Update on heat batteries for cement production, February 2024

Update on heat batteries for cement production, February 2024

Valentine’s Day last week included some ‘hot’ news for the cement sector with the announcement that Electrified Thermal Solutions is preparing to build the first commercial-scale pilot of its Joule Hive thermal battery (JHTB) in San Antonio, Texas. The company is working with the Southwest Research Institute on the project along with Buzzi Unicem USA, 3M and Amy’s Kitchen as industrial partners. Advisors include Imerys. The project update follows the award of a US$5m grant from the US Department of Energy (DOE) in late January 2024.

The funding description from the DOE’s Industrial Efficiency & Decarbonization Office reports that the end goal is to “turn intermittent renewable electricity into constant industrial grade heat” that can replace fossil fuel usage. Electrified Thermal Solutions aims to test its JHTB thermal energy storage system, which uses electrically conductive refractory bricks, to convert and store electricity as heat at temperatures higher than 1700°C. The JHTB power ranges between 1 – 200MW of thermal output, with duration up to tens of hours, enabling ‘very affordable’ high temperature energy storage and on-demand heat. Notably, it can charge and discharge simultaneously, allowing a continuous heat supply.

Electrified Thermal Solutions is not alone in targeting the cement sector. As Global Cement Weekly has covered previously energy storage is a growing topic of interest with a few large-scale electrical battery units running at cement plants in Pakistan and Taiwan. The other big name in thermal batteries for cement production is Rondo Energy. Both Electrified Thermal Solutions and Rondo Energy are using modular three-dimensional arrays of refractory bricks to store thermal energy and then release it, although they are likely to have key proprietary differences. However, Rondo Energy appears to be further along the industrial adoption process so far. Titan Cement and Siam Cement Group (SCG) invested in Rondo Energy in 2022. Then in July 2023 SCG and Rondo Energy said that they were planning to expand the production capacity of a heat battery storage unit at an SCG plant from 2.4 GWh/yr in mid-2023 to 90GWh/yr. For more information on Rondo Energy read the feature by CEO John O’Donnell in the January 2023 issue of Global Cement Magazine.

The reason that this matters, as partly explained above, is that fossil fuels contribute about one third of the CO2 emissions created by heating up the kiln in cement production to make clinker. This is dropping globally due to the uptake of alternative fuels, but burning alternative fuels emits gross CO2, however you account for the emissions. Mass adoption of thermal batteries by the sector could potentially cut out this double-accounting and reduce that third down to the carbon footprint of the refractory bricks used. This would then create knock-on issues concerning what to do with the waste streams instead but that is not a problem for the cement sector. These are worries for another day, as we first need to see how thermal batteries work at scale at a cement plant.

A recent feature in the Economist considered whether the mass adoption of electrical power from renewable sources might be an increasingly viable path to decarbonising industry. Geopolitics, faster-than-expected growth in renewables and new technology are all doing their bit to make this possible. As with so much of the carbon agenda it may alter the very concept of the traditional cement production line or at least the speed of change. Just imagine how a future cement plant might look, decked out with a electrical micro-grid, a heat battery, an oxy-fuel kiln, a carbon capture unit and either a chemical plant or gas pipeline junction. Will it happen? Who knows… but it is an exciting time for the cement sector.