where the 𝐸 * are the specific emissions of the cement. It should be mentioned that this parameter can vary depending on the type of binder (ratio of clinker replacement with low-CO2 components) and production processes (in particular, different ratios of primary and bio fuels used in cement kilns). We used CEM I as the cement with the highest emissions, with 𝐸 * 0.641 𝑘𝑔𝐶𝑂 /𝑘𝑔 (production in Switzerland) . Composite cements, e.g. of type CEM II, have lower emissions. At the same time, the absorption of CO 2 due to the carbonation of the cement in the pellets should be considered, 𝐸 . This is relevant because, due to the small size of the pellets and their high porosity, this process can take place relatively fast during initial conditioning/curing of the pellets. From this point of view, the pellets are similar to recycled concrete aggregates that experience an accelerated carbonation within months after they were crushed from the original concrete elements. According to a recent study , carbonation in such conditions may bind between 6 and 22% of the initial emissions of cement. Assuming 15% of absorption of the original emissions, 𝐸 0.096 𝑘𝑔𝐶𝑂 /𝑘𝑔.