Potential for improving waste energy recovery by using steam cycles in supercritical boilers. Bibliographical study and expert interviews

Summary

The new "supercritical steam cycle" technologies currently installed in large-capacity coal-fired power stations significantly increase their energy efficiency. What about waste-to-energy plants? Are these technologies transferable? This is the aim of this forward-looking study. The study begins with an overview of supercritical cycle plants around the world. At the same time, it gives an idea of the extent to which investment in coal-fired power plants is still very significant in some parts of the world. The study then goes on to detail the associated processes and highlights the obstacles that will certainly prevent their transfer to the waste sector (mechanical constraints, corrosion phenomena, adaptation of equipment to lower-capacity plants). The additional cost generated by the use of the supercritical water cycle cannot be justified by the gain in efficiency in the case of waste plants. However, the study highlights processes based on supercritical CO2. These could make it possible to create more compact facilities that are more compatible with CO2 capture. Developments are underway in this area. It will be interesting to look into this in a few years' time.