Application of Pinch Analysis for Energy Efficient Design of Distillation Column in Petroleum Refinery

Abstract

This study focuses on optimizing the crude preheat train within a petroleum refinery's crude distillation unit (CDU) through the integration of Exergy Analysis, Pinch Analysis (PA), and Economic Analysis for the developed model in Aspen HYSYS. Exergy Analysis is employed to identify energy inefficiencies within the CDU. Initially, the steady-state exergy analysis was carried out using an Aspen HYSYS model to quantify the exergy destructions and exergy efficiencies of all the individual heat exchangers and the overall Heat Exchanger Network. The overall exergy destruction and exergy efficiency of the HEN was 17611.21 kW and 63.34%, respectively. Exergy Analysis reveals that the energy efficiency can be improved for some of the heat exchangers in the network as they contribute 56 % to the overall exergy destruction of HEN. PA, facilitated by Aspen Energy Analyzer (AEA), for pinch analysis of the existing preheat trains of crude distillation unit. The optimized case is also developed for more energy integrated and efficient design of crude preheat train and distillation unit. The optimized case achieved the same energy requirements as of base case with two fewer heat exchangers, reducing the overall capital cost of the crude distillation unit by $ 95716.08 despite the increase in heating and cooling utility costs. Finally, a payback period of 1.18 years has been calculated through an economic analysis for being a crude distillation unit operational.