Slashing CO2

Founded: 2020

HQ: Somerville, MA

Making cement at room temperature.

Big Picture

Cement is the most abundant man-made material on the planet and, at 8% of global emissions, the cement industry is among the biggest emitters. Avoiding dangerous levels of warming depends in no small part on how quickly we decarbonize cement as the Earth heads toward 10 billion primarily urban-dwelling residents. Yet, solutions to date are marginally impactful, unfeasibly expensive, or both.

How it Works

Sublime is fully electrifying cement production by leveraging cheap renewables and chemical storage to make carbon-free lime. Their electrochemical approach replaces an extremely energy- and heat-intensive production process with one that runs at room temperature. Beyond cement, the process can extract valuable materials from waste streams and even take in used concrete as a feedstock.

Unfair Advantage

Their product is a zero-carbon drop-in alternative that makes no sacrifices in the form, fit, and function of conventional cement. Even without carbon pricing, it can also be produced at competitive unit economics in a cut-throat global commodity market. If you factor in even a meager carbon tax—where many markets are headed—and Sublime’s approach is even more competitive.


Ton of CO2e

avoided per ton of cement produced


Leah holds a postdoc from MIT and a PhD from Prof. Jeff Dahn’s lab at Dalhousie University, where she worked in partnerships with 3M and Tesla on improving lithium-ion cell lifetime by optimizing electrolyte chemistry.

Follow: @OhHelloLeah


Yet-Ming Chiang is a Professor of Materials Sciences and Engineering at MIT, a world-renowned pioneer of electrochemistry and advanced materials, and a serial cleantech entrepreneur having previously co-founded Form Energy, Desktop Metal, 24M Technologies, A123 Systems, and American Superconductor Corp.

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