Gas Incinerator also known as gas thermal combustion is used for controlling VOC and malodorous hydrocarbon-based substances emissions. Although it has the disadvantage of destroying the solvents, it can be designed to be energy efficient, and in some cases can be an integrated part of the heat supply to the drying process.
Incinerators can be of two types: conventional, high temperature incinerators where the gases are heated to between 750 and 815°C and held between 0.3-1 second, or catalytic incinerators, where the decomposition is carried out on a metal catalyst surface, usually a platinum/palladium mixture, at lower temperatures, typically 360°C for less than 0.5 second residence time. In both cases, heat recovery options are available to reduce the operating cost.
Almost all incinerators built nowadays incorporate some form of heat recovery (heat exchangers, waste heat boilers and organic fluid heaters).
The only exception to this rule would be if the waste gases contained significant quantities of acidic components such as SOx or chlorine, in which case the risk of corrosion would be unacceptable, or particulates which could foul the heat exchanger surfaces. However, such gases would probably require treatment in some form of gas scrubbing device to reduce other forms of emissions.
In practice, most applications involving VOCs and malodorous hydrocarbon-based substances are not subject to these additional constraints, and heat recovery is an essential feature of the economic justification for incineration.
The three primary types of gas incinerator are: