Progress in pressurized fluidized bed combustion (PFBC) filter cakes and filter cleaning
- Dept. of Energy, Morgantown, WV (United States). Energy Technology Center
- West Virginia Univ., Morgantown, WV (United States). Dept. of Physics
The Pressurized Fluidized Bed Combustion (PFBC) program of the US Department of Energy includes a Second Generation technology with a goal of 45% net efficiency and an Advanced Cycle technology with an efficiency greater than 50%. Both technologies require filtration, at temperatures in excess of 700 C, of fine particles of coal ash and spent and unreacted sorbent from the hot-gas stream. The authors have developed and tested physically realistic equations that allow real-time determination of filter-cake thicknesses from on-line measurements of tube-sheet pressure drops and gas and particle flow rates, and laboratory measurements of filter-cake porosities. The models also accommodate changes of cake-strengths and cleaning produced by changes in particle-size distributions before filtration (e.g., as produced by cyclone detuning). The degree of agglomeration in filter cakes strongly depends on chemical reactions, diffusion, and neck formation, which in turn depend on the operating temperature and frequency of filter-cleaning. When a dolomitic sorbent is used with a filter-vessel temperature of {approximately}700 C, capture of SO{sub 2} by sulfation of MgO (elutriated from the combustor) occurs in the filter cakes. Sulfation reactions produce bonding between particles and thus agglomeration. Agglomeration also can occur by sintering of MgSO{sub 4} or of CaSO{sub 4}; the latter compound also is elutriated from the combustor. However, the end-product produced by sulfation in the filter cakes of the Tidd PFBC demonstration plant was not MgSO{sub 4}, but Mg{sub 2}Ca(SO{sub 4}){sub 3}. The amounts of this compound and the rate at which it was produced also have been determined for the Tidd filter unit.
- OSTI ID:
- 549557
- Report Number(s):
- CONF-960954-; TRN: IM9751%%240
- Resource Relation:
- Conference: 13. annual international Pittsburgh coal conference, Pittsburgh, PA (United States), 3-7 Sep 1996; Other Information: PBD: 1996; Related Information: Is Part Of Thirteenth annual international Pittsburgh coal conference: Proceedings. Volume 2; Chiang, S.H. [ed.]; PB: 819 p.
- Country of Publication:
- United States
- Language:
- English
Similar Records
Evaluation of dust cake filtration at high temperature with effluence from an atmospheric fluidized-bed combustor
Measurements of filter-cake properties