US EPA

8434462 

Meetings & Symposia 

Aromatic recovery unit (ARU): a process enhancement for glycol dehydrators 

Choi, MS; Spisak, CD 

1993 

Publ by Society of Petroleum Engineers (SPE) 

San Antonio, TX, USA 

Proceedings of the SPE/EPA Exploration and Production Environmental Conference 

199-205 

English 

Conoco has developed a standard glycol dehydrator process enhancement to recover hydrocarbons normally vented with water vapor during glycol regeneration. The gaseous hydrocarbons are recovered as a condensate product (stock tank oil) and regenerator fuel. The system has been named 'ARU' (Aromatic Recovery Unit). A prototype unit has been in continuous operation since November 1990. Four other units of the same design have been added and are operating successfully. Cost analyses of the technology indicate very attractive economics, with the prototype having an 8-month payback on capital investment. Field personnel report the ARU requires little operator attention and minimal maintenance, and attribute improved reboiler operations to the ARU. In addition, extensive performance tests have demonstrated significant reduction in aromatic hydrocarbon emissions. Of the 189 Hazardous Air Pollutants listed in the 1990 Clean Air Act Amendments (CAAA), aromatic hydrocarbons (BTEX) and N-hexane appear to be the most troublesome for oil and gas producers. At many production facilities, the emissions from glycol dehydrators may be the only source that exceeds the CAAA limits. With cost-effective technologies like the ARU available, the CAAA with its many provisions may become an insignificant issue. This possibility will be enhanced if we as an industry adopt the position that ARU's are process enhancement. In addition, we must begin upgrading glycol dehydrators with ARU's, in advance of federal and state regulations, for the stated purpose of maximizing products recovery and profits from operations, and calculate our emission inventories with the economically-driven process enhancement already in-place.