|
Affiliation |
Graduate School of Engineering Science Department of Materials Science Applied Chemistry Course |
OKAWA Hirokazu
|
|
|
Graduate School 【 display / non-display 】
-
-2001.03
Niigata University Graduate School, Division of Science and Technology Master's Course Completed
Campus Career 【 display / non-display 】
-
2022.04-Now
Akita University Graduate School of Engineering Science Department of Materials Science Applied Chemistry Course Professor
-
2016.04-2022.03
Akita University Graduate School of Engineering Science Department of Materials Science Applied Chemistry Course Associate Professor
-
2013.04-2016.03
Akita University Graduate School of Engineering and Resource Science Lecturer
-
2004.04-2013.03
Akita University Faculty of Engineering and Resource Science Assistant Professor
Thesis for a degree 【 display / non-display 】
-
Study on the development of new synthesis methods of electrode materials by crystal structural and morphological optimization
大川 浩一
2008.03
Single author
Research Achievements 【 display / non-display 】
-
Tanaka Y.
Ultrasonics Sonochemistry ( Ultrasonics Sonochemistry ) 82 2022.01 [Refereed]
Research paper (journal) Domestic Co-author
-
Nguele R.
Ultrasonics Sonochemistry ( Ultrasonics Sonochemistry ) 80 2021.12 [Refereed]
Research paper (journal) Domestic Co-author
-
Hyperbranched Polyphenylene as an Electrode for Li-Ion Batteries
Lobo L.S.
Energy Technology ( Energy Technology ) 9 ( 10 ) 2021.10 [Refereed]
Research paper (journal) Domestic Co-author
-
Uaciquete D.L.E.
Fuel ( Fuel ) 300 120802 - 120802 2021.09 [Refereed]
Research paper (journal) Domestic Co-author
-
Yoshida K.
Japanese Journal of Applied Physics ( Japanese Journal of Applied Physics ) 60 ( SD ) 2021.07 [Refereed]
Research paper (journal) Domestic Co-author
With the aim of investigating the deposition of Au/Pd core-shell nanoparticles (NPs) on cathode materials to decrease charge transfer resistance, Au/Pd core-shell NPs were successfully synthesized and deposited on LiFePO4 coated with carbon (LiFePO4/C) using ultrasound irradiation. Transmission electron microscopy observation confirmed that dispersed Au/Pd NPs with an average particle size of 7.2 nm were deposited on LiFePO4/C. An X-ray diffraction measurement evidenced a peak shifting from 38.2° to 39.1° upon calcination at 400 °C in Ar atmosphere, which can be attributed to the phase transition of the Au/Pd NPs from core-shell to alloy.
-
1-07 Dissolution Behavior of Mercury Contained in Gypsum Produced from Coal Fired-Power Plant
UACIQUETE Dorcas Linda Ernesto, KATO Takahiro, OKAWA Hirokazu, SUGAWARA Katsuyasu
Proceedings of Conference on Coal Science ( The Japan Institute of Energy ) 58 ( 0 ) 14 - 15 2021.10
<p>Elution test was carried out in gypsum samples produced from a coal fired power plant, in order to understand the dissolution behavior of mercury when these materials are exposed to rain water. Experiments were carried out in 3 kinds of gypsums, two formed in liquid-column absorber desulfurization equipment and one from the jet bubbling type desulfurization equipment. For the elution test, the conventional batch method and the semi-batch method (improved method) were applied. The results revealed that the dissolution behavior of mercury varied significantly with the testing method. Furthermore, dissolution of mercury increased with decreasing pH. Quantification of mercury in eluate carried out by AAS show that in the conventional method, the dissolved mercury is then adsorbed, on the other hand, in the improved method, this behavior is negligible and only dissolution is observed.</p>
-
2-21 Release Behavior of Harmful Elements During Heat Treatments of CCA-treated Wood
KATO Takahiro, HATAKEYAMA Takeshi, OKAWA Hirokazu, SUGAWARA Katsuyasu
Proceedings of Conference on Coal Science ( The Japan Institute of Energy ) 58 ( 0 ) 64 - 65 2021.10
<p>Chromated copper arsenate–treated wood produced by injecting a solution containing sub–percent of chromium, copper, and arsenic (hereinafter referred to as CCA–treated wood) is one of the construction wastes. As fundamental research on the development of clean gasification process for biomass, pyrolysis (400–800°C) which is the initial stage of gasification and CO<sub>2</sub> gasification (1000°C, 0–60min) characteristics of CCA–treated wood were investigated. The release behavior of high volatile arsenic during pyrolysis and gasification of CCA–treated wood was followed. When the CCA–treated wood was pyrolyzed, the release of arsenic proceeded with increasing temperature and the release extent was 41% at 800°C. In the case of gasification, the release extent of arsenic increased with gasification time and 90% of the arsenic was released into gas phase within 60min. Furthermore, it was possible to suppress the release of arsenic by 800°C during pyrolysis by mixing organic sludge rich in iron and calcium with CCA–treated wood.</p>
-
2-12 Removal of Phosphorus from Spent Denitration Catalyst
KATO Takahiro, SAKUSABE Kosuke, OKAWA Hirokazu, SUGAWARA Katsuyasu
Proceedings of Conference on Coal Science ( The Japan Institute of Energy ) 57 ( 0 ) 42 - 43 2020.10
<p>Adsorption of phosphorus on a denitration catalyst degrades the activity of the catalyst during long-term operation of coal-fired power plants. In order to remove phosphorus and to regenerate a spent catalyst from a real coal-fired power plant, leaching behavior with water and ammonium citrate solution was investigated and change of the catalytic activity was observed. When the catalyst was treated with ammonia citrate, 67% of phosphorus could be removed, and the activity was recovered by restoration of ammonia adsorption capacity. A part of phosphorus (29%) was removed by leaching with distilled water, whereas negligible change in activity was observed.</p>
-
1-6 Removal of sulfur and nit rogen from coal extract s using a n ionic liquid
ONODERA Gai, KATO Takahiro, OKAWA Hirokazu, SUGAWARA Katsuyasu
Proceedings of Conference on Coal Science ( The Japan Institute of Energy ) 56 ( 0 ) 12 - 13 2019.10
<p>In a series studies on development of an advanced desulfurizatio n and denit r o gen ation process of heavy hydrocarbon resources under mild conditions effect of coal type on removal behavior of sulfur and nitrogen was investigated for coal extracts by using imi dazolium type ionic liquid. Sulfur and nit rogen in the coal extracts were simultaneously removed during extraction by the ionic liquid. Nitrogen removal depends on the coal type and nitrogen in the coal extracts prepared from high rank coal was easily removed.</p>
-
1-9 Analysis of mercury forms contained in unburned carbon
SAKUSABE Kosuke, TOYOSHIMA Nanako, KATO Takahiro, OKAWA Hirokazu, SUGAWARA Katsuyasu
Proceedings of Conference on Coal Science ( The Japan Institute of Energy ) 56 ( 0 ) 18 - 19 2019.10
<p>Mercury form analysis was carried out by using temperature programed desorption and cold vapor atomic absorption spectrometry. Model samples of mercury-adsorbed carbon were prepared using activated carbon and unburned carbon separated from coal fly ash. The mercury of adsorbed by unburned carbon (UC-Hg) and activated carbon (AC-Hg) showed different desorption temperature. The TPD curves of UC-Hg and AC-Hg were changed with concentration of mercury in the liquid during adsorption. Considering both forms of UC-Hg and AC-Hg, the quantitative analysis of various mercury forms in desulfurization gypsum can be achieved.</p>
◆Original paper【 display / non-display 】
◆Other【 display / non-display 】
Grant-in-Aid for Scientific Research 【 display / non-display 】
-
Grant-in-Aid for Scientific Research(B)
Project Year： 2020.04 - 2021.04
-
Grant-in-Aid for Scientific Research(C)
Project Year： 2019.04 - 2022.03
-
Grant-in-Aid for Scientific Research(C)
Project Year： 2015.04 - 2019.03
-
Grant-in-Aid for Scientific Research(C)
Project Year： 2013.04 - 2016.03
-
Grant-in-Aid for Scientific Research(C)
Project Year： 2012.04 - 2016.03
Presentations 【 display / non-display 】
-
Utilization of tertiary amine solutions and ultrasound irradiation for CO2 desorption at low temperature in a process of CCS
Hirokazu Okawa, Hiroyasu Ito, Tatsuo Fujiwara, Yuya Kitamura, Takahiro Kato, and Katsuyasu Sugawara
USE2020 2020.11 - 2020.11 USE2020
-
Synthesis of large scorodite particles using sonochemical reaction
大川浩一 [Invited]
化学系学協会東北大会 (オンライン) 2020.09 - 2020.09 日本化学会東北支部
-
1-03 石炭火力発電所由来フライアッシュ中の水銀の化学形態
ウアシケテ ドルカス リンダ エルネスト, 作左部 皓輔, 加藤 貴宏, 大川 浩一, 菅原 勝康
石炭科学会議発表論文集 2020 - 2020 一般社団法人 日本エネルギー学会
<p>An analysis was performed by combining the TPD and CVAAS to identify and quantify the mercury forms in the fly ash produced from a coal-fired power plant. The TPD curve of the model sample for each mercury compound showed a unique peak temperature, and the chemical form of mercury was identified by comparing the peak temperature with that of the fly ash. A linear combination of the TPD curve of each model sample was curve-fitted to that of the fly ash. The calculated results revealed that 45% of total mercury is C-Hg in the fly ash followed by HgO, HgS, HgSO<sub>4</sub>・2HgO, HgSO<sub>4</sub> with around 14%.</p>
-
Mercury Forms in Fly Ash and FGD Gypsum Produced from Coal Power Plants
Kosuke Sakusabe, Takahiro Kato, Hirokazu Okawa, Katsuyasu Sugawara
17th InterntionalConference on Coal Science & Technology (ICCS&T 2019) (Krakow,Poland) 2019.11 - 2019.11
-
Removalof Arsenic from Spent Denitration Catalyst by Carbon Reduction
Takahiro Kato, Kosuke Sakusabe, Hirokazu Okawa, Katsuyasu Sugawara
17th InterntionalConference on Coal Science & Technology (ICCS&T 2019) (Krakow,Poland) 2019.11 - 2019.11