Catalyst Testing

SCR catalyst testing is a critical part of successful overall SCR management.  Unbiased and independent catalyst testing and chemical analysis is needed to determine the:

• Initial catalyst performance parameters and chemical composition
   
• Actual catalyst activity, SO2/SO3 conversion and catalyst deactivation rate
   
• Change in chemical composition and identification of catalyst deactivation causes
   
• Determination of initially installed, actual residual, and minimum required DeNOx potentials
   
• Development tracking and forecast of SCR system performance
   

Evonik Steag GmbH was one of the two large scale SCR operators selected by the German Association of Large Power Plant Operators (VGB – Vereinigung der Großkraftwerksbetreiber) for participating in the development of the standard protocol for testing of DeNOx catalyst, “VGB Guideline VGB-R302He, 2nd Edition”. Evonik Steag has also developed a supplement to VGB-R302He which eliminates some remaining ambiguities and defines best practices for bench scale testing based on our long-term bench scale testing experience.

Catalyst testing and chemical analysis is required in order to determine the exact catalyst performance, chemical composition and catalyst deactivation causes and to provide long-term tracking data.  All bench scale catalyst testing should be performed in an independent catalyst testing laboratory which frequently qualifies its accuracy and precision through extensive QA/QC round robin testing to be conducted every 3 to 5 years through VGB. Evonik Steag always participates in these round robin tests and successfully passed these “VGB-certifications”.

Evonik Steag’s VGB-R302He Round-Robin certified SCR catalyst bench scale test reactor in Germany

SCR performance and catalyst deactivation are generally tracked as potential of each individual layer as well as potential of the entire SCR reactor versus operating time.  Each data point generated should be entered into the SCR Performance and Catalyst Potential Tracking Sheet to follow the history of the unit and assist in predicting the need for catalyst cleaning, regeneration, or replacement with new catalyst.

Evonik Steag typically performs a series of catalyst testing procedures:

• Bench scale reactor testing for full elements including
  • SO2/SO3 conversion rate
  • Pressure drop  D p
  • Initial activity K0
  • Actual activity Kact
     
• Micro scale reactor testing for small size catalyst coupons,
   
• XRF analysis for catalyst surface and bulk composition,
   
• SEM analysis for catalyst surface scans (optional),
   
• XRD analysis for mineralogical e.g. coal

Whether developing a SCR management program for a single unit or a fleet of SCRs, your SCR catalyst management strategy should include a perpetual cycle of inspections, tunings, testing and evaluations.

In additional, Evonik Steag takes into account outage schedules, SCR operating schedules (seasonal or year round), power demand curves, unit capacity loading, availability of the specific residual DeNOx potential of each SCR system and possible fleet wide NOx reduction requirements to provide you with an overall plan for your facility.

Our two decades of opeating SCRs has given Evonik Steag the expertise to tailor a plan to assist you in reaching your goal of ensuring the least overall long-term cost while providing the maximum possible lifetime for the installed catalyst with optimal SCR system performance.