Disposable Rubber Gloves Could Become Reusable CO2 Capture Material

Disposable nitrile rubber gloves are manufactured in vast quantities each year, with the majority discarded after a single use. This creates a huge and continually expanding waste stream.

A recent laboratory study points to an alternative fate for the material. Rather than incinerating or landfilling the rubber, researchers have shown it can be converted into a solid that captures CO2 and can be used again and again.

The concept is straightforward yet far-reaching: to turn a product regarded as a waste challenge into a means of controlling emissions.

Turning rubber gloves into CO2 capture material

In their study, Simon Kildahl, a postdoctoral researcher at Aarhus University, and his colleagues describe a technique for transforming discarded rubber gloves into a CO2 adsorbent.

Kildahl says the change could be significant given the sheer volume of this waste material and the fact that incineration is still a frequent destination for mixed plastics or materials that are difficult to recycle.

“A plastic bottle can be recycled relatively easily, as we know from deposit-return systems,” he said. “But other plastic materials are problematic because they cannot be reused in the same way. Therefore, they often end up being burned, which is currently the case for rubber gloves.”

“In our experiments, we converted the glove so that it could capture CO2 instead of becoming a waste product that releases CO2 and other harmful gases during incineration.”

Addressing hard-to-recycle plastics

Kildahl works within the Skydstrup Group at the Novo Nordisk Foundation CO2 Research Center (CORC), a collaboration based at Aarhus University.

Its wider aim is to identify methods for capturing CO2 or turning it into useful products, including fuels created through Power-to-X processes.

This emphasis on carbon capture is linked to another issue the group has investigated for years: how to deal with materials generally viewed as unrecyclable.

Previously, the researchers reported methods of recovering value from mattress polyurethane foam and waste from wind turbine blades, including epoxy and glass fibres.

They are now bringing that approach to nitrile rubber gloves, which occupy a difficult position: they are vital in healthcare, extensively used and commonly thrown away straight after use.

The proposed method is attractive because it seeks to tackle two issues simultaneously. It provides an option for a challenging waste stream while producing a material that could reduce emissions instead of increasing them.

Chemistry transforms rubber glove waste

The laboratory process starts with a basic physical stage: the gloves are broken into smaller fragments. Chemistry then changes the material.

“Specifically, we shred the rubber glove into small pieces. It then reacts with a ruthenium-based catalyst and hydrogen gas, after which it can capture CO2 from simulated flue gas,” Kildahl explained. “In the real world, this could potentially take place at a power plant.”

Rather than melting the gloves down and reshaping them, the team chemically alters the rubber so that it performs differently and serves a new purpose.

Rubber gloves act as a CO2 sponge

The researchers assessed the material with simulated flue gas. This is important because industrial exhaust contains complicated gas mixtures rather than CO2 alone.

The concept also has a practical quality that prevents it from being a single-use solution. Once the material has captured CO2, it can be regenerated.

By heating the rubber-based product, engineers can release the captured CO2 for underground storage or for use in Power-to-X processes. Meanwhile, the material is refreshed and ready to capture further CO2.

This repeated capture-and-release capability is vital for any viable carbon capture technology. If the material deteriorated rapidly or functioned only once, it would merely recreate the waste problem in another form.

Rethinking materials for carbon capture

CO2 capture itself is not a new idea. Existing technologies already extract carbon dioxide from exhaust gases and even directly from the atmosphere.

The distinction in Kildahl’s team’s work lies not in its objective, but in the material it starts with.

Many capture materials need considerable upstream manufacturing, much of which still relies on fossil feedstocks. When a climate solution depends on expanding oil-based production, its total benefit may be reduced.

Rubber waste becomes a climate resource

Rather than creating a new material from the beginning, the researchers use waste that would otherwise be sent to landfill or an incinerator.

They present the glove-derived material as a way to avoid introducing additional fossil inputs into the system. The approach also relates to the scale of the problem identified by the UN Intergovernmental Panel on Climate Change, which has highlighted the need to remove billions of tonnes of CO2 every year by mid-century.

“That is why it is smart to utilize a waste material available in such large quantities, rather than extracting more oil from the ground,” Kildahl said.

“With the rubber glove, we can create a CO2 capture material where almost every atom in the product comes from waste, except for a small amount of hydrogen.”

That is the central case for the chemistry. A glove becomes a resource for carbon capture instead of a source of carbon emissions, while the process is designed to minimise fresh fossil inputs.

Early-stage work with major ambitions

At present, the findings are limited to the laboratory, and this is a substantial qualification. Reactions can work exceptionally well in small laboratory glassware yet behave very differently when engineers try to operate them at industrial scale.

Kildahl describes the project as being in the early-to-middle range of the Technology Readiness Level scale, at around level three or four.

The group is currently operating at gram scale. Its next hurdle is progressing to kilogram-scale runs, where heat transfer, mixing and cost limitations become much harder to control.

“We are working on a gram scale right now, and reactions can look and behave differently when we scale up to kilograms. But our results look very promising,” he said.

Making CO2 capture affordable

Cost presents a further obstacle. At the moment, the process depends on a costly catalyst. A workable route would need a less expensive substitute, much more effective catalyst recycling, or a redesigned method that requires less of it.

Even so, the researchers say they have passed an important milestone: the approach functions in principle. They are now seeking to make the material more durable, affordable and competitive with other carbon capture technologies.

The team has demonstrated that the concept works and considers that the technology could soon advance to later development stages if it can improve scalability, cut costs and raise performance.