The predicted impact of increased formaldehyde emissions from industrial flares on ozone concentrations in Houston, TX.

Abstract:

Houston features one of the largest concentrations of the petrochemical industry in all of North America and flares are widely used there as the final treatment process for unwanted volatile organic compounds. These flares have the potential to produce formaldehyde as the result of incomplete combustion. Formaldehyde emissions are an important precursor to producing hydroxyl radicals and thus can impact atmospheric chemistry and the formation of ozone. Formaldehyde emissions from flares, however, are difficult to measure in situ. Recently, alternative measurement techniques have been developed, like open path optical methods, that allow the direct measurement of flare emissions from the facility’s fence line (Johansson et al., 2014; Pikelnaya, Flynn, Tsai, & Stutz, 2013). This observational data indicates that the emission rate of formaldehyde from flares is about 10-20 times greater than those found in the regulatory models developed by the Texas Commission on Environmental Quality’s (TCEQ). This research will use air quality models to quantify the impact that increased formaldehyde emission from flares will have on Houston ozone concentrations. This study relies on the CAMx model (version 6.1) and emission data developed by Alpine Geophysics LLC (AG) and Climate & Atmospheric Research Associates (CARA) based on the combined databases from TCEQ, U.S. Environmental Protection Agency (EPA), and National Emission Inventory (NEI2008). This model also used meteorology data from the results of WRF-ARW dynamics. The CAMx generated process analysis data will also be used to quantify changes in radical budgets and NOx budgets critical to ozone production.