Use of Fourier Transform Infrared (FTIR) Instrument for Air Toxic Compound Screening and Quantitation in the Natural Gas Industry

Abstract

Abstract In response to the 1990 Clean Air Act Amendments, the Gas Research Institute is investigating emissions of air toxics from natural gas industry sources. As part of this effort, air toxic emissions data has been collected for various gas industry sources using a combination of measurement methods, including extractive Fourier Transform Infrared (FTIR). The FTIR protocol used during the program was initially developed along with quality control/quality assurance (QA/QC) procedures to meet the needs of the air toxics measurement program. Since there are no validated measurement methods currently available for quantifying aldehyde emissions from engines, GRI initiated a field test to validate the extractive FTIR method for measurement of these species using U.S. EPA Method 301 "Field Validation of Pollutant Measurement Methods for Various Media". FTIR and other measurement methods were used in the field to collect air toxics data from sources located at a sour gas plant, as well as internal combustion (IC) engines at compressor stations. At the sour gas plant, emissions were monitored for IC engines, gas turbines, heaters, boilers, and tanks, as well as other sources. This paper presents a summary of the extractive FTIR measurement method, the development of the measurement protocol and reference spectra, and how the method was used in the field for data collection. Also included is a summary of the results using FTIR during the first four measurement campaigns, and a discussion of the FTIR validation effort using EPA Method 301 procedures.