Oxidizers are used for the destruction of vapors produced in the remediation of contaminated sites. These are typically self-contained units and are available with one of two types of combustion processes: thermal oxidation, and catalytic oxidation. Thermal oxidizers are essentially incinerators, with a natural gas or propane burner heating the combustion chamber to a temperature sufficient to cause oxidation of the process stream. The by-products of this combustion are carbon dioxide, nitrogen, and water. These oxidizers can come equipped with heat exchangers, to use some of the heat from the combustion process to pre-heat the incoming process air resulting in lower fuel consumption.
Catalytic oxidizers have a precious-metal catalyst included, which reacts with the volatile organic compounds (VOCs) in the vapor stream, significantly lowering the temperature at which oxidation occurs. By lowering the oxidation temperature the amount of energy required to achieve destruction is much lower. However, the catalyst is susceptible to over-reaction with highly-contaminated vapor streams and consequently, catalytic oxidizers are normally used on lower-concentration vapor streams. Also, the catalyst is subject to fouling and can require frequent cleaning.
Oxidizer units are also available that allow the user to switch from thermal mode to catalytic mode when the contaminant level in the vapor stream becomes low enough.
Thermal and catalytic oxidizers are most often used on sites with petroleum contamination. However, specialized oxidizers are available for the treatment of chlorinated and fluorinated solvents.
When specifying an oxidizer, it is important to consider the air flow rate, all of the contaminants present, and the required destruction efficiency. Oxidizers generally have destruction efficiencies greater than 90%, and can achieve levels above 99%.
MLE Equipment uses oxidizers manufactured by Catalytic Combustion Corporation. Please see the provided specification sheets and manuals for more detailed information on oxidizers.
