ABSTRACT
Low-rank coals with high-moisture content represent a significant resource worldwide and generally consist of sub-bituminous coals and lignites. An estimated 45% of the world’s coal reserves are lignites, some of which are referred to as brown coal. Coal drying is an important and necessary step towards improving the efficiency of its utilisation – be it for gasification for power or fuel gas or high-value chemicals production, or for use in existing and new pulverised coal-fired power plants using high-moisture coals. The chapter presents a summary of a handful of publically available studies and identifies the technical challenges and the immediate needs for research and development. It largely focuses on low-ash, high-moisture, and low-rank coals. Great River Energy has developed and patented a coal drying and coal upgrading technology termed DryFining. The DryFiningTM concept involves utilising waste heat, which may be available in a power station, to partially dry the feed coal in a fluidised bed dryer.
