Control Device Monitoring for Glycol Dehydrator Condensers: Testing and Modeling Approaches

The Maximum Achievable Control Technology (MACT) standards for the oil and natural gas industry are expected to be proposed in early 1997, with promulgation later in the year. These standards will include control device monitoring requirements to show that controlled sources are in continuous compliance with the MACT standard. Since condensers are the most widely used control option for glycol dehydrators, the monitoring requirements for condensers are of particular interest; this requirement may include recording the condenser outlet temperature. Performance testing on all condenser units may be required to establish the appropriate site-specific temperature that indicates whether a unit is achieving the desired level of control. Computer modeling is a less expensive and more flexible alternative for establishing this temperature and defining a site-specific condenser curve, but this approach has not previously been validated through field measurements. Gas Research Institute (GRI) has initiated a field condenser test program to collect the data necessary to validate the use of computer programs, such as GRI-GLYCalC TM and commonly available process simulation packages, in predicting glycol dehydrator vent condenser efficiency. A series of nine test, at seven sites have been conducted to collect these data. This paper will present the results of the field testing (performed on several different condenser types, including air-, glycol-, and water-cooled systems), and make comparisons to the modeling results. The paper will also include general information on the key process parameters affecting condenser performance.