Energy and Exergy Analysis of Steam Generation Unit of a Petrochemical Plant

This study presents the energy and exergy analysis of the steam generation unit of a 120 tonnes per hour capacity Petrochemical Olefins Plant located in the Niger Delta area of Nigeria. Operational data for a period of one year collected from logbook and direct measurements from the plant and used for analysis included pressure, temperature and mass flow rate at entries and exits of the major components, namely combustion chamber, superheater, economizer, air preheater, feed water pump and deaerator. Using energy and exergy equations, the components were analyzed separately and energy efficiency, exergy efficiency and losses were determined. The results indicate that the highest energy loss and exergy destruction occurring in the combustion chamber were 10.734MW and 17.256MW, which represent 60.40% and 63.52% of total energy loss and exergy destruction in the plant respectively. The energy and exergy efficiencies of the combustion chamber were found to be 89.64% and 66.77% respectively. The highest exergy destruction that happened in the combustion chamber is an indication of irreversibility within the combustion process. The findings of this study would enable the plant management to identify components that require priority focus to reduce exergy destruction for plant improvement.