Coal to liquids
AUTHOR: Gordon Couch
DATE: April 2008
There is a great deal of current interest in the possibility of converting coal into liquid transport fuels. This is centred on three key countries with large coal reserves but which have limited resources and reserves of oil and gas, namely China, India and the USA. There has been extensive development work in Japan and there is interest in countries as diverse as Australia, Botswana, Germany, Indonesia, Mongolia, the Philippines, and the UK, as well as in South Africa.The only major coal-to liquids production facility at the time of writing is that of Sasol in South Africa. Several commercial-scale demonstration plants are due to be commissioned during the period 2008-12.The first, using direct liquefaction, is in China with a planned capacity of 1 Mt/y of liquid products. Commissioning is scheduled in 2008.
Only when operational results have been obtained and lessons have been learned from the first group of demonstration plants will it be possible to assess the contribution which the technologies are likely to make. It would seem that because of the high costs involved, and the environmental implications, CTL processes will still only be used in the long term where there is substantial government support for strategic reasons, and where the extra CO2 produced can be effectively stored. The environmental benefits arising from the production of cleaner fuels are significant, but governments are unlikely to require their use. The view expressed by the IEA in World Energy Outlook 2006 is that CTL production is likely to remain a niche activity during the period up to 2030, and the review carried out in this study would tend to confirm this.
This study discusses both direct and indirect coal liquefaction and looks at proposals for hybrid plants. It considers the effects of coal rank and type and the range and properties of the liquid products produced. Research, pilot and demonstration programmes are reviewed, together with a description of current production units – and of plants which are planned or under construction. The review discusses potential developments, some of which have links with polygeneration. It includes country-by-country reviews of current CTL plans, together with a review of the potential environmental footprint of CTL activities. Finally there is a consideration of demand side aspects of the use of liquid transport fuels, and an economic overview of the implications of the large-scale use of CTL technologies.