Wet Scrubber Additive
Uses at Coal Fired Power Plants
MATS Compliance for Mercury Emissions in wet FGD Units
- Provides a fast-acting mercury control option during unit start-up, SCR bypass, ORP excursions, or other events that may trigger higher Hg stack emissions.
- Lowers total stack mercury emissions up to 95%.
- Requires less mercury (Hg) oxidation than other wet scrubber additives to meet MATS compliance.
- Effective over a wider pH (4.5 to 7.0) and ORP (-200 to +600mV) range than traditional wet scrubber additives.
Dissolved Metals Removal from Scrubber Effluent
Redox 5545 was injected into a forced oxidation wet FGD scrubber for a period of 30 days at 10 gallons per hour to evaluate the effect of stack mercury control and dissolved metals removal. The results showed:
To evaluate the effect on stack mercury control and dissolved metals removal in afforded oxidation wet FGD scrubber, Redox 5545 was injected into the scrubber at a rate of 10 gallons per hour for 30 days. In addition to stack mercury (Hg) remaining well below the MATS compliance goal of 1. Lbs/TBtu, concentrations of dissolved mercury were also lowered by 93%, selenite (93%), and arsenic (50%) in the scrubber slurry blowdown.
ORP Control in wet FGD Units
The oxidation-reduction potential (ORP) is highly correlated to Hg re-emission in wet flue gas desulfurization (wFGD) systems in coal-fired power plants. An ORP in excess of +250mV has been shown to promote mercury re-emission. Redox’s products have been used in forced oxidation wFGD units to control ORP resulting in lowering stack mercury (Hg) emissions.
An example of this would be a 1,300 MW station burning bituminous coal with a forced oxidation FGD unit that was experiencing mercury re-emission with an ORP of +650mV. The station injected one tote (300 gallons) of Redox 5545 into the absorber sump and within 15 minutes, ORP was lowered to +200 mV and stack mercury was reduced from 1.7 to 0.50 lbs./TBtu.