Many applications have proven that software systems are just as accurate as the hardware-based CEMS. In addition, virtual analyzers offer other functionalities that can:
- Identify the key variables that cause emissions
- Automatically validate sensors
- Reconstruct emission levels from historical data when the hardware device fails
- Complement and enhance process optimization strategies
Actual regulation requirements insist that periodic tests need to be performed at the stack as well as continuous emission monitoring in order to prove compliance with the legal limits and track eventual violations. A conventional CEMS, however, cannot anticipate pollutant limit violation. A PEMS, on the other hand, could allow plant engineers to directly correlate the relationship between varying operational parameters, predict plant emissions in advance and take action to adjust emissions before violations occur.
The mood around the world regarding the methods used to monitor emissions is changing: Many European regulations now explicitly call for software-based redundancy emission monitoring systems while in the US, several states allow artificial intelligence (AI) technologies based on models like PEMS as an alternative monitoring technique.