Gas Phase Filtration and the Power of Purafil’s Molecular Media
Since the 1960s, Purafil has led the world in gas phase filtration. Our patented media solutions help businesses of all kinds avoid destructive corrosion and noxious odors in their facilities. Our air cleaning technologies ensure that the air in factories, refineries, plants and more is safe and free of harmful chemicals.
But how does our media work? How does our unique filtration system accomplish mass air purification? We tackle these questions and more in the first part of our Molecular Media Blog Series.
Let’s get started.
What is gas phase filtration?
Gas phase filtration (sometimes called molecular or chemical filtration) is the process of removing harmful or unpleasant gaseous contaminants from the air in your environment. To be successful, the filtration process must not allow the chemicals to return to the air.
How does gas phase filtration work?
Think about an air conditioning system. An AC unit forces air through a particle filter and catches dust and other particulate contaminants so they are not released into the air. Gas phase filtration works similarly, but instead of a particle filter, Purafil’s gas phase filtration system uses a fan to push air through a filter where Purafil’s patented, spherical, porous pellets remove gaseous pollutants from the air through a unique chemical process known as chemisorption.
What is chemisorption?
During chemisorption, the media converts harmful gasses from the air into harmless materials that are trapped inside the pellet. This gas phase filtration process is instantaneous and irreversible.
This is different from a process called adsorption, which is reversible. Think of how your clothes smell after sitting near a campfire. You probably need to “air them out.” This air-out process is possible because adsorption does not irreversibly convert one chemical compound into another. Instead, the compounds are released from the fabric. With Purafil’s patented media, once the chemisorption process is complete, there is no going back. Harmful chemicals and odorous air molecules are forever converted.
What is molecular media?
Molecular media, like Purafil’s patented pellets, are physical, tiny balls of activated carbon, alumina, potassium permanganate, and/or other compounds that can provide broad-based or hyper-specific removal of toxic or unpleasant chemicals in the air.
In the early 1960s, Purafil came out with “the purple pellet,” which is a type of media that leverages potassium permanganate to trigger the chemisorption process. Prior to our invention, activated carbon was the only option available to remove harmful chemicals from the air.
Activated carbon is not a bad solution—Purafil offers activated carbon media as well—but it is not a total solution. Certain industries, such as oil refineries, cannot use activated carbon as it poses a potential fire risk. Purafil’s potassium permanganate media, however, offered a new solution to those and other industries—and that was just the beginning.
Purafil’s Designer Media
The purple pellet was a powerful invention, but it was broad-based. It absorbed whatever was in the air, whether it was harmful or not. Certain facilities needed a more tailored solution. Enter: designer media.
Now, Purafil offers multiple forms of designer media artfully crafted to support the unique needs of many industries. Some of our offerings include:
Chlorosorb® Ultra: Chlorosorb® Ultra is especially formulated for use in Purafil’s emergency gas scrubbers to provide protection from a catastrophic release of chlorine gas from on-site storage. This media is commonly used in the water and wastewater industries.
CP Blend: A blend of Chemisorbant and activated carbon media. Chemisorbant media is impregnated with potassium permanganate to provide optimum adsorption, absorption and oxidation of a wide variety of gaseous contaminants.This media is commonly used for IAQ in commercial buildings, i.e. office buildings, hospitals, airports, etc.
OdorCarb Ultra: OdorCarb Ultra consists of spherical, porous pellets impregnated to provide a superior removal capacity for hydrogen sulfide (H2S). Commonly used in the water and wastewater industries for odor control.
Puracarb®: Designed for neutralization of chlorine, hydrogen sulfide and sulfur dioxide, this media is manufactured specifically for the corrosive environments and consists of generally spherical, porous pellets. Composed of carbon, alumina and other binders. Most commonly used in industrial sites for electronic corrosion control.
Puracarb® AM: Puracarb AM targets base gasses such as amines, ammonia, and like compounds. It has a higher removal capacity for applications in fertilizer manufacturing, semiconductor fabs, refrigeration, cold storage applications, and animal agriculture operations. Most commonly used in industrial sites for emergency ammonia scrubbers.
Purafil Chemisorbant: Purafil Chemisorbant targets the removal of hydrogen sulfide (H2S), sulfur dioxide (SO2), nitric oxide (NO), and formaldehyde (CH2O). This media is a broad spectrum oxidizer used in a variety of applications, including for IAQ, archival storage, museums, hospitals, etc.
Purafil SP: Effectively removes hydrogen sulfide, sulfur dioxide, nitric oxide and formaldehyde. Like Purafil Chemisorbant, SP is a broad spectrum oxidizer used in a variety of applications, including for IAQ and semiconductor manufacturing.
Purakol®: Used in Combination with Other Media for Broad-Spectrum Pollutant Removal. This activated carbon media shall consist of virgin grade, activated, non-impregnated carbon. This media is typically used in conjunction with our other medias – and typically acts as a ‘prefilter’ for more specialized medias.
Purafil Select: Removes sulfur oxides and other odorous pollutants from makeup air. Purafil Select is also recommended for the preservation of fruits, vegetables, and flowers because of its effectiveness at removing ethylene, a ripening agent. And like Purafil Chemisorbant and SP is a broad spectrum oxidizer used in a variety of other applications, including for IAQ.
Select CP Blend: A blend of Select and activated carbon media. Removes sulfur oxides and other odorous pollutants from makeup air to provide improved IAQ in commercial buildings, i.e. office buildings, hospitals, airports, etc.
SP Blend: SP Blend is a mix of SP and activated carbon filtration media. It demonstrates a higher working capacity for broad-spectrum oxidation of contaminants in actual field conditions where multiple gas challenges are present. It is commonly used for improving IAQ.
Make Up Air (MUA): MUA is a blend of Purafil SP and activated carbon media. Removes the widest variety of odors and gasses from applications where jet fuel fumes, diesel exhaust and automobile emissions are present. This can be at airports, hospitals, office buildings, etc.
Purafil is proud to offer these designer solutions to suit the needs of many types of businesses. What started as one type of purple pellet has turned into a world of media—literally. Purafil now produces enough media each year to circle the globe 12 times over. Along with our monitoring and gas scrubbing systems, Purafil’s patented media ensure that facilities worldwide can achieve corrosion and odor-free environments.
Molecular media designed with industries in mind
These different media solutions were created in our ISO 17025 accredited lab with the intention of having industry-specific applications. In part two of our molecular media series, we’ll take a closer look at the various uses of Purafil’s media in different industries.
Stay tuned for the next chapter!