Use of open-path FTIR monitoring for emission rate assessment of industrial area sources during winter conditions

摘要

Open-path Fourier transform-infrared (OP-FTIR) was used to collect emission data for a number of chemical compounds for several area sources at a northwestern industrial facility. The data collected was used in conjunction with meteorological measurements to assess the emission rate of several of the compounds from these area sources. The release of a tracer gas at a known emission rate and its subsequent measurement with the OP-FTIR allowed for correction of emission rates to account for local effects on the site specific vertical dispersion coefficients used for emission assessments. The methodology for emission rate assessment is presented, and the implications of correcting for site specific vertical dispersion are discussed. Four area source case studies are included for the study. Most of this data was collected during cold temperature conditions, and some of the data collected during the night time hours, this represents one of the first studies of site specific vertical dispersion under these conditions. Possible impacts of these conditions on emission rate determinations will be presented. The effectiveness of OP-FTIR as a tool for area source emission rate assessment will be evaluated. OP-FTIR was employed for data collection because of its ability to detect the compounds of interest accurately and with reasonable levels of detectability. Emission rate determinations were done for process ponds AA, and BB. Fence-line concentration measurements were also made north of pond AA. The on-site study was conducted from 11/10/97 through 11/26/97. The data collected indicated that moderate to significant levels of two target compounds were being emitted by both pond AA and pond BB. Emission rates were estimated using text book dispersion coefficients and found to overestimate actual emission rates based on tracer gas release significantly. One target compound's emission rate was found to also be related to wind speed.