It seems like 2016 may be the dawning of a new era in mercury control. MATS, the US EPA’s legislation to limit mercury emissions from coal-fired utilities, has been held up by the US Court of Appeals. (http://bigstory.ap.org/article/e4b518da7c7246b590fe7ecea1737e67/appeals-court-leaves-epa-mercury-rule-effect)
Although most US utilities had already decided what action they would take to comply with MATS, some had held off in the hope that they could argue that the costs were prohibitive. Not so. Utilities must now comply or close. Canada moved on mercury control earlier than the US. Some plants have installed mercury controls whereas others, like all three plants in Ontario, have chosen to move away from coal completely.
China has had a mercury emission limit for a few years now. The 30 micrograms/m3 limit is not challenging, especially for a country where FGD and SCR installation rates are above 80%. But there is now talk of a 10 microgram/m3 limit being introduced within the next 5 years, Again, this target is not too onerous, but does signal the will to move towards reduced emissions. China has significant mercury emissions from polyvinyl chloride manufacture, a source that is relatively unique to the country, and also from the expanding cement sector. Under its proposed Minamata Convention national action plan, China intends to target and control emissions from all sectors, with coal combustion being only one of many targets.
Even India has a proposed mercury emission limit, the same as that currently in place in China (30 micrograms/m3). India has also proposed ambitious emission limits for SO2 and NOx which would require FGD and DeNOx technologies on all new plants. This represents a significant investment and a costly one. But it also opens up the potential discussion for Minamata ratification for India, since the co-benefit controls of FGD and SCR systems can be argued as BAT/BEP for mercury. Whilst this doesn’t immediately mean a market for mercury control in the region, it does signal a potential future market, as monitoring and compliance requirements will inevitably tighten in the future.
The EU is finalising mercury emission limits from the coal sector under the new BREFs. The current proposed range, 1-9 micrograms/m3, is a little confusing. The actual limit for each plant will be determined by the fuel, the plant size and age and also by local factors (subject to input from the competent local authority). And so, until each plant works through the permitting system and the BREF evaluation, it is unclear what its the mercury control requirement will be. The 1-9 microgram/m3 range could mean anything from simple co-benefit effects to more expensive mercury-specific controls. But even so, it is clear that mercury control for coal-fired plants in Europe is imminent.
And so 2016 should see a flurry of activity in the commercial mercury world – the emissions monitoring sector should be the first to notice a change. Sorbent tubes may fare better in most of the markets due to the nature of the emission limits – many are based on annual or average values that do not require the continuous reporting provided by more expensive on-line systems. With respect to emissions control, this will, as always, be determined on a plant by plant basis. Plants with FGD and SCR are, to some extent, more likely to use oxidants to enhance mercury control. whereas those without these systems, or where the coal chemistry is more challenging, may opt for sorbents.
Whilst the COP21 discussions in Paris over the last few weeks may suggest that coal is being pushed from the energy mix in some regions of the world, coal will remain base-load in others for decades to come. And it looks like mercury monitoring, abatement and control may become the norm for any coal-fired plant which remains online beyond the next 5-10 years.