LONDON (Reuters) - A British start-up company developing a cement that absorbs carbon dioxide has raised 1 million pounds ($1.7 million) to fund its work, underscoring the growing interest in eco-friendly construction ventures.
Novacem, a spin-out from Imperial College London, is one of a number of young companies tapping new technologies to reduce the cement industry's notoriously large carbon footprint.
With an annual production of more than 2.5 billion tons, conventional Portland cement is responsible for an estimated 5 percent of global CO2 emissions, more than the airline industry.
Novacem believes its "carbon-negative" cement answers the problem because it absorbs more carbon dioxide over its life cycle than it emits.
The trick is to make cement from magnesium silicates rather than calcium carbonate, or limestone, since this material does not emit CO2 in manufacture and absorbs the greenhouse gas as it ages.
http://www.scientificamerican.com/article.cfm?id=carbon-eating-green-cemen