Beneficial Uses & Disposal of Coal Combustion Residues ( CCRs ) Tarunjit Singh Butalia, Ph.D., Research Associate Professor Department of Civil, Environmental, & Geodetic Engineering The Ohio State University Shiv Kumar Dube, Ph.D., Senior Fellow Centre for Resource Security & Development Policy Green Growth & Resource Security Division The Energy and Resources Institute (TERI ) ccp.osu.edu 1
What are Coal Combustion Residues ( CCRs )? CCRs are solid minerals that remain after coal is burned to generate electricity or steam Types: Fly Ash Bottom Ash Boiler Slag Flue Gas Desulfurization (FGD) Materials Wet FGD Materials ( sulfite & sulfate ) Dry FGD Materials (FBC, CFBC, SD, etc.) 2
Beneficial Uses of CCRs Concrete & concrete products Cement production Structural & flowable fills Road base Mineral fillers Gypsum wallboard Soil & waste stabilization Snow & ice control Blasting grit & roofing granules Aggregate Agricultural Mining 3
Existing OSU CCR Program Established 20 years ago by industry and government agencies at OSU College of Engineering Objective: To continue to promote the technically sound , environmentally benign , and commercially competitive uses of CCRs as raw materials in commercial and industrial activity instead of landfilling and pond disposal Implemented about 20 research projects ( lab testing, bench-scale, and full-scale demo projects ) totaling over $20 million external funding with multiple private (utilities , marketers, trade sponsors), federal and state agencies . Model CCR University Program for US – American Coal Ash Association USEPA C2P2 Award Winner for 2008 - Research & Technology Transfer Voice of Trust among national CCR stakeholders (particularly regulatory agencies ) 4
5 US CCR Production & Use
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India: Fly Ash Use & Pathways Forward 7 Fundamental challenge: Indian coal is of low grade, ash content = 30-45%
8 Source: Central Electric Authority
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10 High volume, high value High volume, low value Low volume, high value Market Segments
Cement Industry & Concrete Use of fly ash as pozzolan in cement manufacturing and concrete production High volume (about 40Mt/year), high value use Accounts for 40% of fly ash use in India Requires good quality fly ash Future increases in cement industry will be incremental as technologies are developed for beneficiation / modification of poorer quality fly ashes. Use of good quality fly ash in concrete to replace cement is a promising area of volume increase 11
Structural Fills (Roads, Embankments, Ash Dykes) Designed structural fills for highways, embankments, and dykes for ash ponds High volume (about 15Mt/year), low value use Accounts for about 15% of fly ash use in India Many fly ashes (good / poor quality) can be used for this application Project specific and increases will be minimal 12
Mine Filling Backfilling open cast as well as underground mines Cradle to grave approach High volume (about 10Mt/year), low value use Accounts for about 10% of fly ash use in India All types of fly ashes (good / poor quality) can be used for this application Transportation of ash to the mine is the critical issue Large potential volume increases at mine mouth (pit head) power plants 13
Fly ash from Singrauli power plant under consideration for reclamation of Gorbi Mine 14
Building Products (Bricks, Blocks, Tiles) Use of fly ash in manufacture of bricks, blocks, and tiles High volume (about 15Mt/year), high value use Accounts for 15% of fly ash use in India Good potential for volume increases for power plants located near urban areas 15
Reclamation of Low Lying Areas Use of fly ash as fill for low lying areas High volume (about 12Mt/year), low value use Accounts for about 10% of fly ash use in India Contact of fly ash with groundwater is primary concern due to potential of leaching of trace elements Market for this use has stabilized and future increases will be incremental 16
Agricultural Uses Soil amendment applications Low volume (about 2Mt/year), low value use Accounts for about 2% of fly ash use in India More suitable for horticulture applications and food/feed applications due to concern for accumulation of trace elements in edible plants and meat. Not a significant market for future volume increases 17
India: Pathways Forward Target of 100% utilization of fly ash by December 2017 50/150 = 100% utilization achieved 40/150 = 75% to 100% utilization 15/150 = 60% to 75% utilization 45/150 = Less than 60% utilization Plant modifications: Wet to dry ash handling, silos for storage of ash In-house use by power plants for infrastructure development Transportation is the key issue Subsidy by power plant (100km to 300km) Rail transportation Use of ponded / landfilled ash – fly ash recovery Use of good quality fly ash in concrete to replace cement is a promising area of volume increase Building products use potential for power plants located near urban areas Large potential volume increases at mine mouth (pit head) power plants 18
19 Closing Remarks India power plants should aggressively promote the technically sound , environmentally benign , and commercially competitive uses of CCRs as raw materials in commercial and industrial activity instead of landfilling and pond disposal “In today’s world, the coal industry cannot be complacent and simply state that all practices regarding management of coal combustion residuals and products are in compliance with all related applicable laws. There is a need for more due diligence planning to confirm that scenarios do not occur that result in system failures and environment releases when handling these materials.”
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22 Program Focus Expand use in proven areas Increase use of low carbon fly ash for air entrained concrete Promote use of high carbon fly ash for non-air entrained concrete Full depth reclamation, pervious concrete Driver: CO 2 emission reductions, sustainability, “green” construction Sulfite FGD use in mine reclamation Remove or reduce regulatory & perceptual barriers to use Impact of TVA’s December 2008 ash spill and recent Duke fly ash release Work with USEPA and state EPAs Educating general public Emphasize different types of CCPs (not all of them are fly ash) Develop new or under-used large-volume market applications Fly ash and FGD use in mine reclamation and structural fills FGD gypsum as soil amendment Infrastructure rehabilitation Evaluate .Green Construction Certification Frameworks Explore current USGBC LEED (Leadership in Energy & Environmental Design) certifications