Stack Sample Analysis

Our Stack Sample Analysis Capabilities

• Automated Particle Analysis by SEM-EDS
• Stack sample particle size distribution (including PM10 & PM2.5 for EPA Method 5 samples)
• Stack particle shape analysis
• Stack particulate matter identification
• Stack condensable/ back half catch residue identification (Method 202)
• Stack filter debris analysis
• Ambient air sample characterization
• Litigation Support

Stack samples are tightly regulated by the Environmental Protection Agency (EPA) and individual state agencies. Stack sampling, also known as emissions testing, is a process for evaluating the characteristics of a waste gas stream that is released to the atmosphere. The gas stream may contain solid, liquid, or gas pollutants. Stack testing follows specific test methods and protocols, and it is an important tool in determining compliance with emission limits.

Improvements in particulate control technology result in stacks that are so clean that it is difficult for stack testers to use traditional methods for particle size distribution (PSD) measurement. Using cascade impactors or cyclones could require hours of sampling to obtain sufficient material mass. Furthermore, many emissions sources are not suited for cascade impactors or cyclones. High temperatures, high moisture content, or cyclonic flow conditions may render theses gravimetric techniques impractical or invalid.

For some stacks, PM 10 and PM 2.5 cannot be determined by Method 201A cyclone samplers. To help stack testers and their clients determine particle size distributions for these sources, MVA Scientific Consultants has developed microscopy-based methods of particle size distribution measurements from Method 5 samples. Light microscopy can be used if the minimum particle diameter is no less than 1 micrometer. Transmission electron microscopy (TEM) can be used if the particle diameter is less than 50 nanometers.

These methods have provided valuable compliance data for power generators, boiler operators, cement kilns, waste incinerators, pulp/paper and other operations where particulate emissions must be controlled. These methods can also be used to determine the particle size distributions in engineering studies, providing particle size data for use in design and optimization of emission control systems.

If you are a stack tester, you and your clients may also want to know:

• What is in my particulate emission samples?
• Why are we out of compliance?
• Where in the process do the particles or M202 condensables come from?

MVA can help answer these questions using the same microscopy based particle characterization techniques. Email us at info@mvainc.com.