Securing the Supplies of Fossil Fuels - Energy and Climate: How to Achieve a Successful Energy Transition - page 102

However, in order to limit the risks of climate change, the development
of the use of coal for generating electricity or for producing synthetic fuels
is acceptable only if the CO 2 emitted is captured and stored underground.
The quantities of CO 2 which might result from the combustion of all
the carbon trapped underground in coal deposits are much too large to be
released into the atmosphere [89].
Therefore, although coal certainly has a role to play in the energy mix,
as long as CO 2 capture and storage technologies are not effectively
implemented, its rapid development represents a threat from the stand-
point of climate change.
The deployment of these technologies, which are presented in the next
chapter, will require time and meanwhile the development of power
generation (as well as the production of synthetic fuels) from coal should
be considered with care.
Synthetic fuels
Liquid fuels are presently almost totally produced fromcrude oils through
refining processes. This dependence on oil might be reduced in the future
though the use of synthetic fuels and biofuels.
Different types of feedstock can be used for producing synthetic fuels
(natural gas, coal and biomass). Liquid fuels are produced through a
synthesis process from a gaseous mixture of carbon monoxide (CO) and
hydrogen; this 'synthesis gas' is generated by gasifying the initial raw
material through a thermochemical process.
The most favoured pathway is presently the Fischer-Tropsch synthesis,
so named from the two German chemists, Franz Fischer and Hans
Tropsch, who developed this process during the Second World War,
in order to reduce the dependence of Germany on imported oil. The
long chain hydrocarbons which are produced by the Fischer-Tropsch
process can be transformed into fuels of excellent quality (gas-oil for diesel
engines and kerosene for aviation). Synthetic fuels have been also pro-
duced on a large scale in South Africa, as an answer to the trade embargo
which had been placed at that time. The units which were built at that
time used coal as a feedstock. In 1991, South Africa also built a unit
producing synthetic fuels from natural gas and presently South Africa is
the biggest producer of synthetic fuels, with a production capacity of
around 200 000 barrels per day.
Other players have also developed technologies in this area and the
production of liquid fuels from natural gas (Gas To Liquids or GTL