Professor Rebecca Lunn, University of Strathclyde

How crushing rocks could capture carbon 

The challenge

Global demand for critical materials like lithium and nickel is surging, in part driven by renewable energy technologies, such as wind turbines, solar panels and electric cars. However, the process of extracting rocks from the ground, crushing them, and then chemically processing the crushed rock to produce a usable material, creates substantial carbon emissions. So, while these materials are helping us fight climate change, extracting and processing them is also adding to the problem.  

The innovation

Professor Rebecca Lunn MBE FREng FRSE is working on the answer to this challenge. She has discovered that when silicate rocks – the largest and most important class of minerals that make up the vast majority of the Earth’s crust – are crushed, the breaking of silicon-oxygen bonds in the rock causes an instantaneous energy release that can be used to drive a chemical reaction to trap carbon dioxide onto the rock surface.  

With 72 billion tonnes of waste rock crushed globally each year during mining, this low-energy process could capture around one billion tonnes of carbon dioxide annually, significantly reducing the emissions from mining and material production.  

Through the Green Future Fellowship funding, Professor Lunn is focusing on improving the efficiency of the carbon capture process by identifying which types of silicate rocks trap the most carbon dioxide for the least amount of energy. She will also study the process at the atomic level, understanding how the crushed rock surfaces react with gases, enabling her to predict how stable the captured carbon will be over thousands of years.  

Ultimately, the aim is to scale up the process from the lab to larger demonstrations, working with large multinational organisations to encourage industry-wide take up of the technology. If successful, the project could transform a critical, widely used industrial process into a method to fight climate change.

The innovator

Professor Lunn is a Deputy Associate Principal at the University of Strathclyde, and the Royal Academy of Engineering and BAM Nuttall Research Professor in Biomineral Technologies for Ground Engineering. She has been at the University of Strathclyde for over 20 years. She received an MBE in 2017 and was recognised as an ‘Outstanding Woman of Scotland 2015’ – the only engineer or scientist to have received the award. 

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A serendipitous discovery led to the realisation that the act of crushing rocks could help to trap greenhouse gases, reducing carbon emissions.