Empirical Formula to Predict the NOx Emissions from Coal Power Plant using Lab-Scale and Real-Scale Operating Data

Abstract

The use of fossil fuels has drastically increased throughout the world as the demand for energy increases. Accordingly, it has become critical that we reduce the oxides of nitrogen (NOx) and oxides of sulfur pollutants. Therefore, studies related to these activities have increased. This study was aimed at helping take pre-emptive action on NOx emissions by developing a formula that would predict NOx generation using factors related to the combustion characteristics and basic material properties of coal. In this study, the experiments were conducted using a drop tube furnace, and the correlation between coal’s major characteristics and NOx generation was analyzed and measured. Our results showed that the major factors affecting NOx generation are moisture, fixed carbon, and fuel ratio. Moisture tended to decrease NOx generation by delaying the ignition of coal and fixed carbon exhibited a tendency to be directly proportional to NOx generation. The R2 value for NOx of moisture and fixed carbon were derived as 0.7659 and 0.7063, respectively. Our results also showed that the fuel ratio had an exponential relation with the conversion of fuel-N to NOx. Based on the results of our analyses, we used moisture, fixed carbon, and fuel ratio as the major factors for creating an experimental formula. Through these results, we confirmed that the prediction formula reflects the actual amount of NOx emitted from the powerplants.

Keywords

• NOx concentration
• drop tube furnace (DTF)
• pulverized coal combustion
• empirical formula