Considering market shifts favouring petrochemicals (for example, chemical-grade propylene), what are the optimal unit configurations and combinations, such as FCC/hydrocracking, for increasing high-margin products while reducing low-value streams, such as high sulphur fuel oil (HSFO) and low sulphur fuel oil (LSFO)?Mar-2023
Charles Brandl, Honeywell UOP, email@example.com
Optimal unit configurations for reducing or even eliminating low-value refinery streams like HSFO and LSFO are determined on a case-by-case basis, as this mainly depends on the existing assets/refinery configuration, feed sources, total investment, bankability, and price sets. That said, several optimal configurations can be considered, all of which can be classified into two categories: hydrogen addition and carbon rejection-based configurations.
Conventionally, carbon rejection configurations (SDA + (R)FCC or DCU + (R)FCC)) were typically deemed more economically viable in regions with high hydrogen prices and/or large gasoline markets.
However, considering the, energy transition, which involves the switch from fuels to maximum petrochemicals, decarbonisation and the hydrogen economy, hydrogen addition configurations typically are the preferred choice. This does not mean carbon rejection schemes can no longer be the right solution. For example, when hydrotreating the FCC feed, adding UOP’s latest generation high-propylene FCC (referred to as Flexible Propylene FCC) in addition to extracting aromatics from the heavy naphtha, and reducing the FCC carbon footprint, a lot of the investment criteria in today’s environment can still be met.
For hydrogen addition refinery configurations, several hydrogen addition schemes have been developed. The ones with the highest economic performance expressed as IRR and NPV are typically a combination of SDA or Uniflex (UOP’s slurry hydrocracking technology) + hydrocracking + integrated olefins suite (IOS) + steam cracker and Oleflex (UOP’s propane dehydrogenation [PDH] technology). UOP’s proprietary IOS is a collection of technologies to efficiently integrate and optimise performance of petrochemical complexes in three ways:
- Improve feed quality to steam crackers and catalytic reforming units to maximise the yield of high-value products
- Process propane in a PDH unit instead of a steam cracker to significantly boost olefin yields
- Increase, decrease, or eliminate most by-products to match the operator’s business strategies.