The effect of cement with CCS on greenhouse gas emissions

Abstract

Besides using alternative fuels and materials for cement production, capturing and storing CO2 is necessary to meet climate targets. This report examines the effect of concrete produced with carbon capture and storage (CCS) technology in a construction project. The Vollsveien 9-11 project in Bærum municipality was selected as a case study due to its extensive use of concrete in the load-bearing structural system. Moreover, the building design has selected concrete with minor environmental impacts, such as low-carbon extreme and low-carbon A, to reduce the carbon footprint. The concrete used in the building was replaced with three concrete scenarios with cement from CCS technology: CEM STD-FA Grey, CEM STD-FA EvoBuild, and CEM STD-FA EvoZero. The environmental assessment for the production stage was then compared between the different scenarios at the building scale and for the concrete elements. Additionally, the results were compared with another scenario using industry reference values. The total impact when applying concrete with CEM STD-FA Grey is 3.3% higher than the original design. This slight increase is due to the extensive use of low-carbon extreme in the original project. However, emissions are reduced when the Evo technology is applied. When cement CEM STD-FA EvoBuild is assumed in concrete production, the overall emissions are 3.6% less than the original project. The value is reduced by 12.1% in the scenario with CEM STD-FA EvoZero. When the concrete industry reference value is assumed, the overall carbon impact of the whole building increases by 13.9% compared with the original project. When only the effect of concrete elements is compared, the concrete with CEM STD-FA Grey increases the overall impact of concrete elements by 17.4%. However, the values are reduced by 19.8% and 63.1%, respectively, for concrete with cement CEM STD-FA EvoBuild and CEM STD-FA EvoZero, highlighting the significant potential of CCS technology in reducing the carbon emissions compared to the application of low-carbon extreme concrete. The overall emissions of the concrete elements are 72.1% higher when reference values are used in the comparison. The comparisons at the building level underscore the benefits of cement with CCS technology in reducing the carbon footprint, especially when considering concrete with CEM STD-FA EvoBuild and CEM STD-FA EvoZero in the estimations. These results should assist the ongoing efforts in updating the Environmental Product Declaration (EPD) framework to emphasise and standardise the benefits of the CCS technology.