Predictive Or Continuous? How To Choose The Right Emissions Monitoring System

Predictive Or Continuous? How To Choose The Right Emissions Monitoring System

As firms take increased responsibility for understanding and managing their emissions, industrial plant owners and operators are faced with a new set of challenges. These include tight environmental regulations and emission limits, which require continuous emissions data to monitor and control pollutants released into the atmosphere. Organizations who fail to provide emission data face financial penalties and, in extreme cases, plant shutdowns. Therefore, it is essential that industrial firms have accurate emissions monitoring systems in place. Traditionally, this came in the form of CEMS (continuous emissions monitoring systems) technology. This solution extracts a small sample of gas that is measured by a gas analyser to provide users with an understanding of emission levels.

However, there is new technology on the block: PEMS (predictive emissions monitoring systems). This software-based technology provides a reliable real-time estimation of emission properties through advanced mathematical modelling techniques. Specifically, PEMS leverage predictive models to exploit correlations between process variables, ambient conditions and emission properties. Then the system uses AI to provide emission estimations that are similar in accuracy to conventional hardware analysers.

PEMS solutions have several advantages compared to traditional CEMS technology. This includes increased emission data availability of up to 99.5%, reduced maintenance needs and slick integration. Minimal maintenance needs contribute to an overall reduction in lifecycle costs compared with hardware. Its suitability, which has been recognized by regulatory authorities including the EPA, has caused an increase in uptake. As it does not require any physical equipment, there are lower purchasing costs, no continual maintenance and no need to be replaced. Another benefit is the speed of implementation. Once PEMS are up and running, they require less training and facilitate remote access, provided an online connection is available. Furthermore, while CEMS technology highlights excess emissions levels, it provides no insight as to why this has occurred. PEMS offer a more proactive solution. Specifically, they use dynamic set points to trigger alarms based on information gathered from historical events.

Although PEMS technology is a standalone solution, experts have suggested that it should not be considered a direct replacement for CEMS. Instead, they have promoted tools that include both software and hardware-based emission monitoring, using CEMS and PEMS to harness both technologies’ strengths. For example, the model-based nature of PEMS gives them the edge for boilers, gas turbines or furnaces, where conditions remain relatively stable. Meanwhile, CEMS solutions are more beneficial in fluctuating conditions, such as waste incinerators or complex industrial processes, which are prevalent in the chemicals industry. Although offering both solutions would enable firms to cover a wider range of possible applications, only a few – such as ABB – currently do so.

With increasingly stringent regulations, obtaining accurate, reliable information on emission levels is crucial to maintain compliance. Although PEMS can improve the current offering of CEMS technology, they are not a direct replacement. Instead, firms should look to use both in their emission monitoring processes.

To learn more about emission monitoring technology, please see our latest tech roadmap and visit the research portal.