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Naruhito Omine

Bio: Naruhito Omine is an academic researcher from Hitachi. The author has contributed to research in topics: Scrubber & Flue gas. The author has an hindex of 1, co-authored 1 publications receiving 96 citations.

Papers
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Journal ArticleDOI
01 Jan 2012-Fuel
TL;DR: In this article, the effect of scrubber temperature and pH, ionic mercury concentration in the liquor, total sulfite, and chloride and bromide ion concentration in solution on mercury re-emission was investigated.

106 citations


Cited by
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Journal ArticleDOI
15 Mar 2015-Fuel
TL;DR: In this paper, a general review of the FGD technologies used to abate sulphur emissions from coal-fired power plants, and exposes the major physic-chemical processes occurring during wet limestone FGD is presented.

365 citations

Journal ArticleDOI
TL;DR: In this paper, the authors provide a comprehensive understanding of mercury in coal combustion process and guidance for future mercury research directions, and summarize the knowledge and research developments concerning these mercury-related issues.

283 citations

Journal ArticleDOI
TL;DR: In this paper, the authors reviewed the mercury transformation mechanisms and speciation profiles for flue gases formed in and released from coal-fired boilers, nonferrous metal smelters, cement plants, iron and steel plants, waste incinerators, biomass burning and so on.
Abstract: . Mercury transformation mechanisms and speciation profiles are reviewed for mercury formed in and released from flue gases of coal-fired boilers, non-ferrous metal smelters, cement plants, iron and steel plants, waste incinerators, biomass burning and so on. Mercury in coal, ores, and other raw materials is released to flue gases in the form of Hg0 during combustion or smelting in boilers, kilns or furnaces. Decreasing temperature from over 800 °C to below 300 °C in flue gases leaving boilers, kilns or furnaces promotes homogeneous and heterogeneous oxidation of Hg0 to gaseous divalent mercury (Hg2+), with a portion of Hg2+ adsorbed onto fly ash to form particulate-bound mercury (Hgp). Halogen is the primary oxidizer for Hg0 in flue gases, and active components (e.g., TiO2, Fe2O3, etc.) on fly ash promote heterogeneous oxidation and adsorption processes. In addition to mercury removal, mercury transformation also occurs when passing through air pollution control devices (APCDs), affecting the mercury speciation in flue gases. In coal-fired power plants, selective catalytic reduction (SCR) system promotes mercury oxidation by 34–85 %, electrostatic precipitator (ESP) and fabric filter (FF) remove over 99 % of Hgp, and wet flue gas desulfurization system (WFGD) captures 60–95 % of Hg2+. In non-ferrous metal smelters, most Hg0 is converted to Hg2+ and removed in acid plants (APs). For cement clinker production, mercury cycling and operational conditions promote heterogeneous mercury oxidation and adsorption. The mercury speciation profiles in flue gases emitted to the atmosphere are determined by transformation mechanisms and mercury removal efficiencies by various APCDs. For all the sectors reviewed in this study, Hgp accounts for less than 5 % in flue gases. In China, mercury emission has a higher Hg0 fraction (66–82 % of total mercury) in flue gases from coal combustion, in contrast to a greater Hg2+ fraction (29–90 %) from non-ferrous metal smelting, cement and iron and/or steel production. The higher Hg2+ fractions shown here than previous estimates may imply stronger local environmental impacts than previously thought, caused by mercury emissions in East Asia. Future research should focus on determining mercury speciation in flue gases from iron and steel plants, waste incineration and biomass burning, and on elucidating the mechanisms of mercury oxidation and adsorption in flue gases.

119 citations

Journal ArticleDOI
TL;DR: In this paper, a series of regenerable sorbents based on Zr-Mn binary metal oxides were prepared and employed at a relatively low temperature to capture and recover mercury from coal-fired flue gas.

94 citations

Journal ArticleDOI
TL;DR: The application of phytoremediation techniques has been proven as a promising approach in the removal of Hg from contaminated soil and its combined effects on the ecosystem, and its remediation in the environment.
Abstract: Mercury (Hg) is a pollutant that poses a global threat, and it was listed as one of the ten leading ‘chemicals of concern’ by the World Health Organization in 2017. The review aims to summarize the sources of Hg, its combined effects on the ecosystem, and its remediation in the environment. The flow of Hg from coal to fly ash (FA), soil, and plants has become a serious concern. Hg chemically binds to sulphur-containing components in coal during coal formation. Coal combustion in thermal power plants is the major anthropogenic source of Hg in the environment. Hg is taken up by plant roots from contaminated soil and transferred to the stem and aerial parts. Through bioaccumulation in the plant system, Hg moves into the food chain, resulting in potential health and ecological risks. The world average Hg concentrations reported in coal and FA are 0.01–1 and 0.62 mg/kg, respectively. The mass of Hg accumulated globally in the soil is estimated to be 250–1000 Gg. Several techniques have been applied to remove or minimize elevated levels of Hg from FA, soil, and water (soil washing, selective catalytic reduction, wet flue gas desulphurization, stabilization, adsorption, thermal treatment, electro-remediation, and phytoremediation). Adsorbents such as activated carbon and carbon nanotubes have been used for Hg removal. The application of phytoremediation techniques has been proven as a promising approach in the removal of Hg from contaminated soil. Plant species such as Brassica juncea are potential candidates for Hg removal from soil.

77 citations