Electrification of clinker and calcination treatments in the cement sector by microwave technology – A review

Electrification of clinker and calcination treatments is one of the decarbonation options for the cement industry. In this review, the technological potential of microwave heating to realise this electrification is assessed. In microwave heating, electricity is converted into electromagnetic radiation that can directly and volumetrically be absorbed by the product. A theoretical discussion on basic microwave-material interactions is provided, and the relevant technological aspects are considered. Early feasibility studies are reviewed and interpreted, complemented by a set of dielectric measurements of the relevant raw materials collected from literature. Based on these insights, and supported by relevant journal publications or research project results, different pathways towards scaling-up are discussed, like a combination of conventional and microwave heating, susceptor-assisted microwave heating, and direct microwave heating.