Transitioning SA's Petrochemical Value Chain

Sustainable carbon for Secunda and Sasolburg’s decarbonisation

Sasol has indicated a phased transition towards using sustainable carbon as feedstock in Secunda and Sasolburg, as part of their 2050 decarbonisation pathway. Various potential sources of sustainable carbon have been considered for Secunda in particular:

  • Biomass: Secunda can only scale up use of biomass for production of carbon to a certain level in existing gasifiers, after which significant modifications and/or dedicated biomass gasifiers will be required. Sasol’s Climate Change Report states that existing assets in Secunda could produce up to 8 000 barrels per year of sustainable aviation fuel (SAF). SAF can be blended with regular aviation fuel up to a certain level, after which significant modifications to aircraft are necessary.
  • Process emissions from Sasol: Sasol has proposed that the existing concentrated CO2 stream from Secunda’s own operations could be captured and used as a carbon source in its own processes. It is still unclear whether this will be deemed ‘sustainable’ under future sustainable carbon regulations internationally. These are currently being pioneered by the EU, with whom Sasol is engaging (Business Engagement). This is a particular consideration if Sasol intends to export products. As Secunda decarbonises, however, the availability of this CO2 stream will obviously decline.
  • Process emissions from other industries: Sasol is in talks with Arcellor Mittal to investigate opportunities for capturing carbon released from its steel plant in Vanderbijlpark, as well as from other industries in the surrounding area.

At Sasol’s 2021 Capital Markets Day targets of ~2% sustainable carbon uptake by 2030, ~5-10% by 2040 and 100% by 2050 were indicated. This is a very large ramp up between 2040 and 2050. The NBI’s Chemicals and Petrochemicals Decarbonisation study estimates that, assuming full current production at Secunda, the following volumes of sustainable carbon would be required:

1. If using biomass only, ~40-45 Mtpa of biomass would be required, exceeding South Africa’s total current second generation biomass availability

2. If using mixed sources, ~15-20 Mtpa of biomass would be required, with carbon capture from industrial sources or DAC serving the remainder of the requirement.

Its unclear how far Sasol has progressed in understanding the feasibility of using industrial process CO2, either their own or from other industries, in their processes.