DavidRead Permit WorkShop2007

CAMR and the Cement Industry: Will Mercury Revolatilize? Where Might the Mercury Go?: 

CAMR and the Cement Industry: Will Mercury Revolatilize? Where Might the Mercury Go? 2007 Southeastern Permitting Workshop May 9 to11, 2007 Tampa, Florida D. L. Read State of Florida DEP

So Where are We on Mercury Control?: 

So Where are We on Mercury Control? Clean Air Interstate Rule (CAIR) Requires Significant NOX, SO2 Reductions Clean Air Mercury Rule (CAMR) Requires Significant Hg Reductions Assume 30,000,000 TPY Coal Consumption Assume About 0.1 ppm Hg in Coal Maybe 6,000 lb Hg per year “in” with Coal Florida Allocated ~ 920 lb Hg Total Emissions (Year 2018)

How Will Plants Control Mercury?: 

How Will Plants Control Mercury? Plants Will Primarily Rely on SO2/NOX CAIR Controls Rely on CAIR Co-benefits for Hg CAMR Control Typically Selective Catalytic Reduction (SCR) for NOX Low NOX Burners to Minimize SCR Investment Lime or Limestone Scrubbing (FGD) for SO2 Some Reliance on Sorbent Injection for Hg Control

So Where Will Mercury Go?: 

So Where Will Mercury Go? CAMR does not Address the Fate of Hg Hg Exits with Coal Combustion By-products Fly Ash, Scrubber Sludge, Gypsum, Effluent Concrete, Wall Board, Landfills, Water Treatment Leaching Readmission During Processing What Happens if Some Goes to Cement Kilns?

What About Cement Kilns?: 

What About Cement Kilns? Nothing in CAMR about Cement Plants Recent MACT Hg Emissions Limits and Practices Still Reviewing Impacts of New MACT Rule “LLL” New Rule Already Under Reconsideration Law Suits by States & Private Organizations Is Cement Hg Emission Potential > Coal Unit? How Might this Happen, How to Prevent?

Hg Removal Before CAIR and CAMR at Coal Unit : 

Hg Removal Before CAIR and CAMR at Coal Unit No Great Effort at NOX Control in Furnace, Minimal Hg Removal Depends on Coal, Residence Time, Temperature (Hot/Cold ESP) Hg Removal Tends to Be Better if FF Used for Particulate Control Decent Quality Fly Ash Suitable for Direct Use in Concrete Studies Suggest Hg Stays in Concrete. Desirable Fate! Hg0 >2500 °F Flue Gas Hg(0), Hg(II), Hgp - form important for capture1 ESP/FF Coal & Air Fly Ash to Concrete 5-30% of Hg Loss on Ignition < 6% Air 70-95% 1 Hg(0) = elemental Hg; Hg(II) = oxidized Hg; Hgp = particulate Hg Temp Very Important!

Slide7: 

Sorbent is injected Upstream of the PM Control Device (ESP or FF) Collected Fly Ash and Sorbent are mixed Might not do for Concrete!! Landfill?? Don’t Just Expect Everyone to Install Sorbent Injection for Hg Control! Air ~30%

Activated Carbon/Sorbent Injection Process: 

Activated Carbon/Sorbent Injection Process

Slide9: 

Sorbent injection + Compact Hybrid Particulate Collector Particularly Advantageous for ESPs Goals: 70% SO2, 30% NOX, 90% Hg (Various Sorbents?) Can Send 99% of Fly Ash + Some Hg to Concrete. Good! Sorbent, 1% of Fly Ash + Most Hg to Landfill?? coal Don’t Just Expect Everyone to Install EPRI Toxecon for SO2, NOX, Hg Air ~10% [~ 90% of Hg in Fly Ash Streams]

What if we Add Ammonia Injection Over a Catalyst: 

What if we Add Ammonia Injection Over a Catalyst SCR in Lieu of Reburn – Typically Wouldn’t do Both SCR – Transforms Hg to Collectable Oxidized or Particulate Forms NH3 added to High LOI Makes Fly Ash Worse for Concrete More Attractive for Cement Kilns? Raw Material, Fuel? Hg0 >2500 °F Flue Gas Hg(0), Hg(II), Hgp - form important for capture1 ESP/FF Coal & Air 1 Hg(0) = elemental Hg; Hg(II) = oxidized Hg; Hgp = particulate Hg High LOI/NH3 Fly Ash 25-75% of Hg SOFA LNBs SCR Ammonia Air 25-75%

Slide11: 

SCR Process

Combustion Control for NOX Like LNBs, Reburn, SOFA: 

Combustion Control for NOX Like LNBs, Reburn, SOFA Reburn Hg0 >2500 °F Flue Gas ESP/FF Coal & Air Air 10-60% High LOI Fly Ash 40-90%+ of Hg Less Useful for Concrete SOFA LNBs Humidification NOX Combustion Strategies can Reduce Hg High Loss on Ignition (LOI) Fly Ash Adsorbs Hg Not as Good as ACI, but Lots More of it FF Better than ESP (Usually) When LOI > 6% No Longer Good for Concrete

Reburn and SOFA Effects on NOX and Hg (GE Pilot Plant): 

Reburn and SOFA Effects on NOX and Hg (GE Pilot Plant) But LOI >> 6% Bad Ash!! Landfill?

Add Acid Gas Scrubbing: 

Add Acid Gas Scrubbing Scrubber Removes Much of Remaining Hg There Can be Effluent Streams with Hg Even if Gypsum Product Studies Suggest Gypsum Tends to Hold Hg Total Hg ~ 95% Removal Possible if not Acknowledged. Hg0 >2500 °F Flue Gas Hg(0), Hg(II), Hgp - form important for capture1 ESP Coal & Air High NH3 Fly Ash 25-75% of Hg SOFA LNBs SCR Ammonia Air 5% Sludge, Gypsum 20-70% of Hg Wet Scrubber Limestone or Lime Slurry

FGD Process: 

FGD Process

One Fly Ash Remediation Scheme (GE): 

One Fly Ash Remediation Scheme (GE) Claimed Hg-Free Fly Ash to Concrete For LNB, SOFA, Reburn Re-Evolve Hg in Coker Burn Carbon, Lower LOI Re-Adsorb Hg onto ACI Fly Ash Out to Concrete Activated Carbon Disposal

Another Fly Ash Remediation Scheme: 

Another Fly Ash Remediation Scheme Amount Hg Out with Low LOI Product to Concrete?? Hg Hg Evolved Hg Hg Possible Hg Re-Adsorption As Ash Cools? Hg + NH3 (SCR) Into Silo w/Elevated LOI Fly Ash Does NH3 become N2 or NOX??

High LOI Fly Ash to Cement Kilns?: 

High LOI Fly Ash to Cement Kilns? Fly Ash is Attractive Cement Raw Material (if Unusable in Concrete) Source of Silica, Alumina, Iron. Replaces Bauxite, Sand, Iron Ore The Fuel Value in Elevated/High LOI Fly Ash is Attractive too. One Cement Company’s Fly Ash Use Profile Circa 2002

Other Fly Ash Remediation Processes: 

Other Fly Ash Remediation Processes How Much Hg Out with Low LOI Product to Concrete?? How Much Hg Out with High LOI “Fuel” Product?? Hg In with Elevated LOI Fly Ash Several Kinds of Physical, Electrical, Chemical Separation Processes

What Happens to Hg in a Cement Kiln?: 

What Happens to Hg in a Cement Kiln? Raw Materials In Limestone/Fly Ash Hg Feed Silo (Hg Storage) Possible Hg Bleed E.g. CKD Raw Meal Falls Down Preheater Hg Evolved 100% Hg Out if no Bleed Fuel Hg In Fuel Hg Moves from Internal to External Cycle Mill Off Path Hot Clinker Out (No Hg)

Coal Combustion Byproducts in Concrete & Cement: 

Coal Combustion Byproducts in Concrete & Cement Used Ready-Mix Concrete Plants?

Cement Kilns by State – Not a Regional Problem: 

Cement Kilns by State – Not a Regional Problem Back to Earthjustice

Hg Cycle with Bleed: 

Hg Cycle with Bleed

So Why not Bleed Hg by APCD Dust or Meal?: 

So Why not Bleed Hg by APCD Dust or Meal? Dust Might be Considered Cement Kiln Dust (CKD) If Added to Clinker Might not Meet Type I/II Specs ASTM C150 and AASHTO Specifications to Interpret Might Just be Considered Part of Clinker Can Add CKD for Limited Masonry Cement Market Doesn’t Bother the Euros! Still Considered I/II Cement Euros Claim They Have Addressed their Cement Hg Looks Like Power Hg in U.S. Can Become Cement Hg What Can be Done? Where do We Start?

Final Thoughts: 

Final Thoughts Is Cement Hg Potential > Power Plant Hg? Sense in Removing Hg only to Re-emit? CAIR/CAMR Deteriorating Fly Ash? Need to Determine Fate of Hg in Fly Ash Evaluate Remediation Schemes Follow High LOI Fractions Get Cement Plants to Remove Dust or Meal Ultimately get All Hg into Concrete, Gypsum Assess ASTM C150, AASHTO Requirements Convince DOT’s to Allow Dust/Meal in Cement Maybe a non-Problem? Hope so! Or too Big to Get our Arms Around?