The Use of Advanced Process Monitoring and Control to Optimize Energy Use on an Activated Sludge Plant

This paper will describe the results achieved by applying a Model Predictive Control (MPC) system to an Activated Sludge Plant (ASP) in the UK, with the objective of reducing energy consumption, whilst maintaining compliance within permitted environmental standards. Installation of the MPC system was initially an R&D project to assess if the suppliers performance expectations were valid. The successful outcome of the trial allowed the project to move to a permanent installation assessing the benefits over a longer period. During the R&D Phase the system demonstrated a high availability with an average of 20% energy reduction and peaks of 40% energy reduction when compared to conventional control. To date the system has reliably demonstrated energy savings and offers the potential to contribute significantly to United Utilities objective to reduce its Carbon emissions by 8% by 2012 if the benefits are replicated across the companies asset base of large ASP's.