Billions of masks (as well as gloves and other protective equipment) ended up in unsorted, non-recyclable waste.

What do we do with the billions of masks used around the world? It is a question that perhaps we asked ourselves, during the Covid-19 epidemic, when it was time to throw them away. Masks, gloves and other devices are all plastic objects that must be disposed of in the unsorted , as underlined by the Higher Institute of Health (and possibly placed in bags before being thrown away), so they end up in non-recyclable waste . But today a study published in the Biofuels journal of the Taylor & Francis group highlights that the plastic contained in the masks could be converted and reused to produce biofuel . Leading the research is a group from the University of Petroleum and Energy Studies, India, which explains how this conversion could take place.

Billions of masks in the environment

Currently, attention is focused on how to combat the Covid-19 pandemic , but we must not forget the environment and climate change as well. From the beginning of the coronavirus emergency to date billions of masks have been worn (in Italy about a billion in a month , according to a study ), which can become a further threat to the environment , as the researchers point out. Plastic materials end up in landfills or oceans and it takes decades for them to decompose, as their natural degradation.

Masks, a resource from polypropylene

The authors analysed the composition of the masks. Surgical ones and N95s  are made from polypropylene, a polymer used in many common objects (food containers, plastic bottle caps and labels , car bumpers , coffee capsules and much more). This material could be converted into biofuel for use as a fuel for means of transport . To recycle this polymer, chemical and physical methods are required, which were considered by the authors.

A liquid biofuel

The most frequently used method is that of pyrolysis . In this process the material decomposes by heating it to high temperatures, but in the absence of oxygen (present in classical combustion). In this way the material passes from the solid to the liquid state and is transformed into biocrude or bio-oil , or even pyrolysis oil , a synthetic fuel now studied as an option to replace oil . The authors illustrate the different stages of the process. In particular, they observed that the best results are obtained with pyrolysis (in specific reactors) by keeping the masks between 300 and 400 ° C for one hour .

Biofuel, a resource

This method allows not only to avoid  the serious side effects for health and the environment due to plastic pollution but represents a source of energy that can be exploited, as the authors write in the paper. According to co-author Bhawna Yadav Lamba, this method is among the most promising and sustainable compared to the choice of disposing of them in landfills or in incinerators. This is also because pyrolysis oil, highly biodegradable, would be produced. “The challenges of managing personal protective equipment and increasing energy demand they could be addressed simultaneously with the production of liquid fuels from the device kits ” , explains the researcher. “The liquid fuel generated from plastic is clean and has similar properties to those of fossil fuels .