A case study of the feasibility of using solar concentrating technologies for manufacturing ceramics

The goal of this case study is to determine for the first time the feasibility of using concentrated solar radiation as the source of thermal energy for the various high-temperature thermal processes involved in the manufacturing of construction ceramics. A specific test device, consisting of a ‘volumetric-type’ solar receiver and a treatment chamber, has been designed and built for this purpose. This has been installed and operated in the 60 kWth solar furnace at the R&D Center ‘Plataforma Solar de Almería’. The methodology followed consisted of testing the device for the lowest temperature cycles first to go then for the higher ones successively. It has been concluded that the maximum temperature needed for thermal processes such as ‘drying of raw materials’, ‘third-firing’ or ‘double-firing’ is achievable with this solar technology (up to 1050 °C). Further development of this solar device has turned out to be necessary to meet the requirements of higher-temperature processes like the ‘single-firing’ one (1150 °C) and to improve other aspects like the achievable heating and cooling rates or the uniformity of the thermal treatment over the sample, as well. This project studies the energy transfer processes between a non-conventional, high-quality energy source (concentrated solar radiation), a thermal fluid and a solid matter piece in the search of very specific optical and mechanical properties which confer it a commercial value. Though it is was considered some time ago for the production of the so-called ‘solar fuels’ (hydrogen, pure metals, etc.), this project explores for the first time the integration of very high-temperature solar energy technology into existing ceramics manufacturing industrial process.