The cement production process is one of the most crucial industrial processes worldwide, providing, on the one hand, the most important raw material for the construction industry, and on the other hand, being one of the main sources of carbon dioxide (CO₂) emissions. The growing demand for cement and, at the same time, the great awareness of the industrial and research community to reduce gas emissions make it necessary to investigate the transformation of the traditional cement production process through the development of technologies that will reduce the carbon footprint of the process.
To this direction, the SOLCEMENT project aims at developing and evaluating an integrated system on the basis of using concentrated solar radiation for the process of limestone (CaCO₃) decomposition to calcium oxide (CaO), mainly serving the needs of the cement industry.
The implementation of SOLCEMENT will be achieved through activities on two main axes. The first axis concerns the design, development, optimization and evaluation of an integrated process that will allow efficient use of concentrated solar radiation to fully or partially meet the energy requirements of CaO production for clinker feed. Using solar tower technology, SOLCEMENT provides for the design and construction of a solar furnace to be used as a pre-calciner for the production of CaO. The main objective is to investigate the extent of coverage of the energy requirements of this process, while reducing CO₂ emissions due to partial fuel substitution during preheating and decomposition of CaCO₃. The design of the system will be carried out by means of advanced computational tools, while for the development of the pre-calciner the available 50kWth rated solar kiln platform will be utilized to evaluate the system in real-world conditions.
The second axis involves the development of a compact, high energy density and structurally and chemically stable (upon cyclic operation) storage system of the solar energy offered in order to partially meet the thermal requirements of CaO production under conditions of solar radiation unavailability. The thermal energy storage system will be based on the CaO/CaCO₃ material system due to its high energy density (up to 0.85 kWhth/kg CaO) and its compatibility with the selected production process. Its development will be based on the preparation of complex materials and their formation in organized structures with adequate storage capacity, as well as structural/chemical stability as possible in their multi-cycle evaluation. Through the scaling of active material production, SOLCEMENT aims to evaluate the thermochemical storage system by designing and implementing a customized test facility.