What Is Carbon Mineralisation & Why Does It Matter For Climate Change?
By Seratech
7/30/20243 min read
What is carbon mineralisation?
Carbon mineralisation in building materials has the potential to dramatically reduce carbon dioxide (CO₂) emissions from the built environment. Put simply, it’s the process of incorporating CO₂ into materials such as concrete, where it is turned into stable carbonates.
In this rock-like form, it can be used in different applications including building materials like bricks and board - effectively acting as a carbon store and reducing the carbon footprint of construction materials and buildings.
In nature, mineralisation is a slow, naturally occurring process that takes thousands of years. But scientists today have found ways to speed it up to a matter of hours, or even minutes, and materials like magnesium silicates or calcium silicates lend themselves well to the process; forming stable carbonates such as magnesium carbonate or calcium carbonate when exposed to CO₂.
Seratech’s approach to mineralisation
Seratech, an Imperial College startup, has developed a way to speed up the production of magnesium carbonate by capturing CO₂ emissions from industrial processes and reacting them with magnesium-rich compounds like olivine to make bricks, board and other construction materials. “We’re not just storing carbon; we’re turning it into something useful, something that can help build our future,” says Sam Draper, Seratech CEO.
And while this type of process is often seen to be costly, Seratech has invented a new low-cost, low-energy way of doing it at scale cutting emissions by up to 95%.
“Seratech produces a particular version of magnesium carbonate which when cured, becomes stable and reverts to the rock-like substance you would find in nature,” explains Mike Eberlin, Seratech non-executive director and former Chair of MPA Cement.
Mineralisation as an emerging technology
As an emerging technology, not yet implemented at scale, work is underway by cement companies alongside independent startups to understand how CO₂ mineralisation can be best deployed while demonstrating the economics. Different technologies and pathways are being developed as it continues to gain acceptance as a necessary component to decarbonising hard to abate industries. Competition among scientists is rife to understand which type of materials are best suited to the process and under what conditions.
According to Mohsen Ben Haha who manages a team of scientific experts in mineralogy at Heidelberg Materials, the technology of mineralisation is well understood and tested and there is scope to transform the cement industry into a CO₂ sink through rapid scaling up, but the problem lies in incentivising the use for such materials. For the time being, in most places, with the exception of certain geographies, there is little reason for concrete producers to make the switch from conventional bricks to mineralised ones.
“In places like The Netherlands, Northern Europe and California, where government incentives are in place for emitters to lower their CO₂ emissions and where awareness around climate change is a high priority, we might see things change quite fast. We’re noticing some of our partners in those areas beginning to use CO₂-made bricks rather than traditional ones and it’s quite clear the direction they are moving in,” explains Mohsen.
“The cement industry by nature is conservative and there are many countries where the time scale is likely to be around 5 to 10 years before we see much change”.
Mohsen is convinced that carbon mineralisation will take off in a big way once the exact cost of CO₂ storage becomes clear. Only at that point will emitters start to think about alternative routes to storing CO₂ and mineralisation will be the obvious answer.
Mineralisation vs CCS
As hurdles around deployment of the technology and making it cost effective remain the point of focus, Jan Skocek, R&D Program Manager of Carbonation Technologies at Heidelberg Materials is frank about mineralisation not being the ‘ultimate’ weapon to decarbonising the entire cement industry:
“There are simply not enough materials needed to absorb the 4 bn tonnes of CO₂ emitted annually. As an industry we have no choice but to also work on other solutions, like carbon capture and storage, to fully remove carbon emissions. Mineralisation has the potential to become a relevant lever in the decarbonatization technology portfolio as it is can be nicely integrated with SCM or concrete goods production”.
In Summary
Carbon mineralisation in building materials is a promising approach to reducing the environmental impact of the construction industry by sequestering CO₂ into stable mineral forms within construction materials like concrete. It offers both environmental and material performance benefits, though there are challenges to be addressed for it to become a mainstream solution.