by: Vready Roeslim
Historical Brown Coal Dewatering R&D
> Brown coal is difficult to burn owing to high moisture content
> 100 years and well over $1Bn spent globally trying (unsuccessfully) to develop a commercially economic brown coal dewatering method:
– Exergen CHTD was originally conceived just 6 years ago, in 2001
– Reached "Proof of Concept" at pilot plant in 2004/05 for initial $6 million
– Complete system demonstrated at pilot level by 2007/08 for additional $6 million
> Brown coal is under-utilised despite large deposits close to the surface
> Brown coal remains as massive on-shore resources close to infrastructure
> Only expensive to mine black coal, oil and natural gas resources are left
> Brown coal is only 1/10th the cost of mining black coal ($4/t Vs $40/t)
> Brown coal is low in ash and low in impurities, but very high in moisture
> Dried brown coal will feed PF & IGCC Power Stations & CTL plants
> Only the "Albatross" of moisture content holds brown coal back
Brown Coal Dewatering Technology:
- Direct Contact Drying – simple, evaporative, no GHG benefit
– Waste Heat Briquetting – requires integration, evaporative, no GHG benefit
– Steam Fluidised Bed Drying (SFBD) – requires integration, evaporative
– Hydrothermal Dewatering (HTD) – required efficient continuous autoclave
– Mechanical Thermal Expression (MTE) – batch process, difficulty up-scaling
Source: A Climate for Change by Ian Kraemer
Brown Coal Dewatering -Overview Techmology-
