Coal Gasification & the Environment


About Gasification

Coal gasification consists of converting the solid coal to synthetic gas or in short, syngas (comprised mainly of hydrogen and carbon monoxide), which is processed to remove contaminants (such as sulphur) and used as feedstock for synthesis of various chemical products such as ammonia (the basis for urea) and methanol or used directly as a fuel source for power plants.

Gasification provides the following benefits:

Higher utilisation for low rank coal

Coal gasification offers considerably higher energy conversion efficiency than traditional boiler combustion, particularly for lower rank coals - such as those in the Collie region. The pressurised system enables efficient transfer of energy and control over the various process steps.

More than just power

Gasification allows coal to be converted to a large range of chemical and clean fuel products. Gasification also enables the use of syngas as an energy source in modern Integrated Gasification Combined Cycle systems.

Environmentally friendly performance

Gasification minimizes the emission levels of SOx (sulphur oxide), NOx (nitrogen oxide) and harmful particulate by-products of traditional coal combustion making it comparable to natural gas based systems. Water consumption is also markedly less than in power generation plants. Wastewater is cleaned to an acceptable quality, or re-used in the process.

Future-ready for carbon capture

Gasification is recognised as the most cost effective route to carbon capture for both bio and geo-sequestration. CO2 produced is pure and concentrated (without excess oxygen and large volumes of nitrogen from air combustion).

Value, not emissions

Gasification allows complete sulphur capture and recovery, for use as a saleable product.

The ash in the coal is largely converted to vitreous slag, which is essentially non leaching and only half the volume of fly ash. Markets exist for this slag such as sandblasting grit, road surface and cement additive.