Sarah Luehmann
DURAG , Germany
- Conference: Mercury and Dioxin Monitoring
- Presentation: Mercury emission monitoring in coal-fired power plants
- Presentation Time: Thursday 10:20
Since 2017 Head of Product Management, DURAG GROUP (Hamburg, Germany)
2011 - 2017 Product Manager Environmental Monitoring, DURAG GROUP (Hamburg, Germany)
2006 - 2011 R&D engineer and team manager for optics and spectroscopy at m-u-t (Wedel, Germany)
2000 - 2006 University degree in physics, Hamburg University (Germany) and Uppsala University (Sweden)
Mercury (Hg) is a toxic heavy metal naturally present in our environment which is of growing global concern. Coal burning is one of the most significant anthropogenic sources of mercury emissions to the atmosphere making more than 85 % of these emissions.
India as one of the world’s fastest growing economies has recently taken measures for reducing mercury emissions from thermal power plants. The latest Environmental Standard for Thermal power plants specifies a mercury emission limit value of 0.03 mg/m3 for all units having a capacity of 500 MW.
Within the European Union the new Best Available Techniques (BAT) associated emission levels for total mercury of 1 - 4 µg/m3 for hard coal-fired power plants and 1 - 7 µg/m3 for lignite-fired power plants as yearly average are considerably below the current European emission limit values. In order to comply with the new emission levels Hg specific reduction measures have to be applied such as for example fuel pre-treatment, carbon sorbent injection or boiler bromine addition.
For continuous measurement of total mercury emissions in flue gases cost-efficient analysers are required allowing reliable emission monitoring. A total mercury analyser with a thermo-catalytic reactor for reduction of Hg(II) to Hg(0) using Atom Absorption Spectrometry (AAS) will be presented. The technique is widely used for mercury analysis and is particularly advantageous allowing for separate analysis of the mercury species Hg(0) and Hg(II). The determination of the ratio between the species enables plant operators to optimize the flue gas cleaning process by implementing specific and efficient measures for mercury removal. The presented technology allows for cost-efficient real time monitoring of total mercury concentrations and holds potential for reducing costs of mercury removal from flue gas.
We discuss the advantages of continuous Hg measurement in comparison with discontinuous methods such as long-term sampling. Furthermore we present practical examples for continuous Hg measurements at different stages of the flue gas cleaning system.