Flue gas in steam boiler contains emissions which can not be acceptable for environment and health. They are nitrogen oxide (NOx) and sulfur oxide (SOx). Nitrogen oxide is formed when combustion process burn certain fuels (coal, gas, and oil) at high temperature. NOx can give bad problem for environment and health because it help to make global warming, form acid rain and form toxic chemical.
Either small level or high level of NOx will danger for human. In small level, NOx will impact human’s health such as irritation in eyes or nose, nausea, headache, asthma, visual impairment and shortness of breath. If human breathing air with high NOx content will affect to swelling of throat, reduced oxygen intake adn will even lead to death.
Sulfur Oxide (Sox) are compounds of oxygen molecules and sulfur. Sulfur in flue gas of steam boiler is generated by combustion process in burn fuels which contain sulfur. Sulfur emission will impact danger for health and environment. In health, sulfur emission will effect to reduction of lung function, irritation of throat, and premature mortality. In environment, sulfur emission will give detrimental effect to vegetations in agriculture and forest. They will tend to less productive and die premature because of its effect.
Therefore, engineer who designs steam boiler should consider effect of NOx and SOx emission, they should be treated before escape from stack into the atmosphere.