Physical and chemical characteristics of cenospheres from the combustion of heavy fuel oil

Photomicrography of particle cross sections, measurements of density, porosity, and surface area, and determinations of chemical compositions, have been used in conjunction with SEM of surface structure to characterize cenospheres generated by combustion of residual oil in a steam power plant. Large and small cenospheres, which respectively fall into the 100-200 and small 20-40 micron range, are spheroidal and hollow, with at least one blowhole; outer/inner diameter ratios for the shells are of the order of 1.3-1.4. Typically, a cenosphere contains only about 18 vol pct solid material. The presence of S, Fe, Na, and V in substantial concentrations presage high temperature heat exchanger surface corrosion problems due to cenosphere deposition.