In Essen (Germany), Verallia is experimenting with hydrogen combustion in its glass furnaces

In Verallia’s decarbonization roadmap, we have set ourselves the mission of exploring all innovative technical solutions related to glass melting, to be ready to seize the best opportunities to reduce the carbon footprint of our activities, depending on geographies and energy availability. Electrification of furnaces remains the main focus, particularly through hybridization. At the same time, we are investigating the use of biofuels and green hydrogen. Thus, we have already implemented renewable energies such as biogas, biofuel, or syngas at several sites around the world. However, integrating hydrogen requires more in-depth consideration, particularly due to the chemical peculiarities of this gas, which is the smallest existing molecule. On issues such as the tightness/permeability of pipelines, flow control devices, what modifications need to be made to the plants? For an equivalent volume, hydrogen produces three times less energy than natural gas, what consequences will this have during melting? Hydrogen combustion generates water and various compounds, what will be the impacts on glass quality and air emissions? How will the furnace react over time? What daily operational adjustments need to be considered? If a fuel change is never “plug and play,” this observation is particularly true for hydrogen! We have therefore opted for a step-by-step approach.

A 5-year partnership with ArcelorMittal

Before starting this project with ArcelorMittal in Essen, we conducted an initial test campaign at the Verallia Zaragoza plant in Spain. For several days, the furnaces operated with a mixture containing up to 60% hydrogen, delivered by truck. This experiment, carried out with the support of Air Liquide, allowed our R&D teams to characterize the implementation, equipment, safety, monitoring issues, and above all, to characterize all elements related to combustion, performance, furnace control, and emission impacts. In Essen, we are moving up a gear. ArcelorMittal supplies its hydrogen-rich energy gas from the Bottrop coking plant, a by-product of coke production. Uniper, provides the pipeline for gas transportation between our two industrial plants, about 3.5 km apart. The five-year contract for gas deliveries allows us to test the long-term effects of hydrogen use in the two furnaces at the Verallia plant in Essen Karnap.

Our goal is to ensure that hydrogen provides a large portion of the furnace’s energy needs for the coming years. To our knowledge, this is a world first for the glass industry.

Depending on the hydrogen injection rate, the Essen Karnap plant will see its CO2 emissions reduced by 8 to 10% per year. Admittedly, at this stage, it is not green hydrogen but a co-produced hydrogen that was not previously valued. Its use in glass furnaces therefore represents a real advance in terms of energy transition. Therefore, this project is strongly encouraged by the German authorities.

The partnership came into action at the end of 2024, and the Essen Karnap glass factory is now operating with a large portion of hydrogen. We will conduct various simulations, closely analyze all data to have the technical keys that would allow us to consider other energy conversions in the future if this solution proves relevant. Because let’s not hide it: there are still many hurdles to overcome, particularly the availability of green hydrogen and the economic aspects of the cost of this energy.

At Verallia, we are convinced that there will not be a single and unique solution to decarbonize glass production. Depending on the territories where our plants are located, depending on the resources and energy policies of the countries, some decarbonization options make more sense than others. We are preparing, with the R&D teams and the operational teams, for these different options by validating as many technologies as possible. With this long-term hydrogen supply project, another box is checked in Verallia’s decarbonization strategy.

photo credit: ©️hallojosh