Coal to Liquids

Coal can be readily converted into a variety of fuels, with a number of key advantages:
• Coal-derived fuels are sulphur-free, low in particulates, and low in nitrogen oxides.
• With carbon capture and storage, life cycle CO2 emissions can be reduced by as much as 20% compared to conventional oil products.
• Coal is available worldwide enabling countries to access domestic coal reserves and decrease reliance on oil imports – improving energy security.
• Coal liquids can be used for transport, cooking, stationary power generation, and in the chemicals industry.

Increasing vehicle traffic, particularly in developing countries, is driving oil demand. Alternative fuels such as CTL may have significant benefits for local air quality.

South Africa has been producing coal-derived fuels since 1955 and has the only commercial coal to liquids (CTL) industry in operation today. Currently around 30% of the country’s gasoline and diesel needs are produced from indigenous coal. The total capacity of the South African CTL operations now stands in excess of 160,000bbl/d.

There are two different methods for converting coal into liquid fuels, direct and indirect liquefaction.
• Direct liquefaction works by dissolving the coal in a solvent at high temperature and pressure. This process is highly efficient, but the liquid products require further refining to achieve high grade fuel characteristics.
• Indirect liquefaction gasifies the coal to form a ‘syngas’ (a mixture of hydrogen and carbon monoxide). The syngas is then condensed over a catalyst – the ‘Fischer-Tropsch’ process – to produce high quality, ultra-clean products.
An array of products can be made via these processes – ultra-clean petroleum and diesel, synthetic waxes, lubricants, chemical feedstocks as well as alternative liquid fuels such as methanol and dimethyl ether (DME).


Investment
The increase in oil price, growth in demand for liquid fuels, and energy security concerns is leading to rapid development of CTL industries in several countries around the world.

The low price of coal compared to other fuels is a major driver and has generated significant interest in CTL fuels worldwide. Studies suggest liquid fuels can be produced from coal at around $27 to $45/bbl; well below oil prices which reached almost $80/bbl.

CTL plant is cheaper to build than most other alternative fuel plants but more costly than a conventional oil refinery.

The capital cost of CTL plants is expected to decrease through the ongoing development of technology.


Market Potential
CTL is particularly suited to countries that rely heavily on oil imports and that have large domestic reserves of coal.

There are a number of CTL projects around the world at various stages of development. The most advanced project is in China where, Shenhua started construction of a 50,000bbl/d CTL plant. Projects are also under development in the US and Australia and there is strong interest from other countries including Indonesia, Germany and India.