JOURNAL OF CHEMICAL ENGINEERING OF JAPAN
Print ISSN : 0021-9592
Volume 53 , Issue 2
Showing 1-7 articles out of 7 articles from the selected issue
Editorial Note
Separation Engineering
  • Yuling Lv, Kai Guo, Limin He, Leicheng Shi, Yun Cao
    Type: Research Paper
    2020 Volume 53 Issue 2 Pages 49-57
    Published: February 20, 2020
    Released: February 20, 2020
    JOURNALS FREE ACCESS

    The present research theoretically studes the forces and motion characteristics of the water droplets. The solution of the differential equation expressing the velocity of the water droplet is given. The influence mechanism of frequency on separation performance under the electromagnetic coupling field was explored experimentally. The experimental results show that the electric field and the electromagnetic coupling field were affected by the change of frequency simultaneously, and the separation efficiency was changed under the combined action of them. Within 500 Hz, when the frequency is higher than the turning frequency, the separation efficiency of emulsion treated by the electromagnetic coupling field is less affected by frequency, and the optimal frequency formula is still valid.

    Download PDF (1313K)
Thermal Engineering
  • Tomomi Sasaki, Kazunori Kuwana
    Type: Research Paper
    2020 Volume 53 Issue 2 Pages 58-63
    Published: February 20, 2020
    Released: February 20, 2020
    JOURNALS FREE ACCESS

    This paper discusses the effects of buoyancy on the shape of an axisymmetric diffusion flame above a submillimeter burner, with a focus on the deviation of flame height from the well-known Péclet number scaling. Experiments of butane-air flame were conducted for two different burner diameters, 0.5 and 0.9 mm, to vary the relative strength of buoyancy. On the other hand, numerical simulations were conducted at a fixed burner diameter, 0.5 mm, but at varied gravity levels. Both experimental and numerical results showed that enhanced buoyancy tends to increase the flame height while decreasing the flame width. In particular, the flame height increased by as much as a factor of two. A simple analytical model was then developed. The model is an extension to the one developed by Roper, in which the axial velocity was assumed to be uniform in the radial direction, r. The present model adopts a more realistic axial-velocity distribution that decreases with an increase in r. The use of the point-source approximation enables a simple analytical solution for the flame shape. The change in flame shape owing to enhanced buoyancy predicted by the present model qualitatively agrees with experimental and numerical observations.

    Download PDF (689K)
Chemical Reaction Engineering
  • Mitsuaki Echigo, Akio Inaya, Norihisa Shinke, Kazuhiro Hirai, Takeshi ...
    Type: Short Communication
    2020 Volume 53 Issue 2 Pages 64-67
    Published: February 20, 2020
    Released: February 20, 2020
    JOURNALS FREE ACCESS

    A high-performance CO preferential oxidation (PROX) catalyst was developed for the CO removal process of residential polymer electrolyte fuel cell (PEFC) systems. A durability period of >10 years for the CO PROX catalyst was demonstrated in a single-stage CO PROX removal reactor of a natural gas fuel processor for residential PEFC systems. It was confirmed that the CO concentration was reduced to below 10 ppm, which is the required level for PEFCs, in a natural gas–reformed gas under several operating conditions by the single-stage CO PROX removal reactor over the CO PROX catalyst after 90,000 h of operation.

    Download PDF (206K)
  • Wei Zhang, Guoying Xie, Yujie Gong, Dongxu Zhou, Chen Zhang, Qiaona Ji
    Type: Short Communication
    2020 Volume 53 Issue 2 Pages 68-72
    Published: February 20, 2020
    Released: February 20, 2020
    JOURNALS FREE ACCESS

    The present work investigates the non-catalytic oxidative desulfurization of diesel oil using ozone in a biphasic oil/acetonitrile system. The organosulfur compounds in diesel could be well extracted to acetonitrile for ozone oxidation. With acetonitrile as the reaction solvent, the oxidation rates of organosulfur compounds sharply increased. The oxidation reactivities of these organosulfur compounds increased in the order of DBT<4,6-DMDBT<BT. GC-MS analysis showed that the oxidation product of BT was 2-mercaptobenzaldehyde, while the oxidation products of DBT and 4,6-DMDBT were their corresponding sulfones. The sulfur content of real diesel could be reduced from 1450 to 48 µg/g in the biphasic oxidation system, and the sulfur removal reached nearly 97%. This process provides a new perspective on ultra-deep desulfurization of diesel fuel.

    Download PDF (516K)
Micro and Nano Systems
  • Tetsuya Yamamoto, Osamu Tonomura, Aichiro Nagaki
    Type: Research Paper
    2020 Volume 53 Issue 2 Pages 73-77
    Published: February 20, 2020
    Released: February 20, 2020
    JOURNALS FREE ACCESS

    In this study, a reaction process for the asymmetric hydrogenation of acetophenone was developed using a T-shaped micro/milli-reactor and a homogeneous catalyst, (S)-RUCY® (RuCl[(S)-daipena][(S)-xylbinap]). The results clarified the following points: 1) it is important to separately supply the catalyst and the raw materials to the reactor in order to avoid decreasing the conversion during continuous operation of the process, 2) the micro/milli-reactor can increase the transfer rate of hydrogen to the liquid phase, compared with conventional batch reactors with forced stirring. The reaction time of the micro/milli-reactor required to complete the reaction is several seconds, corresponding to one hundredth of that in the batch reactor, and 3) by adjusting the channel size and flow rate, an increase in the production volume of a single reactor is examined, and the productivity when using four single reactors obtained as a result is comparable to the production on an industrial scale.

    Download PDF (709K)
Materials Engineering and Interfacial Phenomena
  • Hirotaka Sone, Shuhei Yoshida, Takuya Kageyama, Manabu Tanaka, Takayuk ...
    Type: Research Paper
    2020 Volume 53 Issue 2 Pages 78-83
    Published: February 20, 2020
    Released: February 20, 2020
    JOURNALS FREE ACCESS

    Lithium nickel oxide nanoparticles were synthesized by induction thermal plasma. The forming mechanism of the nanoparticle crystal structure was investigated based on nucleation theory and thermodynamic considerations. Synthesized Li–Ni-oxide nanoparticles were nonstoichiometric Li0.4Ni1.6O2 (space group Fm3m) of the Li-deficient system. Stoichiometric LiNiO2 was difficult to synthesize because of its lower thermodynamic stability when compared with NiO in high-temperature region of more than 2248 K. Reactions forming NiO were predominant at temperatures above 2248 K. LiNiO2 forming reactions were unlikely to occur because Li2O was hard to condense onto NiO nuclei above 2248 K. Therefore, nonstoichiometric Li0.4Ni1.6O2 is easily generated. This was because Ni had a stable divalent valence and formed a strong bond with O. The Gibbs free-energy change suggested that the divalent Ni2+ (NiO) is more stable than trivalent Ni3+ (LiNiO2) at temperatures above 2248 K. This study investigated factors affecting the control of Li–Ni-oxide nanoparticles formed in thermal plasma.

    Download PDF (2695K)
feedback
Top