Tuning Reactive Crystallization Pathways for Integrated CO₂ Capture, Conversion, and Storage via Mineralization.

Area of Science:

• Materials Science
• Electrochemistry
• Environmental Science

Background:

• Achieving carbon neutrality necessitates efficient CO2 capture, conversion, and storage technologies.
• Anthropogenic CO2 emissions pose significant environmental challenges.
• Valorization of industrial waste streams is crucial for sustainable practices.

Purpose of the Study:

• To develop an electrochemical pathway for CO2 capture and conversion using earth-abundant alkaline resources.
• To cogenerate high-value products alongside CO2 management.
• To establish a sustainable and scalable approach for carbon neutrality.

Main Methods:

• Electrochemical desilication of alkaline industrial residues to produce Ca- and Mg-hydroxide.
• CO2 capture using solvents like Na-glycinate.
• Reaction of CO2-loaded solvents with Ca- and Mg-hydroxides to form carbonates for storage.
• Electrochemical regeneration of sorbents to produce high-purity CO2, H2, and O2.

Main Results:

• Feasibility demonstrated for crystallizing Ca- and Mg-hydroxide during electrochemical desilication.
• Effective CO2 capture and mineralization using Na-glycinate solvents (97% for Ca(OH)2, 78% for Mg(OH)2).
• High charge efficiencies (up to 95%) achieved during electrochemical regeneration of sorbents and CO2 production.

Conclusions:

• The integrated electrochemical approach offers a scalable pathway for CO2 capture, conversion, and valuable product co-generation.
• This method utilizes earth-abundant resources, contributing to a circular economy.
• The findings provide a scientific basis for advancing sustainable climate, energy, and environmental solutions.