Question

Which technology combusts volatile organic compounds (VOCs) at high temperatures to convert them into carbon dioxide and water vapor?

• A. Vapor Recovery Systems
• B. Electrostatic Precipitators (ESP)
• C. Thermal Oxidizers
• D. Fabric Filters

Hint:

• Thermal Oxidizers (or incinerators) destroy VOCs and other combustible gaseous pollutants by burning them at high temperatures.
• The combustion converts VOCs into CO$_2$ and H$_2$O.
• Catalytic oxidizers use a catalyst to achieve combustion at lower temperatures.
• Vapor recovery systems aim to capture and reuse VOCs.
• ESPs and Fabric Filters are for particulate matter control.

Answer 1

The Correct Option is C

The technology described, which uses high-temperature combustion to convert VOCs into less harmful substances like CO$_2$ and H$_2$O, is known as Thermal Oxidation or incineration.

• Thermal Oxidizers (option c): These are air pollution control devices that destroy VOCs and other combustible hazardous air pollutants (HAPs) by heating them to a sufficiently high temperature (typically 760°C to 870°C or higher) in the presence of oxygen for an adequate residence time. This high-temperature combustion process breaks down the organic molecules into carbon dioxide (CO$_2$) and water vapor (H$_2$O). Sometimes catalysts are used to lower the required combustion temperature (catalytic oxidizers). Regenerative Thermal Oxidizers (RTOs) and Recuperative Thermal Oxidizers use heat recovery systems to improve energy efficiency.

Let's look at other options:

• Vapor Recovery Systems (option a): These systems are designed to capture and recover valuable VOC vapors that might otherwise be emitted to the atmosphere (e.g., from gasoline loading operations or storage tanks). Recovery can be through methods like condensation, adsorption, or absorption. The goal is recovery, not necessarily destruction by combustion (though recovered VOCs might later be used as fuel or destroyed).
• Electrostatic Precipitators (ESP) (option b): Used to remove particulate matter using electrostatic charges. Not for gaseous VOCs.
• Fabric Filters (Baghouses) (option d): Used to remove particulate matter by filtration through fabric bags. Not for gaseous VOCs.

Therefore, thermal oxidizers are the technology that fits the description of combusting VOCs. \[ \boxed{\text{Thermal Oxidizers}} \]