CO2-sucking cement for precast, reduces emissions by 70 percent

pile-o-stone

Interesting article in the excellent "Tree Hugger" site, where a pre-cast concrete manufacturer is using CO2 rather than water in it's curing process, reducing overall carbon in it's production by 70% and also reducing the curing time from 28 days with Portland cement to 24hrs. Win-Win.

https://www.treehugger.com/sustainable-product-design/lafargeholcim-selling-co2-sucking-cement-precast-reduces-emissions-70-percent.html

"The product is the result of a six-year collaboration between LaFargeHolcim and Solidia and uses a special binder — produced at lower temperatures — and patented curing process that uses CO2 rather than water. By adding and absorbing CO2, Solidia Concrete reaches strength in less than 24 hours unlike precast concrete made with Portland cement, which takes 28 days to reach strength. Solidia reduces the overall carbon footprint in precast concrete by 70%. In addition, the new product reduces the cement plant’s carbon emissions by up to 40%.

This concrete can be made in a conventional cement kiln with the heat turned down, so it works within the existing systems of production. According to Kevin Ryan in Inc, the process subs out some of the traditionally used limestone for a synthetic version of the mineral wollastonite.

"If I have to tell people to go buy some new equipment, a new kiln," says CEO Tom Schuler, "no one's going to adopt it." Solidia's manufacturing process can be done in existing facilities and costs about the same as--and, perhaps soon enough, less than--traditional cement-making methods."