DSI

Introduction to DSI

Breen Energy Solutions provides a broad range of technologies and services to the Fossil Fuel Power Generation Industry that help utilities manage their emissions, and the Balance-Of-Plant (BOP) impacts resulting from their emissions control systems.

Breen has developed a suite of interlocking technologies to assist in plant Fuel Flexibility demonstrations. Baseline conditions for furnace/convective slagging, Air Heater differential pressure and post air heater sulfuric acid levels
are characterized using specialized instrumentation. Then, based on consultation with plant personnel, custom mitigation processes are mobilized. These include Dry Sorbent Injection (DSI) systems for SO3 mitigation using Lime, Trona and other dry sorbents and Activated Carbon Injection (ACI) systems for Mercury (Hg) control. Other technologies include the AbSensor- AbS/SO3 flue gas condensable species (Ammonium BiSulfate, Sulfuric acid etc.) measurement probe, Thermap Air Heater model which predicts fouling deposits depth & location in rotary air heaters and DySC – Dynamic Speed Contolled Soot Blower Systems for effective cleaning of rotary air heaters prone to fouling.

Dry Sorbent Injection Systems

As coal fired power plants faced increased environmental regulations amid commercial viability concerns, a growing number of plants have adopted Dry Sorbent Injection (DSI) as an answer to compliance and efficiency requirements. Fortunately, or unfortunately, there are as many sorbents and injection locations as there are issues. In an effort to
understand and quantify the performance of a selected sorbent process, individual plants often execute on-site demonstrations of the process. These demonstrations are expensive to mobilize and implement and an improperly designed or executed program can yield conflicting results.

Breen is uniquely positioned to provide sorbent and process independent guidance through this difficult process. Our experience with multiple coals, plant configurations, sorbents and gas chemistries allows us to assist our customers in:

  • Baseline/Characterization of existing plant SO3 and HCl levels throughout the gas stream
  • Assistance in proper Sorbent Selection based on plant specific process and performance drivers
  • Injection Location and Bias determination to provide maximum condensable capture without negative impact on SCR, Air Heater and particulate control systems
  • Process Optimization and Credible Evidence demonstration to provide hard evidence of both system operating costs and compliance assurance through normal plant operating variations

Baseline/Characterization

Each plant is unique in its ability to generate and dissipate SO3 compounds. Breen’s field engineering staff, using our patented condensable measurement technology, monitors the level of SO3 based material at the Economizer Outlet, SCR Outlet, Air heater Outlet and ESP/FF Outlet during extended periods of normal plant operation. Comparing this information with plant historian data for such variables as boiler load, excess O2, boiler cleanliness and SCR NOx/NH3 distribution provides a solid understanding of how and where sulfate compounds evolve in the plant gas stream.

Understanding the impact of normal plant operations on sulfate condensable is the first step toward designing a suitable sorbent injection process to control it.

Sorbent Selection

Based on the measure SO3 compound life cycle, specific plant drivers are determined. These could include furnace/superheat fouling, SCR MOT issues, Air Heater fouling, ESP performance and corrosion issues and visible stack emissions (blue plume). Which sorbent (generally between magnesium, calcium and sodium based compounds) is best is a function of plant layout, operating issues and relevant air/water quality emissions requirements.

Breen has significant experience with all of these materials and works closely with the plant to select the sorbent most likely to provide controllable management of the plant’s condensable related issues.

Injection Location and Bias Determination

Breen Energy has a fleet of fully staffed and instrumented temporary injection systems designed to provide a high level of flexibility in terms of injection location and control. Our equipment is suitable for injection rates as low as a few hundred pounds/hour of sorbent to as much as 20,000 pounds/hour. Each system has four individually controlled feed systems, each capable of feeding controllable split trunk lines.

Using this process, sorbent material can be individually metered/biased/ monitored to eight simultaneous injection locations. This allows determination of the proper amount of sorbent, as well as the proper distribution of that sorbent between functional injection locations for varying plant operating conditions (load, SCR performance, fuel sulfur, etc.).

Considering the potential for combined condensable/filterable particulate emissions limits, this approach allows the site to optimize the distribution of sorbent to match the distribution of acid vapors, minimizing both condensable and filterable emissions.

Process Optimization and Credible Evidence Development

Once the sorbent injection locations/splits have been determined, Breen program management works with plant engineering and environmental staff to develop an optimized injection process complete with predictive emissions feedback.

This last step is critical in that it provides the plant with continuous credible evidence that its sorbent injection process is in compliance with state and federal emissions requirements. Lack of this step often forces the plant to inject minimum fixed amounts of sorbent, regardless of changes in plant conditions. This forced minimum often causes both cost and balance of plant issues that can lead to landfill, water and process performance problems over time.

THIRD PARTY, INDEPENDENT, SORBENT INJECTION DEMONSTRATION SERVICES:

Breen provides full, turn-key, demonstration services that allow the utility and the generating station to develop an
understanding for the sorbent chemical and mechanical process, a commercial foundation for feasibility considerations and a working control/feedback process to assure compliance with both internal and external drivers.

Breen also provides a family of state-of-the-art measurement instruments for continuous monitoring of acid gas condensable compounds. These instruments all have significant track records in full scale, closed-loop control of acid gas mitigation systems.

Additionally, Breen provides a variety of specialty sorbents and processes to aid the electric generating industry in
compliance with US MACT and CSAPR requirements. These sorbents/processes include:

  • Oil Based MgO dispersion for localized slag control
  • Fuel Lean Gas Reburn (FLGR) for simultaneous reduction
    in plant NOx and SO2 levels.

Breen provides a variety of solutions for acid gas management to match your situation. From fuel lean gas reburn to testing and measurement, Breen applies the best solutions for mitigating and managing acid gas. Contact us to discuss a demonstration.