Swiss scientists have determined 80% cuts to emissions from the concrete sector are possible without using carbon capture technology.
Scientists working with the Swiss Federal Institute of Technology have said that changing how cement and concrete are made, transported and used could cut sector emissions by 80%.
Cementitious materials make up more than half of all materials used in construction, and while they are low embodied energy materials, the widespread use of them means that they account for approximately 8% of global emissions.
Up to 60% of the emissions from the cement sector come from the production of clinker, the active component of cement. This primarily uses calcium carbonate as a source of calcium for the clinker, but releases a great deal of CO2. Outside of carbon capture technology, use of new efficient kilns could mean ”a 10% improvement in the best case scenario at the global level [of emissions]”, says the report.
The report, headed by project manager Aurélie Favier, acknowledges that the process behind cement production is already efficient, and as such, carbon savings can be made in other areas with use of new technologies and opitmisation of material needed use.
“Considering all the stages in the value chain, reductions of up to 80% CO2 emissions compared to the 1990 values is achievable by 2050 without using carbon capture and storage technologies,” the report states.
Improvements to the value chain recommended in the report include:
- Significant increase in the use of alternative fuels
- Recycling of concrete with fines reused as raw material for clinker production
- Optimisation of the concrete mix design via better aggregate packing
- Strictly not exceeding the requirements of codes and standards to avoid the over use of cement in concrete.
The group also concluded that total decarbonisation to keep the sectors in line with a 1.5ºC Paris climate agreement target was “technologically feasible” but would “require very large investments in the cement industry” and up to 80% carbon capture.