How QC Mangers Can Evaluate the Net Impact of CO₂ Mineralization

Understanding the true cost of carbon isn’t just a matter of emissions—it’s about balancing every pound of carbon dioxide (CO₂) injected, purified, shipped, and mineralized in concrete, and recognizing how CarbonCure’s breakthrough process offsets those ‘carbon costs’ to deliver net climate benefits.

Our CO₂ utilization approach mineralizes CO₂ through reaction with hydrating cement (ready mix and precast). In each approach, a mineralization efficiency can be assumed where almost all of the utilized CO₂ is fixed as a calcium carbonate reaction product.

The implementation of the technology is accompanied by net new power consumption and transport emissions. CO₂ supplied by the merchant market would have an energy consumption of about 200 kWh/tonne liquid CO₂ produced¹. The CO₂ emissions rate from industrial energy consumption is estimated at 52.7 g CO₂/MJ or 189.7 g CO₂/kWh². The energy emissions associated with the capture, compression, and liquefaction of one tonne of liquid CO₂ results in about 0.038 tonnes CO₂ emitted. A 10% improvement in the carbon impact of energy by 2030 would lower the impact to 0.034 tonnes.

The transport of the CO₂ to the locations of utilization will be associated with a CO₂ emission. A representative rate of CO₂ emissions for freight transport would be 97 g CO₂/tonne-km of freight³. Moving one tonne of liquid CO₂ 200 km from the point source emitter to the utilization site would result in emissions of 0.019 tonnes CO₂. By 2030 the rate would improve to 89 g CO₂/ tonne-km and reduce the emissions to 0.018 tonnes CO₂.

The transport of the CO₂ to the locations of utilization will be associated with an energy consumption (estimated at 0.037 kWh/kg CO₂ injected)³ for an emissions of 0.007 tonnes of CO₂. A 10% improvement in the energy consumption rate by 2030 would reduce the emission to 0.006 tonnes CO₂. The other factors related to CO₂ utilization (e.g. the production and transport of the injection equipment) are minimal compared to the gas processing, gas transport and equipment operation. The overall impacts of the capture, transport and injection of CO₂ can be determined per tonne of CO₂ utilized. The compiled results are summarized in Table 1 and show that the process emissions in 2030 are about 5.8% of the total utilization.

Additionally, the operation of the injection equipment is associated with an energy consumption (estimated at 0.037 kWh/kg CO₂ injected)⁴ for an emissions of 0.007 tonnes of CO₂. A 10% improvement in the energy consumption rate by 2030 would reduce the emission to 0.006 tonnes CO₂. The other factors related to CO₂ utilization (e.g. the production and transport of the injection equipment) are minimal compared to the gas processing, gas transport and equipment operation⁵. The overall impacts of the capture, transport and injection of CO₂ can be determined per tonne of CO₂ utilized.

 TABLE 1: Estimated process emissions impact of CO₂ utilization in 2020 and 2030

CarbonCure for Ready Mix

CO₂ is added at a rate of 0.15% by weight of cement to ready mix concrete with a binder loading of 345 kg/m3 and a 2030 cement loading⁶ of 276 kg/m3. The addition of CO₂ increases the cement efficiency and maintains the compressive strength and thereby allows for the cement loading to be reduced by 5% without any compromise in performance. There are 14 kg/m3 of cement avoided in the modified concrete mix. The injection of CO₂ at 0.393 kg/m3 results in 0.354 kg of mineralized CO₂/m3. Taking into account the process emissions, the net mineralization is 0.331 kg CO₂ mineralized/m3 concrete. An additional 11.7 kg CO₂/m3 concrete is attributable to the avoided cement.

And if you’re interested in learning more about CarbonCure, contact us.

• 1. 26 H.-W. Häring ed: Industrial gases processing. Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim (2008).
• 2. International Energy Agency, Data and Statistics. Energy topic - CO₂ emissions indicator; Indicator - Carbon intensity of industry energy consumption; Country or Region - WORLD. iea.org/data-and-statistics. Accessed 2020-04-11
• 3. M.N. Taptich, A. Horvath, and M.V. Chester. Worldwide Greenhouse Gas Reduction Potentials in Transportation by 2050. Journal of Industrial Ecology 20, 329–340 (2016). Regional heavy heavy-duty truck emissions rates reported for 2010 and 2030. Median of regional averages of 2010 and 2030 used for 2020 scenario, median of report 2030 rates used for 2030 scenario.
• 4. S. Monkman and M. MacDonald. On carbon dioxide utilization as a means to improve the sustainability of ready-mixed concrete. Journal of Cleaner Production 167, 365–375 (2017).
• 5. S. Monkman and M. MacDonald. On carbon dioxide utilization as a means to improve the sustainability of ready-mixed concrete. Journal of Cleaner Production 167, 365–375 (2017).