If you drive into Boston from NH on I-93, you know Boston Sand and Gravel, with its industrial site tucked between the highway and the train tracks just north of the Charles River. It seems like a throwback to Boston’s gritty days, so it was cool to see that it’s experimenting with the use of low-carbon cement. I read about it in CleanTechnica (story here):
The Sublime process takes place at room temperature, which eliminates the need for extreme heating. … Instead of using limestone as the primary ingredient — which releases carbon dioxide when heated — the Sublime process uses a variety of non-carbonate raw materials.
As you probably know, making cement is a major greenhouse-gas emitter not just because of the energy it uses but because of the gases emitted from processing the raw materials. Finding a “green” alternative that still works is a big, big challenge.