CEM - Abstract

Abstract Information :

The US EPA has two (2) other methods for continuous emission monitoring for particulate matter (“PM”). These are PM continuous emission monitoring systems (“PM CEMS”) and PM continuous parametric monitoring systems (“PM CPMS”). The use of PM CEMS or PM CPMS can dependent on the specific rule. Some rules allow the facility the option to chose which method they want to use for compliance. PM CEMS uses a full calibration curve with a minimum of 15 data points which spans the majority of the facility’s permitted emission range. A PM CPMS is a linear relationship of the average of three (3) data points forced through instrument zero. As facilities started using the PM CEMS option for compliance, the data started to show how the affects of low PM emissions can distort the final relationship. In some cases the CPMS curve makes it appear that the facility is almost constantly out of compliance, when in fact they are no where close to the actually emission limit. This presentation will look at data from several facilities where the normal PM concentration in the stack was very low and show how using only this data can affect the relationship of the PM monitor and the reference method and ultimately the perceived emission rate based on that relationship. It is very difficult to develop a representative relationship for the full range of any instrument by only using a limited range of data. This is especially true to PM emissions. This presentation will provide data comparing the PM CEMS results versus the PM CPMS results to illustrate the issues with using a limited data range to establish an overall relationship for the PM monitor. We will show that lower PM concentrations are great for compliance, but can provide difficulties when trying to develop a correlation between the reference method to a PM monitor output.