Corrosion and Deposits from Combustion of Solid Waste—Part VI: Processed Refuse as a Supplementary Fuel in a Stoker-Fired Boiler

Abstract

The utilization of shredded and magnetically separated municipal refuse to supplement high-sulfur coal as fuel in a stoker-fired boiler was investigated, using the facilities of the Columbus, Ohio, Municipal Electric Plant. Corrosion probe exposures were used to show the effectiveness of cofiring with high-sulfur coal to reduce chloride corrosion of boiler tube metals by refuse. Reduced emissions of SO2 from the high-sulfur coal also resulted from dilution of the coal with refuse and by action of alkaline components of the refuse. It was demonstrated that 700 hr corrosion rates with refuse and high-sulfur coal were 5–10 times less than those with bulk refuse burning, and approximated those from coal alone. In some runs sulfur dioxide emissions were reduced by about ten percent more than the refuse dilution factor. The cofiring with refuse had no significant effect on grate ash composition, but the ash fusion temperature was lowered about 100°F.

Superheater Corrosion In Biomass Boilers: Today's Science and Technology

“…Sulfation also reduced the chlorine content of the deposits, again making make them less corrosive. Krause and others concluded in 1979 [149] that corrosion rates increase significantly when the S/Cl ratio in a boiler fuel falls below 2 and that corrosion was not problematic when the S/Cl ratio exceeded 4. In 2000, Salmenoja and Mäkelä [69] stated that the best way to avoid corrosion when firing biomass was to keep the S/Cl ratio in the fuel greater than 2 and, preferably, greater than 4.…”