Treatment of Gaseous Emissions to Atmosphere

Absorption. Absorption is used mainly for the removal of oxides 

Particles charged in field migrate to earthed plates 

When the bed is saturated, regeneration of the adsorbent is necessary. Carbon beds are typically regenerated with steam, hot air, or a combination of vacuum and hot gas. 

Flares. Flares are used for the combustion of waste hydrocarbon gases in which the rates may vary over a wide range and for emergency releases. Steam injection is usually used to enhance mixing and the formation of a clean flame. 

Incineration. Incinerators were discussed in Sec. 11.1. When incinerators are used to treat gaseous pollutants in relatively low concentration, auxiliary firing from fuel or other waste material normally will be necessary. The capital and operating costs may be high. In addition, long duct lines are often necessary. 

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