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# c INSTITUTE OF CLEAN AIR COMPANIES



### Memorandum March 18, 2009 1730 M StreetNW Suite 206 Washington, DC 20036-5603 Telephone 202.457.0911 Fax 202.331.1388 David C. Foerter,ExecutiveDirector Email: dfoerter(@icac.com Chad S. Whiteman,DeputyDirector Email: cwhiteman@icac.com

TO: Walt Stevenson, U.S. Environmental ProtectionAgency, OAQPS FROM: Chad Whiteman, DeputyDirector, Institute ofCleanAir Companies SUBJECT: Selective Non-Catalytic Reduction Technology Costs for Industrial Sources

The Institute ofCleanAir Companies (ICAC) is the national trade association ofcompanies that supply airpollution emission control and monitoring technologies for electric powerplants and other stationary sources. ICAC represents more than ninety ofthe leading manufacturers providing emissions control solutions for affected industries as well as employment opportunities across the 

# u.s. The following memo provides a briefdescription ofthe selective non-catalytic reduction (SNCR) technology and some real-world cost information for various industrial sector applications. The SNCRtechnology is a post combustion emissions control technology thatuses a chemicalprocess for removing NOx from flue gas. Inthe SNCRprocess, a reagent, typically urea or anhydrous gaseous ammonia, is injected into the hot flue gas, and reacts with the NOx, converting it to nitrogen gas and watervapor. No catalyst is required for this process. Instead, it is drivenby the high temperatures normally found in combustion sources. SNCRis "selective" inthat the reagentreacts primarilywithNOx. Theprincipal components ofthe SNCR system are the reagent storage and injection system, which includes tanks, pumps, injectors, distribution modules, and associated controls. The combustion unit acts as the reactorchamber simplifying the SNCRprocess. Thereagent is generally injected within the boiler superheater andreheaterradiant and convective regions, where the combustion gas temperature is at the required temperaturerange. The number ofinjection ports and location is determined by flue gas flow and temperature profiles. Selective non-catalytic reduction technology was first applied commercially in 1974 and has been installed on approximately 400 applications worldwide. Applications includeutility boilers and a broadrange ofindustrial applications including installations onthe following: wood-firedboilers, coal-firedboilers, co-generationboilers, pulp andpaper, steel industry, refmeryprocess units, process heaters, cementkilns, municipal waste combustors, glass melting furnaces, hazardous wasteincinerators, and othercombustion sources. A cross-section ofthe various industrial sector deployment experiences was taken in order to develop the following cost data. ICAC identified 126 SNCR installations on Municipal Waste Combustors in the United States and Europe inICAC's February 2008 whitepaper titled, "Selective Non-Catalytic Reduction for Controlling NOx Emissions." These installations include more than 50 SNCRinstallations on municipal waste combustors in the United States. Forthe SNCR systems installed in the U.S., the percentNOx emission reduction ranges between 25 to 72 percent with the average being 42 percent NOx reduction. The primary regulatory drivers for NOx reductions from these SNCR systems are command-andcontrol programs that mandate a specific NOx limit in their operating permit. There is no incentive to reduce NOx emissions beyond the permitted limit due to potential increases in operating costs from the injection ofadditional reagent or added capital equipment costs to improve the SNCR system performance. Ifmarket-based regulatory programs were implemented for these municipal waste combustors, there would be additional incentives to increase the NOx reduction performance where proven to be cost effective. InFigure 1, the installed cost ofmore than fifty different SNCR installations was compiled in order to compare the installed costs for various sizes ofindustrial applications. The installed cost ofthe equipment is expressed in dollars perunit size ($/mmBtu/hr) and is plotted against the boiler gross heat input (mmBtu/hr), which indicates the unit size. The installed cost represents the cost ofall of the capital equipmentplus the cost ofinstalling the equipment at the end-user site. The operation and maintenance costs are not included in the capital equipment cost but are largely made up ofthe cost ofthe reagent. A logarithmic best-fit curve was applied to the data to develop the dashed line. As demonstrated bythe data, the capital costs for SNCR technology are low due to the small amount ofcapital equipment required. Similar to most technology applications, SNCR technology becomes progressively more cost effective the larger the boiler size. The cost curve indicates that units less than 75 mmBtu have higherrelative capital costs even though the SNCR technology is a low capital cost technology.Figure 1. Actual SNCR Installed Capital Costs on Industrial Sources

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InFigure 2, the cost effectiveness ofmore than fifty SNCR applications for NOx reductions on industrial sources is compared for vanous unit sizes. The cost effectiveness ofSNCRis expressed in dollars perton ofNOx removed and is plotted against the boiler heatrate (mmBtu/hr), which indicates the unit size. The cost effectiveness numbers considerboththe installed costs (capital equipment, installation expenses, and annual O&M costs) compared to the incremental reduction of NOx from the baseline NOx emissions for each givenunit for the year. The cost effectiveness for both**a~ual** operation and ozone season operation (May 1st

- September 30th) wereplotted. A logarithmic best-fit curve was applied to both the annual and ozone season costs and is represented by the dashed lines in Figure 2. As demonstrated by the data, SNCR technology is more cost effective when operated yearround due to the increase in the NOx reduced over a longer operating period. Similar to most technology applications, SNCR technology becomes progressively more cost effective the larger the boiler size. The cost curve for the fifty applications analyzed indicates that the majority ofthe ozone season applications have cost effectiveness values less than $4000/ton even for smallerunits. An even greaterpercentage ofthe applications have cost effectiveness values less than $3000/ton for annual operation ofthe SNCR technology.Figure 2. Actual SNCR Cost Effectiveness for NOx Reductions on Industrial Applications

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As the above cost curves indicate, SNCR technology is a proven technology that canbe cost effectively applied to a wide range ofindustrial applications. The technology has emerged as a co 

### t effective solution for small and large unit size applications due to the low capital cost ofthe installed equipment.