Thermal stability of mercury captured by ash

Aurora M. Rubel, James C. Hower, Sarah M. Mardon, Matthew J. Zimmerer

Research output: Contribution to journalArticlepeer-review

18 Scopus citations


The thermal stability of mercury captured by ash was studied by sampling ash throughout the collection train of two Kentucky power plants. Sampling occurred over multiple years and involved both fresh and archived samples. During one ash collection episode, sampling was from the combustion of a single pulverized coal feed. The other collections involved ash from blended feeds. Ash was collected from economizer, mechanical and electrostatic precipitator hoppers. Feed coals, rejects and bottom ash were also sampled. Fractions of all the samples were heated in a thermal analyzer to maximum temperatures increased sequentially from 100 to 500 °C in 100 °C increments. The mercury content of the spent material was then determined by analysis of the solids for Hg. From this data the thermal decomposition temperature of the captured mercury was determined. The total mercury captured by each sample, thermal stability of the mercury in relation to collection site, and correlations between mercury capture and chemical composition of the sample were also determined. The data showed that mercury was released between 300-400 °C for all ash samples. The thermal release of Hg between 300-400 °C was studied in greater detail by following the Hg release in several samples at 25 °C intervals from 300-400 °C. The concentration of mercury captured in the ESPs hoppers was greater than in the ash collected from the economizer or mechanical separators.

Original languageEnglish
Pages (from-to)2509-2515
Number of pages7
Issue number17-18
StatePublished - Dec 2006

Bibliographical note

Funding Information:
Mardon was supported by a grant from the National Coal Quality Inventory (administered by the US Geological Survey) and by a grant from CONSOL Energy in support of undergraduate research.


  • Fly ash
  • Mercury
  • Thermal

ASJC Scopus subject areas

  • General Chemical Engineering
  • Fuel Technology
  • Energy Engineering and Power Technology
  • Organic Chemistry


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