Open AccessBed material agglomeration during fluidized bed combustion. Technical progress report, April 1, 1995--June 30, 1995
Author(s) -
Ronald Brown,
M.R. Dawson,
J.L. Smeenk
Publication year - 1995
Language(s) - English
Resource type - Reports
DOI - 10.2172/196536
Subject(s) - agglomerate , economies of agglomeration , coal , pyrite , aluminosilicate , fluidized bed , combustion , mineralogy , fluidized bed combustion , materials science , metallurgy , chemical engineering , chemistry , composite material , biochemistry , organic chemistry , engineering , catalysis
During this quarter, agglomeration tests were conducted in a laboratory-scale fluidized bed combustor using coal and {open_quotes}model{close_quotes} components which allowed controlled amounts of clays and pyrites to be added during the test. These tests permitted a more direct evaluation of the interaction between iron compounds and aluminosilicates. With additional clay and pyrite (under simulated local reducing conditions found at coal feed locations) large agglomerates formed. The agglomerates were many times larger than those formed with a standard coal feed. When only clay was added to the fuel (no additional pyrite), agglomerates formed but they were much smaller and very friable. These tests support the hypothesis that local reducing conditions promote the interaction of iron in a +2 state and aluminosilicate material in the coal which leads to agglomeration during fluidized bed combustion. Also during this quarter, a deposit which formed in a fluidized bed boiler of a Texas-New Mexico Power Company was analyzed to determine the chemical and mineralogic mechanisms responsible for deposit formation. Mineral phases were determined by x-ray diffraction (XRD). Bulk chemical composition was determined by x-ray fluorescence spectroscopy (XRF). Polished sections of the deposit were made for optical and scanning electron microscopy