Pressurized fluidized bed coal combustion exposure testing of gas turbine and heat exchanger materials

The Exxon Research pressurized fludized bed (PFB) coal combustion facility, known as the miniplant, was constructed to demonstrate the feasibility of this coal combustion technique for environmentally acceptable energy production. This facility has been in operation since 1974, and has operated for 2500 test hours, during which over 600,000 lb of 2-4% sulfur coal were combusted in beds of limestone or dolomite. The paper shows that encouraging information is obtained from the miniplant hot corrosion/erosion test concerning the ability of certain heat exchanger and gas turbine materials to exist in a pressurized fluidized bed combustion environment. Although the tests were of short duration, many materials appear promising, and long-term direct hot corrosion/erosion of turbine material under actual PFB coal combustion conditions is needed for firm establishment of relevant criteria.