Innovation: Store CO2 in concrete
Image: Biomason
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Store CO2 in concrete
- The world uses 4 billion tonnes of concrete every year
- For every metric tonne of cement produced, one metric tonne of CO2 goes into the atmosphere
- Fossil fuels like powdered coal are required to melt limestone to produce cement, resulting in a more CO2 emissions.
- The active ingredient, Portland cement, accounts for about 8% of global greenhouse gas emissions, primarily through carbon dioxide released during production.
- Several companies are now finding ways to permanently store CO2 in concrete. Not all are ‘carbon-negative’ as claimed, however the processes are innovative and look promising.
- Here in Aotearoa, GNS has been awarded $10,407,101.00 through the Endeavour Research Programme fund over 5 years, to develop an iron-based cement that sequesters CO₂ and is a direct drop-in replacement for Portland cement.
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Several other companies are alos finding ways to permanently store CO2 in concrete. Not all are ‘carbon-negative’ as claimed, however the processes are innovative and look promising (Video 1). See:
- Carbon Cure uses CO2 from industrial emitters
- Carbicrete uses mineral waste and CO2 as raw materials
- Blue Planet uses CO2 as raw material for making carbonate rocks
Use algae to grow cement
Biomason uses a natural non-modified non-pathogenic bacteria to grow biocement® building material without heat, using a process similar to hydroponics. The species used is commonly found in natural environments across the world.
It takes around 72 hours for Biomason’s tiles to reach full cure strength (traditional concrete can take up to 28 days to cure) and the product is 3 x stronger than concrete (Video 2).
In marine environments, self-sustaining natural marine microorganisms that source nutrients from seawater, are used to propagate calcium carbonate precipitation (similar to how beach rock is formed, but over much short time frames). The result is the sustained structural integrity of products with self-healing abilities. This process can be used to quickly build breakwaters and other ‘hard’ coastal/marine structures.
See: ‘Tiny algae could help fix concrete’s dirty little climate secret – 4 innovative ways to clean up this notoriously hard to decarbonize industry.’ – The Conversation, Sept. 2022 (Video 3)
