where, 𝑚 indicates the masses of different components (biochar, cement and water) that make up the C-LWA pellets. In our case, 𝑚 : 𝑚 2: 1 (see section 2.1). is the ratio of molar masses of CO 2 and C (conversion factor from C to CO 2 ) and the minus sign accounts for the actual sink. The water included in the calculation, 𝑚 , refers to the water contained in the pellets in their dried state (as a reference state we assumed 24 h at 80 °C). As water stored in the pores of the pellets should be lost in this condition, we assumed that only water bound by the hydrated cement remains in the pellets. This is mostly chemically bound water, approximately 0.23 g/g of the reacted cement .