Mercury transformations in the exhausts from lab-scale coal flames

Fujiwara, Naoki

doi:10.1016/s0016-2361(02)00156-4

Cited by 38 publications

(32 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In flue gas from coal-fired power plants, mercury is usually present in ionic, particulate, and elemental states (Korpiel and Vidic, 1997;Fujiwara et al, 2002). Due to its high solubility in water, the ionic state of mercury can be removed by treatments such as wet scrubbers.…”

Section: Introductionmentioning

confidence: 99%

Elemental mercury oxidation in an electrostatic precipitator enhanced with in situ soft X-ray irradiation

Wang

et al. 2014

Journal of the Air & Waste Management Association

View full text Add to dashboard Cite

Corona discharge based techniques are promising approaches for oxidizing elemental mercury (Hg 0 ) in flue gas from coal combustion. In this study, in-situ soft X-rays were coupled to a DC (direct current) corona-based electrostatic precipitator (ESP). The soft X-rays significantly enhanced Hg 0 oxidation, due to generation of electrons from photoionization of gas molecules and the ESP electrodes. This coupling technique worked better in the positive corona discharge mode because more electrons were in the high energy region near the electrode. Detailed mechanisms of Hg 0 oxidation are proposed and discussed based on ozone generation measurements and Hg 0 oxidation behavior observations in single gas environments (O 2 , N 2 , and CO 2 ). The effect of O 2 concentration in flue gas, as well as the effects of particles (SiO 2 , TiO 2 , and KI) was also evaluated. In addition, the performance of a soft X-rays coupled ESP in Hg 0 oxidations was investigated in a lab-scale coal combustion system. With the ESP voltage at +10 kV, soft X-ray enhancement, and KI addition, mercury oxidation was maximized.Implications: Mercury is a significant-impact atmospheric pollutant due to its toxicity. Coal-fired power plants are the primary emission sources of anthropogenic releases of mercury; hence, mercury emission control from coal-fired power plant is important. This study provides an alternative mercury control technology for coal-fired power plants. The proposed electrostatic precipitator with in situ soft X-rays has high efficiency on elemental mercury conversion. Effects of flue gas conditions (gas compositions, particles, etc.) on performance of this technology were also evaluated, which provided guidance on the application of the technology for coal-fired power plant mercury control.

show abstract

Section: Introductionmentioning

confidence: 99%

Elemental mercury oxidation in an electrostatic precipitator enhanced with in situ soft X-ray irradiation

Wang

et al. 2014

Journal of the Air & Waste Management Association

View full text Add to dashboard Cite

show abstract

“…10 TiO 2 does not exhibit catalytic activity by itself except under ultraviolet (UV) radiation. 27 Other than oxides, carbon sites in fly ash are also believed to be responsible for mercury oxidation. 10 Extent of mercury oxidation was found to be correlated with the level of UBC.…”

Section: Introductionmentioning

confidence: 99%

Impact of Fly Ash Composition on Mercury Speciation in Simulated Flue Gas

Bhardwaj

Chen

Vidic

2009

Journal of the Air & Waste Management Association

View full text Add to dashboard Cite

The impact of different fly ash samples on mercury speciation in simulated flue gas at 140°C was evaluated in this study. Experiments were conducted in a fixed bed reactor to determine the impact of fly ash morphological characteristics and chemical composition on mercury uptake and oxidation. No homogeneous mercury oxidation was observed at 140°C. Mercury uptake tests with different fly ash samples revealed that loss on ignition (LOI), surface area, and particle size all had positive effects on mercury oxidation and adsorption (i.e., as the above parameters increased, mercury adsorption and oxidation also increased). Experiments with pure inorganic components showed that alumina (Al 2 O 3 ), silica (SiO 2 ), calcium oxide (CaO), magnesium oxide (MgO), and titania (TiO 2 ) do not promote mercury oxidation or adsorption. Ferric oxide (Fe 2 O 3 ) and unburned carbon, on the other hand, showed significant mercury oxidation and capture.

show abstract

“…Higher chlorine content in coal leads to increased effi ciency of Hg oxidation, and also to a higher content of fl y ash-bound mercury. Results from the studies focused on mercury conversion in fl ue gas discussed by Fujiwara et al (2002) have proved that only combustion of coals with considerable chlorine content leads to the formation of large amounts of mercury in its oxidized form, however, the observed Hg oxidation effi ciency did not rise with the increase of the time of Hg remaining in fl ue gas. In the case of fl ue gas cooling, distribution of mercury between solid and the gaseous phase changes towards an increase in the content of solid particle-bound Hg.…”

Section: Heterogeneous Reactionsmentioning

confidence: 99%

Transformations of mercury in processes of solid fuel combustion – review

Czaplicka¹,

Pyta²

2017

Archives of Environmental Protection

View full text Add to dashboard Cite

Abstract:The paper presents current reports on kinetics and mechanisms of reactions with mercury which take place in the exhaust gases, discharged from the processes of combustion of solid fuels (coals). The three main stages were considered. The fi rst one, when thermal decomposition of Hg components takes place together with formation of elemental mercury (Hg 0 ). The second one with homogeneous oxidation of Hg 0 to Hg 2+ by other active components of exhaust gases (e.g. HCl). The third one with heterogeneous reactions of gaseous mercury (the both -elemental and oxidised Hg) and solid particles of fl y ash, leading to generation of particulate-bound mercury (Hg p ). Infl uence of exhaust components and their concentrations, temperature and retention time on the effi ciency of mercury oxidation was determined. The issues concerning physical (gas-solid) and chemical speciation of mercury (fractionation Hg 0 -Hg 2+ ) as well as factors which have infl uence on the mercury speciation in exhaust gases are discussed in detail.

show abstract

Mercury transformations in the exhausts from lab-scale coal flames

Cited by 38 publications

References 10 publications

Elemental mercury oxidation in an electrostatic precipitator enhanced with in situ soft X-ray irradiation

Elemental mercury oxidation in an electrostatic precipitator enhanced with in situ soft X-ray irradiation

Impact of Fly Ash Composition on Mercury Speciation in Simulated Flue Gas

Transformations of mercury in processes of solid fuel combustion – review

Contact Info

Product

Resources

About