Amazon’s Seaport tower first to use MIT spinout’s low-carbon cement

Amazon’s Seaport tower first to use MIT spinout’s low-carbon cement

Amazon’s Seaport tower first to use MIT spinout’s low-carbon cement

By Greg Ryan 

Four years after it was founded, Somerville startup Sublime Systems has the first commercial application of its low-carbon cement: Boston’s largest “net-zero” building, the new Inc. tower that’s going up in the Seaport District.

Contractors for WS Development poured concrete that contained roughly three tons of Sublime cement at One Boston Wharf Road last week. Amazon has leased the 17-story tower, which is expected to open later this year, to complement another tower next door that it opened in 2022.

For a project the size of One Boston Wharf, those three tons do not amount to much: the product only makes up a portion of the building’s ground-floor slab.

Still, it marks a milestone for both an industry that state officials want to dramatically expand as well as the sort of building material that real estate developers and companies may increasingly seek out to cut down carbon emissions from construction.

Sublime uses electrochemistry to produce its cement, avoiding the fossil-fueled kilns that help make the manufacturing of cement one of the biggest contributors to climate change on the planet.

The MIT spinout has raised tens of millions of dollars in venture funding and plans to open a factory in western Massachusetts in 2026, but until this month it had only done testing and “validation pours” with the limited amount of cement it can make out of its Somerville pilot facility.

Chestnut Hill-based WS connected with Sublime after WS executive Yanni Tsipis read about the startup in an MIT publication last fall. The timing worked out where the WS project was able to serve as the first commercial customer for the cement. It was poured in what will be the building’s ground-floor public space. The portion of the floor made with the Sublime product is marked off, with a plaque posted to notify passersby of the use of the technology.

“We hope that the pour at One Boston Wharf Road illustrates the power of the possible,” Tsipis said.

Sublime executives foresee similar uses of the cement in the near future — limited pours that have a public-facing component to raise awareness about the product.

“It’s really important for all the complex players in the construction industry to understand about the availability and applications (of the cement) and to build trust,” said Joe Hicken, Sublime’s vice president of business development and policy.

Sublime’s product addresses what is known as a building’s “embodied carbon”: the emissions caused not by day-to-day operations like heating and cooling, but by its construction materials over their lifespan, including their creation and installation. (“Net zero” buildings target emissions from day-to-day operations.) Businesses are becoming more interested in restricting their embodied carbon. The city of Boston recently proposed collecting data on embodied carbon for new development and one day potentially putting limits on it.

The industry has a long way to go before anything resembling the widespread use of low-carbon cement. Right now, Sublime can make about 250 tons of its cement a year out of Somerville. When it comes online, the Holyoke facility will be able to produce 30,000 tons of the product annually, enough for 17 three-story parking structures, Hicken said. Given Sublime’s locations here, Massachusetts is meant to be a major market for the cement.

The goal is ultimately to produce more than 1 million tons per year, enough to build 60 or so stadiums annually, and to make low-carbon cement so commonplace that Sublime becomes a “boring company” whose product does not inspire plaques in building lobbies, Hicken said.