Somerville startup is pouring greener cement for a low carbon future

From Boston’s towering buildings to sidewalks that sit below, concrete is everywhere you look. Globally, cement production makes up eight percent of carbon emissions. If it were its own country,  cement production would be the third largest emitter of CO2,  next to China and the United States.

So imagine the impact on climate change if developers could use a low carbon cement in their concrete.

One Somerville startup is working to making it happen, and one Boston building is using it for the very first time.

“Today's cement is made in massive fossil-fueled kilns, and it's made from a mineral called limestone, which is 50% by weight, CO2,” explained Leah Ellis, CEO and co-founder of Sublime Systems.

“Sublime gets around this problem by breaking down minerals in a different way.”

Sublime is replacing the high temperatures, fossil fuels and combustion process with an ambient temperature process.

“Because we’re doing this at room temperature, we can actually use other minerals besides limestone. So we're avoiding all sources of CO2 emissions,” Ellis said.

The Somerville startup first proved their theory with an almond-sized piece of cement.

Today they produce 250 tons a year. With an $87 million co-op agreement from the Department of Energy, Ellis has hopes of setting a production milestone of 30,000 tons at its future home in Holyoke.

Strength testing is essential to making sure they have a viable product.

“We test it in our labs, then we send it to a third party. They test it and we make sure those results match. Then we send it to our customer and they test it both in the lab and outside the lab in so many different ways,” Ellis said.

Yanni Tsipis of WS Development said the Sublime process passed all the tests.

“We're very proud to be the first commercial application of Sublime Systems, concrete product anywhere in the world,” Tsipis said.

Though not in the entire facility, Sublime’s concrete is in use today at the bottom floor of One Boston Wharf, a WS Development leased by Amazon.

“The pour went really well. Nobody could tell that this cement was different from any other type of cement they'd seen,” Ellis said.

 “We really look forward to incorporating it also into future projects, including it at larger scales, so that we can continue to try to show the development and construction industry what's possible in terms of a carbon free future,” Tsipis said.

Sublime Systems has more pours in the pipeline, but they can’t disclose the projects just yet.