Air filtration is all about making the air cleaner. And what could be greener than removing contaminants from the air? In this post, we’ll take a look at why that may not necessarily be the case, depending how the air is filtered.
Activated Carbon: A Dirty Solution for Cleaning Air
Activated carbon is one of the most common materials used for cleaning chemicals from air. In 2016, 577 million tonnes of activated carbon will be used for air purification purposes, mostly for the industrial market. And especially in this industrial market, it is certainly very green to remove contaminants from air used in polluting processes. However, producing the activated carbon itself is not a particularly green process.
Activated carbon is derived from elemental carbon or some kind of other carbon-rich precursor. This precursor is then either given a high-temperature chemical treatment, or is treated via pyrolysis and then oxidation. After the activation process, the activated carbon may be further treated with a polymer coating or impregnation with other elements to increase its functionality.
A summary of the activated carbon production process. There are a number of high-temperature and resource-intensive steps throughout the process.