JOURNAL OF CHEMICAL ENGINEERING OF JAPAN
Online ISSN : 1881-1299
Print ISSN : 0021-9592
Volume 42, Issue 3
Displaying 1-9 of 9 articles from this issue
Separation Engineering
  • Koji Machiya, Shigeru Ieda, Masaru Hirano, Hiroshi Ooshima
    Article type: Research Paper
    2009 Volume 42 Issue 3 Pages 147-152
    Published: March 20, 2009
    Released on J-STAGE: March 20, 2009
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    A drug substance, (8-(2,6-dichlorobenzoyl-amino)-3-hydroxymethyl-2-trifluoromethylimidazo [1,2-a] pyridine (named BPPI)), developed for osteoporosis treatment, has two crystal polymorphs: an unstable B01-form and a stable B02-form. In the early stage of development, only the B01-form was always obtained from an ethanol/water solution. However, after improvements in purity of BPPI, only the B02-form was obtained. Four major impurities incorporated in the B01-form are identified and 4 analogues of BPPI are separately synthesized. The inhibitory effects on the solvent-mediated transformation of the B01-form to the B02-form are examined to explain the disappearance of the B01-form and the new appearance of the B02-form. As a result, it is found that the dimer of BPPI, which was a by-product of the last reaction of BPPI synthesis, had inhibited nucleation of the B02-form crystals. 0.107 mg/mL of dimer completely inhibited the transformation of the B01-form. The inhibitory effect of the dimer on the nucleation of the B02-form is discussed by focusing on the failure of two intermolecular hydrogen bondings that should be formed in the B02-form crystal.
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Chemical Reaction Engineering
  • Dahlia Diniyati, Kayoko Morishita, Liuyun Li, Takayuki Takarada
    Article type: Research Paper
    2009 Volume 42 Issue 3 Pages 153-159
    Published: March 20, 2009
    Released on J-STAGE: March 20, 2009
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    Catalytic activity of coal chars on the water–gas shift (WGS) reaction has been investigated in a fixed bed reactor at various temperatures in the range of 700–900°C. Two coal chars employed in this study (char A and char B) are signed with relatively high ash contents. The results show that WGS reaction occurred over both chars. Under the experimental conditions studied, the reaction rate towards hydrogen formation may be described as: rH2 = 2.17 × 109 exp(124,800/RT)(pCOpH2OpCO2pH2/K) for char A and rH2 = 8.0 × 108 exp(127,900/RT)(pCOpH2OpCO2pH2/K) for char B. The two chars showed different catalytic behaviors. Gas yield obtained from WGS reaction over char A was higher than that from char B. The higher catalytic activity of char A in WGS reaction was due to the combination of higher specific surface area, the presence of very fine and well-dispersed particles of mineral matters on the char surface, and also the high content of iron oxide fixed for each experiment. Demineralized char A still showed a catalytic activity due to the abundant amount of mesopores, whereas it was lower than char A, which indicates the importance of the mineral matters on the progress of WGS reaction.
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  • Lu Zhou, Yu Guo, Masayuki Yagi, Huabo Li, Jun Hatakeyama, Jian Chen, Y ...
    Article type: Research Paper
    2009 Volume 42 Issue 3 Pages 160-171
    Published: March 20, 2009
    Released on J-STAGE: March 20, 2009
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    An anodic alumina supported 17.9 wt% Ni catalyst shows an excellent catalytic performance during steam reforming of methane at 700°C under W/F = 6.33 × 10–3 g-cat·h/L, even when compared with some commercial Ni and Ru reforming catalysts. This is considered to be the result of the existence of an interfacial NiAl2O4 layer, which could anchor the top metallic nickel particles to prevent them from reacting with the alumina support and sintering, thereby, effectively suppressing carbon deposition. Nevertheless, for the industrialization of anodic nickel catalysts, some effort should be made to alleviate the deterioration of anodic supports, because when subjected to a higher W/F as 1.27 × 10–3 g-cat·h/L, the catalyst shows irreversible deactivation, and little improvement is seen by increasing nickel spinel content and metal loading or modifying the impregnation solution pH.
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  • Jian Chen, Yu Guo, Nobuhisa Uesawa, Lu Zhou, Huabo Li, Yi Yao, Qi Zhan ...
    Article type: Research Paper
    2009 Volume 42 Issue 3 Pages 172-183
    Published: March 20, 2009
    Released on J-STAGE: March 20, 2009
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    A series of anodic alumina supported silver/titanium catalysts (Ag/Ti/Al2O3) were synthesized to investigate the effect of Ti on the selective catalytic reduction of NO with propene.
    In the low temperature region, the SCR activity was greatly enhanced on Ag/Ti/Al2O3 compared to Ag/Al2O3, and this promotion became more significant with increasing Ti loading. Adding Ti to an anodic alumina support did not cause obvious improvement of activity, indicating that the presence of Ti acted as a catalytic promoter of Ag, but did not directly participate in the SCR reaction. The result of NOx-TPD in flowing He showed that no obvious difference in the desorption performance of ads-NOx species was found between Ag/Al2O3 and Ag/Ti/Al2O3. However, in flowing O2/C3H6/He the desorption peak of nitrate species was decreased by about 50°C when Ti was present. The promoted partial oxidation of the reducing agent was believed to be a main reason. The result of H2-TPR suggested that besides Ag+ ion and metallic Ag another type of silver existed in Ag/Ti/Al2O3, possibly a moderately agglomerated Agnδ+ cluster.
    Additionally, in comparison with the SO2-aged Ag/Al2O3 catalyst, the SO2-aged Ag/Ti/Al2O3 catalyst provided a favorable tolerance to SO2 poisoning, and led to higher activity. A relatively lower SO2 adsorption amount and a faster reduction rate of sulfate species by propene were considered to be a reasonable interpretation.
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  • Eri Fumoto, Teruoki Tago, Takao Masuda
    Article type: Research Paper
    2009 Volume 42 Issue 3 Pages 184-190
    Published: March 20, 2009
    Released on J-STAGE: March 20, 2009
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    Ammonia in animal wastes causes eutrophication of the soil when these wastes are used as liquid fertilizer. Accordingly, it is desirable to recover ammonia from these wastes. We investigate the following two methods for recovery of ammonia: (i) recovery of gaseous ammonia, which was generated by aeration of the ammonia gas, by adsorption on the magnesium phosphate adsorbent derived from magnesium ammonium phosphate (MAP); and (ii) recovery of aqueous ammonium ions by adsorption on the same adsorbent. The adsorbent was prepared by treatment of MAP at 378 K, and the XRD pattern of the adsorbent shows that MAP structure disappeared after the treatment. Gaseous ammonia and aqueous ammonium ions were adsorbed on the adsorbents, and the amounts of ammonium ions adsorbed were larger than that of gaseous ammonia. The adsorption isotherms of aqueous ammonium ions and gaseous ammonia exhibited Langmuir- and Henry-type characteristics, respectively, indicating different adsorption mechanism between aqueous ammonium ions and gaseous ammonia. It was found that MAP structure was re-formed in the presence of water after the aqueous ammonium ions adsorption, while the structure of the adsorbent had hardly changed after the gaseous ammonia adsorption. The low adsorption energy (–3.0 kJ/mol) of gaseous ammonia indicates that physical adsorption. Consequently, adsorption of aqueous ammonium ions is a suitable method for recovery large amounts of ammonia, and we demonstrate that large amounts of ammonium ions are recovered from cow urine after hydrothermal treatment of it.
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Biochemical, Food and Medical Engineering
  • Masaru Sakata, Takashi Kawai, Shigeto Kayane, Hiroshi Ooshima
    Article type: Research Paper
    2009 Volume 42 Issue 3 Pages 191-197
    Published: March 20, 2009
    Released on J-STAGE: March 20, 2009
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    The continuous production of Glucose-1-phosphate (G-1-P) using immobilized potato phosphorylase was investigated. Potato phosphorylase was immobilized on a strongly basic anion-exchange resin, HPA-25 through contact of the resin with potato juice or wastewater of a potato-starch factory. The immobilization was highly selective for phosphorylase among proteins contained in potato juice and the wastewater. The immobilized phosphorylase could be used for the continuous G-1-P production over one year without significant deactivation. By using a 100-L column reactor packed with immobilized phosphorylase of 14.1 U·mL-carrier–1 at the superficial linear velocity of 0.034 m·h–1 and the space velocity of 3.1 × 10–9 m3·U–1·h–1, 185 mM G-1-P, which is the maximum concentration potentially expected from 516 mM dextrin and 2000 mM phosphate, was continuously produced.
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Micro and Nano Systems
  • Takeshi Katsuda, Toshiro Maruyama
    Article type: Research Paper
    2009 Volume 42 Issue 3 Pages 198-203
    Published: March 20, 2009
    Released on J-STAGE: March 20, 2009
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    We propose a model based on chemical kinetic analysis for the growth of a multicellular tumor spheroid. The growth of avascular tumor cells is simulated by an autocatalytic reaction where the cell itself converts glucose and oxygen into a new cell. Glucose is assumed to be the limiting substrate, and its depletion gives rise to the necrosis of tumor cells. Since the depletion is assumed to be the major cause of the central necrosis, the death of tumor cells is determined by the critical value of the concentration. The concentration profile of glucose inside the tumor is obtained from a reaction-diffusion equation. The characteristic features of the experimental results are demonstrated well in this model.
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Materials Engineering and Interfacial Phenomena
  • Masaru Hirano, Koichi Igarashi, Kouji Machiya, Rui Tamura, Hiroto Tue, ...
    Article type: Research Paper
    2009 Volume 42 Issue 3 Pages 204-211
    Published: March 20, 2009
    Released on J-STAGE: March 20, 2009
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    An imidazopyridine derivative developed for osteoporosis treatment (a bone proton pump inhibitor, abbreviated BPPI) was crystallized in two kinds of alcohol. Two crystal polymorphs appeared: an unstable B01 form and a stable B02 form. The B01 form was obtained only from an ethanol solution and was never obtained from a methanol solution. The B02 form was obtained from a methanol solution. In order to understand these different behaviors in the appearance of polymorphs from alcohol, the intra- and inter-molecular interactions of BPPI molecules in solution were analyzed by NMR. As a result, the conformation of BPPI molecules and the structure of molecular aggregates in solution were found to resemble those of the polymorphic crystals that appeared in each alcohol. This result suggests that the control of the conformation of solute molecules is important at first to control the appearing polymorph.
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Environment
  • Winarto Kurniawan, Chris Salim, Hirofumi Hinode
    Article type: Research Paper
    2009 Volume 42 Issue 3 Pages 212-218
    Published: March 20, 2009
    Released on J-STAGE: March 20, 2009
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    Soot oxidation catalysts are prepared by treatment and impregnation of Na- and H-mordenite with potassium-containing solutions (KOH, KCl, KNO3, and K2CO3). Treatment with KOH increased the soot oxidation activity of Na-mordenite, which is attributed to an increase in alkali content. The presence of macropores of the sample improved soot–catalyst contact by increasing the surface over which soot and active sites can be in good contact, and thus also contributed to the increase in activity. The activity of H-mordenite was influenced by treatment with high KOH concentration, but not with low KOH concentration. Impregnations with potassium increased the activity of Na-mordenite, with KNO3 impregnation yielding the highest activity. The combination of treatment with KOH and impregnation with KNO3 further increased the activity of samples. The improvement in activity is attributed to the presence of the alkali element and NO3 species, and of macropores that promoted good soot-active sites contact.
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