SDA Performance Demonstrates MATS Compliance
Kevin Redinger of Babcock & Wilcox Power Generation Group showed the slide in Figure 8 at Electric Power 2013. In most of these cases B&W spray drier absorbers (SDA) are meeting the MATS limits. For filterable PM emissions, bag material and leaks need to be considered. There seems to be no degradation in performance over the bag life.
Figure 8. 2010 UMACT ICR Data for B&W SDA Installations
|
INSTALLATION |
HCI (lb/MBtu) |
Mercury (lb/TBtu) |
Filterable PM
|
|
Walter Scott 4 (790 MW) |
0.000038 |
0.720 |
0.0034 |
|
Weston 4 (530 MW) |
0.000077 |
0.893 |
0.0066 |
|
TS Power Project (220 MW) (Newmont Nevada Energy) |
0.000022 |
0.867 |
0.0056 |
|
Hawthorn 5A (540 MW) |
0.000072 |
5.30 |
0.0011 |
|
Spruance Genco 2 (57 MW) (Coal-and tire-firing) |
0.000017 |
0.0026 |
0.0183 |
|
MATS Limits |
0.002 |
1.2 |
0.030 |
For HCl control nothing specific needs to be done when controlling SO2 at 0.04-0.08 lb/MMBtu. If needed, lime flow could be increased and baghouse cleaning could be optimized. For mercury control, PAC can be injected and halogens can be added for speciation enhancement.
For new coal-fired units with SDA, PAC and baghouses, mercury levels of less than 0.333 lb/TBtu (the MATS for non-low rank virgin coal) have been observed in short term field testing. But the question is sustainability and measurement concerns.