Recycling carbon dioxide in the cement industry to produce added-value additives: a step towards a co2 circular economy
CO2 from the flue gases of a rotary kiln in a cement industry (CO2: 25 vol%) will be used for the production of value-added chemicals (acid additives for cement formulations) and materials (CaCO3 nanoparticles to be used as concrete fillers). A circular-economy-approach is enabled: the CO2 produced by cement manufacturing is re-used in a significant part within the plant itself to produce better cement-related products entailing less energy intensity and related CO2 emissions by a quadratic effect.
Ionic liquids (bare or amine-functionalised) will be the key technological playground for the efficient and cost-effective (<30 €/ton) purification of CO2 to a purity grade sufficient for the above mentioned utilisation paths. A dedicated pilot plant (flue gas flow rate: 50 Nm3/h) will be developed, based on the knowledge-based selection of the best ionic-liquids composition and operating conditions.
Within a final TRL 6 integrated system demo campaign, the thereby derived CO2 will be utilised in parallel to: 
-) promote the precipitation of nano-CaCO3 powders which act as strength enhancer and accelerator of the hydration rate.
-) synthesize through electrocatalytic and catalytic pathways formic acid, oxalic acid and glycine to be used as hardening acceleration promoters, grinding aids or ionic liquids additives, respectively. 
Distinctive features of the RECODE approach are the high process intensification and scale-up-ability; the use of low-grade heat sources; the meaningful reduction of CO2 emissions (>20% accounting for direct and indirect means) and the good market potential of their products at a mass production scale.
The first two years of the project will be focused on the development of key functional materials and process units at TRL 4-5, the third year on the assembly of single-process lines certified at TRL 5-6, and the fourth year on the assembly and testing at a cement manufacturing site (TITAN) of the TRL 6 integrated CO2 process.