Liquid fuels


South Africa also has a sophisticated synthetic fuels industry, producing gasoline and diesel fuels from the Secunda coal-to-liquids (CTL) and Mossel Bay gas-to-liquids (GTL) plants.

South Africa produces liquid fuels, such as petrol, diesel and paraffin, by three methods: (i) crude oil refining, (ii) coal to liquid fuels, and (iii) natural gas to liquid fuels [DoME et al, 2002].

South Africa’s estimated natural gas resources and reserves in 2003 were 20 trillion cubic foot and 5 trillion cubic foot respectively [DME, 2003], equivalent to 21.7 EJ and 5.4 EJ.

South Africa’s estimated oil resources and reserves in 2003 were 5 billion barrels and 0.4 billion barrels respectively [DME, 2003], equivalent to 30.5 EJ and 2.4 EJ.

Crude oil refining

South Africa has four crude oil refineries: Sapref, Enref, Calref and Natref.. The products of the refineries are petrol (about 35%), diesel (32%), residual fuel oil (20%), paraffin (4%), jet fuel (7%), avgas (0.7%), LPG (1%) and refinery gas (0.8%). The ratios of petrol to diesel can be altered slightly by changing operating conditions [DoME et al, 2002].

Coal to liquid fuels

South Africa plays a leading role in the world by far in converting coal to liquid fuels. Sasol has two large units at Secunda which produce diesel, petrol and other fuels from coal. The earlier unit at Sasolburg is now dedicated to making chemicals from coal. Approximately 23% of South Africa’s liquid fuel is made from coal at Secunda. Secunda produces considerably more petrol than diesel.

The advantage of the coal to liquid fuel process is that it saves on foreign exchange since the feedstock is local. It has also stimulated a unique range of products which are sold around the world. The disadvantages are that the process is inherently inefficient and polluting, releasing large amounts of carbon dioxide. [DoME et al, 2002].

It is unlikely that any more coal to oil plants will be built in South Africa. The focus seem to have shifted towards to natural gas as the feedstock instead of coal. This allows a cleaner, more efficient and more economic process. Already a pipeline is being planned to bring in natural gas from Mozambique to the Sasolburg plant, where it will be a feedstock for chemical production [DoME et al, 2002].

Gas to liquid fuel

The Mossgas plant on the south coast makes liquid fuels from an off-shore natural gas field. It produces about 7% of South Africa’s liquid fuels. The fields are not large but there is the possibility that gas could be piped to Mossgas from elsewhere in Africa. Similarly the coal to liquid fuel plants at Secunda could be converted to making liquid fuels from natural gas piped in from Africa. Sasol has developed a process to make exceptionally clean diesel from natural gas and is likely to exploit this around the world [DoME et al, 2002].

The discovery and proposed exploitation of a natural gas dome containing methane and some of the highest concentrations of helium in the world – South Africa’s first onshore gas in the Free State find has created much excitement and visions of a local gas hub [NUS, 2016-06]. The discovery of natural gas reserves in neighbouring Mozambique provides a huge opportunity for South Africa to procure some of its supply from relatively clean [NUS, 2016-08].

References

Department Of Minerals And Energy, Eskom, Energy Research Institute, University Of Cape Town (2002) ‘Energy Outlook For South Africa’

Department Of Minerals And Energy (2003)

NUS Consulting, (201x-xx), ‘South Africa Market Energy Report’, NUS Consulting,