Carbon Dioxide Uptake by Brazilian Cement-Based Materials

Abstract

The worldwide cement industry plays an important role in addressing the climate change challenge. Brazil’s cement industry currently has 91 cement plants with an installed production capacity of 94 million tons per year and has started to calculate the net CO2 emissions to achieve a carbon-neutral cement sector by 2050. Accordingly, the carbon dioxide uptake due to mortar and concrete carbonation is subtracted from the carbon dioxide emitted by the chemical reaction for the calcination of lime, i.e., the calcination process performed during clinker production. Now-adays, the Intergovernmental Panel on Climate Change (IPCC) Guidelines for National Greenhouse Gas (GHG) Inventories to report the GHG emissions do not include any calculation procedure to consider the mortar and concrete carbonation. However, the Intergovernmental Panel on Climate Change (IPCC)’s Sixth Assessment Report (AR6) recognizes the physico-chemical process known as carbonation. Brazilian net carbon dioxide emissions of cements produced from 1990 to 2019 are estimated considering the carbon dioxide uptake during the service-life and end-of-life and secondary usage stages (Tier 1). This is a fundamental scientific and technological novelty that changes the current approach to estimate the carbon dioxide emissions due to the Portland cement clinker production. Even considering the relative novelty of this approach, it should be promoted in the future and included in the national inventory report (NIR). The carbon dioxide uptake by mortar and concrete carbonation for 30 years is about 140 million tons. Within this thirty-year period about 483 million tons have been released due to the calcination process.

Carbon Dioxide Uptake Estimation for Spanish Cement-Based Materials

“…Estimation of carbon dioxide uptake by cement-based materials involves interdisciplinary efforts to assess scientific evidence for policymakers. Accordingly, the results presented in this study are classified as "very high confidence" since these findings are robust; they are based on consistent lines of high-quality research [48] and there is a great scientific agreement on concrete carbonation estimation, which is well-established in the scientific community [32,51]. In addition, the likelihood term associated with the projection of carbon dioxide uptake presented in this study is "very likely", referring to the 90-100% probability according to the IPCC guidance note which translates each likelihood term into a probability interval [49].…”

Dry-wet cycles durability of solid waste based cementing materials solidifying different characteristic soils

“…However, the production of cement represents an industrial process with high carbon emissions. It is estimated that one tonne of cement results in the emission of 0.8 tonnes of carbon dioxide [5,6]. Consequently, the extensive utilisation of cement in the context of soil solidification is likely to result in significant environmental degradation.…”