Brown coal has a low heat value because it has a high moisture content. So it produces more CO2 than black coal does when burnt for power.
The solution is to either dry the coal, or convert it to syngas.
This page has been taken from: http://www.hrl.com.au/new-technology/w1/i1041902/
HRL’s IDG Technology
HRL’s Integrated Drying and Gasification (IDG) technology combines pressurised drying of high moisture fuel with the gasification of the dried fuel to produce synthesis gas (syngas).
In the IDG process, dried fuel is gasified using steam with air or oxygen to produce hot syngas. Hot syngas is used to evaporate the moisture present within the wet fuel. Drying of the fuel cools and humidifies the syngas. The cooled syngas is filtered to remove particulate matter before further processing. Combustion of the char and ash extracted from the gasifier and particulate filter is used to raise steam for use within the process.
Integration of the fuel drying with the gasification in this way minimises the requirements for fuel drying external to the gasification system and heat exchangers to cool the syngas. This reduces both capital and on-going costs.
Syngas from the IDG technology is readily transformed into a wide range of products using well established gas processing technologies. HRL has confirmed the suitability of IDG syngas for use within these technologies, including the removal of sulphur species and CO2 from the syngas.
Applications of IDG Technology
Works Approval for the 600 MW Dual Gas Demonstration Project was granted in 2012 with conditions. The Project is currently on hold.
Kawasaki Heavy Industries, Ltd. (KHI) and its subsidiary Kawasaki Hydrogen Engineering Australia Pty Ltd (KHEA) (a KHI subsidiary incorporated in Australia), (KHI Group) has signed a licence to use HRL’s IDG technology within a proposed pilot scale Hydrogen Energy Supply Chain (HESC) project.
Ammonia can be made from the hydrogen.
Syngas can also be converted to: synthetic natural gas, liquid fuels, chemicals and plastics.