CO2 emission reduction in the cement industry by using a solar calciner

This paper discusses the techno-economic potential of solar thermal calciner technology in the cement industry. On the basis of a solar calciner test rig built at the German Aerospace Center (DLR), a solar cement plant is designed and the heliostat field is calculated. The energy balance in the solar calciner is analyzed and different scenarios are investigated. The achievable CO2 avoidance rate for solar cement plants for the considered scenarios lies between 14 and 17%. CO2 avoidance costs are 118 EUR/t in a conservative base case and can be as low as 74 EUR/t depending on the chosen direct normal irradiation (DNI), reactor efficiency and solar multiple. A strong impact of the reactor efficiency on the costs was shown. Increasing the reactor efficiency by 15% points reduces the avoidance costs by 26%. Additionally, the CO2 emission reduction potential is calculated for Spain through 2050. It was found that for solar calciners, replacing the fossil fuel in the conventional calciner, emission reductions in the Spanish cement industry range between 2 and 7% by 2050. Implementation of a controlled sequestration of the CO2 in the solar calciner shows a big impact and emission reductions from 8 to 28% can be achieved