Performance improvement of a crude oil distillation unit

•The improvement capability of a crude distillation unit (CDU) was investigated.•The process improvement methodology included exergy and heat integration analysis.•The overall energy demand of the CDU was reduced within considerable investment.

This study builds on an earlier investigation carried out on an existing crude oil distillation unit (CDU). The energy and exergy efficiencies of the plant are low and opportunity for plant improvement was established. The methodology adopted for improving the plant performance uses process simulation techniques, and the combined exergy and traditional retrofit methods to show what the process is capable of achieving under considerable expense on the required capital investment. The process improvement carried out resulted in the increase in the overall CDU energy and exergy efficiency by 4.0 and 1.6% respectively, reduction in emissions by 14.2% and savings in utility bill by $1.61 million per annum. The required capital investment for retrofits amounted to $3.78 million with a payback time of 2.35 years.