Exergy analysis of an atmospheric residue desulphurization hydrotreating process for a crude oil refinery

The exhaustion of petroleum reserves and the declining supply of conventional feedstock have forced refineries to use heavier crude oil in their production. Removing the undesirable components containing sulphur and metals in the atmospheric residue (AR) fraction requires extensive catalytic hydrotreating (HT) atmospheric residue desulphurization (ARDS) process. In this work, we endeavour to collect and present a comprehensive dataset to develop and simulate the ARDS HT model. This model is then used for an exergetic analysis to evaluate the performance of the ARDS HT model regarding the exergy destruction, the location of losses and exergetic efficiency. The massive exergy destruction is caused by significant differences in chemical exergy of source and product streams during separations, fractionation and reactions. The exergy destruction in the equipment independent of chemical exergies such as heat exchangers, pumps and compressors is relatively low. This exergetic analysis revealed that the majority of the processing equipment in the ARDS HT process performed satisfactorily. However, the remaining equipment requires improvement for its performance in regards to exergetic efficiency or/and avoidable exergetic losses. To enhance the efficiency of the equipment that is intensive in terms of exergy and energy use, the use of clean and high purity renewable hydrogen and several process rectification is proposed.