PM2.5 Emission Factors for Arizona Sand-Producing Plants

摘要

Air Control Techniques, P.C. conducted a series of PM2.5 emission tests to measure emission factors at two sand-producing facilities in near Phoenix, Arizona. The scope of testing included a 20 x 6 foot vibrating screen, and a cone crusher at the Cemex plant in Avondale, Arizona and a conveyor transfer point at the Lafarge North America plant in Surprise, Arizona. Air Control Techniques, P.C. used PM2.5 BGI PQ200 FRM samplers to measure the concentrations of PM2.5 in the sample gas stream from sampling arrays attached to the sides of the process equipment being tested. The mass flux of PM2.5 fugitive particulate matter through the array was determined by multiplying the ambient air flow rate through the array by the measured PM2.5 concentration. This sampling approach is similar to the testing procedures used by Air Control Techniques, P.C. in 2013 to measure PM2.5 emissions from similar types of equipment at a crushed stone plant in Burlington, North Carolina. The sampling arrays were modified slightly based on the experience gained during the Burlington tests. The results of the tests included emissions of 2.0 × 10~(-5) pounds of PM2.5 per ton of stone for the conveyor transfer point, 1.4 × 10~(-5) pounds of PM2.5 per ton of stone for the vibrating screen, and 2.5 × 10~(-3) pounds of PM2.5 per ton of stone. The conveyor transfer point and crusher emission factors are slightly higher than the PM2.5 emission factors presently included in AP42 Section 11.19.2. The vibrating screen PM2.5 emissions are slightly lower than the AP42 Section 11.19.2 value. The addition of the Arizona emission factors in this paper and similar data published last year from Burlington, North Carolina will supplement the PM2.5 emission factor data already present in the AP42 Section 11.19.2 emission factor data base. The data from the Arizona tests are especially useful due to the moisture levels and size distributions, which were quite different than previous tests on crushers, screens, and conveyor transfer points. The expanded set of PM2.5 emission factors is important because operators of crushed stone and sand-producing facilities in many states are now being asked to supplement existing emission inventories with PM2.5 emissions data.