The Experts below are selected from a list of 162 Experts worldwide ranked by ideXlab platform

Naomichi Sakai - One of the best experts on this subject based on the ideXlab platform.

  • Cycle simulation of the UT-3 thermochemical hydrogen production process
    International Journal of Hydrogen Energy, 1992
    Co-Authors: HIDEO KAMEYAMA, Motoji Sakurai, Rezai Amir, Mitsugu Aihara, Yuzuru Tadokoro, T. Yamaguchi, Tisato Kajiyama, K. Yoshida, T. Sato, Naomichi Sakai
    Abstract:

    We have been studying the economical and technical feasibility of the UT-3 thermochemical hydrogen production process. In this paper, the result of the simulation study of the cycle is discussed, which indicates that a steady cycle operation can be achieved if three Fe-reactors and two Ca-reactors are connected in an effective order. In the UT-3 process the Solid Reactant is hydrolyzed and brominated. The simulation study of the fixed-bed reactors showed that the direction of the gas flow must be changed in the alternation of hydrolysis and bromination. © 1992.

K. Yoshida - One of the best experts on this subject based on the ideXlab platform.

  • Analysis of a reaction mechanism in the UT-3 thermochemical hydrogen production cycle
    International Journal of Hydrogen Energy, 1996
    Co-Authors: Makoto Sakurai, N. Miyake, Atsushi Tsutsumi, K. Yoshida
    Abstract:

    Abstract The UT-3 thermochemical hydrogen production process consists of four gas-Solid reactions, two Ca-compounds reactions and two Fe-compounds reactions. In this process, it is important to obtain the Solid Reactant with high reactivity and durability. Bromination of CaO included in the UT-3 cycle was analyzed to clarify the mechanism of this reaction, and a reaction model was proposed. Simulated results showed a good agreement with observed data.

  • Cycle simulation of the UT-3 thermochemical hydrogen production process
    International Journal of Hydrogen Energy, 1992
    Co-Authors: HIDEO KAMEYAMA, Motoji Sakurai, Rezai Amir, Mitsugu Aihara, Yuzuru Tadokoro, T. Yamaguchi, Tisato Kajiyama, K. Yoshida, T. Sato, Naomichi Sakai
    Abstract:

    We have been studying the economical and technical feasibility of the UT-3 thermochemical hydrogen production process. In this paper, the result of the simulation study of the cycle is discussed, which indicates that a steady cycle operation can be achieved if three Fe-reactors and two Ca-reactors are connected in an effective order. In the UT-3 process the Solid Reactant is hydrolyzed and brominated. The simulation study of the fixed-bed reactors showed that the direction of the gas flow must be changed in the alternation of hydrolysis and bromination. © 1992.

HIDEO KAMEYAMA - One of the best experts on this subject based on the ideXlab platform.

  • Cycle simulation of the UT-3 thermochemical hydrogen production process
    International Journal of Hydrogen Energy, 1992
    Co-Authors: HIDEO KAMEYAMA, Motoji Sakurai, Rezai Amir, Mitsugu Aihara, Yuzuru Tadokoro, T. Yamaguchi, Tisato Kajiyama, K. Yoshida, T. Sato, Naomichi Sakai
    Abstract:

    We have been studying the economical and technical feasibility of the UT-3 thermochemical hydrogen production process. In this paper, the result of the simulation study of the cycle is discussed, which indicates that a steady cycle operation can be achieved if three Fe-reactors and two Ca-reactors are connected in an effective order. In the UT-3 process the Solid Reactant is hydrolyzed and brominated. The simulation study of the fixed-bed reactors showed that the direction of the gas flow must be changed in the alternation of hydrolysis and bromination. © 1992.

Masahiko Aihara - One of the best experts on this subject based on the ideXlab platform.

  • decarbonation and pore structural change of ca Solid Reactant for cao co2 chemical heat pump
    Journal of Chemical Engineering of Japan, 2008
    Co-Authors: Masahiko Aihara, Takashi Takeuchi, Takeshi Yoshii, Yohei Shimazaki, Hitoshi Habuka
    Abstract:

    Cyclic reaction performances and pore structural change of Ca-Solid Reactants for the CaO/CO2 chemical heat pump designed for upgrading and storing high-temperature thermal energy were studied. It was observed that Solid Reactants prepared using CaCO3 particles have micro-order pore structure among particles and nano-order pore structure in the particles. With the proposed model, in which the pore structure change during reactions is considered, the numerical analysis suggested that the decarbonation rate was determined by nano-order pore structure change. In experiments of cyclic reaction at 923 K, pore volume change corresponding to the greater part of the total volume change between carbonation and decarbonation was observed in the range from 10 to 30 nm of pore radius.

  • Decarbonation and Pore Structural Change of Ca-Solid Reactant for CaO/CO2 Chemical Heat Pump
    Journal of Chemical Engineering of Japan, 2008
    Co-Authors: Masahiko Aihara, Takashi Takeuchi, Takeshi Yoshii, Yohei Shimazaki, Hitoshi Habuka
    Abstract:

    Cyclic reaction performances and pore structural change of Ca-Solid Reactants for the CaO/CO2 chemical heat pump designed for upgrading and storing high-temperature thermal energy were studied. It was observed that Solid Reactants prepared using CaCO3 particles have micro-order pore structure among particles and nano-order pore structure in the particles. With the proposed model, in which the pore structure change during reactions is considered, the numerical analysis suggested that the decarbonation rate was determined by nano-order pore structure change. In experiments of cyclic reaction at 923 K, pore volume change corresponding to the greater part of the total volume change between carbonation and decarbonation was observed in the range from 10 to 30 nm of pore radius.

  • carbonation decarbonation of ca Solid Reactant derived from natural limestone for thermal energy storage and temperature upgrade
    Journal of Chemical Engineering of Japan, 2007
    Co-Authors: Masahiko Aihara, Keiko Tanaka, Mayuka Watanabe, Takashi Takeuchi, Hitoshi Habuka
    Abstract:

    The carbonation and decarbonation of the Ca Solid Reactant prepared by the natural limestone powder were analyzed about the effect of annealing temperature on the reactivity and the durability in repetitive operation. The Solid Reactants annealed at 1073 K and lower had the larger reproducible pore volume in the range from 10 to 25 nm, and showed the higher conversion of carbonation. The Solid Reactants annealed at 1273 K indicated the excellent durability of repetitive cyclic procedure, which was comparable to that of the Reactant prepared by the metal alkoxide method.

  • development of porous Solid Reactant for thermal energy storage and temperature upgrade using carbonation decarbonation reaction
    Applied Energy, 2001
    Co-Authors: Masahiko Aihara, Toshiyuki Nagai, Junro Matsushita, Yoichi Negishi, Haruhiko Ohya
    Abstract:

    Cyclic reaction performances of Solid Reactants for a CaO-CO2 chemical heat-pump designed for upgrading and storing high-temperature thermal energy were studied. Solid Reactants composed of CaO as the Reactant and CaTiO3 as the inert framework were prepared using the conventional powder method or the metal alkoxide method. Upon experiments of cyclic operation between CaO carbonation and CaCO3 decarbonation at 1023K, the reaction reversibility of the Solid Reactants with the inert CaTiO3 framework was steady, whereas that of the Solid Reactant without the inert framework decreased with sintering of the Solid particles during cyclic operation. Reaction rates for the first carbonation and the decarbonation of Solid Reactant prepared using the alkoxide method were about 1.8 and 2.4 times faster, respectively, than for those prepared by the powder method due to the smaller average diameter of Reactant particles derived from the alkoxide method.

  • Development of porous Solid Reactant for thermal-energy storage and temperature upgrade using carbonation/decarbonation reaction
    Applied Energy, 2001
    Co-Authors: Masahiko Aihara, Toshiyuki Nagai, Junro Matsushita, Yoichi Negishi, Haruhiko Ohya
    Abstract:

    Cyclic reaction performances of Solid Reactants for a CaO-CO2 chemical heat-pump designed for upgrading and storing high-temperature thermal energy were studied. Solid Reactants composed of CaO as the Reactant and CaTiO3 as the inert framework were prepared using the conventional powder method or the metal alkoxide method. Upon experiments of cyclic operation between CaO carbonation and CaCO3 decarbonation at 1023K, the reaction reversibility of the Solid Reactants with the inert CaTiO3 framework was steady, whereas that of the Solid Reactant without the inert framework decreased with sintering of the Solid particles during cyclic operation. Reaction rates for the first carbonation and the decarbonation of Solid Reactant prepared using the alkoxide method were about 1.8 and 2.4 times faster, respectively, than for those prepared by the powder method due to the smaller average diameter of Reactant particles derived from the alkoxide method.

T. Yamaguchi - One of the best experts on this subject based on the ideXlab platform.

  • Cycle simulation of the UT-3 thermochemical hydrogen production process
    International Journal of Hydrogen Energy, 1992
    Co-Authors: HIDEO KAMEYAMA, Motoji Sakurai, Rezai Amir, Mitsugu Aihara, Yuzuru Tadokoro, T. Yamaguchi, Tisato Kajiyama, K. Yoshida, T. Sato, Naomichi Sakai
    Abstract:

    We have been studying the economical and technical feasibility of the UT-3 thermochemical hydrogen production process. In this paper, the result of the simulation study of the cycle is discussed, which indicates that a steady cycle operation can be achieved if three Fe-reactors and two Ca-reactors are connected in an effective order. In the UT-3 process the Solid Reactant is hydrolyzed and brominated. The simulation study of the fixed-bed reactors showed that the direction of the gas flow must be changed in the alternation of hydrolysis and bromination. © 1992.