SCR systems are designed to operate within tight tolerances for the distribution of ammonia-to-NOx at the inlet to the SCR catalyst. Operation outside of the allowable tolerances increases ammonia consumption, ammonia slip and stack NOx emissions, and total system backpressure (due to downstream ammonia salt formation). On top of that, it also reduces the effective life of your SCR catalyst. Ammonia Injection Grid Tuning with Environex helps you:
Sub-optimal ammonia-to-NOx distribution can be the result of flaws in the system design, changes in plant operating profile, plugging of AIG nozzles or other system maintenance issues, changes in combustion dynamics, or the gradual degradation of SCR system components over time. The goal of AIG tuning is to reduce variability in ammonia-to-NOx distribution to the greatest extent allowed by the system design. This is achieved by balancing the flow through the ammonia distribution valves to carefully match ammonia distribution to the SCR inlet NOx profile. Environex has a proven track record of successfully tuning ammonia injection grids to reduce ammonia slip and ammonia consumption.
AIG Tuning with Environex has reduced stack NOx and ammonia slip emissions as much as 50% and ammonia consumption by up to 25%.
AIG tuning should be performed upon commissioning, after SCR catalyst replacement, when there are any major changes to your plant’s operating profile, after any GT upgrades or changes to the plant combustion dynamics, or after any catastrophic HRSG events. The AIG tuning process is also effective in identifying bypass around the catalyst and catalyst “dead spots”. Some systems are more sensitive to ammonia-to-NOx distribution than others. Systems with high NOx conversion requirements and low ammonia slip limits have the highest risk and are most likely to benefit from AIG tuning. Those with more lenient limits and lower NOx conversion requirements are less sensitive and may not benefit greatly from tuning. Connect with the Environex team to find out if your systems are good candidates for AIG tuning.