Validation of a Test Method for the Measurement of Methanol Emissions from Stationary Sources

Abstract

Title III of the 1990 Clean Air Act Amendments designated methanol as a pollutant to be regulated. The U.S. Environmental Protection Agency (EPA), through a contract with Research Triangle Institute, has developed a method for measuring methanol emissions from stationary sources. The methanol sampling train (MST) consists of a glass-lined heated probe, two condensate knockout traps, and three sorbent cartridges packed with Anasorb® 747. Samples are desorbed with a 1:1 mixture of carbon disulfide (CS 2 ) and N,N-dimethylformamide (DMF). Condensate water and CS 2 / DMF samples are analyzed by gas chromatography with flame ionization detection. The MST has a practical quantitation limit of approximately 3 ppm for a 20-L sample. Samples were shown to be stable for at least two weeks after collection.Field tests of the MST and the National Council of the Paper Industry for Air and Stream Improvement (NCASI) methanol sampling method were conducted at two pulp and paper mills. Sampling and analysis procedures followed EPA Method 301 requirements.The sampling location for the first field test was the inlet vent to a softwood bleach plant scrubber, where the methanol concentration was approximately 30 ppm. The mean IMPLICATIONSUnder Title III of the Clean Air Act Amendments (CAAA) of 1990, methanol is one of 189 toxic chemical species that will be regulated in stationary source emissions. The U.S. Environmental Protection Agency (EPA), through a contract with Research Triangle Institute (RTI), has developed a test method for measuring methanol emissions from stationary sources. The test method has been validated at two field test sites according to EPA Method 301 procedures. A summary of the experimental procedures and estimates of the precision and accuracy of the test method under field conditions are described in this paper. The test method is beneficial to the regulatory agency and to industry personnel for measuring methanol emissions from stationary sources.recovery of spike was 108.3% for the MST method and 81.6% for the NCASI method. Although neither method showed significant bias at the 95% confidence level, the betweenmethods bias was significantly different.A second field test was conducted at a vent from a black liquor oxidation tank where the methanol concentration was approximately 350 ppm. Mean spike recoveries were 96.6 and 94.2% for the MST and NCASI methods, respectively. The biases of the two methods and the between-methods bias were not significantly different for the second field test.