Evaluation of Bias in the Measurement of Condensable Particulate Matter with Method 202

Abstract

In the present study, positive and negative biases when measuring condensable particulate matter (CPM) was measured according to US EPA Method 202. Four factors were considered to measure and improve CPM overestimation: SO2 absorption, the volume of condensate, oxygen content, and residence time. Negative biases were evaluated using weight loss caused by static electricity, vapor pressure of the particles, rinsing volume, beaker size, and filter paper holder. Finally, a forced ventilation chamber was designed to reduce the drying time of the organic sample. The results revealed that artifacts produced by SO2 could not be eliminated. The homemade condensate-divert impinger did not reduce the amount of artifacts because the oxidation of SO2 already occurred when it came into contact with water while passing through the Graham condenser. The residence time, volume of condensate, and oxygen content can all increase CPM overestimation. Therefore, field sampling should be performed as quickly as possible. Furthermore, electrostatic neutralization of the beaker should be performed before weighing it. Because of the high volatility of the material with high vapor pressure, nitrogen purging may reduce the particle mass with high vapor pressure. Furthermore, when the CPM sample was transferred from the beaker to the tin, a smaller beaker size led to lower residual mass. A 4% particle loss was measured according to the leakage of particles between the filter paper

The Behavior and Removal of Condensable Particulate Matter in Flue Gas in a Multi-Field Force: A Modeling and Experimental Study

“…However, the current conventional APCDs have poor removal efficiency for CPM, with experiments showing that the removal rate of LLT-ESP for CPM ranges from 60.9% to 78.89% [8]. Huang et al collected and measured CPM before and after EBF and ESP in the factory, and found that the removal rates of ESP and EBF for CPM were 77.34% and 79.23%, respectively [9]. A study conducted on a super−low emission and coal−fired unit showed that its existing low−temperature electric precipitator, seawater desulfurization and wet electrostatic precipitator devices were effective in removing CPM [10].…”