Exergetic analysis of atmospheric distilation plant: a case study of WRPC refinery

Abstract

Exergetic analysis of atmospheric distilation plant of Warri Refinery and Petrochemical Company (WRPC) was conducted to evaluate exergy efficiencies and irreversibilities in each unit of the system with aim of identifying potential ares for improvement. The process simulation was carried out using commercial simulator HYSYS 2003. The results of the simulation compared reasonably well with actual plant process parameters with a relative error of 7.22%. The highest irreversibility occured in the main fractionator followed by TPA, IPA, kerosene stripper, BPA, LGO stripper and HGO strippers with their respective values of 80.17, 5.05, 5.01, 0.77, 0.76, 0.42 and 0.12 GJ/h, of processed crude. The main cause of thermodynamic irreversibility in the system was due to uncontrolled mixing of process streams without due consideration of their potential to produce work. Base on the assessment of the system, the stage by stage exergy profile generates ideas about how the improvement can be made in order to reduce irreversibilities in the components. After modification, the exergy efficiencies show an increase of 21.8% for the fractionator, 19.5% in KERO striper, 15.3% in HGO striper and 10.3% in the LGO striper.