Selective Catalytic Reduction (SCR) catalysts used for NOx control deactivate over time and eventually reach a point where air permit limits can no longer be met. Routine laboratory testing of SCR catalyst samples is the most accurate and dependable way to track performance and determine when the catalyst needs to be replaced to ensure your plant can continue to operate reliably, without any emissions-imposed limitations. With replacement catalyst lead times anywhere from several months up to a year (and possibly longer due to supply chain issues), proactive management and testing of your SCR catalyst is essential for budget planning and outage scheduling to avoid costly expedite charges and forced outages.
Since Environex does not sell SCR catalysts or systems, our independent perspective is trusted to provide unbiased projections of remaining catalyst life, troubleshoot causes of accelerated deactivation, and identify opportunities to improve future catalyst formulations and designs. Our client-centric testing services are focused on providing the fastest turnaround and most thorough results in the industry so that you get the information you need when you need it. Environex follows VGB and EPRI guidelines for SCR catalyst testing and served on EPRI’s committee to establish testing protocols for SCR and CO catalysts from gas turbine applications.
With over 30 years of experience working with SCR catalysts and systems, Environex has seen it all. We have tested thousands of SCR samples from all major catalyst suppliers, spanning the full range of applications and industries – high-temperature catalysts from peaking plants, conventional combined cycle and cogeneration catalysts, high- and low-dust catalysts from coal and biomass plants, refinery SCR catalysts, fertilizer production facilities, steel manufacturing, and more. If you are experiencing problems with your SCR catalyst or just want an idea about what to expect based on comparable applications, Environex has the breadth and depth of experience to provide the answers you are seeking.
Since the SCR reaction is temperature-dependent, Environex tests SCR catalyst samples for NOx conversion performance across a range of temperatures and ammonia flows to simulate actual plant operating conditions. Most other testing facilities test at a single design condition, which does not provide the information needed to project performance across the full range of plant operations. Environex selects the range of test conditions based on the unique operating profile of your facility. This allows our engineers to make the most accurate projection of remaining catalyst life.
In addition to knowing how much your catalyst has deactivated, Environex believes it is important to know why your catalyst was deactivated. The why is normally overlooked by other testing companies. We incorporate chemical and physical analyses with catalyst performance testing to pinpoint the causes of catalyst performance loss. The most common deactivation mechanisms for SCR catalysts are poisoning, fouling, and thermal damage. In some cases, it is possible to mitigate or eliminate causes of accelerated deactivation after they are identified.
Failure Analysis: If your catalyst fails prematurely, it is important to identify the causes of failure so that they do not become an ongoing problem for subsequent catalyst charges. Failure analysis testing identifies the causes of catalyst failure and the extent to which they have caused performance loss. It may be possible to eliminate or mitigate causes of failure once they are identified. If not, alternate catalyst formulations or designs that are more resilient to performance loss may be identified and specified.
Baseline Testing: Baseline testing of new SCR catalysts provides an important benchmark for planning future catalyst management activities. Performance testing of a baseline sample allows for the most accurate tracking of catalyst performance loss for your specific batch of catalyst. Chemical and physical analyses of a baseline sample enable you to track contaminant levels and monitor deactivation mechanisms as the catalyst ages.
Dual Function Catalyst Testing: Testing of dual-function catalyst samples is similar to SCR catalyst testing. The main difference is that the performance testing component includes the measurement of both NOx and CO removal efficiency across the range of plant operating conditions. Chemical and physical analyses are still included to identify the causes of performance loss.
Factors beyond SCR catalyst performance can impact plant emissions performance. For a more comprehensive look at overall emissions control system performance, we recommend a Full SCR System Evaluation. This combination of detailed plant operating data analysis, thorough on-site system inspection, and SCR catalyst core sample mapping allows us to distinguish system problems from catalyst problems and develop an action plan to optimize SCR system performance and maximize catalyst life.