Shell cleans up with coal

Two of the world's biggest mining and energy groups joined forces last week in an attempt to capitalise on the emerging area of clean coal technology.

Shell and Anglo American aim to maximise the commercial benefits from the fast-growing field by taking joint stakes in coal conversion projects, combining Anglo American's extensive coal reserves and mining capabilities with Shell's leading-edge technologies.

The aim is to extract, gasify then convert coal into, among others, hydrogen and liquid hydrocarbons. Burning the synthesis gas generated by coal gasification emits far lower quantities of greenhouse gases and pollutants than standard coal burning and is the cleanest way to harness its energy potential.

Coal gasification is the partial combustion of carbonaceous materials such as coal and petroleum coke and requires only 20-30 per cent of the oxygen needed for complete combustion.

The primary product is syngas, a mixture of carbon monoxide and hydrogen, which still contains 80 per cent of the original energy in the coal. Another 15 per cent of energy is recovered in the form of steam. Energy losses in total as a result of gasification are just five per cent.