Air Pollution Control/
Particular industries that benefit from VOC abatement systems include: chemical processing, due to its use of VOCs such as benzene, methylene chloride, hexane, styrene and perchloroethylene for various processes; industrial manufacturing, since VOCs can be found in many sealants, solvents and adherents used to manufacture various components; construction and architecture, in which VOCs can often be found in diverse building materials; and others such as electronics, petrochemical, medical and automotive. VOCs are regulated by the Environmental Protection Agency (EPA), when they are released in the air, in water or on land, the United States Department of Labor (DOL) and the Occupational Safety and Health Administration (OSHA) when they are released in the workplace and by the Pipeline and Hazardous Materials Safety Administration (PHMSA) when they are being transported.
VOC abatement is typically accomplished through VOC adsorbents, VOC concentrators, VOC oxidizers and VOC abatement systems. VOC adsorbents are materials that can be used to adsorb and desorb VOCs, including minerals such as zeolite and activated carbon. VOC concentrators allow air contaminated with VOCs to pass through an adsorbent so that the VOCs can be adsorbed, allowing the exhausted air to be cleaned of any organic molecules. Afterwards, a portion of the adsorbent is heated by either hot gas or air to remove the organic molecules and regenerate the adsorbent so that it can be reused. There are two main types of VOC concentrators: rotary concentrators and fluid bed concentrators. Rotary VOC concentrators use wheel fabricated from an adsorbent that functions to continuously remove organic molecules from contaminated air streams, whereas fluid bed VOC concentrators utilize multiple adsorbent beds for organic molecule removal from contaminated streams, with the regeneration process occurring in one bed while adsorption is still taking place in the other beds. VOC oxidizers can be catalytic or thermal, and function to convert harmful VOCs to nontoxic carbon dioxide and water vapor. Lastly, VOC abatement systems differ from other types of equipment in that typically a concentrator and an oxidizer or other type of regenerative unit is combined in the system.
