How to tackle cement's massive CO2 problem, with Sublime Systems' Leah Ellis
Nov 15, 2023
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Dr. Leah Ellis, co-founder and CEO of Sublime Systems, discusses how her company is producing low-carbon cement using an electrochemical approach. They aim to tackle cement's massive CO2 emissions problem which accounts for 8% of global CO2 emissions. The podcast covers Ellis' background in chemistry, the basics of cement, the outrageous amount of cement produced annually, scaling up Sublime's operations, and envisioning a carbon-free cement industry in 2035.
Cement production accounts for 8% of global CO2 emissions and is projected to increase 50% by 2050 if no action is taken.
Sublime Systems has developed an electrochemical approach to cement production that produces carbon-free cement, aiming to compete with traditional cement and decarbonize the industry by 2035.
Deep dives
The Environmental Impact of Cement Production
Cement and concrete production contribute to a significant amount of carbon emissions, with cement alone being responsible for 8% of global CO2 emissions. As the demand for infrastructure and construction continues to rise, the amount of cement produced annually is projected to increase, exacerbating the environmental impact. However, there is a need to find alternative methods to produce cement that do not release carbon into the atmosphere.
Sublime Systems, co-founded by Dr. Leah Ellis, has developed an electrochemical approach to cement production that operates at ambient temperature and uses renewable electricity. Instead of relying on fossil-fueled kilns and thermal decomposition of limestone, Sublime Systems uses an electrochemical reactor to break down inert minerals and produce reactive cement powder. The process can extract calcium from a variety of sources, including industrial wastes and basaltic rocks, resulting in a cement similar to Roman cement but without carbon emissions.
The Future of Carbon-Free Cement
Sublime Systems' technology has undergone successful testing and certification to meet industry standards for performance cement. While currently operating a pilot plant, the company is planning to commission its first commercial plant by early 2026. The ultimate goal is to compete with traditional Portland cement on both cost and scale, and to collaborate with existing cement manufacturers to decarbonize cement production worldwide. With the industry rapidly adopting performance-based standards, it is expected that by 2035, the cement used for construction will be significantly different and produced using carbon-free methods.
Cement accounts for 8 percent of global CO2 emissions. The production of one ton of Portland cement — the kind most commonly used — results in one ton of CO2 released into the atmosphere. And since cement is exceptionally cheap and the most massively produced man-made material in the world, those emissions are going to grow. “In a do-nothing scenario, emissions from cement are projected to increase 50 percent between now and 2050,” says Dr. Leah Ellis, co-founder and CEO of Sublime Systems.
Ellis’ company is producing low-carbon cement by replacing the traditional high-temperature, fossil fuel, combustion-driven kiln with an electrochemical approach that operates at ambient temperature and uses renewable electricity.
“I like to say Sublime is the electric vehicle of cement making.”
Covered in this episode:
[3:18] How Ellis’ background in chemistry led to making carbon-free cement
[5:51] Why defining cement by its performance is important
[7:48] The basics of cement
[9:29] The outrageous amount of cement produced annually
[11:29] How Sublime Systems produces cement with fewer carbon emissions
[18:06] The ability to compete economically
[23:04] Scaling up Sublime’s operations
[26:37 The leaky tap analogy to understand the climate crisis
[29:53] A vision for the cement industry in 2035
For show notes and a full transcript, head to the episode page.
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