Dr Helen Atkinson, C-Capture, Global Cement Magazine September 2020
Due to a highly competitive market, modern cement plants are very efficient, which limits the scope to further reduce CO2 emissions via efficiency improvements. Therefore, the cement industry is taking an increased interest in carbon capture and storage (CCS) in order to significantly reduce CO2 emissions from cement production.
The World Business Council for Sustainable Development estimates that 500Mt/yr of CO2 must be captured from cement production using CCS by 2050 in order to stay within the 2°C scenario defined by the UN Paris Agreement. Significantly more will have to be captured to achieve net-zero emissions from the sector.
There are, however, significant challenges that need to be addressed when assessing the feasibility of large-scale deployment of CCS at cement plants. Firstly, deployment of CCS technology requires substantial investment, and in a price-sensitive industry, these costs are not easily passed on to the consumer.
Second is the question of what to do with the captured CO2. In some countries, this question is now being answered. For example, the industrial clusters of the UK are making progress with roadmaps for CO2 transport and storage infrastructure. However, these are only useful for cement plants located in or near a cluster. Thirdly, there are additional challenges due to the nature of the fl ue gas from cement plants, which have high levels of O2, SOx, NOx and dust.
As the calls for a post-COVID economic recovery that prioritises climate goals grow louder, it has become clear that economic stimulus packages for industry must tie in with the goal of net-zero CO2 emissions by 2050. Now is an opportune time for companies to invest in technologies such as CCS. Regarding the fate of the captured CO2, the cement industry is uniquely placed, with options directly relevant to the building sector. Many are developing technologies that turn CO2 into building materials. These include the production of aggregates via the combination of CO2 with waste ash, as well as mineralisation processes. CO2 can also be used to accelerate the rate at which concrete cures.