Method and System for Converting Carbon Dioxide into Solid Carbonates
1 October 2026
Affiliation
A*STAR
Focus topic
CO2-to-Aggregates
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Summary
This patent discloses a low-temperature, low-pressure mineral carbonation process that converts captured carbon dioxide (CO₂) into stable solid carbonates for permanent carbon sequestration. Unlike conventional direct aqueous pressure carbonation (DAPC) technologies that require high temperatures (>150°C) and high pressures (>115 bar), the invention uses thermally activated ultramafic minerals such as serpentine or olivine together with ammonium carbonate solutions to achieve carbonation under mild conditions, including room temperature and atmospheric pressure. CO₂ is first absorbed by aqueous ammonia to form ammonium carbonate, which then reacts with the activated mineral feedstock to produce magnesium carbonate and silica while simultaneously regenerating the ammonia for reuse. The process creates a closed-loop carbon capture and mineralization system with significantly reduced energy demand and operating costs.
Key Achievements:
Developed a one-step mineral carbonation process that operates at room temperature and atmospheric pressure
Permanently converts CO₂ into stable solid carbonates, providing long-term carbon sequestration
Uses ammonium carbonate as a recyclable reaction medium, enabling regeneration and reuse of ammonia
Eliminates the need for expensive high-pressure carbonation reactors and compressors required by conventional processes.
Demonstrated carbonation efficiencies of approximately 40-45% under mild operating conditions.
Achieved substantial reductions in process economics, including an estimated ~40% reduction in sequestration cost and major reductions in electricity and heat consumption
Applicable to abundant ultramafic minerals such as serpentine and olivine, improving scalability for industrial carbon capture deployment
Produces potentially useful solid carbonate and silica by-products alongside carbon sequestration.
What makes this novel compared to best-in-class technology?
Unlike conventional carbon mineralisation routes that require pure mineral feedstocks or high-pressure conditions, this process uses thermally activated ultramafic rock (naturally abundant) and regenerates ammonia in a closed loop, reducing operating costs.
The combination of accessible feedstock, ambient-pressure operation, and reagent recovery addresses key cost and scalability barriers in mineral carbonation.
Current TRL
1-3
Relevant for
Industrial CO₂ emitters, construction materials producers seeking carbon-sequestered aggregates
About
Inventors: Jie Bu, Tze Yuen Yeo, Paul Sharratt
Affiliation: Agency for Science, Technology and Research (A*STAR), Institute Of Sustainability for Chemicals, Energy And Environment (ISCE2)
Related IPs: ID ref [Z2012-569] Method of Producing Metal Carbonate From an Ultramafic Rock Material
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