CO₂ utilization for concrete production: Commercial deployment and pathways to net-zero emissions

Area of Science:

• Construction Materials Science
• Environmental Engineering
• Sustainable Chemistry

Background:

• The cement and concrete industry contributes approximately 10% to global anthropogenic carbon dioxide (CO2) emissions.
• Urban expansion and infrastructure renewal drive the demand for cement and concrete.
• Reusing waste CO2 in construction materials promotes circular carbon economies and carbon-negative development.

Purpose of the Study:

• To provide a holistic overview of upscaled technologies for CO2 utilization in cement-based materials manufacturing.
• To analyze the interplay of these technologies in achieving net-zero emissions (NZE) in the concrete sector.
• To identify diversified NZE strategies tailored for various construction products.

Main Methods:

• Review and analysis of industrial-scale CO2 utilization technologies in cement and concrete production.
• Scrutiny of the current status of NZE agendas in the concrete sector.
• Examination of decarbonization pathways for different concrete products.

Main Results:

• Small precast and lightweight concrete elements are leading in carbon-neutral manufacturing.
• Ready-mix concrete presents significant decarbonization challenges, requiring pre-carbonated ingredients, ideally from alkaline wastes.
• Diversified NZE agendas are crucial, acknowledging the varied nature of built products.

Conclusions:

• Combining CO2 utilization with low-CO2 cement development is essential for effective decarbonization strategies.
• Tailoring strategies for individual products is necessary to accelerate the transition to NZE in construction.
• The paper outlines credible pathways and research needs for implementing sustainable construction practices.