Electric Utilities Environmental Conference - Phoenix, AZ - January 30, 2012

• Designing and Operating a Reliable DSI System

  Authors	Greg Filippelli, Martin Dillon, Aaron Oakley, Randy Boerema
  Abstract	Reliable systems to inject dry alkaline materials are required by plants to meet compliance limits outlined in both the Mercury and Air Toxics Standards (MATS) and the Cross States Air Pollution Control Rule (CSAPR). Most dry sorbent injection (DSI) systems installed over the past several years were designed to mitigate SO3 rather than meet compliance. Many of these systems have suffered from operations issues related to buildup in the metering and conveying components, which required significant maintenance and resulted in compromised reliability. Systems designed to inject dry hydrated lime often allow chemical reactions to occur in the injection system, ultimately resulting in carbonate formation and buildup. Systems designed for injection of sodium-based sorbents often suffer from build-up of sorbents in the equipment. This paper provides the design concepts for this novel commercial Dry Sorbent Injection system and operating results that demonstrate improvements in system reliability.

  
  
• Retrofit Options to Meet the MATS
  

  Authors	Sharon Sjostrom, Connie Senior, Cameron Martin
  Abstract	Compliance planning for electric generating units (EGU) is complicated. There are pending compliance requirements under the Mercury and Air Toxics Standards (MATS) and the Cross States Air Pollution Control Rule (CSAPR) for several pollutants. Application of a control technology can impact the effectiveness of existing or planned technologies for other pollutants. For example, dry sorbent injection (DSI) for HCl may impact particulate emissions or the effectiveness of activated carbon for mercury control. Significant configuration and performance information is available through the recent EGU MACT information collection request, results from recent technology demonstrations and experience from commercial installations. These data have been analyzed in the context of current emissions regulations. This paper will provide a performance review of several coal and air pollution control combinations and retrofit options that meet cost and performance targets under a multi-pollutant regulatory landscape.



• Solid Sorbent as a Retrofit CO2 Capture Technology: Sorbent Selection and 1MW Pilot Design
  

  Authors	Travis Starns, Holly Krutka, Sharon Sjostrom, Travis Starns, Cody Wilson
  Abstract	ADA Environmental Solutions (ADA) recently completed a multi-year project to assess the viability and accelerate development of solid sorbents as a CO2 capture retrofit technology. This project included an in depth materials study as well as a high level evaluation of one potential 430 MWe conceptual design. Key results from the sorbent screening and high level cost assessment will be presented. The information collected and knowledge gained during the viability assessment is being funneled into a subsequent project where a 1 MWe pilot is being designed and will be constructed and operated using actual flue gas. The sorbent selection and the conceptual design for the 1 MWe pilot will be described. These projects are being funded by the DOE National Energy Technology Laboratory’s Innovations for Existing Plants (IEP) Program.

  
  
• ACI and DSI Systems: Procurement Planning for the MATS
  

  Authors	James Mitchell, Jean Bustard, Cameron Martin, Bob Wewer, Greg Filippelli, Rich Miller
  Abstract	Reliable systems to inject dry alkaline materials are required by plants to meet compliance limits outlined in both the Mercury and Air Toxics Rule (MATR) and the Cross States Air Pollution Control Rule (CSAPR). Most dry sorbent injection (DSI) systems installed over the past several years were designed to mitigate SO3 rather than meet compliance. Many of these systems have suffered from operations issues related to buildup in the metering and conveying components, which required significant maintenance and resulted in compromised reliability. Systems designed to inject dry hydrated lime often allow chemical reactions to occur in the injection system, ultimately resulting in carbonate formation and buildup. Systems designed for injection of sodium-based sorbents often suffer from build-up of sorbents in the equipment. This paper provides the design concepts for this novel commercial Dry Sorbent Injection system and operating results that demonstrate improvements in system reliability. Reliable systems to inject dry alkaline materials are required by plants to meet compliance limits outlined in both the Mercury and Air Toxics Rule (MATR) and the Cross States Air Pollution Control Rule (CSAPR). Most dry sorbent injection (DSI) systems installed over the past several years were designed to mitigate SO3 rather than meet compliance. Many of these systems have suffered from operations issues related to buildup in the metering and conveying components, which required significant maintenance and resulted in compromised reliability. Systems designed to inject dry hydrated lime often allow chemical reactions to occur in the injection system, ultimately resulting in carbonate formation and buildup. Systems designed for injection of sodium-based sorbents often suffer from build-up of sorbents in the equipment. This paper provides the design concepts for this novel commercial Dry Sorbent Injection system and operating results that demonstrate improvements in system reliability. The new Mercury and Air Toxics Standard (MATS) in combination with the Cross States Air Pollution Control Rule (CSAPR) will increase demand for activated carbon injection (ACI) systems for mercury control and dry sorbent injection (DSI) systems for HCl control. Per ICAC, prior to the Mercury and Air Toxics Standard (MATS), power companies had awarded contracts for activated carbon injection (ACI) systems to control mercury emissions from greater than 155 coal-fired boilers producing over 58 GW. This number is expected to triple in the three years between issuance of the final MATR and the compliance date. DSI systems will be installed to comply with control HCl emission requirements in MATR and SO2 control for CSAPR. Some estimates predict about 300 to 400 DSI systems will be procured. Many of the components for these two systems overlap. Lessons learned from the operation and installation of the first wave of commercial mercury control systems will be presented, as well as recommendations to both ACI and DSI system users to manage procurement costs, scheduling, quality assurance, and performance.

  
  
• Multimedia Impacts if Halogen Injection for Mercury Control in Coal-Fired Boilers
  

Authors	Connie Senior, Sharon Sjostrom, Ken Baldrey
Abstract	Mercury emissions compliance planning for electric generating units (EGU) is complicated by the need to control multiple air emissions as well as to comply with regulations for water discharge and solid waste disposal. Halogen injection into the boiler has been shown to be effective for control of mercury air emissions in specific cases. Bromine or chlorine injection, either into the boiler or with the fuel, can increase the fraction of mercury removed in the particulate control device or in the scrubber (if present). Bromine can also be added to the boiler in the form of brominated activated carbon for mercury control. These mercury control options can result in additional air emissions of halogen compounds or water emissions via leaching of fly ash or discharge of scrubber wastewater. This paper will provide a review of air and water emissions of halogens used for mercury control, based on a decade of experience at full-scale power plants.