| OCR Text |
Show International Flame Research Foundation 1998 Flame Research Committee 11-15 October 1998 DISCUSSION All the air toxics emissions data for process heaters and boilers have come to renewed focus in the past couple of years with the establishment in 1996 of the Industrial Combustion Coordinated Rulemaking (ICCR), federal advisory committee. The U S E P A has initiated this multi-stakeholders process in order to develop national emissions standards for hazardous air pollutants (HAPs) for all combustion devices nationwide, pursuant to section 112 of the Clean Air Act, as amended in 1990. The law mandates that the standards be technology based (initially, followed by the assessment of residual risk, after controls) and are known as "Maximum Achievable Control Technology", or M A C T . Over the past two years the ICCR coordinating committee, through its various technical working groups, have assembled all the data needed as technical back up in the promulgation of emissions standards for the various device categories. Process heater benzene, formaldehyde and PAH emissions from natural gas, refinery/process gas, and combinations of these gasses are shown in Figures 3-5. Field data from the API/WSPA and ICCR databases are plotted, along with the results of the full-scale PERF laboratory studies. The emissions are reported in pounds per million Btu (lbs/MMBtu). The fuel type description and data source, and the total number of data points in each group are noted on the x-axis. A data point is a single test run, and normally there are three test runs per each sampling event on any given heater. This graphical summary is based on all the sources cited above, including the A R C O tests at L A R , as reported in this paper. The field results compare very well with the PERF laboratory tests and the 1998 API/WSPA database. Emissions from process heaters firing these gaseous fuels are at or near the limits of detection. In addition, the consistency of the results indicates that despite natural process variability - and uncertainties associated with field testing - overall emissions of organic air toxics are very low, and the emissions are not significantly affected by the gas composition. Using the mid-range for the derived emission factors in Table 1 would produce a rough estimate of organic air toxics emissions, in the neighborhood of 0.05 tons per year for a 100 MMBtu/hr process heater. A typical refiner}' with 6000 MMBtu/hr firing rate would produce roughly 3 tons per year for all organic toxics. |
