As a result of increasing regulatory pressure, emissions of benzene, toluene, ethyl benzene, and the xylene isomers (BTEX) and other volatile organic compounds (VOC) from the regenerator still vent of glycol dehydration units have become a major concern of the natural gas industry. The Clean Air Act Amendments (CAAA) of 1990 have provided an impetus for air toxics regulations, and several states are regulating or considering regulating these units. To address this issue, the Gas Research Institute (GRI) and Radian Corporation have initiated research in three areas related to these emissions: the development of sampling and analytical methods, emissions modeling, and emissions control.
This paper contains background information on glycol dehydration units, their emissions, and legislation pertinent to these emissions. It also discusses the R-BTEX process for controlling emissions and the results of initial field experiments.