Generation and emission characteristics of SO2 from fuel oil combustion in boilers

Key words: 
• oil-fired boiler /
• sulfur dioxide /
• emission factor /
• emission characteristics

Abstract: The combustion of fuels in boilers is one of important sources of air pollutants. It has very important impacts on human health, air quality and climate changes. The impacts of sulphur contents of fuel oil and excess air coefficients on sulphur conversion rates, emission factors and emission concentrations of SO2 were studied by means of statistical analysis method and based on the fuel oil analysis data and the actual test data of SO2 emissions from 62 oil-fired boilers in China，actual capacity of boilers≤10.5 MW. Furthermore, the mathematical relationships of SO2 emission factors based on fuel consumption (EFC)and fuel heating value(EFH),and emission concentrations of SO2(C′SO2) converted into standard state and excess air coefficient is 1.2, with sulphur contents were obtained. The results indicate that in fuel oil combustion, excess air coefficients＞1， EFC, EFH, and C′SO2 present a highly significant positive linear correlation with sulphur contents, and are independent of excess air coefficients. These correlations are EFCC=18.86602×S, EFH=443.78751×S, and C′SO2＝1 509.28337×S, respectively. Sulphur conversion rates and emission factors based on sulphur content of fuel oil are independent of sulphur contents and excess air coefficients, and their average values are 96.3% and 1.93kg/kg, respectively.