Advanced Clean Coal Technologies and Low Value Coals
AUTHOR: Katerina Rousaki and Gordon Couch
DATE: November 2000
This study investigates the application of low value coals to advanced clean coal technologies, namely Integrated Gasification Combined Cycle (IGCC), Circulating Fluidised Bed Combustion (CFBC), Pressurised Fluidised Bed Combustion (PFBC), and supercritical Pulverised Coal Combustion (PCC). Subcritical PCC units up to 1000 Mwe size and the current, smaller CFBC units, all with subcritical steam are used as the base case with which to compare the advanced technologies. About one third of the coals used worldwide can be considered as low value. These are mainly low rank coals, lignites or subbituminous coals, but can also include higher rank coals with high moisture and/or high ash and/or high sulphur content. Low value coals are commonly of a lower calorific value and although not generally internationally traded, they can be locally strategically important.
The report includes a country overview of low value coal deposits. The impact of coal characteristics (mainly ash, moisture and sulphur) on each advanced technology is discussed. The application of each technology and the experience gained with low value coals to date is outlined. Key variables which will influence the opportunities of the technologies in the market place are discussed. Based on the relatively limited experience gained, mainly during the past ten years, the potential for the application in the future of these technologies to low value coals is assessed on a country by country basis.