Metallurgical purification without emissions - Aurubis Annual Report 2020/21

In a pilot project at the Hamburg plant, Aurubis successfully tested the use of hydrogen in the anode furnace. This facilitates a reduction process without CO₂ emissions.

Photo: Aurubis: Metallurgical cleaning without emissions — **Thorben Edens, R&D Project Manager:** “Hydrogen could replace fossil fuels in the production process in the medium term, making production more climate-friendly overall.”

Successful pilot project

Aurubis was the first company in the copper industry to test the use of hydrogen on an industrial scale. In a pilot trial extending over several weeks at the Hamburg plant, we used a gaseous mixture of hydrogen and nitrogen in place of natural gas to pole copper melt in the anode furnace during production. Poling refers to a metallurgical purification process or a reduction process in melted metal. When feeding in the gas mixture, excess oxygen bound to the copper is drawn out of the copper melt.

In the current process using natural gas as a reducing agent, carbon dioxide (CO₂) is formed as a by-product. These CO₂ emissions can be avoided when a gas mixture is used in reduction – in this case, water vapor is the only by-product of poling. A regulating station plays a crucial role in this pilot process, keeping the pressure in the anode furnace constant through the feed nozzles. Factsheet Hydrogen

The foundation for a future with hydrogen

This project enabled us to test the reaction of the facilities to the hydrogen fed into them, and we were able to get this production step up and running smoothly. As a result, Aurubis has laid the foundation for additional Group activities with hydrogen thanks to the technical experience gathered in the pilot.

Photo: Aurubis: Melting process — The test series was carried out in the anode casting wheel in Hamburg.

Photo: Aurubis: Harings and Tschentscher — First Mayor of Hamburg Peter Tschentscher (right) was also impressed by the successful pilot test (shown here with Roland Harings).

“With the successful launch of the hydrogen pilots, Aurubis visualizes a carbon-neutral future with the help of innovation.”
— Roland Harings, CEO