# Fixing cement’s carbon problem

- Show: [Catalyst](https://hardwarepodcasts.com/podcast/catalyst)
- Published: 2022-11-17
- Length: 43m
- Page: https://hardwarepodcasts.com/podcast/catalyst/2022-11-17-fixing-cements-carbon-problem

## Summary

Leah Ellis, co-founder and CEO of Sublime Systems, explains how her company uses electrochemical processes to produce cement at room temperature, avoiding the high-temperature kilns and limestone decomposition that cause 8% of global emissions. Shayle Khan of Energy Impact Partners discusses the limitations of current decarbonization strategies, including supplementary cementitious materials like fly ash and post-combustion carbon capture, highlighting why they offer only incremental reductions. The conversation covers the technical properties of Portland cement, the centralized nature of cement production versus the distributed ready-mix market, and the economic argument that low-carbon cement's 'green premium' is negligible compared to total construction labor costs.

## Chapters

- [0:04](https://hardwarepodcasts.com/podcast/catalyst/2022-11-17-fixing-cements-carbon-problem#t=4) Introduction: The Scale and Emissions of Cement
- [5:43](https://hardwarepodcasts.com/podcast/catalyst/2022-11-17-fixing-cements-carbon-problem#t=343) Cement Chemistry and the History of Portland Cement
- [13:50](https://hardwarepodcasts.com/podcast/catalyst/2022-11-17-fixing-cements-carbon-problem#t=830) The Value Chain: From Kilns to Ready-Mix Concrete
- [19:50](https://hardwarepodcasts.com/podcast/catalyst/2022-11-17-fixing-cements-carbon-problem#t=1190) Decarbonization Pathways: Carbon Capture and Alternative Fuels
- [21:33](https://hardwarepodcasts.com/podcast/catalyst/2022-11-17-fixing-cements-carbon-problem#t=1293) Supplementary Cementitious Materials and Fly Ash Shortages
- [27:40](https://hardwarepodcasts.com/podcast/catalyst/2022-11-17-fixing-cements-carbon-problem#t=1660) CO2 Injection and the Carbonation of Concrete
- [32:35](https://hardwarepodcasts.com/podcast/catalyst/2022-11-17-fixing-cements-carbon-problem#t=1955) Sublime Systems' Electrochemical Cement Process
- [40:03](https://hardwarepodcasts.com/podcast/catalyst/2022-11-17-fixing-cements-carbon-problem#t=2403) Market Adoption and the Economics of Low-Carbon Cement

## Topics

- [Energy & climate tech](https://hardwarepodcasts.com/topic/energy-and-climate-tech)
- [Materials & manufacturing processes](https://hardwarepodcasts.com/topic/materials-and-processes)
- [Scaling production](https://hardwarepodcasts.com/topic/scaling-production)
- [Pricing, margins & unit economics](https://hardwarepodcasts.com/topic/pricing-and-unit-economics)

## Most relevant to

early-stage companies

## Mentioned

- Sublime Systems (company)
- Energy Impact Partners (company)
- CarbonCure (company)
- Energy Hub (company)

## Related episodes from other shows

- [Reinventing Cement: The Breakthrough That Could Cut 8% of Global Emissions with Greg Williams](https://hardwarepodcasts.com/podcast/hardware-to-save-a-planet/2025-03-27-reinventing-cement-the-breakthrough-that-could-cut-8-of-global-emissions-with-gr) (Hardware to Save a Planet)
- [Literally unearthing a climate solution with Cody Finke of Brimstone](https://hardwarepodcasts.com/podcast/how-i-built-this/2023-11-16-literally-unearthing-a-climate-solution-with-cody-finke-of-brimstone) (How I Built This)
- [Re-Engineering Chemical Production for Carbon Dioxide Removal with Dr. Laura Lammers, Founder and CEO of Travertine](https://hardwarepodcasts.com/podcast/hardware-to-save-a-planet/2022-11-24-re-engineering-chemical-production-for-carbon-dioxide-removal-with-dr-laura-lamm) (Hardware to Save a Planet)
- [Building a decarbonization army with Shashank Samala of Heirloom](https://hardwarepodcasts.com/podcast/how-i-built-this/2024-02-08-building-a-decarbonization-army-with-shashank-samala-of-heirloom) (How I Built This)
- [120. Carbon Soaking Concrete](https://hardwarepodcasts.com/podcast/the-next-byte-podcast/2023-05-02-120-carbon-soaking-concrete) (The Next Byte Podcast)

## Citing this page

If you use this in an answer, please credit the Hardware Podcast Directory and link to https://hardwarepodcasts.com/podcast/catalyst/2022-11-17-fixing-cements-carbon-problem. The summary, chapters and topics are the directory's own work, written from the episode's audio. The episode itself, its title and its audio belong to Catalyst.