Harnessing microbes to grow cement

Spotted: Cement has a huge carbon footprint – contributing up to 8 per cent of total global emissions. Much of this comes from the process of heating limestone to very high temperatures. This not only uses a tremendous amount of energy but also releases carbon dioxide directly. Now, startup Biomason has developed a way to ‘grow’ a cement substitute using micro-organisms.

The startup uses a process similar to how coral reefs and shells are formed, where organisms lay down layers of calcium carbonate. The company starts with recycled aggregate. This consists of the tiny bits of material that are held together by cement in concrete. Biomason then adds a strain of bacteria, along with the calcium, carbon and nutrients the bacteria needs to grow. As the micro-organisms grow, they produce calcium carbonate, which acts like a glue to secure the aggregate together.

The process operates at room temperate, reducing the need for heating. It also cures more rapidly than cement, and the end product is stronger than traditional concrete. The company is currently making small quantities of a tile called Biolith for industrial clients. Because the process can use existing concrete production facilities, it should be relatively cheap to scale up. Currently, several concrete producers are examining ways to incorporate Biolith production into their plants.

Biomason founder Ginger Krieg Dosier explains that the product does not need to be disruptive in order to make a big difference. “It didn’t make sense to disrupt everything in the entire concrete value chain. From day one, even before Biomason was named, it was very important for us to develop a technology that was easy to use, especially with existing concrete producers.”

Tackling the high environmental cost of concrete production is very high on the list of green researchers and entrepreneurs. Some of the other ideas we have seen at Springwise include solar-powered cement production and a bio-concrete made from weeds and shells.

Written By: Matthew Hempstead