Particulate and Opacity Control - Program 76

Transcription

1 Particulate and Opacity Control - Program 76 Program Description Program Overview Fossil-based power generators must meet ever-tightening opacity and particulate emission limits at minimum cost, despite aging equipment, varying fuel properties (coals, biofuels), and added loadings (often of difficult-tocollect ash). Power generators need cost-effective particulate control upgrades for plants, which are facing stricter emission limits, using changing fuels, or injecting carbon or alkali sorbents for the capture of mercury, other hazardous air pollutants (HAPS), and SO x. If their plants are burning medium- to high-sulfur coal, they need robust, reliable, low-cost, low-plant-impact measures to avoid blue plumes and sulfuric acid fallout. Certain early adopters of wet ESPs have experienced corrosion due to the buildup of acidic species in the recirculated water. The Electric Power Research Institute s (EPRI s) Particulate and Opacity Control program (Program 76) seeks or develops and evaluates emerging technologies that economically satisfy particulate emission and opacity limits under a variety of operating conditions, including changes in ash properties and loadings, fuel sulfur content, and the imposition of stricter limits. Research Value EPRI increases the number of demonstrated technologies that can achieve members' particulate and opacity performance goals at least cost, while minimizing the impact of these controls on power plant operations. Members of this program can use the results of this R&D to achieve: Savings of as much as $10 $30/kW by avoiding more expensive electrostatic precipitator (ESP) upgrades; greater savings if an ESP fix avoids replacement by a baghouse Savings in replacement power costs due to opacity-driven derates Extended bag life and lower pressure drop through better fabrics for baghouses Continued ash sales and avoidance of ESP upgrades if operational modifications can avoid alkali injection for SO 3 reduction, or if these modifications and/or optimized alkali injection systems can reduce the quantity of alkali injected. Improved effectiveness of activated carbon mercury control through alternatives to SO 3 flue gas conditioning for high particulate matter (PM) capture in ESPs Approach Projects conceive of or find and demonstrate least-cost upgrades for meeting increasingly stringent particulate/opacity limits specifically, those that might be proposed by the U.S. Environmental Protection Agency (EPA) under the Maximum Achievable Control Technology (MACT) rules that the Agency is developing for all HAPS, especially trace metals. This work also addresses upgrades needed to counter the potential impacts of changed particulate properties on ESP or baghouse performance, of loss of startup/shutdown and upset exemptions, and of ESP performance deterioration. R&D involving ESP upgrades for lower emissions and difficult fly ash seeks and demonstrates advanced power supplies, flow modifications, and novel ESP technologies that counter the effects of high-resistivity ash, sodium depletion in hot-side ESPs, rapping losses, and, potentially, changed ash properties. These property changes can be caused by switching to biofiring (cofiring or 100% biofuel firing); increased unburned carbon; injected carbon (primarily for mercury control); alkali injection (primarily for SO x but also for other HAPS acid gases); and, possibly, selenium control. Activities range from fly ash characterization studies to field tests of emerging technologies (e.g., PMscreen and new electrode designs), to demonstration of water management approaches developed for an earlier wet ESP program to current commercial systems to avoid corrosion. p. 1

2 Research for optimized baghouse performance for all fly ash develops methods to extend bag life, reduce pressure drop, avoid cleaning puffs, and detect leaks, all irrespective of fly ash properties. R&D for robust, least-cost acid emission reductions identifies fuel, combustion, and/or boiler operation modifications that could reduce SO 3 formation in the boiler; completes any remaining work needed to routinely and optimally inject alkali sorbent with minimum sorbent usage and without the feeding problems encountered in early sorbent injection installations; provides updates on industry experience with SO 3 controls; and maintains Tech Watch for novel mitigation measures. Accomplishments EPRI provides power companies with solutions to solid and aerosol particulate emissions that do not attract the attention of equipment suppliers due to small return on investment or high risk. EPRI conducts unbiased, thirdparty tests of new commercial offerings to demonstrate their performance and to assist their developers in improving the product. Recent examples include: Enhancements to EPRI's ESP performance software, ESPM, to improve prediction accuracy when treating flue gas with alkali sorbents or increased carbon content. This program is used widely to troubleshoot performance issues, or to predict the impact on particulate emissions/opacity of changing fuels or implementing upgrades. Extended time between off-line cleaning on hot-side ESP using EPRIswitch. Further, by the end of 2010, EPRI expects to have demonstrated the ability of (a) the Rapid Onset Pulse Energization (ROPE) power supply to provide high-efficiency collection of high-resistivity fly ash (i.e., fly ash from coals with low sulfur content) without the need for SO 3 flue gas conditioning, and (b) EPRIswitch with polarity reversal to eliminate the need for sodium conditioning for hot-side ESPs. Success in these efforts not only would reduce operation and maintenance (O&M) costs, but also avoid the negative effects of SO 3 on mercury capture by activated carbon and of the added sodium on the salability of the fly ash collected in hot-side ESPs. Identification of a flow control design that nearly eliminated ESP hopper re-entrainment of fly ash with elevated carbon content in one ESP. Reduction of ESP particulate emissions by 40-70% in a novel polishing device, EPRI's PMscreen. Particulate removal efficiencies greater than 99.9% with a moderate-size ESP plus ElectroCore. Lower-pressure-drop baghouse fabrics that retain high particulate collection. Current Year Activities The program R&D for 2011 will complete any work still needed to demonstrate the effectiveness of advanced power supplies (ROPE and EPRIswitch) in achieving collection of high resistivity ash by cold- or hot-side ESPs, respectively, without alkali addition. It will also continue to develop PMscreen, a low-cost particulate polishing system. Other activities will seek and inform members of new fabrics and best practice baghouse operations, develop guidelines for upgrading ESPs to meet their new challenges, and enhance the reliability and reduce the cost of SO 3 control. Specific efforts will include: Demonstration at large scale of PMscreen as a low-cost polishing device (e.g., to counter particulate increases due to sorbent injection air pollution controls and/or to meet more stringent emission limits) Search for and testing of new fabrics to simultaneously reduce pressure drop and emissions during cleaning while resisting degradation due to sorbent injection Determination of fly ash properties with cofiring or 100% firing of biofuels and the impact of these properties on ash collection by both ESPs and baghouses Demonstration of ability of computational fluid dynamics (CFD)-designed hopper baffles to reduce ESP performance degradation with high unburned carbon or injected activated carbon ESPM upgrades that can better predict particulate emissions/opacity with high-frequency power supplies Completion of the SO 3 depletion module in fundamentally-based SO 3 formation and depletion models; determination of ability to actually achieve significant SO 3 reductions through boiler operational changes or deeper coal cleaning/upgrading via application in pilot- or full-scale tests Particulate and Opacity Control - Program 76 p. 2

3 Estimated 2011 Program Funding $1.8M Program Manager George Offen, , Summary of Projects Project Number Project Title Description P ESP Upgrades for New Emission Limits, Small Units and/or Difficult Fly Ash P Optimized Baghouse Performance for All Fly Ash P Robust, Least-Cost Acid Emission Reduction This project will develop low-cost upgrades to ESPs that meet the new challenges of complying with increasingly stringent emission limits, collecting difficult ash, and/or avoiding emission increases despite higher inlet loadings. s to ESPM, EPRI's performance prediction tool, will support these technology developments. Through surveys of high-performing baghouse installations, sharing the lessons learned, and promoting/supporting the development of advanced fabrics, this project will document best practices and develop bag materials that consistently produce lower emissions, longer bag lives, and lower O&M costs. This project identifies and demonstrates lower-cost and more-reliable SO 3 /sulfuric acid mitigation strategies, reducing back-end corrosion and eliminating blue plumes. Particulate and Opacity Control - Program 76 p. 3

4 P ESP Upgrades for New Emission Limits, Small Units and/or Difficult Fly Ash (069166) Key Research Question The EPA is considering the adoption of more stringent particulate emission limits as a way to satisfy a mandate to promulgate Maximum Achievable Control Technology (MACT) standards for solid particle trace metals identified as (HAPS: arsenic, beryllium, cadmium, cobalt, chromium, manganese, nickel, lead, and antimony; mercury and selenium also are HAPS, but are considered separately, because they can be emitted as both vapors and adsorbed onto fly ash). In addition, many ESPs are too small to meet current emission/opacity limits, are being used to collect a higher-resistivity dust than the design fly ash (e.g., following a switch to Powder River Basin [PRB] coal or after implementation of calcium-based sorbents for SOx reduction), or are hot-side ESPs that continue to experience performance issues. These situations along with the desire to eliminate SO 3 flue gas conditioning in plants that use activated carbon injection for mercury control (SO 3 interferes with carbon effectiveness in capturing mercury) will require the upgrade of many ESPs, and the industry and public would benefit from lower-cost approaches than adding or replacing the ESP with a baghouse. Several advanced power supplies have the potential to meet this need, but need to be proven for a number of applications. Other technologies, such as low-cost polishing devices, may be competitive and provide better performance and merit further development and demonstration. A number of these ESPs have difficulty meeting their emission/opacity limits due to the high carbon content in the ash as a result of low-nox burners or activated carbon injection (ACI) for mercury capture or risk having this problem in the near-term as they implement ACI to meet state-mandated mercury limits. Earlier work by EPRI identified hopper re-entrainment of carbon particles as the primary cause of the elevated emissions, and recent tests found a design that virtually eliminated this effect. To determine the widespread applicability of hopper flow management systems especially the very effective approach found in 2009 flow distribution designs need to be developed, evaluated via computational fluid dynamic (CFD) models, and then demonstrated and optimized on full-scale ESPs. Power companies constantly face questions about the impact of fuel changes on ESP performance and the benefits of proposed upgrades. More recently, biofuels (cofired or 100% fired) have become a fuel of interest to respond to climate change challenges and Renewable Portfolio Standards (RPSs). To answer these questions on ESP performance, environmental control engineers need a comprehensive, reliable, and accurate computer model. EPRI's ESPM model is such a tool and is effective, but needs updating as more is learned about ESP performance with difficult-to-collect ash. Early adopters of wet ESPs placed behind the flue gas desulfurization (FGD) system have experienced corrosion and could benefit from guidance on material selection and water chemistry management to avoid these issues. Approach EPRI will conduct one to three additional demonstrations of EPRIswitch, alone or in conjunction with Southern Company's ROPE technology, at plants burning PRB or injecting calcium sorbents for SO x control, as well as at one additional hot-side ESP suffering performance degradation due to sodium depletion. Demonstration of PMscreen as a low-cost polishing device will continue, subject to interest by host sites and other collaborative partners. For ESPs experiencing carbon re-entrainment, EPRI will use computational fluid dynamics (CFD) models to design flow devices that minimize hopper re-entrainment (even of light carbon particles) for one to two units, fabricate/install them, and conduct performance testing to demonstrate the value of this approach. EPRI will continue to develop its polishing device, PMscreen, focusing on low-cost ways to improve its capture performance to >70% without excessive pressure drop. Approaches being considered include the use of other screen materials, pre-charging the ash, or locating the device downstream of the FGD (instead of a wet ESP). Particulate and Opacity Control - Program 76 p. 4

5 To determine ESP performance when firing/cofiring biofuels, EPRI will seek or measure ash properties, ESP electrical parameters, and resulting emissions/opacity at sites firing/cofiring biofuels or conducting a test burn. (Findings from sites equipped with a baghouse will be reported under P ) EPRI will use the results to improve/fine-tune the algorithms in ESPM. If biofuels degrade ESP or baghouse performance, EPRI will develop an R&D program to overcome these problems, which may include combustion improvements as well. At the end of this effort, EPRI will update its ESPM model to more accurately reflect ESP performance with these fuels. With the widespread introduction of high-frequency power supplies, it is important to verify that the electrical performance algorithms in ESPM correctly describe the charging and collecting processes. Accordingly, EPRI will revisit these first-principles algorithms, update them if needed, and test the results against field data. The ideal test location would be one with a well-operating, small ESP in which performance could be measured before and after retrofitting it with a new high-frequency power supply. EPRI expects to identify algorithm changes and incorporate them into ESPM in Validation, testing, and release of the next version of ESPM would occur in In addition, assuming a successful feasibility study in 2010 under the Technology Innovation program, EPRI will begin the process of designing and testing a novel configuration that physically integrates "cool pipes" for charging (high-resistivity) particles with the collection plates, leaving the rest of the plate to operate at a lower voltage and, therefore, avoid back corona. At a minimum, this approach could be a fallback option in the event that advanced power supplies do not reach their potential. Field tests would require collaborative partners. EPRI also will seek additional sites to test the performance and operability of the new generation of wet ESPs located post-flue gas desulfurization (FGD) systems in new plants. (Field tests will require supplemental funding for any special equipment and detailed sampling.) The operability investigation will include work to determine the cause of early corrosion onset in some of the newly installed post-fgd wet ESPs. In this task, EPRI will build off its substantial experience with FGD materials of construction and its earlier development of water management guidelines for wet ESPs. Pending experience gained in these applications, EPRI may revisit its earlier concept of converting the last field of a conventional ESP to wet operation, taking advantage of the lessons learned during that earlier work. The most important lessons dealt with management of water flow inside the ESP and, as noted, its chemistry. This revisit will include an assessment of the potential value of using membrane plates instead of metallic ones when converting the last field to wet operation. Impact By having EPRI develop and demonstrate low-cost ESP upgrades or other solutions to increasingly stringent particulate emission limits and/or issues caused by difficult ash, power companies can: Save as much as $15 $25/kW if EPRIswitch or other advanced power supplies avoid the need for an additional ESP field, or as much as $40 $80/kW if they avoid a polishing baghouse. Enable the use of sorbent injection for SO 2 control in small or low-capacity-factor plants by avoiding the additional cost of a baghouse. How to Apply Results Power plant owners and operators will be able to procure and tune EPRIswitch, integrated with ROPE if needed, to meet their particulate/ opacity emission limits at much lower cost than other options. They also will receive information about advanced power supplies that can make them better able to understand and assess other advanced power supplies. Similarly, the reports on hopper baffles for ESPs collecting high-carbon fly ash will provide guidance on the design and expected effectiveness of this approach, and those on PMscreen will give engineers the information they need to decide on the adequacy of this polishing device for their situation. Predicting the benefits of any of these approaches can be done by running ESPM, a model that has been modified over the years to increase its ease of use, robustness, and applicability. Particulate and Opacity Control - Program 76 p. 5

6 2011 Products Low-Cost ESP Retrofit Devices for New Challenges: MACT Limits, Increased PM Loading, High-Carbon Ash, or Biofuels: Results of all 2011 upgrade work in a one-stop-shopping report advanced power supply field tests; CFD model-designed flow devices for reduced hopper reentrainment and field application results if host site(s) are found soon enough; preliminary assessment of biofuels firing/cofiring impact on ESP performance; PMscreen large-scale field results; and, possibly, performance of wet ESPs. 12/31/11 Future Year Products Low-Cost ESP Retrofit Devices for New Challenges: MACT limits, Increased PM Loading, High-Carbon Ash, or Biofuels: of 2011 report based on an additional year of data, expected to be mostly field testing by EPRIswitch and Other Advanced Power Supplies for Difficult ESP Applications -- : of 2011 report, with majority of report being new field test results. Also may have initial indication of joint operation of ROPE and EPRIswitch to create fuel-insensitive ESP. Low-Cost ESP Retrofit Devices for New Challenges: MACT limits, Increased PM Loading, High-Carbon Ash, or Biofuels: Final report in series with field test results on original set or new technologies introduced in EPRIswitch and Other Advanced Power Supplies for Difficult ESP Applications: Final report in series with field test results of EPRIswitch, with or without ROPE, on one to three installations with high-resistivity ash (PRB or sorbent injection for SO x mitigation) and on one to two hot-side ESPs with sodium depletion issues. 12/31/12 12/31/12 12/31/13 Report 12/31/13 Report P Optimized Baghouse Performance for All Fly Ash (069167) Key Research Question Power companies increasingly are turning to baghouses (aka fabric filters) to realize multiple benefits: very low total particulate emissions independent of fuel properties; substantial reduction of trace metals through the capture of fine particulate; high capture rates of mercury on unburned or activated carbon; and the potential to also capture selenium, sulfuric acid, other acid gases (especially hydrochloric acid [HCl] and hydrofluoric acid [HF]), and any organic gases present in the flue gas via sorbent injection. However, baghouses can experience high-pressure drop after only a few months or years of operation, and this imposes an energy penalty on the power plant or a cost penalty for frequent bag replacements. Further, it is unclear if current baghouses and baghouse operation practices can routinely meet the ultra-low emission limits being considered by regulatory agencies (e.g., lb/mbtu filterable PM) Additionally, bag materials can fail within 1-3 years of installation, which adds an undesirable cost to the system and runs the risk and expense of forced outages. Research is needed on new bag materials that are stronger, resistant to flue gas species (especially sulfuric acid, chlorine, and bromine), porous enough to avoid undue pressure buildup, and still highly efficient during both normal capture operation and cleaning cycles. Particulate and Opacity Control - Program 76 p. 6

7 Companies operating or planning to install baghouses also can benefit by learning how other users maximize the performance and minimize the costs of their baghouse operations; a leveraged collaborative search for and synthesis of these lessons learned is the most cost-effective way to obtain this knowledge Approach EPRI will continue to monitor R&D activities by bag material suppliers in search of new fabrics that address one or more of the above challenges. EPRI also will try to conceive, as well as search for, novel ideas that it can suggest to the material suppliers, and then test the samples that suppliers produce. Based on surveys conducted in to gather the field experiences of a number of new baghouse installations, EPRI will document the lessons learned by the individual baghouse operators, analyze these lessons to determine if there are any trends or common experiences, and provide initial ideas on fabric selection guidelines for different fuels and back-end temperatures, as well as baghouse startup procedures to minimize premature bag failures (acid attack, blinding, etc.). Other topics to be considered for this guideline include: Methods to reduce emissions during cleaning (potentially including changes to the air flow patterns in the baghouse based on CFD modeling) Instruments to detect leaks Decision criteria on when to replace bags Critical features to include in modeling studies Special considerations when firing or cofiring biomass Future opportunities applying novel concepts. In parallel, EPRI will begin to address any unresolved problems uncovered during the site surveys, as well as any new issues that might arise when operating baghouses to meet the particulate limits that may be imposed by MACT regulations. EPRI also will try to determine operational (pressure drop, cleaning frequency) and emissions variability by evaluating 3-6 months of readings from the continuous mass particulate emission monitor at 1-3 sites that have particulate CEMs but no FGD. To optimize the pressure drop and mercury control effectiveness at TOXECON sites, EPRI will continue tests begun in 2010 on the benefits of changing particle properties (especially size) and/or mass loading of the ash entering the polishing baghouse. Impact Success in addressing the issues identified for baghouses will lead to: Increased intervals between bag replacement for challenged baghouses from the current 2-3 years to potentially 4-5 years, at a typical amortized savings of $0.5M/yr for a 500-MW plant (plus reduced downtime). These savings depend on success in developing and demonstrating more durable and acidresistant fabrics; implementing procedures that avoid acid attack on the bags during transients; and demonstrating reliable leak detection monitoring systems so bag replacement is done only when needed. Maintaining pressure drop across the baghouse below 5-6 in. H 2 O, vs. allowing it to increase, e.g., to 10 in. H 2 0, saving as much as $200,000/year or more for a 500-MW plant. More compact designs of baghouses, with higher air-to-cloth ratios and online cleaning, saving 10-20% in capital costs. Potential savings that could range from modest to large, depending on the errors avoided by the next wave of installations or the changes in O&M practices adopted by current and future users as a result of learning best practices from the survey. Potential avoidance of emission limit violations by understanding the variability in baghouse emissions. Particulate and Opacity Control - Program 76 p. 7

8 How to Apply Results Plant engineers can use the survey findings, periodically presented at advisory meetings and documented in the planned guideline, to improve the performance of their existing baghouses, reduce operations and maintenance (O&M) costs, and avoid potential derates due to opacity excursions. Engineering/procurement staff can use the results to specify the most cost-effective baghouses for their needs, accounting for capital vs. O&M cost tradeoffs. Corporate environmental engineers can gain an understanding of future possibilities by following the progress of the R&D in novel fabrics; they then can use this understanding to recommend optimal particulate control strategies Products Current Practices in Power Plant Pulse-Jet Fabric Filters: Analysis of lessons learned by baghouse operators surveyed in , identification of common issues and best practices in avoiding or managing them, initial guidance on selecting bag materials for each application, and guidance on start-up procedures to minimize bag blinding and maximize bag life. 12/31/11 Future Year Products Current Practices in Power Plant Pulse-jet Fabric Filters: of 2011 report with more definitive information. Pulse-jet Fabric Filter Design and O&M Guidelines: of 2012 report with long-term experience on new installations and in capturing MACT-limited pollutants. 12/31/12 12/31/13 Report P Robust, Least-Cost Acid Emission Reduction (101447) Key Research Question Power companies are concerned about visible blue plumes caused by sulfuric acid mist, new limits on SO 3 and sulfuric acid emissions, and boiler impacts due to high SO 3 and sulfuric acid concentrations in the colder section of the air preheater and downstream components. Plants that need to reduce SO 3 emissions currently can only capture SO 3 that has been formed, for example, by injecting alkali sorbents or adding a wet ESP. As both approaches are expensive, and sorbent injection can have negative side impacts, power plants seek lower-cost approaches such as mitigating the initial formation and/or enhancing the depletion of SO 3 through modified boiler operations and coal cleaning. At plants using sorbent injection, operators need guidance on sorbent specification, handling, transport, and injection to maximize sorbent utilization and greatly reduce current maintenance. Approach EPRI will continue to work with its collaborative members to complete any work still needed to develop and demonstrate robust, low-maintenance alkali sorbent storage, handling, transport, and injection systems, especially for hydrated lime, as well as the design of injection systems that minimize sorbent usage for any given application. EPRI anticipates that the causes of hydrated lime plugging in transport lines and injectors will be resolved at the laboratory scale in 2010, and that the needs in 2011 will be to demonstrate the validity of these findings and associated countermeasures at several field sites and with sorbents from a number of Particulate and Opacity Control - Program 76 p. 8

9 different suppliers. In parallel with research on methods to avoid/reduce pluggage in conventional lime hydrate systems, EPRI will continue to study the possibility that a modification to its on-site sorbent activation process (SAP) can be used to produce a hydrate on demand that also avoids pluggage issues (e.g., because it is created and transported immediately without aging). Simultaneously, the project will continue to track supplier developments and new offerings, evaluating (to the extent the supplier and host plants agree) those that seem promising. In parallel, EPRI will complete its development of mechanistic models that correctly simulate formation and depletion of SO 3 in the power plant (burner to economizer exit), with an emphasis on the depletion processes across the economizer (the least well understood and modeled step in the process). Tests of SO 3 concentration along the flue gas path conducted in 2010 (fourth site tested in this project) will be modeled in 2011 to determine how well the model fits the measured behavior. Assuming reasonable agreement in the furnace and convective pass, further development will focus on depletion mechanisms at economizer temperatures. Lehigh University's Energy Research center has postulated a mechanism and developed a partial set of reaction rate data. They will complete this effort in The other model developer, Southern Research Institute, also will be asked to address this challenge. Once completed, the models will be used to guide the designs of mitigation strategies such as combustion modifications to reduce homogeneous oxidation in the furnace, deep coal cleaning to remove iron, and adjustment of sootblower timing to minimize catalytic formation of SO 3 on boiler tubes. EPRI will work with members to select and test the most promising SO 3 minimization strategies at host power plants. Impact By finding and demonstrating cost-effective methods to reduce SO 3 concentrations experienced in the post-air preheater region of a coal-fired boiler, this RD&D effort will: Minimize back-end corrosion. Reduce the potential for derates to avoid opacity violations, which could cost hundreds of thousands of dollars per event in replacement power. Save as much as $1 $2 million/year for a 500-MW plant if it can avoid alkali injection, or a fraction thereof if it can only reduce the amount injected. Reduce the risks of legal actions due to nearby touchdowns of a sulfuric acid plume. How to Apply Results Engineers can use the reports that present the results of the model runs on mitigation options to identify the most favorable SO 3 reduction strategies for their plant and coal. They then can run the model (or have it run for them) to predict the effectiveness of these strategies under a number of different scenarios. Members also can join the Sulfur Oxides Control Interest Group (SOXIG), a supplemental project that provides a forum for technology exchanges among practitioners Products New Approaches to SO3 Mitigation in Coal-Fired Boilers: This is an update of a 2010 report on methods to achieve reliable, low-maintenance operation and effective injection of lime hydrate systems, with the addition of field experience at multiple plants. It will include guidelines for both calcium- and sodium-based sorbents. It also will provide a summary of recent installations and new technology offerings. The report also will summarize any useful results from tests intended to demonstrate SO 3 reductions through management of the formation/depletion mechanisms, such as combustion modifications and deeper coal cleaning. 12/31/11 Report Particulate and Opacity Control - Program 76 p. 9

10 Future Year Products New Approaches to SO3 Mitigation in Coal-Fired Boilers: of 2011 report with additional field test results from R&D programs and experience at commercial installations of SO 3 reduction systems (typically alkali injection). Guidelines on SO3 Mitigation in Coal-Fired Boilers: Guidelines for reducing SO 3 flue gas concentrations along the flue gas path and at the stack (for given SCR behavior), including strategies to reduce SO 3 formation and best practices to control it once formed. 12/31/12 12/31/13 Report Particulate and Opacity Control - Program 76 p. 10