Still alive, but different in the future? Decarbonisation of industrial steam boilers from a multi-dimensional perspective

The first steam applications were already invented two millennia ago; due to its versatility, industry will still need steam in the future. In view of the current climate targets, a shift towards carbon-free steam-generation is required while it is still mostly based on fossil fuels today. Future alternatives that are based on the direct use of renewable electricity or green hydrogen are not yet economically favourable or they are still under development, also due to the comparatively high electricity prices. This paper therefore investigates CO2-neutral steam generation in two respects: First, compared to the current state of the art, which electricity-based technologies are available for steam generation and what is their development status? And second, how are the technologies evaluated in comparison to the current fossil reference technology from a multi-dimensional perspective encompassing ecological, economic and technical criteria? In this paper, these questions are addressed along three applications for steam generation in the paper, food and chemical industries. For this purpose, a concept for a multi-dimensional analysis with a perspective up to the year 2050 is introduced and applied. The required data was obtained from literature, a quantitative model and 19 semi-structured interviews with industry representatives, manufacturers and research institutions. The results indicate that various alternative technologies (electrode boilers, heat pumps, hydrogen-fired steam boilers) are available, but their technology readiness level varies. To contribute to their widespread deployment in industry, policy making will have to ensure competitive economic as well as ecological and infrastructural framework conditions with a long-term perspective.