Use of FGD Gypsum in Agricultural Applications EPA Resource Conservation Challenge National Workshop March 26, 2009 Washington DC Ken Ladwig Senior Project Manager keladwig@epri.com 262-754-2744
Electric Power Research Institute Established in 1973 Independent, non-profit R&D Collaborative research, voluntary membership EPRI s mission is to conduct research on key issues facing the electric power industry on behalf of its members, energy stakeholders, and society. 2
EPRI CCP Research Portfolio Characterization Disposal CCP Management Utilization Environmental Risk 3
New Comprehensive Research Collaborative Sustainable Management of CCPs Objectives Minimize Environmental Risk Increase CCP Use Improve Outreach Strengthen Partnerships EPA, USDA, FHWA, RMRC, National Laboratories, Universities www.epri.com (CCP webpage under development) 4
CCP Generation and Collection Economizer Furnace Economizer Ash Collection FGD Absorber Air Heater Particulate Collector Bottom Ash/Slag Collection Fly Ash Collection FGD Gypsum Collection Stack 5
Flu Gas Desulfurization (FGD) Flue Gas Scrubbing - removes sulfur dioxide (SO 2 ) from flue gas First installations in the 1970s Acid rain Wet systems and dry systems Significant increases expected over the next decade Clean Air Interstate Rule (CAIR) FGD systems react a base with the acid gas to produce a solid product requiring use or disposal 6
FGD Product Terminology Wet Systems FGD Gypsum (Forced Oxidation) Scrubber Sludge (Natural/Inhibited Oxidation) Dry Systems Spray Dryer Absorber Material Duct Sorbent Injection Material Furnace Sorbent Injection Material Fluidized Bed Combustion Material 7
FGD Gypsum - Beneficial Use Agriculture Concrete 1% 1% Aggregate 1% Cement 7% Wallboard 90% FGD Gypsum Use 9.2 million tons (75%) 2007 ACAA Survey Data 8
FGD Gypsum Characterization The Ohio State University ~35 FGD gypsum samples ~10 mined gypsum samples Total composition Leaching (SPLP and DI Water) Gypsum purity Grain size Moisture 9
FGD Gypsum Characterization Trace Constituents - Median Concentrations (7 Plants) 60.0 50.0 FGD Gypsum Commercial Gypsum Concentration, mg/kg 40.0 30.0 20.0 10.0 0.0 Ni Sb Cr Se Zn V B Li Ba Source: EPRI unpublished data 10
FGD Gypsum Characterization Trace Constituents - Median Concentrations (7 Plants) 2.0 FGD Gypsum Commercial Gypsum 1.6 Concentration, mg/kg 1.2 0.8 0.4 0.0 Be Co Hg Cd Tl Mo Pb As Cu Source: EPRI unpublished data 11
FGD Gypsum Characterization Mercury Milestone Lumex Digest Average ug/g ug/g ug/g ug/g Number 29 29 29 29 Mean 0.313 0.342 0.240 0.299 Median 0.179 0.170 0.143 0.169 Maximum 1.407 1.631 1.042 1.360 12
FGD Gypsum in Agricultural Applications Benefits of FGD Gypsum Amelioration of subsurface acidity Source of plant nutrients Improve soil physical properties Increase infiltration Reduce P and N in surface water runoff Remediate sodic soils No-till cropping on clay soils Synthetic soils/horticultural use Mineland reclamation www.soils.usda.gov 13
Decrease Subsurface Acidity (Al +3 ) Al +3 in subsoils is toxic to plants Ca exchanges with Al SO 4 forms complexes with Al +3 Result is greater depth of root penetration From Dave Kost, 2006 Workshop 14
Decrease Subsurface Acidity (Al +3 ) Contorted tap roots due to Al toxicity Straight tap roots in absence of Al From Lamar Larrimore, 2006 Workshop 15
Nutrient Source - Sulfur From Dave Kost, 2006 Workshop 16
Nutrient Source - Sulfur North Dakota Site 2008 Canola S deficiency Very good response 17
Nutrient Source - Calcium Increases: Available calcium (soluble) Peanut pod calcium Ca for pod development must enter pod directly From Lamar Larrimore, 2006 Workshop 18
Nutrient Source - Calcium Higher Calcium Increases Shelf Life of Tomatoes From Lamar Larrimore, 2006 Workshop 19
FGD Gypsum Use in China Sodic Soils 20
National Network of Sites Purpose Demonstrate agricultural benefits across different regions, soil types, and crops Address environmental acceptability of agricultural use Determine appropriate application rates Develop resources for technical assistance Nationwide, multi-year study led by The Ohio State University 21
Network Sites State Sites Year Started Crop North Dakota 3 2007 Wheat, Canola New Mexico 2 2008 Alfalfa Arkansas 1 2008 Cotton Indiana 2 2008 Corn, Soybean Ohio 2 2008 Mixed Pasture, Corn N. Alabama 2 2008 Bermudagrass Pasture S. Alabama TBD 2009 TBD Wisconsin TBD 2009 TBD Illinois TBD 2009 TBD Missouri TBD 2010 TBD 22
Experimental Design Replicate 1 FGD gypsum (3 rates) Replaced material (3 rates) Control (no application) Replicate 2 FGD gypsum (3 rates) Replaced material (3 rates) Control (no application) Replicate 3 FGD gypsum (3 rates) Replaced material (3 rates) Control (no application) Replicate 4 FGD gypsum (3 rates) Replaced material (3 rates) Control (no application) Randomized complete block 23
Data Collection Crop yield Soil quality Soil water quality Plant tissue metals Mercury Meteorological data 24
Ecotoxicity Earthworm Study 6 field sites; 3 in 2008 and 3 in 2009 Collect worms from high application rate plots Analysis for mercury, arsenic, selenium, and other trace constituents Fresh and depurated worms The Ohio State University 25
Greenhouse Study Climate Controlled 65 Tubs replicating 3 field sites Mercury volatilization High application rate effects Leaching Ecotoxicity University of Nevada-Reno 26
2009 FGD Gypsum in Agricultural Workshop November 17-19, 2009 Hyatt Regency Indianapolis 170 attended 2007 Workshop Sponsors EPRI, ACAA, USDA-ARS, US EPA, Southern Company www.fgdproducts.org 27
Questions 28