DAF Optimization: Production Increases Require Engineering and Automation to Achieve Operational Excellence and Continuous Improvement Goals

This paper presents a case study of the efforts made by the Valero Memphis Refinery (the Refinery) towards continuous improvement of its wastewater treatment system. The Refinery was in a situation where production increases were desired as regulatory requirements were tightening. The Refinery upgraded its wastewater treatment equipment, and then focused on optimization through engineering solutions, maintenance and automation with limited real estate. Equipment upgrades were made by the addition of a Dissolved Air Flotation (DAF) Unit in 1991 and two new API Separators in 1992. Since then, the Refinery has found innovative ways to manage the existing equipment to reduce key pollutant concentrations while throughput has significantly increased. Recent changes to the Dissolved Air Flotation (DAF) System are presented which improved compliance and the Refinery's goal towards operational excellence in wastewater management. The Refinery history, wastewater discharge location, wastewater system improvements and the results of these improvements are reviewed.