Impact of conversion to low-NO_x burners on ash characteristics

A research initiative focusing on the changes in coal-combustion byproducts that result from the conversion of coal-fired boilers to low-NO_x burners has been implemented at the Center for Applied Energy Research (CAER). This paper presents selected results from the first such study, the conversion of East Kentucky Power's 116 MW, wall-fired unit No.1 at the John Sherman Cooper Station in Pulaski County, Kentucky. Samples of the coal feedstock and fly ash recovered in several downstream collection vessels were collected prior to and following conversion and extensively analyzed. The results presented in this report include total carbon, petrography, mineralogy, particle size, and leaching characteristics. The major changes noted in the fly-ash properties include an increase in carbon content, a slight increase in particle size, and a decrease in glassy components in the ash following conversion. Those changes induced by the conversion to low-NO_x burners are evaluated in terms of the potential impact on the marketability of the fly ash.