Hydrogen technologies for a CO2-neutral chemical industry - a plant-specific bottom-up assessment of pathways to decarbonise the German chemical industry

With approximately 21 % of total emissions in Germany, the industrial sector is one of the major emitting sectors, accounting for almost 30 % of final energy demand and predominantly using fossil fuels. Hydrogen based on renewable electricity can have a key role in the transition towards a CO2-neutral industrial production, since its use as an energy carrier as well as a feedstock in various industrial process routes is promising. One of the most important industries with great potential for hydrogen use is the chemical industry, in particular the production of basic chemicals like ammonia and methanol. While many scenarios towards 2050 see an important role for hydrogen in the 2050 supply mix for the industry sector, they are less specific on the path towards 2050 and the role of hydrogen e.g. in 2030. Here, we assess the role of hydrogen in the mid-term and further detail the possible paths towards 2050 by taking into account the specific replacement and modernisation cycles of the production plant stock and assess today's maturity of hydrogen-based technologies. The analysis includes a thorough literature review as well as the development of a plant-specific database. By considering the age structure of basic chemical process installations in Germany, 33 % can be replaced by 2030 and 89 % by 2050. This results in 11 % that have to be replaced before the end of their lifetime for getting CO2-neutral until 2050. A replacement of 100 % would lead to cumulated capital investments of about e26 billion and yearly operating costs of e15 billion. The re-assessment and benchmarking of a scenario taken from the literature for the selected products by integrating results from the analysis of plant modernisation cycles shows, that the plant replacements and market diffusion of alternative production routes could be integrated faster than assumed in the literature.