Can green hydrogen replace natural gas in industrial hot-dip galvanising? This is the question that surface specialist ZINQ, together with its partners Westphalian University of Applied Sciences and ProPuls GmbH, is investigating in the „H2Rollout“ project. The funded development project is currently underway at the Castrop-Rauxel site; concrete practical tests on the galvanising kettle during ongoing operations are planned for a later date. Initially, simulations, design work and safety-related preliminary investigations will be carried out before the modified flat-flame burner can be used in reality.

Hot-dip galvanising requires temperatures of over 450 °C. Up to now, natural gas has supplied this energy. Hydrogen is a carbon-free alternative: it burns without CO2, but brings with it a different flame characteristic. As a result, the flame reacts differently and the temperature distribution in the kettle changes. How the technology can be integrated into demanding industrial everyday life is precisely what the stakeholders want to find out.

Gradual preparation for subsequent practical application

„We want to understand early on how we can use hydrogen safely and efficiently,“ says Robert Mill, Head of Automation and Plant Technology at ZINQ Technologie GmbH, the innovation hub of the ZINQ Group. „Technology, regulation, infrastructure and costs have to align for this. That is why we are simultaneously examining how our sites can be reliably supplied with hydrogen in the future.“

At the Castrop-Rauxel site, a pilot environment is currently being set up for subsequent testing: the plan is to further develop a hydrogen-compatible flat-flame burner so that it could prospectively replace the existing natural gas version. The transition to operation on the galvanising bath will take place in stages following the completion of current modelling and safety analyses, and will be guided by their results.

Scientific monitoring and technical development

Westphalia University of Applied Sciences is simulating the flow conditions within the burner, supporting the design phase and analysing potential impacts on emissions, efficiency and safety. ProPuls GmbH, which is also involved, is developing the appropriate control and regulation technology so that the burner will later be able to reliably maintain the tight temperature ranges of the zinc pot. All steps are initially taking place under simulation conditions, thus preparing for a planned real-world test.

An industry-wide project

„H2Rollout is part of the H2Raum initiative and is funded by the Federal Ministry of Education and Research under the T!Raum – TransferRäume für die Zukunft von Regionen programme. Until 2028, the project is investigating the fundamental feasibility of converting flat-flame burners to hydrogen, using the hot-dip galvanising plant in Castrop-Rauxel as an example. The results are later intended to serve as a guide for other galvanising plants and energy-intensive industries that also require high process heat.

Planet ZINQ as a framework

The initiative fits into the Planet ZINQ circular business model, with which ZINQ is systematically driving the transition towards a climate-neutral circular economy. Planet ZINQ pursues three goals: zero carbon, zero waste and zero pollution. The H2Rollout project potentially contributes to the zero carbon goal by exploring ways to achieve CO2-neutral process heat. Robert Mill summarises it as follows: „We are learning step by step, simulating, validating and sharing our knowledge. Following the positive outcome of the analyses, we are moving to real-world testing with the aim of using pure hydrogen at ZINQ for the first time: in the long term, this will create not only climate-neutral galvanising for us, but also a transferable model for an entire industry.“