NEWS RELEASE                                   MAY 2005

Scrubbers In Other Countries Remove More Mercury Than U.S. Emits

Power plants in the U.S. emit 48 tons per year of mercury.  Power plants outside the U.S. remove more than 50 tons per year of mercury, and this quantity will increase to over 80 tons by 2010.  This new finding by the McIlvaine Company is based on its individual plant data and forecasts contained in the Utility Environmental Upgrade Tracking System.

A big debate is raging over the co-benefits of scrubbing.  (How much mercury will be reduced by installing scrubbers?)  Another debate centers on the contribution of mercury from China and other countries.  Therefore, the analysis of mercury reduction efforts in other countries is of high importance.

Worldwide, 291,000 MW of coal-fired power generation capacity is equipped with scrubbers.  Only one third of this capacity is in the U.S.  By 2012 more than 500,000 MW of scrubbers will be operating worldwide.  The combination of scrubbers for SO₂ control and SCR for NO_x is particularly effective in reducing mercury.  By 2012 over 250,000 MW of capacity worldwide will be equipped with both SCR and scrubbers.

A common misconception is that most waste-to-energy plants remove mercury through the use of activated carbon injection.  This is true in the U.S., but the U.S. has only a tiny fraction of the waste-to-energy plants worldwide.  Plants outside the U.S. capture most of the mercury in scrubbers.  The Bayer facility in Germany is removing more than 95 percent of the mercury in a scrubber following the SCR.  (This unit also uses chemical additives to improve scrubber efficiency.)

Some waste-to-energy facilities in Europe are using scrubbers for up to 85 percent of the mercury capture and are using activated carbon for an additional 5 to 10 percent reduction.  China and other Asian countries are presently embarking on a big program to build waste-to-energy facilities complete with scrubbers.

China and Russia, along with some other less developed countries, have long used scrubbers for power plant particulate control.  These devices capture more than 50 percent of the mercury, but only achieve 95 percent particulate reduction.  Over the last decade many of these have been replaced by more efficient precipitators.  While these new precipitators are much better at removing dust, they are much poorer at removing mercury.  The result has been increases of mercury emissions from these facilities.

This negative trend is more than offset by the huge investment in SO₂ removal scrubbers and the investment in SCR.  In Europe most coal-fired power plants are equipped with SCR for NO_x reduction followed by precipitators for particulate control and then followed by SO₂ scrubbers.  The Germans respond to the argument that the U.S. is the only country to regulate power plant mercury by pointing out that since all there coal-fired plants have scrubbers and SCR, they do not have a mercury emission problem. Their concern about mercury is evidenced by the fact that they do regulate the mercury emissions from the scrubber wastewater discharges. 

China has a bigger scrubber program underway than does the U.S.  It is also starting to install some SCR units.  In Taiwan and Japan all coal-fired units are equipped with scrubbers and most also have SCR.

The trend in Europe and Asia towards co–combustion of biomass with coal will also have a big impact in reducing mercury emissions.  The reason is that biomass has less mercury and more chlorine.  The chlorine in the biomass reacts with the mercury in the coal to form a soluble mercury chloride which is easily captured in the scrubber.  This co-combustion trend is being driven by the greenhouse gas concern, but the net effect will be both CO₂ and mercury reduction.

For more information in the Utility Environmental Upgrade Tracking System, click on:  http://www.mcilvainecompany.com/energy.html