Faculty Profiles - GOKON Nobuyuki

4-4-3 Kinetic analysis of thermal reduction of Two-Step Water-Splitting cycle using CeO_2

SATO Yusuke, ISHIDA Tomoya, HATAMACHI Tsuyoshi, GOKON Nobuyuki, KODAMA Tatsuya

Proceedings of the Annual Conference of The Japan Institute of Energy 22 180 - 181 2013

Language：Japanese Publisher：The Japan Institute of Energy

Cerium oxide was examined as a redox material on cyclic reactivity for converting high-temperature heat into chemical fuels via solar two-step thermochemical water-splitting. The thermal reduction of the cerium particles was conducted at 1000-1500℃, and oxygen production rate were measured. The kinetics of oxygen production for thermal reduction step was analyzed, then Arrhenius parameter and reaction model equation were evaluated.

DOI： 10.20550/jietaikaiyoushi.22.0_180

4-4-5 Solar Demonstration of thermochemical two-step water splitting cycle using CeO_2/MPSZ ceramic form device by 45kW_<th> KIER solar furnace

CHO Hyun Seok, KAWAKAMI Shintaro, MYOJIN Takuya, HATAMACHI Tsuyoshi, GOKON Nobuyuki, KODAMA Tatsuya, KANG Yong Heack

Proceedings of the Annual Conference of The Japan Institute of Energy 22 184 - 185 2013

Language：Japanese Publisher：The Japan Institute of Energy

Joint international project of Niigata University (Japan) -Korean Institute of Energy Research, KIER (Kora) on the "Solar demonstration of Water-Splitting Reactor using Ceramic Foam Device" aims to develop a novel-type of solar reactor with reactive cerium- or iron oxides-coated foam devices for high-temperature two-step thermochemical water splitting cycle, and to demonstrate its performances on sun with a 40-kW_<th> solar furnace. The reactive CeO_2 foam device for the two-step water splitting is proposed and prepared by Niigata University, Japan, and involves coating an inert zirconia foam with reactive CeO_2 or ferrite-zirconia redox materials. The project includes the development of reactive foam devices, the new design and the fabrication of solar reactor with the reactive foam devices, and finally the solar demonstration on the KIER's 45-kW_<th> solar furnace in Korea. In this paper, highly-active CeO_2 particles were used as a redox material for preparing CeO_2 foam devices. A ceramic foam disk made of MgO partially-stabilized Zirconia (MPSZ) was used as a ceramic matrix that was coated with the CeO_2 particles. Solar thermochemical two-step water splitting was demonstrated using the prepared CeO_2-coated MPSZ (CeO_2/MPSZ) foam devices in Korea.

DOI： 10.20550/jietaikaiyoushi.22.0_184

4-4-4 Two-step thermochemical water splitting reaction of CeO_2 by internally-circulating fluidized

OMORI Kei, TOKUNAGA Shunta, WATANABE Naoya, HATAMACHI Tsuyoshi, GOKON Nobuyuki, KODAMA Tatsuya

Proceedings of the Annual Conference of The Japan Institute of Energy 22 182 - 183 2013

Language：Japanese Publisher：The Japan Institute of Energy

Thermochemical two-step water-splitting cycle, which utilizes concentrated solar radiation as a energy source and uses steam as a chemical source, is a one of the most promising hydrogen productions from water, We are developing 2 types of windowed solar chemical reactors with internally-circulating fluidized bed of cerium oxide particles for hydrogen production via thermochemical two-step water-splitting. In the present work, the performance of each solar reactor with the internally circulating fluidized beds was examined for two-step water splitting of thermal reduction and water-decomposition using their particles under 5kW_<th> sun-simulator.

DOI： 10.20550/jietaikaiyoushi.22.0_182

CO2 gasification of coal cokes using internally circulating fluidized bed reactor by concentrated Xe-light irradiation for solar gasification Reviewed

Nobuyuki Gokon, Ryuta Ono, Tsuyoshi Hatamachi, Li Liuyun, Hee-Joon Kim, Tatsuya Kodama

INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 37 ( 17 ) 12128 - 12137 2012.9

The basic study about reforming biomass-tar using catalysts for solar energy biomass gasfication Reviewed

Liuyun Li, Gokon Nobuyuki, Kodama Tatsuya, Tadaaki Shimizu, Hee Joon Kim

SolarPACES 2012, Marrakech, Morocco, September 11-14, 2012. 2012

Heat Transfer characteristics of internally circulating fluidized bed solar reactor Reviewed

Atsushi Sakurai, So Sakuma, Gokon Nobuyuki, Koji Matsubara, Kodama Tatsuya

SolarPACES 2012, Marrakech, Morocco, September 11-14, 2012. 2012

COMPARISON STUDIES OF REACTIVITY ON NICKEL-FERRITE AND CERIUM-OXIDE REDOX MATERIALS FOR TWO-STEP THERMOCHEMICAL WATER SPLITTING BELOW 1400 degrees C Reviewed

Tatsuya Kodama, Nobuki Imaizumi, Nobuyuki Gokon, Tsuyoshi Hatamachi, Daiki Aoyagi, Ken Kondo

PROCEEDINGS OF THE ASME 5TH INTERNATIONAL CONFERENCE ON ENERGY SUSTAINABILITY 2011, PTS A-C 1617 - 1623 2012

Steam gasification of coal cokes using fluidized bed reactor for solar thermochemical conversion Reviewed

Nobuyuki Gokon, Ryuta Ono, Kei Omori, Tsuyoshi Hatamachi, Li Liuyun, Hee Joon Kim, Tatsuya Kodama

SolarPACES 2012, Marrakech, Morocco, September 11-14, 2012. 2012

Two-step switching test of water-splitting process using internally-circulating fluidized bed reactor Reviewed

Kei Omori, Nobuyuki Gokon, Tsuyoshi Hatamachi, Tatsuya Kodama

SolarPACES 2012, Marrakech, Morocco, September 11-14, 2012. 2012

Solar Demonstration Project on a Novel Fluidized Bed Reactor for “Single-processed” Thermochemical Water-splitting Cycle with a Beam-Down Concentrating System at Miyazaki Reviewed

Tatsuya Kodama, Nobuyuki Gokon, Kei Omori, Yoshinori Nagase, Katsushige Nakamura

SolarPACES 2012, Marrakech, Morocco, September 11-14, 2012. 2012

4-5-1 Development of Ni/MgO-Al_2O_3 catalyst foam device for use as a solar reformer

SHIMAWAKI Kazunori, NAKAMURA Shohei, HATAMACHI Tsuyoshi, GOKON Nobuyuki, KODAMA Tatsuya

Proceedings of the Annual Conference of The Japan Institute of Energy 21 230 - 231 2012

Language：Japanese Publisher：The Japan Institute of Energy

Catalytically-activated ceramic foam device has been developed as a solar receiver/absorber for use in methane reforming under concentrated solar radiation as an energy source. Ni/MgO-Al_2O_3 catalysts were loaded on the SiC ceramic foam. Catalytic activity and kinetics for methane reforming were studied using Ni/MgO-Al_2O_3/SiC foam device under Xe-light irradiation and electric furnace, respectively.

DOI： 10.20550/jietaikaiyoushi.21.0_230

4-5-2 Studies of Na2CO3/MgO molten salt solar receiver reactor tube

TAKAHASHI Shogo, KURITA Shinji, HATAMACHI Tsuyoshi, SAKURAI Atsushi, GOKON Nobuyuki, KODAMA Tatsuya

Proceedings of the Annual Conference of The Japan Institute of Energy 21 232 - 233 2012

Language：Japanese Publisher：The Japan Institute of Energy

Double-walled reactor tubes with molten-salt thermal storage were developed for solar air receiver to generate electricity and for solar reforming to produce solar fuel. A mixture of Na_2CO_3 and MgO was loaded as a thermal storage medium into the outer annulus of that. Performances of the reactor tubes were studied as an air receiver and as a reformer tube in the present study.

DOI： 10.20550/jietaikaiyoushi.21.0_232

4-4-3 Thermochemical water-splitting by reactive foam devices

SATO Naoki, KAWAKAMI Shintaro, MYOUJIN Takuya, HATAMACHI Tsuyoshi, GOKON Nobuyuki, KODAMA Tatsuya, SEO Taebeom

Proceedings of the Annual Conference of The Japan Institute of Energy 21 226 - 227 2012

Language：Japanese Publisher：The Japan Institute of Energy

We have developed reactive foam devices for solar thermochemical two-step water-splitting to produce hydrogen from water. We have researched the hydrogen production activity of the reactive foam devices by 3kW sun-simulator in Niigata University and by 5kW dish type solar concentrator in Inha University in Korea. Solar hydrogen productions were cyclically demonstrated for nine cycles at solar irradiation test at Korea.

DOI： 10.20550/jietaikaiyoushi.21.0_226