Low-carbon cement — without compromise.


Today, creating cement is an energy and carbon-intensive process. Roughly half of the carbon emissions come from combusting fossil fuels required to heat a kiln to 1400-1500° C, and the other half comes from the CO2 emitted when the limestone chemically decomposes inside the kiln.
Sublime's technology eliminates both of these emissions sources. Instead, we use an electrochemical process that can turn abundantly available non-carbonate rocks and centuries of industrial waste that don’t release CO2 when they are decomposed into cement at ambient temperature — eliminating the need for fossil fuels entirely.
Sublime’s electrolyzer is a variation of a water-splitting electrolyzer. One electrode produces a solution that extracts calcium from inert minerals, leaving behind a reactive silicate. The second electrode produces alkalinity, which precipitates calcium (also known as lime) as a pure, reactive solid. Reactive calcium and silicates are blended in a low-temperature process to make the final product — Sublime CementTM.
This ASTM C1157-compliant cement will be the first to commercial scale that approaches 'true' zero carbon — rather than just 'net' zero — by avoiding CO₂ emissions in the first place and foregoing the need for carbon capture and storage.

A one-for-one replacement for ordinary portland cement (OPC)
While our process is different, what Sublime produces adheres to strict industry-accepted standards.
Sublime Systems produces high-performance, low-carbon cement that has similar (or better!) ultimate strength, durability, slump, and set time as the cement we use today for our buildings and infrastructure.
0
Sublime is rapidly scaling our high-performance, low-carbon cement production as a true zero process that doesn’t emit carbon.
1:1
The needs of the construction ecosystem are at the center of our work. Sublime CementTM is a drop-in replacement for today's portland cement, creating a frictionless replacement for ready-mix concrete producers that meets or exceeds ASTM C1157 standards.
$
Sublime Systems is actively driving down the cost curve with a commitment to produce cost-competitive cement at scale without relying on carbon credits at our end plants.
Low-carbon cement — without post-combustion carbon capture
Sublime Systems avoids carbon emissions altogether, so there is no added expense or complexity of carbon capture, utilization, and storage (CCUS).
Sublime CementTM requires neither heat (therefore no fossil fuels) nor carbonate feedstock. Our technology innovations will allow us to finally make a true zero-carbon cement — the way we believe cement will be made for millennia to come!

>90% CO₂ Reduction Possible | Fossil Fuel Use | Cost | Embodied Energy | Meets Ready-Mix Specs | |
---|---|---|---|---|---|
Sublime CementTM |
>90% CO₂ Reduction Possible Ideal |
Fossil Fuel Use Ideal |
Cost Ideal |
Embodied Energy Ideal |
Meets Ready-Mix Specs Ideal |
Cement today (OPC) |
>90% CO₂ Reduction Possible Insufficient |
Fossil Fuel Use Insufficient |
Cost Ideal |
Embodied Energy Ideal |
Meets Ready-Mix Specs Ideal |
OPC + Carbon Capture |
>90% CO₂ Reduction Possible Ideal |
Fossil Fuel Use Insufficient |
Cost Ideal |
Embodied Energy Insufficient |
Meets Ready-Mix Specs Suboptimal |
Supplementary Cementitious Materials |
>90% CO₂ Reduction Possible Suboptimal |
Fossil Fuel Use Insufficient |
Cost Ideal |
Embodied Energy Ideal |
Meets Ready-Mix Specs Suboptimal |
Carbonated / CO₂-Cured |
>90% CO₂ Reduction Possible Suboptimal |
Fossil Fuel Use Insufficient |
Cost Suboptimal |
Embodied Energy Ideal |
Meets Ready-Mix Specs Insufficient |
Ideal
Suboptimal
Insufficient