We can make concrete carbon-neutral

Concrete is the lifeblood of construction worldwide, but cement manufacture is already responsible for more than 8% of global carbon dioxide emissions.

Even with renewable energy, about 60% of these emissions are unavoidable since production of Portland cement requires breaking down limestone, releasing CO₂ into the atmosphere. For construction to continue to support world development, its carbon footprint must be reduced.

At Seratech, our researchers in collaboration with Imperial College, London,  have developed a new cement technology that can facilitate the production of carbon neutral concrete. In a simple chemical process, we use carbon mineralisation to absorb carbon dioxide emissions at source using flue gases directly from the cement kiln.

This is the safest and most long-lived form of carbon capture and storage (CCS) available and uses raw materials that are abundant and inexpensive.

Our product, called Sera, is a cementitious material that can be used as a replacement for cement in concrete in exactly the same way as fly ash from coal-fired power stations or GGBS from the steel industry are now.

These materials reduce cement content in concrete and therefore emissions, but are available in reducing quantities as energy generation shifts towards more renewable sources and recycled steel is preferred. Sera will fill this growing gap as the “new fly ash”.

Carbon-neutral concrete can be achieved when around 35% of the Portland cement is replaced with Sera, a mix which is already proven to provide excellent concrete for construction use.

Barney Shanks is co-founder of Seratech