H2Mare-PtX-Wind: Influences of water chemistry, microbiology and hydrogen on the corrosion of components for offshore Power-to-X plants

Project description:

In 2020, the national hydrogen strategy was issued by the German federal government. In the field of energy research, the "Wasserstofftechnologien 2030" research offensive included three hydrogen flagship projects founded by Federal Ministry of Education and Research as major drivers for Germany's entry into the green hydrogen economy. In the H₂Mare flagship project, the project partners are to research the offshore production of hydrogen as well as possible downstream products. The energy produced by offshore wind turbines is to be used directly on-site for the production of hydrogen by means of electrolysis without grid connection. In this way, areas farther from the coast can be developed for energy production, the application and construction process for grid connection is eliminated, and the electricity distribution grid is relieved. In addition, the PtX-Wind subproject will also consider the offshore production of hydrogen downstream products. The production of basic chemicals such as liquid methane, methanol, ammonia and Fischer-Tropsch synthesis products on a floating platform will be investigated. Both on-site extraction of the synthesis gas components, e.g. carbon dioxide and nitrogen from the air or the sea and hydrogen by electrolysis, and delivery of the reactants by ship will be analyzed.

Technical Challenges:

On the technical side, the challenges of adapting the chemical production plants to the dynamic operating conditions offshore must be mastered by means of suitable intermediate storage and optimization of the processes, by permanently ensuring that the water treatment of the seawater meets the high requirements for subsequent electrolysis processes, and by developing a low-maintenance, durable plant design for all process components in order to realize safe operation and the highest level of environmental protection. For this purpose, initial experience with plant operation at sea is to be gained during the project period by means of a floating test platform erected on pontoons near the coast. At the end of the project, these results together with the knowledge gained from simulations via the creation of a digital twin will be used to develop a comprehensive concept of a research platform, which will subsequently be used to clarify the final issues of offshore PtX processes.

Research subject:

The research focus of this subproject is the fundamental evaluation of internal corrosion of equipment and piping on the PtX platform using electrochemical and spectroscopic methods in general and also internal corrosion facilitated by diffusion and permeation of hydrogen or microbial growth. In particular, a detailed study of the risk of microbiologically influenced corrosion (MIC) on internal components (control cabinets, cooling system, wastewater pipes) depending on the bacterial species and environmental conditions, an evaluation of the influence of hydrogen on the susceptibility of piping and components to corrosion for the different PtX plants, and an analysis of the influence of chlorides on the degradation of electrode materials used for seawater electrolysis will be carried out.

For this purpose, the corrosion kinetics, possible influences of microbial growth (biofilm formation, microbially influenced corrosion), the protective effect and durability of coatings as well as the susceptibility of used materials to hydrogen-induced corrosion are to be investigated using various electrochemical investigation methods. Permeation measurements, slow strain rate tensile tests and TDA analyses will be used to look more closely at the precise interactions between materials and hydrogen. These investigations will be accompanied by an in-depth material characterization, within which the surface and coating properties of the investigated materials will be characterized by various material analytical, metallographic and electron microscopic methods. In addition, corrosion products formed are to be determined and quantified, and these results are to be made available to project partners for an evaluation of possible environmental effects. The results obtained on the materials side are to be incorporated into recommendations for the selection of materials for plant and platform construction and also used in the design of standards and training content.