ice particle size compared to those of brine systems without surfactants. It is concluded that no brine system is economical for ice slurry generation by a vacuum production system.View full abstractDownload PDF (876K) -
Bokkyu Choi, Sunmook Lee, Masahiro Iizuka, Yuichiro Otsuji, Chihiro Fu ...Article type: Research Paper
2009 Volume 42 Issue 6 Pages 452-456
Published: June 20, 2009
Released on J-STAGE: June 20, 2009
JOURNAL RESTRICTED ACCESSThe positive electrodes of nickel metal hydride (NiMH) batteries were doped with Al to improve the discharge capacity of NiMH batteries and its effects on the electrode performance were studied. Al-doped α-Ni(OH)2 electrodes were prepared by co-precipitation method. The characteristics of the positive electrode in KOH solution were investigated with charge/discharge cycles. The elution of doped Al into the electrolyte was observed as the number of charge/discharge cycles increased, which was confirmed by the ICP-AES analysis of the electrolyte after repeated charge/discharge cycles. This subsequently led to the decrease in the discharge capacity. However, it was found that the addition of Al ions into the electrolyte stabilized α-Ni(OH)2 and resulted in the increased discharge capacity.View full abstractDownload PDF (1605K)
- |<
- <
- 1
- >
- >|