New carbon capture technology has high capacity and low cost

Carbon capture and storage has been seen as an uneconomical solution to reducing carbon emissions, with the capture of CO₂ emissions from a power station currently requiring about 30% of the total electricity it produces. But thanks to Dr Matthew Hill, a researcher at CSIRO Materials Science and Engineering, the capture of carbon emissions is now cheaper than ever before.

Dr Hill has conducted research into metal-organic frameworks (MOFs) - ultraporous crystal-like materials made from very lightweight atoms. Dr Hill’s specially developed MOFs are capable of storing 300% more CO₂ than currently used materials - a 160-fold increase in storage density compared to the atmosphere.

The MOFs are able to store so much because of their structure, which is similar to building scaffolding and creates a massive surface area. Hill explained that this surface area includes both outer and inner surface areas, with 99% of it on the inside.

“The maximum surface area created in 7000 m² for one gram of material, or a spoonful worth of MOFs,” Dr Hill said. “To put this in perspective, a football field is 5000 m².”

But MOFs have their own challenges as well - for the materials to be financially viable, they need to be re-used. This means the CO₂ gas compressed in the framework needs to be released - luckily, 70% of the gas can be released through sunlight alone.

A further problem lies in the large amount of electricity required to transport and store the captured CO₂ in underground sites. Hill suggests removing this need for transport and storage by selling the CO₂. He and his colleagues are currently working on converting captured CO₂ into marketable products such as food for organisms, plastic or low-emission fuel.

Dr Hill originally started working with MOFs in 2008 as a storage option for the hydrogen gas required to fuel a hydrogen car, but later redirected his efforts to the problem of climate change. He has been awarded the 2012 Eureka Prize for Emerging Leader in Science for his research.