FIELD ASSESSMENT OF A NEW METHOD FOR ESTIMATING EMISSION RATES FROM VOLUME SOURCES USING OPEN-PATH FTIR SPECTROSCOPY

An auto-positioning open-path Fourier Transform Infrared (FTIR) spectr ometer can be used to directly measure vertical concentration profiles in a plume downwind from an emission source. The multi-component anal ysis capabilities of FTIR spectroscopy allow simultaneous measurement of diverse downwind pollutant species. Using concentration measurement s and meteorological data, it is possible to estimate the emission flu xes across the plume and, thus, the emission rates of pollutants from the source. The field assessment goals were to conduct the first in a series of field tests of a new measurements system developed to perfor m such emission rate determinations, and to evaluate the system's perf ormance and feasibility. For these purposes, a simple volume source si mulator was constructed to emulate process equipment leaks encountered at chemical plants, refineries, and other facilities. By metering the release rates from the volume source simulator, ''actual'' release ra tes were compared to the ''estimated'' release rates calculated using the measurements system. Using simple data screening techniques, over 90% of the field tests conducted produced run-average emission rate es timates within 20% of the actual emission rates. Half of the tests wer e within 10% of the actual emission rates.