ABSTRACT
Volatile organic compounds (VOCs) generally are fuels that are easily combustible. Through combustion, which is synomonous with thermal oxidation and incinceration, the organic compounds are oxidized to CO
and water, while trace elements such as sulfur and chlorine are oxidized to species such as SO
and HCl. Three combustion processes that control vapor emissions by destroying collected
vapors to prevent release to the environment are (a) thermal oxidation — flares, (b) thermal oxidation and incineration, and (c) catalytic oxidation. Each of these processes has unique advantages and disadvantages that require consideration for proper application. For example, flares are designed for infrequent, large volumes of concentrated hydrocarbon emissions, while thermal oxidizers are designed for high-efficiency treatment of continuous, mixed-hydrocarbon gas streams, and catalytic oxidizers are designed to minimize fuel costs for continuous, low-concentration emissions of known composition. The design of the basic processes can be modified for specific applications, resulting in the overlap of the distinctions between processes. For example, ground flares are basically thermal oxidizers without heat recovery that frequently are used for intermittent flow of relatively low volumes of concentrated VOC streams.
