Study of NOx, SOx, and CO mechanisms based on actual plant data

Cement plants have been facing an increasing number of restrictions regarding emissions over the last decade. When building a new plant in the USA today, it now takes longer and requires a lot more work to obtain a permit than it does to specify the most cost- and energy-efficient system for clinker production. A relatively large number of existing wet kiln plants may obtain a permit allowing the same amount of pollutants to be emitted. A 50% to 100% increase in clinker production may be obtained without exceeding the emissions limits of the original process by converting to a semi-wet or dry system. Particulate matters were the first pollutant to be regulated. Since then NO_x , SO_x and CO have been the pollutants most commonly talked about. Lately, with the evolution of better analytical equipment, species like total hydrocarbon, volatile organic compounds, dioxin, furans and heavy metals have become regulated, especially for plants burning hazardous waste. This paper deals with the mechanisms known to be involved in the formation and decomposition of NO_x, SO_x and CO. The data supporting the theories have been collected from operating plants around the world