Measurement and Enhanced Monitoring of BTEX and VOC Emissions from Glycol Dehydrators

Abstract

Abstract The Clean Air Act Amendments of 1990 and activities by several states have resulted in increasing regulatory pressure on emissions of benzene, toluene, ethylbenzene, and xylenes (BTEX) and total volatile organic compounds (VOC) from glycol dehydration units. There are no standard sampling and analytical methods established by regulatory agencies for determining emissions from glycol dehydrators, and the methods initially used by the industry showed significant variability in results. To address this lack of methods, the Gas Research Institute (GRI) began an effort to develop measurement methods and emission estimation techniques for glycol dehydrators. Ten methods were evaluated based on the criteria of ease of use, cost, and precision and bias in a series of field experiments at ten sites. The results of the project showed that GRI-GLYCalc™ should be used to initially screen a large number of units and that atmospheric rich/lean glycol measurements should be made to refine these initial estimates. GRI has also initiated efforts to assist the industry in complying with enhanced monitoring requirements for glycol dehydrators. These enhanced monitoring protocols may be based on using condenser temperatures in conjunction with computer programs such as GRI-GLYCalc. Additional test data will be collected using the methods developed in the previous efforts to validate the computer program predictions for condenser control efficiencies.