SCR Services

Maximizing SCR Performance

Services from SCR Design to Catalyst Management 

Fuel Tech provides a full range of SCR Management Services. Our comprehensive service program is not simply focused on catalyst management, but encompasses overall SCR system management. As such, our approach does not adhere to traditional catalyst management or owner/catalyst supplier contractual concepts. We partner with owners and operators to ensure that NO_X removal objectives are achieved at the lowest cost without impacting the operating reliability of the units.

• Minimize operating costs of SCR systems
• Optimize SCR process design
• 55,000+ MW experience in SCR process design
• 20,000 MW experience in AIG tuning services

We have been involved with SCRs for the control of NO_x and ammonia (NH₃) slip emissions on boiler units, simple cycle and combined heat and power systems and incinerators firing coal, gas, oil, and other types of waste fuels.

Our primary focus centers around optimizing process design, catalyst selection, and performance of SCR systems on coal- and natural-gas utility units. Our experience base also spans the full range of SCR applications, including industrial and MSW systems. The design of SCR systems, installation and start up support, ammonia injection grid tuning, performance testing, trouble shooting and operation & maintenance support are among the many services we offer.

We offer our clients unique, experience-based know how focused on the design, operation and maintenance of SCRs, which to date includes more than 55,000 MWs of SCR process design and 20,000 MWs of AIG Tuning services. Fuel Tech's services are targeted to minimize the operating costs of the SCR system, to diagnose operating problems, to enhance overall performance and to assist end users in implementing the most comprehensive catalyst strategies.

Enabling SCR Performance to Exceed Expectations

SCR Troubleshooting and Optimization

Fuel Tech assists operators in identifying on-going operational issues, while designing and applying improvements to the SCR system in order to enhance overall performance. Our specific services provided in this area include: system audits and inspections, catalyst test sample removal and analysis, field test measurements, catalyst cleaning and regenerations consulting, outage planning and supervision, assessment of fuel planning on SCR behavior, and computational and experimental flow modeling and optimization.

Our comprehensive program of services regarding catalyst management and SCR system performance enhancements is one of a kind in the industry. The program is not simply focused on catalyst management, but encompasses overall SCR system for the owner's fleet is of the utmost importance to Fuel Tech. The consulting services associated with Fuel Tech's programs are designed to compliment and supplement the performance guarantees and warranties provided by the SCR and/or Catalyst OEMs.

Requirements for Annual SCR Operation

Fuel Tech can review SCR operational procedures to ensure proper annual operation. This includes all operating sub-systems of a typical SCR. Fuel Tech can also evaluate seasonal catalyst performance and provide a solution for year-round operation. Catalyst management plans can be updated accordingly to coincide with unit outage schedules.

Specification Review & Preparation

We review turnkey specifications with special attention paid to, design data, guarantees, process design, equipment, catalyst design, and potential impacts on boiler and unit operation. We prepare technical specifications for clients. Our focus includes catalyst selection, ammonia injection grid design, flow modeling and flow correction requirements, reagent system requirements and performance guarantees.

SCR Process Arrangement & Component Design

We can assist in defining parameters for SCR design to suit your requirements. Historical boiler operating data will be reviewed and assessed to determine unit process data at full, mid and low loads. Fuel Tech assists clients in selecting SCR catalyst performance requirements so that the client's NO_x emission control strategy is effectively met with minimum negative impact due to NH₃ slip and SO₂ to SO₃ oxidation. We will help define process distribution requirements so that long term performance and operational demands are achieved.

CFD Modeling Services

With the use of Computational Fluid Dynamics (CFD) modeling, we recommend optimal arrangements of duct configuration and flow correction devices in order to maintain appropriate flue gas velocities, temperature distribution, fly ash distribution, and NH₃ to NO_x distribution within the SCR system. Fuel Tech provides our clients with the sizing, design, and configuration of the NH₃ injection grid, static mixer, large particle ash screen, GSG™ Graduated Straightening Grid, and turning vanes.

Physical Flow Modeling Services

We also offer physical (or experimental) flow modeling services for SCR systems. The material of construction for the physical model is carbon steel with sufficient transparent areas to allow inspection of all internal critical areas of the model. Only state-of-the-art measurement devices are used during the modeling, including: hot-wire anemometers, peizo-electric pilot tubes.

Modeling carried out using a three dimensional flow model similar in geometry to the full size SCR system can include the following:

• Boiler backpass from economizer inlet plane
• Boiler backpass economizer and ash hoppers
• Superheat pass and Reheat pass dampers
• SCR inlet ductwork complete
• Flow correction devices including flue gas flow straightening grids at SCR inlet
• LPA screen, ammonia injection grid
• SCR reactor - either single or dual reactors as required
• Catalyst
• Bypass system complete
• SCR outlet ductwork up to, and through, all airheaters
• Dampers and expansion joints
• Ductwork and reactor ash hoppers
• Internal structural members (grating, braces, gusset plates)

Testing Criteria

• System Pressure Loss Tests
• Fly Ash Dropout Testing
• Flue Gas Velocity Distribution Upstream of NH₃ injection
• Flue Gas Velocity Distribution Upstream of the Catalyst
• Velocity Distribution at Large Particle Ash Screen
• Velocity at Floors and Structural Members
• Flue Gas NO_x and NH₃ Distribution