Scientists produce ecological cement from algae for the first time in the world

An industry responsible for 7% of the planet’s annual greenhouse gas emissions – Manufacture of Portland cement – it can suddenly become neutral or even carbon negative. That’s what promises after a team of scientists led by the University of Colorado at Boulder in the United States discovered a way to remove carbon dioxide from the air with the help of microalgae.

The result of the process is a sustainable cement produced from biogenic limestone (i.e. a material made from living organisms). Instead of traditionally burning limestone and clay in a kiln, The researchers decided to grow microalgae called coccolithophores.They are also known as calcifying phytoplankton, as they can form calcium carbonate deposits during photosynthesis.

Even more impressively, unlike natural limestone structures that can take millions of years to form in the oceans, this version of biogenic cement produced by coccolithophores can occur in real time.

How did the idea of ​​making mossy cement come about?

HE insight While diving in Thailand, where he honeymooned in 2017, CU Boulder professor Will Srubar thought of the invention of biogenic cement. Underwater, the environmental engineer marveled at the naturally built calcium carbonate structures around coral reefs. “If nature can grow limestone, why can’t we? – he would then ask.

After returning, Srubar and his crew began to produce large quantities of calcium carbonate using only sunlight, seawater, water-soluble carbon dioxide and coccolithophores. Scientists estimate that about 800,000 hectares of open lagoons (0.5% of the land area in the United States) can produce. all the cement the country needs today.