Cement: Can We Build Without the Carbon?
Heating limestone to make cement clinker releases carbon dioxide from the limestone itself, whatever heats the kiln. This video follows the two separate fixes to that problem: making less clinker, and capturing the carbon dioxide that clinker production still produces.
It traces Joseph Aspdin's 1824 Portland cement patent in Leeds through to the modern limestone-to-clinker process, then explains lower-clinker blends including LC3, which researchers at ETH Zurich report cuts CO2 by around 40% using half the clinker of ordinary cement.
The video is equally clear about limits: Brevik captures about half of one plant's emissions, not all of it; Heidelberg's evoZero near-zero product claims use mass-balance accounting, not a physical zero-carbon guarantee; and as of 25 May 2026, the SEI/LeadIT tracker projects less than 2% of the entire cement industry's emissions being captured by 2035, even with more than 175 projects in development worldwide.
Every figure is on screen with its source and date.
In these topics
Tags
Chapters
- The carbon inside a bridge
- How Portland cement became the default
- From limestone to clinker
- Two sources of CO2
- Make less clinker first
- Capture the remaining exhaust
- Follow the CO2 to permanent storage
- What a working plant proves
- Who pays for lower-carbon cement?
- One factory versus an industry
- Can we build without the carbon?
Sources and credits
Photo credits (Wikimedia Commons)
- Portland cement clinker nodules with 10 cm scale; Commons upload 2007: LinguisticDemographer at English Wikipedia, Public domain - https://commons.wikimedia.org/wiki/File%3ALDClinkerScaled.jpg
- Oolitic limestone sample, Salem/Spergen Limestone, Indiana; photographed 5 April 2001: Mike Davis, CC0 - https://commons.wikimedia.org/wiki/File%3AOolitic_limestone_%28GeoDIL_number_-_297%29.jpg
- Raw clay sample used for pottery in northern Ghana, 20 April 2024; raw clay illustration only, not calcined clay or a verified LC3 feedstock: Alooissah, CC0 - https://commons.wikimedia.org/wiki/File%3AClay_soil_for_moulding_pots.jpg
- Rotary cement kiln at Górażdże cement plant near Chorula, Poland, 8 May 2006: Jb957, CC0 - https://commons.wikimedia.org/wiki/File%3ACement_kiln_in_Gorazdze_Cement_plant.JPG
- Historic Allis-Chalmers rotary kiln at First Portland Cement Co., South Africa, published in Cement Age December 1910; not Aspdin’s 1824 kiln: Editorial staff and correspondents of the journal Cement Age, Public domain - https://commons.wikimedia.org/wiki/File%3AAllis-Chalmers_rotary_cement_kiln_photo_in_Cement_Age_1910_v11_n6_p398.png
Primary sources
- MPA Cement, 'Portland Cement: 200 Years of Building for the Future' (2024) - Joseph Aspdin's 1824 Portland cement patent, Leeds.
- PCA, 'Roadmap to Carbon Neutrality' (Jan 2024) - ~60% of US cement-plant CO2 from calcination; CaCO3 -> CaO + CO2 chemistry.
- Brevik CCS, 'Project Update' - first CO2 captured 12 Feb 2025; first liquefaction 5 May 2025; 1,000 tonnes stored 9 May 2025.
- Norwegian Ministry of Energy, Longship release (17 Jun 2025, corroborated via thelocal.no and esgnews.com) - NOK 34bn total cost including 10 years' operation, NOK 22bn state support.
- ETH Zurich, 'Green change in a grey industry' (Nov 2023) - LC3: 50% clinker, ~40% CO2 cut vs ordinary cement.
- IEA/IRENA/UN Climate Champions, 'Breakthrough Agenda Report: Cement' (2023) - 75% average 2023 production-cost premium for low-emission cement.
- SEI/LeadIT (25 May 2026, corroborated via decarbonfuse.com) - 175+ CCUS/calcined-clay projects tracked; <2% of cement emissions projected captured by 2035; 38 projects projected operating by 2035; ~4bn tonnes cement and ~8% of global CO2 in 2024.
- Heidelberg Materials, Carbon Bank: Transactions (undated) - evoZero mass-balance accounting, used cautiously; page did not fully render on re-fetch 9 Oct 2026.
Not regulated financial advice.