The International Energy Agency (IEA) Implementing Agreement for Cooperation in the Field of Fluidized Bed Conversion (FBC) of Fuels Applied to Clean Energy Production provides a framework for international collaboration on energy technology development and deployment. Currently 18 countries are active Contracting Parties: Austria, Canada, China, Czech Republic, France, Finland, Greece, Hungary, Italy, Japan, Korea, Portugal, Poland, Russia, Spain, Sweden, United Kingdom and USA.

Fluidized beds offer several advantages over pulverised fuel combustion, notably low NOx emission, in-process capture of SO2 and the ability to burn a wide range of low-grade and potentially difficult fuels (including waste and biomass), as well as mixed fuels. The "conversion" (combustion or gasification) of solid fuels for production of heat and/or electricity can be made by various fluidised bed techniques working at atmospheric pressure or under pressure, usually: "bubbling" and "circulating" fluidized beds. Supercritical steam conditions can be used for fluidised bed boilers (atmospheric and pressurised) and efficiencies in the range of 45 per cent may be attained in the near future.

In addition, the technology can be employed for incineration and existing units have been successfully used for the disposal of high level PCB contaminated wastes, oil remediation and the elimination of low calorific wastes. The technology is also used in the metallurgical industry among others.

The Implementing Agreement on Fluidised Bed Conversion aims to bring together experts wishing to work on common problems. The main activity is technical exchanges during meetings and workshops. Participants are carrying out research on operational issues in support of local commercial fluidised bed conversion activities and sharing the results. Mathematical modelling has been a major activity in the past and a "1D" model for atmospheric fluidised bed combustion of coal has been developed and the exchanges in "3D" modelling of gas/solid flows as been very fruitful in permitting the development of knowledge of local solid concentration and heat transfer.

In addition, efforts are undertaken in the field of:

  • solids attrition and fragmentation
  • NOx and N2O formation and reduction
  • sorbent reactivity and sulphur capture mechanisms
  • bed sintering/agglomeration problems
  • ash utilisation.

The Agreement has published a series of compilation of outstanding papers on R&D activities in fluidised bed conversion and a guide book for the use of the "1D" CFB