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The cement industry is one of the major sources of CO 2 emissions and is likely to contribute to further increases in the near future. The carbonate looping process has the potential to capture CO 2 emissions from the cement industry, in which raw meal for cement production could be used as the sorbent. Cyclic experiments were carried out in a TGA apparatus using industrial cement raw meal and synthetic raw meal as sorbents, with limestone as the reference. The results show that the CO 2 capture capacities of the cement raw meal and the synthetic raw meal are comparable to those of pure limestone. The CO 2 capture capacity of limestone in the raw meal is lower than for pure limestone. The difference in the CO 2 capture capacity decreases with an increase in cycle number. The calcination conditions and composition are major factors that influence the CO 2 capture capacity of limestone. At 850°C in N 2 , the capacity of synthetic raw meal was similar to that of pure limestone, whereas at 950°C in N 2 and in a CO 2 -rich atmosphere there was a significant difference. The SEM and BET analyses indicate that sintering is the main reason for the lower capture capacity of the limestone in the raw meal. The main components of the raw meal used along with the limestone have different effects on the CO 2 capture capacity of the limestone. Al 2 O 3 has the most negative effect, followed by Fe 2 O 3 , whereas SiO 2 showed no effect. These interactions can be observed as a correlation between the measured surface area and the CO 2 capture capacity. The XRD results indicated an increase in crystallite size and the formation of new phases due to the reaction between the main components of the raw meal and the limestone, which also has an effect on the CO 2 capture capacity. The formation of dicalcium silicate was also observed by XRD analysis in the calcined synthetic raw meal. The effect of calcination conditions and compositions on the CO 2 capture capacity as a function of cycle number is described by a correlation equation. This equation is used to determine the decay constant (k) and residual CO 2 capture capacity (X r ). This shows that raw meal could be used as a sorbent for the easy integration of the carbonate looping process into the cement pyro process for reducing CO 2 emissions from the cement production process.

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The ash behavior during suspension firing of 12 alternative solid biofuels, such as pectin waste, mash from a beer brewery, or waste from cigarette production have been studied and compared to wood and straw ash behavior. Laboratory suspension firing tests were performed on an entrained flow reactor and a swirl burner test rig, with special emphasis on the formation of fly ash and ash deposit. Thermodynamic equilibrium calculations were performed to support the interpretation of the experiments. To generalize the results of the combustion tests, the fuels are classified according to fuel ash analysis into three main groups depending upon their ash content of silica, alkali metal, and calcium and magnesium. To further detail the biomass classification, the relative molar ratio of Cl, S, and P to alkali were included. The study has led to knowledge on biomass fuel ash composition influence on ash transformation, ash deposit flux, and deposit chlorine content when biomass fuels are applied for suspension combustion.