Fireside Issues Associated with Coal-Biomass Cofiring
نویسندگان
چکیده
This document describes the motivations for and the effects of cofiring biomass with pulverized coal (pc) in pc-fired boilers. Such cofiring represents a near-term, low-risk, low-cost option for reducing the net CO2 emissions from the power generation sector. This document focuses on four of the critical fireside issues associated with cofiring: ash deposition, NOx production, corrosion, and carbon burnout. Specific guidelines are suggested in each of these areas. Pilot-scale data indicate that biomass ash deposition rates and NOx emissions can either exceed or be less than those of coal, depending on the type of biomass used. The potential for chlorine-based corrosion is seen to be less significant for cofire blends than for pure biomass fuels in most cases, but may not always be negligible. Biomass particles much larger than coal particles can be consumed in a pc boiler, but at sizes of 1/8 inch or larger there is increased chance of incomplete combustion. Prudent choices of fuels, boiler design, and boiler operation should lead to little or no fireside problems during cofiring. Less prudent choices can lead to significant boiler damage and operational costs.
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