Esa Kari Vakkilainen is a graduate of Lappeenranta University, Finland, where he now works as professor of Sustainable Energy Systems. His professional career focuses on steam boilers especially combustion of biofuels. When fluidized beds were commercialized he worked in boiler industry especially for steam generator thermal design. In addition to CFB, Professor Vakkilainen has been involved with biomass boilers such as Kraft recovery boilers as Research Manager and Technical Manager. Before his current position in academia, he was employed by Jaakko Pöyry Oy, International consultants to pulp and paper as leading technology expert – energy and environment. Esa Vakkilainen has lectured on boilers at all major continents and been chairman of several international technical conferences.