4th. General Assembly (Madrid) 

The Nippon Gases offices in Madrid hosted the 4th General Assembly of the Twinghy project on 8 and 9 October.  

Since the last face-to-face meeting, significant progress has been made. The first milestone has been reached: the validation of the prototype of the new hybrid burners for hydrogen and natural gas in the reheating furnace. Following positive tests at Fives Stein‘s Bar Le Duc facility, the burner met the requirements for NOx emissions, structure and thermal profile. It has been proven that the burner can operate with a mix of natural gas and hydrogen and is designed to maintain the same productivity even when the hydrogen content is reduced.  

The partners meeting in Madrid agreed to give the green light to the production of the 8 burners that will be used in the 2026 tests. With a focus on these tests, the action plan has been defined for the installation of the new burners in August and December 2025, in coincidence with technical shutdowns of the pilot plant, Celsa 3 (Barcelona, Spain). This represents a major challenge as the new larger burners are accompanied by new piping systems and electrical connections, which will have to be installed in a reduced space.  

Concerning the development of the Digital Twin, the BSC reported good results with regard to burner behaviour and continues with the promising development of the first digital twin of a reheating furnace in Europe. In parallel, we continue with the development of the physical heat transfer model and experiments related to the influence of hydrogen on refractory materials as well as CFD simulations.  

The consortium is very satisfied with the progress of the project and with the recent start-up of the manufacturing process of the new burners, a key development is achieved to move towards the implementation of solutions to reduce CO2 emissions in the steel industry.