The Thermo Scientific Continuous Emissions Monitoring System (CEMS) for the measurement of Total Reduced Sulfur (TRS) is designed to meet the needs of the pulp and paper industry in complying with the regulatory requirements of 40 CFR part 60 as set forth by the U.S. EPA.
In order to measure TRS in accordance with the federal regulations, the sample must measured on a dry basis and be corrected to a fixed Oxygen (O2) content. This is accomplished by extracting the sample from the process using the Thermo Scientific PRO902C Low-Flow Dilution Probe.
First, the sample is passed through a water removal device to provide a dry sample. The oxygen content is measured and the sample is diluted to an appropriate level, depending on the site conditions.
The diluted sample is sent through a sample line to the instrument cabinet and passes through a selective scrubber where Sulfur Dioxide (SO2) is removed and TRS is allowed to pass. Next, the sample is routed to a thermal oxidizer where the TRS compounds react with O2 under high temperature, and is then sent on to the Model 43i Pulsed Fluorescent SO2 analyzer.
The result of this process is that TRS compounds are converted to SO2 in a 1:1 ratio. This means the SO2 reading from the analyzer is a true representation of the amount of TRS in the sample.