Carbon Dioxide Uptake Estimation for Spanish Cement-Based Materials

Abstract

The Intergovernmental Panel on Climate Change (IPCC), which is the United Nations body for assessing the science related to climate change, has recently recognized the natural carbonation process as a way of carbon offsetting with mortar and concrete. Accordingly, this activity could be recognized as a carbon removal process for which certification should be granted. The aim of the certification of carbon removal is to promote the development of adequate and efficient new carbon removal processes. Therefore, the main objective of this study is to provide reliable results on carbon dioxide uptake by cement-based materials in Spain. Yearly, greenhouse gas emissions are reported to the United Nations Framework Convention on Climate Change (UNFCCC) by each country, and the natural carbonation should be added up to the carbon accounting. Therefore, natural carbonation should be included in the IPCC Guidelines for National Greenhouse Gas Inventories, and such accounting information should be made available promptly to the national regulatory authorities. This paper provides the results of carbon dioxide uptake by Spanish cement-based materials from 1990 to 2020 by using an easy method of estimating the net carbon dioxide emissions (simplified method) considering the carbon dioxide released by the calcination during clinker production (process emissions). The outcome of this study reveals that there was 93,556,000 tons of carbon dioxide uptake by the mortar and concrete manufactured in Spain from 1990 to 2020.

Carbonation Resistance of Ternary Portland Cements Made with Silica Fume and Limestone

“…In addition, carbon dioxide uptake by mortars and concretes has recently been included in the Global Carbon Budget report [ 43 ] since natural carbonation stores permanently carbon dioxide. Furthermore, these blended cements usually absorb more carbon dioxide than CEM I [ 7 , 9 , 11 , 18 ]. Then, appropriate methodologies for future concrete mix design should consider durable and sustainable aspects, i.e., to ensure the reinforced concrete service life but also to account for carbon dioxide uptake [ 6 ].…”

“… Global carbon dioxide uptake by cement-based materials from 1960 to 2023, reported by the Global Carbon Budget report, and the carbon dioxide uptake estimated by the Tier 1 methodology «source: Ref. [ 7 ]». …”

“…It means that above 700 Mtons/year could be attributed to the carbonation sink. This estimation is compared to the carbon dioxide uptake estimated by the Tier 1 methodology (dashed line green in Figure 1) defined and calculated in reference [7]. Accordingly, a ternary cement made with Portland cement clinker, limestone powder, and a third cement constituent, for example, coarse silica fume, can be a promising construction product due to the good experience [34,44], the adequate availability of the constituents, and the low environmental impact.…”

“…Efforts to lower the carbon dioxide emissions from Portland cement manufacturing include alternative fuels and raw materials during Portland cement clinker production and low-carbon cements with a low clinker factor. In addition, for climate change mitigation purposes, a more specific and complete inventory may be needed by considering the carbon dioxide uptake by cement-based materials [ 7 ]. Through this, it would be possible to establish a more complete life cycle inventory of concrete in terms of carbon footprint [ 8 , 9 , 10 , 11 , 12 ].…”

“…It means that above 700 Mtons/year could be attributed to the carbonation sink. This estimation is compared to the carbon dioxide uptake estimated by the Tier 1 methodology (dashed line green in Figure 1 ) defined and calculated in reference [ 7 ].…”