VOC Abatement is not really a dehumidification process, but it looks very much like it. Munters rotor technology is used to optimise the VOC Abatement process by using a Zeolite rotor instead of a desiccant rotor.
What is a VOC?
VOC stands for Volatile Organic Compound. Volatile chemicals produce vapours at room temperature. Organic is a chemical containing carbon molecules. Volatile Organic Compounds include industrial chemicals, solvents, alcohols, and even gasoline. VOC's combine with sunlight to form atmospheric ozone, or smog.
What is Zeolite?
Zeolite is a naturally occurring mineral, in crystal form. Natural zeolite is made of hydrous aluminium silicates of sodium, calcium, potassium or barium.
Natural zeolite is hydrophilic (water loving) and readily adsorbs and desorbs water. Synthetic zeolites have been developed for commercial applications. Over 70 types of synthetic zeolites have been created.
Hydrophobic zeolite is an inorganic crystal with properties suited to adsorbing VOCs. Hydrophobic zeolite is a stable crystal. The zeolite's inert properties mean that it does not promote chemical reactions. It is also non-flammable to extreme temperatures and will not react with strong acids.
How do Zeolites Work?
The basic structure of a zeolite is a tetrahedra or pyramid formed by silicon dioxides (SiO2) The tetrahedra have one silicon atom in the center and oxygen at each of the corners.
Zeolites are linked by sharing the oxygen atom. Linked zeolites form pores. The size of the pores is determined by the number of zeolite molecules that are joined together. As a crystal the zeolite has a set structure, therefore each type of zeolite has a distinct arrangement of zeolite molecules. As each type of zeolite is unique each pore size is unique.
The size of the organic compound determines which zeolite pore size is best suited for adsorption. Munters Zeol uses a mixture of hydrophobic zeolites with different pore sizes. This mixture allows a wide range of organic solvents to be adsorbed. Most commercially available solvents are adsorbed by our hydrophobic zeolites.
A VOC is attracted and held in the zeolite pore by a weak attractive force. (This is a weak physical attractive force between chemically neutral compounds.) The VOC will remain in the pore until energy (e.g. heat) is applied. The heat overcomes the attractive force and the VOC breaks free from the zeolite and is released into the air.
When VOC laden air flows past zeolite molecules, the zeolite acts as a reverse filter or molecular sieve, capturing the compounds which will adsorb and allowing the compounds that are too large to flow past.