Operational and Maintenance Planning of Compressors Networks in Air Separation Plants

Abstract

In this chapter, a general optimizasion-based approach for the integrated operational and maintenance planning of compressor networks in air separation facilities is presented. The proposed mathematical programming model considers operating constraints for compressors, performance degradation for compressors, several types of maintenance policies and other managerial aspects. The operating status, the power consumption, the startup and the shutdown costs for compressors, the compressor-to-header assignments, the timing and the type of necessary maintenance tasks as well as the outlet mass flow rates for compressed air and distillation products are optimized. The power consumption in the compressors is expressed by regression functions that have been derived using technical and historical data. The proposed optimization model can be readily used within a rolling horizon scheme to deal with uncertainty. Several case studies of the air separation plant of BASF SE in Ludwigshafen are solved. The results clearly demonstrate the considerable energy and total cost savings due to the simultaneous planning of operational and maintenance tasks.