Fine and Coarse Particulate Continuous Emissions Monitoring System

Baldwin Environmental, Inc., will demonstrate the feasibility and practicality of applying beta attenuation monitors (BAMs) to quantify hourly concentrations of fine particulate matter (PM2.5; particles with aerodynamic diameters less than 2.5 μm) and coarse PM (PM10-2.5; particles with aerodynamic diameters between 2.5 μm and 10 μm) in diluted extracts from stacks at hazardous waste combustors. BAMs quantify mass by measuring the reduction in flux of electrons generated by a radioactive source through a filter tape that collects particles. The U.S. Environmental Protection Agency (EPA) and other regulatory agencies need PM2.5 and coarse continuous emissions monitors (CEMs) to better estimate and control emissions that affect public health, visibility, and climate. Although BAMs are widely used for ambient PM10 monitoring, they exhibit differences with respect to filter samples depending on the composition of the particles collected. These differences are exacerbated in source samples owing to the large fraction of semi-volatile material and hygroscopic components, like sulfates. Modern CEMs must be able to accurately quantify PM mass in emissions with high moisture contents and with condensable and semi-volatile compounds. These CEMs should pass Performance Specification 11 (PS-11) and be equivalent to PM2.5 measured by dilution stack samplers that are being developed by EPA to better represent PM as it would appear after dilution and cooling. Stack dilution sampling for PM2.5 is widely recognized as a better approach than hot-stack sampling to represent PM effects on health, visibility, and climate. Modern CEMs also should provide for simultaneous measurement of PM2.5, PM10-2.5, and other variables such as black carbon (BC) in a package easily mounted at a sampling port and for obtaining accurate data with minimal operator intervention. This project will combine a newly developed BAM that simultaneously measures PM2.5, PM10-2.5, and BC with an extraction-dilution system. Through testing of simulated stack samples, it will quantify the extent to which such a configuration can accurately portray mass concentrations as they appear in the atmosphere immediately after cooling. This testing will determine the optimum dilution ratios and aging times needed to obtain relative humidities that create a stable mass concentration and size distribution. This feasibility testing will be translated into a practical design, applicable to a wide number of incinerator waste inputs, operating conditions, and stack configurations in anticipation of a Phase II project to develop a commercial prototype. The design intends to meet PS-11. EPA Conditional Test Method 039 will be used as a guideline for the prototype design. Phase III will carry the prototype to a commercial product.