Hot-gas filter ash characterization

One of the key difficulties in the development of advanced pressurized fluidized-bed combustion (PFBC) and integrated gasification combined-cycle (IGCC) systems is the need to remove particulates from the gas stream at high temperatures and pressures. Research has revealed numerous cases of ash cake buildup on filter elements that has been difficult to remove using on-line jet pulsing. The objectives of this research are to: (1) determine the mechanisms by which a difficult-to-clean ash is formed and how it blinds or bridges hot-gas filters; (2) develop a method to determine the rate of blinding or bridging based on analyses of the feed coal and sorbent and on the operating conditions; and (3) provide suggestions for ways to prevent filter blinding and bridging by the troublesome ash. Four tasks are being performed: Task 1--field sampling and archive sample analysis; Task 2--laboratory-scale testing; Task 3--bench-scale testing; and Task 4--computer modeling. Results are presented from the first two tasks