Second-generation pressurized fluidized bed combustion (PFBC) plants promise higher efficiency with lower costs of electricity and lower stack emissions. With a 16.55 MPa/538°C/538°C/63.5mmHg (2400 psig/1000°F/1000°F/2.5 in Hg) conventional steam cycle and a 3% sulfur Pittsburgh No. 8 coal, a 45% efficiency and a cost of electricity about 20% lower than that of a pulverized coal fired plant with stack gas scrubbing are being projected. Foster Wheeler Development Corporation has constructed, and is operating, a second-generation PFBC pilot plant at the Foster Wheeler research facility (the John Blizard Research Center) in Livingston, NJ, USA. Initial results of the pilot plant carbonizer test programme supporting the development of this new type of plant are presented.