My knowledge of the SASOL process is some 15 years out of date , but to the best of my knowledge it only survived due to subsidies.
This was developed during the aparteid sanctions as the government realised that the country could be vulnerable to a blockade on fuel , as they had/have no indigenous oil in the country. However they did have vast supplies of coal, so the process of carbonylation was dusted off (it was actually used by Germany in WWII to produce fuel for aircraft as they too had no native oil) , refined , and eventually went into production.
I think the original unit has long been superseded with larger more efficient plants, but again this was not a "clean" process. However with more modern technology it is possible to put in sufficient abatement systems to satisfy environmental regulations at additional cost.
The only real issue is cost , it has never worked without subsidies, and until crude oil runs down much further this is unlikely to be economically viable.
