Emissions Reduction & Horsepower Re-Rate: A Case Study
In 2003, the El Paso Corporation Southern Natural Gas facility located near White Castle, Louisiana was required to propose a plan for reducing the station NOx emissions for 80%. There were 10 units located at the facility, three of which were low horsepower (550 hp each) engines. The remaining seven engines were comprised of 3 GMVA-8, 1 GMVA-10, 2 GMVC-10 and 1 GMVH-12. The project scope required retirement of the three smaller engines and uprating of the 7 remaining engines to maintain the FERC permitted station horsepower. This had to be accomplished while achieving the required NOx reduction. As part of the project, all centrifugal blowers were removed from the GMVA and GMVC series machines and new ABB turbochargers were installed. The GMVH received turbocharger modifications to enhanced air delivery. The turbocharger changes required replacement or installation of new unit level charge air cooling systems, cooling water control systems, and cooling system capacity modification. Enhanced mixing technologies and automatic balancing were employed to achieve the desired emissions performance and re-rate of the unit horsepower. Other systems modified during the course of the project included free air and exhaust, lubrication and compressor cylinders. The project concluded successfully in 2005 resulting in improvement in fuel economy and reduction in maintenance all while reducing the emissions. This paper brings the details of a real project and the operation results to those who may be faced with similar opportunities.