The temperatures at which air pollutants are destroyed and the methods employed to generate the heat used in the process are among the differences.
When process exhaust streams contain volatile organic compounds (VOCs) or hazardous air pollutants (HAPs), an effective means remediation is necessary to meet clean air requirements.
A rotary concentrator effects VOC removal through a two step process. First, the air pollutant is removed from the airstream using a zeolite rotating wheel. Second, the concentrated air pollutant is destroyed using a regenerative thermal oxidizer.
Both thermal and catalytic oxidizers promote a chemical reaction of air pollutants with oxygen at elevated temperatures that destroys the pollutants by converting them to carbon dioxide, water and heat. Thermal oxidizers are offered in two types: regenerative or recuperative. Regenerative thermal oxidizers use ceramic media packed into heat transfer beds or canisters. Oxidation is achieved as the pollutants pass through the beds, which act as heat exchangers and retention chambers. Recuperative thermal oxidizers use a heat exchanger to preheat incoming air. Oxidation is achieved as the exhaust gases are passed through the heat exchanger and into the combustion chamber.
Catalytic oxidizers utilize industrial-grade catalysts to support oxidation of the pollutants at lower temperatures than thermal oxidation systems.
One of the most important specifications for pollution control systems is destruction removal efficiency (DRE).