Select the best VOC control strategy

Volatile organic compounds (VOCs) are among the most common pollutants emitted by the chemical process industries (CPI). Accordingly, VOC emission control is a major portion of the CPI's environmental activities. Reduction of VOC emissions in areas that exceed the current national ambient air quality standard for ozone of 0.12 ppm is mandated under Title I of the Clean Air Act Amendments of 1990. In addition, Title III of the Amendments requires reduction of the emission of 189 hazardous air pollutants, most of which are included under the definition of VOCs as well. Thus, some sources may be controlled under two separate sets of regulations with potentially differing requirements. This makes the selection of controls especially difficult--what may be the cost-effective choice today could prove inadequate in the near future and costly to upgrade. Therefore, intelligent planning is essential for defining a cost-effective emissions control strategy. This article discusses VOC emission control from a process design standpoint. It first outlines the factors that must be considered when selecting a technology. Then it reviews the technologies available for VOC control and where each can and cannot be used.