ACC-Biocement: A Carbon Capture Technology for Soil Improvement
1 October 2026
Affiliation
NTU
Focus topic
CO2-to-Aggregates
Carbon-negative amorphous biocement for soil improvement
Summary
Cement is among the largest single sources of global emissions, and this substitute absorbs CO₂ instead of releasing it. Sporosarcina pasteurii bacteria, a calcium chloride and ammonia solution, and pressurised CO₂ at 350 kPa are atomised together and dried into a stable amorphous calcium carbonate powder that can be stored and transported, then activated on site with a 0.5M calcium and urea solution.
Achievements: treated sand reached 1.7 MPa unconfined compressive strength within 8 hours and 8.5 MPa by 48 hours, attaining full strength of about 10 MPa after 7 days. Portland cement at the same 2.5% dose was near zero at 8 hours, 0.1 MPa at 2 days, and needed 28 days for full strength, so curing time falls by around 75%. X-ray diffraction showed calcite rising from 25.4% at 8 hours to 92.8% at 96 hours, while pH held between 7 and 7.5 throughout. Calcium carbide sludge can supply the calcium, and the ammonium chloride is recycled.
Carbon abatement is net negative, combining CO₂ consumed in production with cement displaced.
What makes this novel compared to best-in-class technology?
Ordinary cement emits CO₂ as it is made. This material absorbs CO₂ instead. Drying it rapidly in hot air is the key step, because it holds the product in a highly reactive form rather than letting it turn into ordinary chalk.
TRL Level
4-6
Relevant for
Ground improvement and geotechnical contractors, land reclamation projects, construction materials suppliers
About
Inventors: Chu Jian, Zhang Zheng, Wang Kangda, Wu Shifan
Affiliation: Nanyang Technological University, Singapore (NTU), School of Civil and Environmental Engineering (CEE)
Contact NTU for licensing opportunities and more information.
Please quote ID ref [2024-037] in your email.