State of Practice for SNCR Robert J. Schreiber, Jr. Schreiber, Yonley & Associates Research Conducted for the Portland Cement Association

2 Project Tasks Task 1: Literature Search Task 2: Terminology / Methodology Task 3: Identification of SNCR Reagents Task 4: Regulatory Consideration and Applicability of SNCR Task 5: Current State of Practice for SNCR Use Task 6: Current State of Practice for SNCR Installation Task 7: Experience in Other Industries

4 Task 1: Literature Search PCA provided summary –Search terms SNCR or Selective Non-Catalytic Reduction; and Ammonia / Urea / Reagent; and Oxide / Emission / Pollutant; 2000 – 2007 publish date –SYA requested specific titles

5 Task 2: Terminology / Methodology Terminology: –NOx Formation Thermal NOx Prompt NOx Fuel NOx Feed NOx –Amidogen ion (NH 2 amine radical) –Reducing Reagents Ammonia –Anhydrous –Aqueous Urea Biosolids

6 Task 2: Terminology / Methodology Terminology: –Normalized Stoichiometric Ratio Molar ratio –Ammonia –Urea –Reagent Utilization –Ammonia Slip –SNCR Effectiveness –Percent NOx reduction

7 Task 3: Identification of SNCR Reagents Reagents: –Primary reagents Ammonia –Anhydrous (RMP, PSM, Homeland Security) –Aqueous Urea – Other reagents Cyanuric Acid (C 3 H 3 N 3 O 3 ) Biosolids Processed Photographic water

8 Task 3: Identification of SNCR Reagents Reagents: –Primary reagents Suppliers Costs Special considerations –PSM –RMP –Homeland Security

9 Task 4: Regulatory Considerations –Clean Air Act NOx NAAQS –Clear Skies Legislation –Clean Air Interstate Rule (CAIR) –Ozone Transport Commission –South Coast Air Quality Management District

Other Regulatory Considerations Regional Haze (BART) –NOx affects PM 2.5 –PM 2.5 non-attainment areas –Regional Planning Organizations

15 Task 4: Regulatory Considerations –State Specific Reductions –Department of Homeland Security Aqua ammonia 20% or greater Anhydrous ammonia

16 Task 5: Current SNCR Practice –Operating Issues Temperature –Where to inject the reagent High turbulence Sufficient residence time

17 Task 5: Current SNCR Practice –Operating Issues Reagent handling –Ammonia is a toxic chemical RMP PSM –Urea solutions are more viscous Delivery system must allow for this

18 Task 5: Current SNCR Practice –Operating Issues Ammonia slip –Ammonia emissions –Odors –Inefficient use of reagent –Impact on synthetic gypsum from scrubber –Ammonium salt formation

SNCR Equipment Required –Reagent tank –Distribution system –Control system –CEMS for NO x & ammonia required to determine optimum ammonia injection rate to maximum NO x control & minimize ammonia slip –If urea used, water treatment system & heat traced storage & piping required

Reagent Tank

Reagent Injection System

SNCR Until Recently, SNCR Limited to PH or PH/PC Kilns SNCR Used Extensively in Europe for NOx Control One Plant in Europe Using SNCR on Long Wet Kilns Two plants in U.S. Tested SNCR on Long Wet Kiln Systems & Expect to Use SNCR to Comply with New Ozone SIP Requirements

SNCR in Wet Kilns Urea injector Location °C

27 Task 6: Current SNCR Installations

28 Task 6: Current SNCR Installations

29 Task 6: Current SNCR Installations

RACT / BACT / LAER Database The RBLC database has identified the following SNCR applications –Branford Cement (Suwanee) Permit limit of 1.95 lb/ton –American Cement Permit limit of 1.95 lb/ton –Sumter/Center Hill Cement Permit limit of 1.95 lb/ton –Brooksville Cement Plant (Florida Crushed Rock) Permit limit of 2.4 lb/ton at startup (180 days) then limit of 1.95 lb/ton –Thompson Baker Cement Plant (Florida Rock) Permit limit of 2.45 lb/ton (180 days) then limit of 1.95 lb/ton –Lehigh Mason City Permit limit of 2.85 lb/ton

SNCR Controls in Europe (Cement) (2005) CountryNumber of SNCR Plants Denmark1 (by end of 2005) Germany> 30 France14 (by end of 2005) Great Britain1 (by end of 2005) Italy< 10 Austria5 Sweden3 Switzerland4 Spain1

32 Task 7: Current SNCR Use in Other Industries –Electric Utility Industry Exxon patented ammonia SNCR in 1975 EPRI patented urea SNCR in 1980 –Current trend is multi-pollutant strategies Economics To meet more stringent requirements

SNCR Cost Considerations Anhydrous Ammonia: –Delivered cost is approximately $850 per ton –Truck contains 22 tons Aqua Ammonia: –Delivered cost is approximately $950 per ton (anhydrous basis) –Truck contains 4.5 tons (anhydrous basis) Urea: –Delivered cost is approximately $250 per ton for a 50% solution

Reagent Cost Example –Assumptions Uncontrolled NOx emissions = 1000 tpy –NOx is 90% NO, 10% NO 2 % Reduction = 40% Total NOx Reduced = 400 tons Ammonia used as reagent –Cost of 19% ammonia = $950/ton anhydrous basis –Cost of anhydrous ammonia = $850/ton –Cost of 50% urea = $250/ton NSR = 1.0

Reagent Cost Example Annual Usage (tons) Price ($/ton)Annual Reagent Cost ($/yr) Anhydrous Ammonia ,300 19% Aqua Ammonia 2,836 (as 19%) 950 (anhydrous basis) 511,100 50% Urea2,065 (as 50%) ,250

SNCR Cost Considerations Ammonia costs have increased in the past year. –80% of US ammonia usage is agricultural –40% of US ammonia usage is for corn –Ammonia demand increase is driving cost With an ammonia system, cost analysis must include RMP, PSM compliance costs Ammonia increases provided by AirGas

SNCR Cost Analysis (cont.) Operating costs: –Reagent: $500,000 –Utilities: $235,000 Electricity –Labor and Materials: $99,500 –Overhead: $151,000 Taxes Administration Insurance –Total Operating Cost: $1 MM/YR

Reagent Cost Effectiveness Reagent costs have increased –Cost Effectiveness in 2007 (reagent$ /ton NOx removed) Anhydrous: $808/ton 20% Aqua: $921/ton Urea: $826/ton –Cost effectiveness in 2008 (reagent$ /ton NOx removed) Anhydrous: $1,143/ton 20% Aqua: $1,227/ton Urea: $1,290/ton

39 Summary SNCR is a mature technology –Application is more easily applied to PH/PC systems –NOx reductions of 30-60% typical –Consideration must be given to Temperature Turbulence Residence Time NSR

40 Summary SNCR is a mature technology –Potential adverse affects Ammonia slip –Odors –Formation of ammonium salts –Detached plume NOx may increase if the temperature is too high