•  
  •  
 

Keywords

Exergy analysis, heat exchanger network, crude distillation unit, fired heater, thermodynamic irreversibility, refinery energy efficiency, scenario analysis

Document Type

Research Article

Abstract

Crude distillation units are among the most energy-intensive systems in petroleum refineries because crude oil must be heated to the required atmospheric-column inlet temperature before fractionation. Although conventional heat-integration analysis quantifies heat recovery, it does not identify the degradation of energy quality caused by finite-temperature heat transfer and combustion irreversibility. This paper presents an exergy-based scenario analysis of the crude preheat-train heat exchanger network (HEN) and fired heater in an industrial crude distillation unit at Azzawiya Oil Refining Company (ARC), Libya. A base case was validated using steady-state energy balances and then evaluated using component-level physical exergy balances. Two feasible rematching scenarios were assessed without adding new exchangers or external utilities. The base HEN recovers 44.823 MW of process heat but destroys 5.154 MW of exergy, with the top pump-around (TPA)/crude exchanger, bottom pump-around (BPA)/crude exchanger, and residue/crude exchanger contributing more than 80% of network irreversibility. Scenario 1 reduces HEN irreversibility to 4.987 MW but does not reduce heater duty. Scenario 2 slightly increases HEN irreversibility to 5.201 MW, while reducing fired-heater duty from 23.10 MW to 22.09 MW and increasing overall system exergy efficiency from 44.98% to 45.82%. The results show that refinery preheat-train improvement should be judged at the integrated HEN-and-heater level, not only by exchanger-level irreversibility.

html

Publication Date

30-6-2026

First Page

12

Last Page

21

Download

Share

COinS