Impact of the Multihole Wall Air Coupling with Air Staged on NOx Emission during Pulverized Coal Combustion

Abstract

Air-staged combustion is one of the most sophisticated and effective technologies for reducing NOx emission during pulverized coal combustion. However, it may also result in problems of high-temperature corrosion, slagging, and highimperfect/incomplete combustion loss. In order to prevent these problems, the multihole wall air coupling with air-staged technology (MH&AS) has been developed. The aim of this work is to investigate the impact of MH&AS on NOx emission by applying a laboratory scale of a MH&AS furnace. The results show that there existed an optimal multihole wall air ratio to significantly reduce the NOx emission. For example, with burner air ratios of 0.6, 0.7, 0.8, and 0.9, the corresponding optimal multihole wall air ratios were 0.100, 0.075, 0.050 and 0.025, respectively. The air distribution mode with a smaller burner air ratio and its optimal multihole wall air ratio were more conducive for NOx reduction. Furthermore, the influence of coal properties on NOx emission was also evaluated. The higher the fuel ratio, the larger the optimal multihole wall air ratio, whereas the finer the pulverized coal, the smaller the optimized multihole wall air ratio. There was a critical moisture content for the specified coal to obtain the minimum of NOx emission. In addition, the effect of MH&AS on the burnout was also explored. The optimal multihole wall air ratio could simultaneously make a minimum amount of NOx emission and the ultimate value of burnout. Finally, the mechanism of NOx reduction by char during MH&AS combustion was proposed.

Behavior of Pb During Coal Combustion: An Overview

“…Particular attention is currently being paid (e.g.,) to an abatement of CO 2 emissions (e.g., oxy-fuel combustion [71]), to decreasing fouling/slagging by staged coal combustion [89], or mitigating NO emissions using low-NO burners [90]. As these modern combustion technologies provide promising results for wider industrial utilization, detailed elucidation of heavy metals behavior also under these conditions would be beneficial.…”

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

“…In general, moisture hinders combustibility and causes a delay in coal ignition. According to Ma et al, the moisture content is believed to be related to NOx emissions and this factor can be used to define minimum NOx emissions from the coal [18]. Figure 3(c) shows the correlation between NOx concentration and fixed carbon from the industrial…”