Development of a medium-high temperature waste heat recovery hybrid thermal energy storage layout, based on red mud, a disregarded and potentially hazardous solid waste of the aluminium industry

Solutions developed

Encapsulating PCMs in solid matrices, consisting of refractory materials, has been found to resolve most of these issues. These new materials can be used to store both sensible and latent heat (hybrid TES) potentially outperforming current TES systems. The properties of red mud (RM), a currently disregarded and potentially hazardous waste of the aluminium industry, make it an ideal candidate for PCM encapsulation. REDTHERM aims to scale up the recently discovered, by the researcher, red mud-molten salt material and demonstrate, for the first time, its performance in a novel medium-high temperature WHR layout using real industrial settings.

Main results

Europe’s industrial sector generates up to 30 % of heat-related CO2 emissions, with the European industrial thermal processes requiring around 20 % of the European energy demand. Currently, energy-intensive industries make use of waste heat recovery technologies. However, they have grown inefficient. Thermal energy storage (TES) is a technology likely to replace them, utilising phase change materials (PCM) to absorb and release medium-to-high heat. The EU-funded REDTHERM project aims to utilise these findings and Red mud, a hazardous waste material of the aluminium industry, to develop a novel thermal energy storage layout technology. REDTHERM aims to vastly improve recycling but also to contribute to the creation of a circular economy.