Hrastnik1860 conducts hydrogen furnace trials with Sorg

Hrastnik1860 and Sorg will conduct an industrial-scale trial to heat a glass melting furnace with hydrogen.

Hydrogen can substantially reduce CO₂ emissions from the combustion of a glass melting furnace, with the use of green hydrogen avoiding them altogether.

The two companies had worked on a laboratory and pilot scale to test the use of hydrogen for glass production.

Sorg has already tested various burner types, and newly developed gas-oxygen and underport burners (SDB) are being prepared on an industrial scale.

The Sorg SDB underport burner has been operated with 100% H₂ in the GWI Hy-Glass project, while another test with a natural gas/H₂ and LPG/H₂ mixture starts in early 2024.

In this industrial style set with Hrastnik1860, the safety measurement, control system and calculation software were designed specifically for hydrogen and was delivered.

Installed on a furnace so that both hydrogen and pure operation with hydrogen or gas can be supplied in normal operating conditions, the existing gas and oxygen supply equipment were utilised in the process chosen by Sorg.

The H₂ supply and control systems meet all applicable standards and regulations, as well as gaining official approval for safety.

During December 2023, the oxyfuel-powered glass furnace of Hrastnik1860 was switched from gas to hydrogen.

Individual burner pairs were gradually switched to hydrogen and the hydrogen content in the gas was gradually increased.

Gas content was reduced to an energy equivalent, and the oxygen was adapted to the lower oxygen demand.

Only the Vol-% - H₂ proportion was set on the control system, with all heating parameters calculated and controlled automatically.

The burners were operated with 100% hydrogen for several days.

A second test switched the melting furnace burners directly from 100% natural gas to 100% hydrogen.

This trial shows the possibility of switching to hydrogen with the appropriate system technology and control.

The results suggest that it’s relatively easy to switch and revert a furnace to hydrogen by adapting the heating system to the different physical properties of gas and hydrogen.

Operational changes were also within the expected range and controllable.