In about four months, startup Prometheus Materials expects to begin producing portland-cement-free “bio-masonry” units to replace embodied carbon-intensive cementitious masonry units, known as concrete block. The bio-blocks contain drastically less embodied carbon, thanks to a patent-pending photosynthetic bio-cementation process that combines nature's living microalgae with water, sunlight and CO₂.
The secret juice in the block is a biological binding agent, dubbed bio-cement, that replaces all of the portland cement, reducing EC in the material by 90%, says the startup. “We have discovered a way to accelerate the [bio-cementation] process,” and create a binding agent similar to the material that coral uses to build reefs and oysters use to generate shells, says Loren Burnett, co-founder, president and CEO of Prometheus.