(44b) Maximizing Energy Efficiency and Profitability in Crude Distillation Units

In the last few years, many oil companies have been implementing retrofit projects to reduce energy consumption. Environmental guidelines are driving companies to stamp sustainability concepts into their business, planning their future for carbon neutrality. However, some projects aiming to maximize energy efficiency may neglect their impact on refinery profitability.

Including new pumparounds in existing towers is an important tool to improve energy efficiency. Nevertheless, it has a huge impact on fractionation due to reduction of vapor-liquid flow rates in the sections above where it is installed. Keeping high-value products, like Diesel, out of the conversion downstream units, also maximizes refinery profit while saves some energy consumption avoiding reprocessing.

In 2021, PETROBRAS created a corporate program called RefTOP – World Class Refining, which has tracked several opportunities regarding process units and power generation in the sites assessed.

This work will focus on the methodology used to identify energy savings in two of PETROBRAS’ Crude Distillation Unit (CDU) based on pinch technology concepts and process integration. Additionally, the impact of this heat integration on the production profile of the entire refinery was assessed.

The first CDU retrofitted resulted in decreasing 21,0 Gcal/hr (83,3 MMBtu/hr) of energy consumption, while raised the atmospheric heater inlet temperature on 16^oC (61^oF). No diesel cut was lost to FCC unit.

The second promoted an increase in 40% of the ULSD (ultra-low sulphur content) diesel oil and enabled a 30% reduction in atmospheric furnace emissions.