AbstractIn recent years, considerable experience and insight regarding the behavior of materials and components in the bubbling pressurized fluidized-bed combustion (PFBC) of coal has been developed, largely as a result of the operation of a fleet of 80-MW(e) PFBC-based power plants installed by ABB Carbon. The first plant went into operation over 10 years ago and it appeared timely to review this practical experience and to document areas where improvements have been made, or can be suggested.In keeping with general bubbling-bed experience, the in-bed heat exchanger and water-wall tubes experienced metal loss. Other plant areas that experienced difficulties were the hot-gas cyclone system, the gas-turbine expander, and some balance-of-plant items including solids-handling equipment, valving, and expansion joints. The captured dust removal lines from the cyclones sometimes plugged sending high dust loadings over to the turbine expander. Consequently the turbine blades experienced material deposition and significant erosion damage. Concerns about turbine longevity in this application have led to attempts to develop high-temperature filter systems that protect the turbine by removing all the dust from the flue gas prior to expansion. These filters have themselves suffered from a range of materials problems, which is not unexpected for a relatively new technology. The current experience of these and other materials issues is reviewed.Keywords: bubbling pressurized fluidized-bed combustion of coal

The wastage of in-bed heat transfer surfaces has recently emerged as a potentially serious problem for both pressurized and atmospheric fluidized bed combustors. The experimental pressurized fluidized bed combustion facility at Grimethorpe has accumulated a considerable quantity of data covering the wastage of in-bed tubes obtained during a total of just over 3600 h of operation. The combustor operated with different tube banks, with some degree of wastage being experienced with each one. The data are described, evidence for possible solutions is presented, and plans for future tests at Grimethorpe to prove these solutions are outlined.