Since 2002, PetroSA’s technology joint venture company, GTL.F1, has been involved in research and development (R&D) and commercialisation efforts focused on the Low Temperature Fischer-Tropsch (LTFT) technology. The LTFT technology was developed for both local and international markets and designed for diesel, wax and lubricant base oil production from natural gas, coal or biomass. PetroSA’s proposed indigenous and imported gas feedstock scenarios align well the long-term efforts that the Technology Development Department has been undertaking within GTL.F1.
PetroSA is currently exploring the possibility of combining its own GTL.F1 technology with another competing LTFT technology. The idea is to develop a composite, which encompasses the best aspects from both technologies, in an endeavour to become the third large-scale provider of the LTFT technology in the world. Technical assessment of the GTL.F1 and the other technology has shown its potential compatibility for use in the Gas-to-Wax project in Mossel Bay.
The Gas-to-Wax project is part of the Key Focus Area: Sustainability in PetroSA’s corporate plan. The project has the capacity to provide a long-term future for the Mossel Bay GTLR facility, by improving gas feedstock affordability. A high gas affordability unlocks exploration and also the development of PetroSA’s indigenous gas opportunities, which would otherwise not have been explored due to the low gas affordability of the current Mossel Bay GTLR operation. Any gas conversion process, which produces high-value products such as wax, expands the range of feasible gas feedstocks that can be processed. This will include commercially traded gas sources such as LNG and CNG.
The proposed Gas-to-Wax concept is based on a 1 Train Gas Loop operation, using about 100 MMSCFD of gas as feedstock for the production of 200 kt pa of high value waxes. In addition, the PetroSA Gas-to-Wax GTL complex will also produce up to 1 000 bpd of chemical-grade naphtha and 3 000 bpd of distillates. All the wax produced will be conveyed by rail to the port of Coega, Port Elizabeth, for export.
The Gas-to-Wax project will maximise the use of the existing Mossel Bay GTL facility. The facility has most of the process units required for processing gas, and has all the required offsites, utilities and logistics infrastructure. This will significantly reduce the required CAPEX, when compared to a similar greenfields LTFT project, albeit that a new LTFT reactor system, as well as new product upgrading and wax logistics facilities, will have to be installed.
Economic analysis of the project shows a substantial improvement in break-even gas price affordability. This means that, in the future, PetroSA will be positioned to afford gas from the recent Total offshore discoveries in Block 11B/12B south of Mossel Bay, as well as potential gas supply from PetroSA’s Block 9/11 opportunities.