Development of gaseous mercury removal in flue gas using powder of wasted DeNOx catalyst

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H04300
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 64020:Environmental load reduction and remediation-related
• Research Institution: Nagoya University
• Principal Investigator: Yoshiie Ryo 名古屋大学, 工学研究科, 准教授 (60293544)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 水銀 / 煙道ガス / 脱硝触媒 / 排ガス処理

Outline of Final Research Achievements

Pulverized De-NOx sample was examined in both mercury oxidation and capturing experiments as a sorbent. As a result, the De-NOx catalyst showed high mercury capture performance, compared with activated carbon. Although elemental mercury was physically absorbed on De-NOx catalyst at first, the catalytic oxidation between mercury on De-NOx catalyst and oxygen in flue gas contributed to extend mercury capturing by De-NOx. Furthermore, De-NOx catalyst maintained high mercury capture performance even at 743 K higher than the operating temperature of SCR. In contrast, the De-NOx catalyst oxidized almost all gaseous mercury in simulated flue gas containing HCl, which worked as an oxidizer. Products of the oxidation with HCl seemed to be mercury chloride, and it was too volatile to remain on De-NOx catalyst. XANES speciation for mercury captured by De-NOx catalyst indicated that mercury captured in inert N2 was elemental mercury, while mercury captured in flue gas without HCl was HgO.

Free Research Field

環境エネルギー工学

Academic Significance and Societal Importance of the Research Achievements

2017年8月水俣条約発効により各種燃焼・焼却プラントの水銀放出規制が本格化する中で，これまでに水銀捕捉用に開発されている高性能の各種活性炭では，表面酸化反応を促進する様々な添加剤添着のため高コストとなっている．これに対して，本研究で水銀捕捉剤に提案する脱硝触媒は，脱硝反応のための触媒酸化作用と水銀吸着作用を併せ持つ．つまり，使用済み脱硝触媒を粉砕して得られる微粉末を再利用することで，添加剤不要・低コスト・高機能水銀酸化捕捉剤が実現する．