How China Can Leapfrog
Title of Slide
the World in
Mercury Emission Reductions
Sid Nelson Jr.
Impressive Development Throughout China
But EverEver-Increasing Pollution
Mercury from Power Plants
Chinese Coals Average ~50% Higher Hg
China
USA
0.00
0.05
0.10
0.15
Average coal Hg content, ppm, dry basis.
Various sources. The difference may be even greater.
0.20
Overview of the Mercury Problem
Source: U.S. EPA
Effects Observed in Small Newborn Samples
2006 Jedryckowski, et al., “Effects of Prenatal Exposure to Mercury on
Cognitive and Psychomotor Function in One-Year-Old Infants:
Epidemiologic Cohort Study in Poland,” Annals Epidemiology 16:439–447.
2006 Marques, et al., “Maternal mercury exposure and neuro-motor development
in breastfed infants from Porto Velho Brazil” Int J Hyg Environ Health, 210(1):51.
2007 Gao, et al., “Prenatal exposure to mercury and neurobehavioral development
of neonates in Zhoushan City, China,” Environmental Research, 105:390-399.
2007 Suzuki, K., et al., “Associations of neonatal neurobehavioral status with
cord blood PCB, maternal hair mercury, and maternal fish intake in the
Tohoku Study Of Child Development ,” Organohalogen Compounds, 69:262.
2007 Xue, et al., “Maternal fish consumption, mercury levels, and risk of
preterm delivery,” Environmental Health Perspectives, 115(1):42. (U.S.)
In the U.S., Hg from Fish Lowers IQ
Oken (2005):
• lowering Hg 50% raises IQ = 2 points
Oken (2008):
• lowering Hg 50% raises IQ = 1.5 points
Lederman (2008):
• lowering Hg 50% raises IQ = 2.5 points
Oken, E., et al., “Maternal Fish Consumption, Hair Mercury, and Infant Cognition
in a U.S. Cohort,” Environmental Health Perspectives, 113(10):1376, 2005.
Oken, E., et al., “Maternal Fish Intake during Pregnancy, Blood Mercury Levels, and
Child Cognition at Age 3 Years in a US Cohort,” Am J Epidemiol 167:1171–1181, 2008.
Lederman, et al., “Relation between Cord Blood Mercury Levels and Early Child Development
in a World Trade Center Cohort,” Environmental Health Perspectives, 116(8):1085, 2008.
in the fish
Fish MeHg Varies Directly with Deposited Hg
• Isotopically enriched Hg(II)
(90.9% 202Hg+2) was spiked into
large, isolated lake sections
• Uptake monitored in zooplankton,
benthic invertebrates, & fish
• “We conclude that concentrations
of spike MeHg in the food web
of the mesocosms were
directly proportional to the
rates of Hg(II) loading.”
Orihel, et al., “Experimental evidence of a linear relationship between inorganic mercury loading
and methylmercury accumulation by aquatic biota,” Environ. Sci. Technol. 41: 4952, 2007.
How Is Hg Done in the U.S.? ACI
B-PAC
H-PAC
C-PAC
ESP
/FF
Boiler
300F
700F
Air Preheater
Fly Ash
Brominated Powdered Activated Carbon Injection (ACI) before the ESP
ACI System
Lances sticking
into the ductwork
We have installed
10 systems
10-cm transport
line
Silo to hold the PAC
& blower(s)
& sold many millions
of kgs of brominated
carbons
Delivering
brominated PAC
Over 100 ACI Systems Sold
Can be expensive for 90%
(but “micro-injection” is
not & is suited to plants
without FGD)
55,000 MW
of capacity
Leverage Hg Reductions from Scrubbers
China
USA
0.00
0.20
0.40
0.60
0.80
Fraction of Power Plants with FGD
1.00
Many Chinese Coals Have Low Halogens
High Cl
Low Cl
USGS preliminary data on 305 samples
Vosteen, “Chinese Low Chlorine Coals Need Bromine for
Co-Benefit Mercury Capture,” EUEC Conference, 2010.
Oxidize Hg(0) with CaBr2 on Coal
While wet scrubbers
remove most of the Hg+2
from the flue gas,
they remove essentially
zero of the Hg(0)
Adding a small amount of
bromide to the coal can
change Hg(0) to Hg+2 so
the scrubber can remove it
Very Simple & Inexpensive
Just drip a CaBr2 salt solution onto the coal
Chinese Wet Scrubbers
100
Usually ~ 70%
from ESP+FGD;
But sometimes
much less
Guizhou Guizhou Guizhou Guangdong Shanxi Beijing
(SCR)
Wang, et al.,”Mercury emission and speciation of coal-fired power plants in China,”
Atmos. Chem. Phys., 10, 1183–1192, 2010.
Two More
1.00
This one low
Hg very low
capture
M e rc u ry R e d u c t io n
0.90
0.80
0.70
0.60
0.50
0.40
0.30
0.20
0.10
0.00
Hebei
Zhang et al., “Mercury Emissions from
Six Coal-Fired Power Plants in China’”
Fuel Processing Technology, 1033, 2008.
No SCR
SCR On
Ozone
Season
Wu, et al., “Evaluation of mercury speciation and
removal through air pollution control devices of a
190 MW boiler,” Environmental Sciences, 227, 2010.
D
Dombrowski (URS) et al., “Near and Long Term Options for Controlling
Mercury from Power Plants,” MEGA Symposium, August 2008.
Luminant Monticello Station
TX Lignite/PRB & LSFO + KNX™ CaBr2
- CaCl2 not work, but CaBr2 did:
30% 85% with ~100 ppm
Benson, EERC, Richardson, URS, et al., “Large-Scale Mercury Control Technology Testing for Lignite-Fired Utilities –
Oxidation Systems for Wet FGD,” DOE NETL Hg Control R&D Program Review, 2006.
NRG Energy’
Energy’s Limestone Station
Coal Blend with Wet Scrubber
Tried CaBr2 with & without PAC
Conditions
%Hg Removal
Baseline
30%
0.5 lb/MMacf
50%
100ppm CaBr2
70%
0.5 + 100 ppm
80%
1.6 + 280 ppm
90%
30% 70% with 100 ppm
We Energies’
Energies’ Pleasant Prairie Plant with SCR
- PRB coal
- SCR
- Wet FGD
- KNX™ = CaBr2
55% 90%
with 10-20 ppm
Rini, et al., “Full-scale Test Results From a 600 MW
PRB-fired Unit Using Alstom’s KNX™ Technology
for Mercury Emissions Control” Air Quality VII, 2009.
Costs Are Tiny Compared to Other Pollutants
Costs in the USA
SO2: Scrubbers
NOx: SCR
PM: Fabric Filter
Hg: ACI
Hg: CaBr2
$/kW
$250
$150
$60
$3
$1
• Work underway on United Nations global
legally binding instrument on mercury
• China can inexpensively lead the way
TakeTake-Home Messages
1. Every year that China delays reducing Hg, it lower its IQ
2. Brominated activated carbon in the U.S., but can be expensive
3. Adding small amounts of CaBr2 to the coal can result in
significantly improved Hg co-reductions in FGD at many plants
4. Very simple, very cheap, and very cost-effective
5. With CaBr2 on FGD (and micro-injection without FGD), China
can leapfrog the U.S. & the world in Hg reductions