Through the use of new technology, Schott group, which is a Mainz-based company, has been able to produce optical glass. This is a major breakthrough, as the company has been able to produce this glass through only using 100% hydrogen, at an industrial scale.

The company discovered that this was possible, by going through a long process of continuously using grey hydrogen to heat its furnace for three days. This was done in order to melt the optical glass and in 2023, Schott put the process through rigorous laboratory-scale testing. The results form these tests revealed that the process was ready to be scaled-up to an industrial level and this process will occur in the second half of April 2024.

During the test, the large-scale tank was filled with grey hydrogen three times at the Mainz facility. The reason for choosing grey hydrogen over green hydrogen, was because renewably produced hydrogen, remains in short supply.

Chairman of Schott’s Board of Management Dr Frank Heinricht, spoke about this choice, saying, “We deliberately decided to use it so that we wouldn’t lose any time testing its technical feasibility.”

Optical glass is a very difficult product to manufacture, as the highest homogeneity and transmission properties are required, in order to make the production process a success. It is only if the glass meets the high product requirements, that it will then be processed through to the point where it is ready to be sent to customers, goods and measurement technology sectors.  

In order to make this all possible, whilst Schott funded a lot of the project themselves, they also had various institutions offer them financial support. The German Federal Ministry of Education and Research BMBF, supported the tests that were performed and furthermore, the EU’s NextGenerationEU also provided financial backing to the project.

Schott’s Project Manager, Dr Lenka Deneke, said ‘hydrogen will be used over natural gas commercially “if the tests show that the quality of the glass is also right and the glass properties remain unchanged.”’ She continued, saying that ‘if the glass quality meets requirements, “Hydrogen would indeed be a suitable technology option. We would then have confirmation that the use of 100% hydrogen instead of fossil fuels delivers the same quality under industrial conditions.”’