The block, called the Carbon Buster, incorporates more than 50 percent recycled aggregates and combines this with Carbon8’s carbonated aggregates derived from by-products from waste-to-energy plants.
The companies say the building block has captured more carbon dioxide than is emitted during its manufacture — 14kg CO2 per metric ton.
Carbon8’s technical director, Dr. Paula Carey, says the company identified an end use for thermal residues from waste to energy plants. By mixing the residue with water and carbon dioxide, it creates a product that the UK Environment Agency says is a suitable virgin aggregate replacement.
Following the EA review, Carbon8 built a £1 million ($1.6 million) carbonation plant in Brandon, Suffolk, adjacent to Lignacite’s masonry plant. Here, the residue is carbonated, mixed with binders and fillers before being pelletized and used as a key ingredient in the Carbon Buster block.
Lignacite uses sand and gravel from its quarry adjacent to the block plant. This, combined with the use of recycled waste material, such as wood shavings, glass and shells, meant the company’s masonry products always had a minimal carbon footprint, it says. Despite these efforts, however, the cement content previously used made it impossible to generate products that were carbon negative until it produced the Carbon Buster.
Lignacite says it was the first block manufacturer in the UK to introduce recycled and waste materials into its products, and one of its ranges already contained 90 percent waste materials.
In the US, several companies have announced carbon capture projects in the last two months. Earlier this week, Akermin said it has successfully tested its Biocatalyst Delivery System at the National Carbon Capture Center in Wilsonville, Ala. The pilot unit has operated continuously for several weeks capturing close to 90 percent CO2 from flue gas with significant rate enhancement and no degradation in performance, the cleantech company said.
Last month, Aker Solutions won a contract to perform the world’s first tests for capturing carbon dioxide emissions from a cement production plant.
Also in May Air Products announced it was operating a Department of Energy demonstration project that will capture about 1 million tons of CO2 in an enhanced oil recovery project in Texas.