Nickel speciation and aerosol formation during combustion of kerosene doped with nickel nitrate aerosol in a premixed burner

A controlled laboratory scale burner was used to combust kerosene oil doped with varying concentrations of sulfur (organic form) and nickel (as an ato mized 0.23 theta m nickel nitrate aerosol). The resultant size distribution and speciation of the nickel aerosol was determined as a function of the d istance from the burner outlet. In the high temperature region, nickel oxid e was the dominant species formed, followed by a conversion to amorphous ni ckel sulfate at lower temperatures. The presence of sulfur in the fuel resu lted in a greater degree of volatilization and formation of a higher concen tration of smaller sized nickel species aerosol. Thermogravimetric analyzer tests were also used to establish the first order reaction rate constant f or NiO formation. A mechanistic description for the formation of the submic rometer mode is proposed which includes volatilization/nucleation, direct c onversion to NiO, and possible breakage.