Expertise for the Hydrogen Age

Ultimately, the steel industry is seeking to eliminate CO₂ emissions altogether. In a process known as carbon direct avoidance (CDA), it is possible to reduce iron ore directly and prevent the formation of CO₂ almost entirely. In partnership with the company Salzgitter, researchers from Fraunhofer IKTS are now working on this process in the BMBF-funded project MACOR. To date, coal has been used for the direct reduction of iron ore. This new process uses hydrogen as the reducing agent, which cuts CO₂ emissions by as much as 95 percent, depending on the degree of implementation of this technology. The hydrogen for this purpose is produced by means of electrolysis powered by renewable energy, and the iron then turned into steel in an electric arc furnace powered by electricity generated from renewable sources. A highly promising approach here is high-temperature electrolysis. Demonstrators on a scale of 100 kilowatts are already in operation. The next step will be to transfer this process to the gigawatt scale. Once again, Fraunhofer IKTS will play a vital role, providing ancillary research and heading up process simulation in particular.

Steel production is not the only sector of industry to produce waste gases and wastewater. In Colyssy, a project in partnership with the company Johann Bergmann, researchers from Fraunhofer IKTS are developing an integrated process for the commercial exploitation of industrial waste gases and wastewater from a lime works. The objective is to produce useful chemicals. This process features a combination of high-temperature co-electrolysis, CO₂ separation by means of special ceramic membranes, and the Fischer-Tropsch synthesis with a newly developed, scalable reactor concept. This produces synthetic waxes, which can then be used as lubricants or as base materials for the production of cosmetics. The plant is scheduled to start operation in 2021. Fraunhofer researchers are also working on process development. This involves simulating and enhancing the entire process. By coupling the individual process steps at the lime works, it is also possible to use by-products from the Fischer-Tropsch synthesis in the combustion process, which creates options for greater flexibility.

In a related area, mine water heavily contaminated with minerals and sulfates can be treated with the RODOSAN process, which was developed by Fraunhofer IKTS. Here, three things happen in parallel: hydrogen is recovered from the mine water to serve as an energy carrier; iron in the mine water is reduced and thereby recovered; and toxic substances, especially sulfur, are concentrated and recovered for use in fertilizers. Between 45 and 70 percent of the sulfates contained in the mine water can be removed in this way. A pilot plant with a capacity of 6 cubic meters per hour is available for the purposes of technical analysis and process optimization.

• Ceramic technologies for highly efficient power-to-X processes
• Water and waste water technology

The transition to a sustainable energy system poses a fundamental question. If renewable power cannot be fed into the grid immediately, how can it be stored at the place where it is generated? In other words, how can locally generated power be made available in order to cover fluctuating demand? This is where P2X technology enters the equation. Here, renewable power is used for electrolysis, and the hydrogen thereby produced is stored and then converted into chemicals, fuel or gas. This process is known as power-to-chemicals, power-to-fuel or power-to-gas. An example of a power-to-gas application is the ICOCAD project from Fraunhofer IMM. Using an innovative reactor system, CO₂ recovered from biogas plants and biorefineries is converted to methane through the addition of hydrogen produced via the electrolysis of water. At present, researchers are developing new plant designs, conducting tests on a pilot scale and installing a reactor in an existing plant. In a related project, they are also working on catalysts for this process that are long-lasting and resistant to poisoning and coking. The modular design of the reactor means that it can be easily adapted to the size and specifications of the carbon dioxide and hydrogen sources.

The eSource^® platform evolved out of the Fraunhofer lighthouse project Electricity as a Raw Material. All in all, ten Fraunhofer Institutes are working to develop and enhance processes that use renewable power to synthesize key basic chemicals. One of the demonstrators developed for this purpose exhibits the electrochemical production of hydrogen peroxide (H₂O₂) from oxygen and hydrogen. Hydrogen peroxide is used as an oxidation agent in the chemical industry. Direct synthesis of hydrogen peroxide from molecular oxygen and hydrogen would offer an economic, safe and clean alternative to the current production process, which involves strict safety requirements. In the greoKEMS project, funded by the Federal Ministry for Economic Affairs and Energy (BMWi), researchers from Fraunhofer IFF are currently investigating energy efficiency in the field of process engineering and exploring ways of comparing different energy values.

• Fraunhofer Institute for Microengineering and Microsystems IMM

Regardless of which P2X or other hydrogen technology is used, it is always based on hydrogen produced by means of electrolysis with renewable power. Fraunhofer IMWS is therefore building a test and experimentation infrastructure for electrolyzers in the megawatt range – up to a scale of 5 megawatts – at the Leuna Chemical Park. Four project stations, each with space for two or three 40-foot containers, are to be available from 2020. Project partners will be able to reconstruct the entire process chain, including downstream processes such as methanol synthesis. Researchers will assess the projects, supervise test equipment, run various test cycles and evaluate the results. The hydrogen generated by these projects can be fed into the 150-kilometer pipeline that connects various chemical parks in the region.

Partners to the project GreenHydroChem Mitteldeutsches Chemiedreieck are likewise seeking to enhance electrolyzer performance. This project was among the winners of the competition to become one of the living labs for the energy transition. A team comprising Fraunhofer IMWS and the companies Siemens and Linde is focusing on three aspects and their intelligent combination: production – large-scale electrolysis; transport – a hydrogen pipeline; and storage – a hydrogen cavern together with bulk users of green hydrogen. The partners intend to use and expand existing infrastructure for this purpose. This involves, for example, work by Siemens to upscale the electrolyzer from 5 megawatts to 50 megawatts. Fraunhofer researchers are providing the accompanying research and producing a guideline for the electrolysis. This includes a scientific analysis of the production gases during operation. The Green-Hydro-Chem project is located in Leuna and scheduled to run until 2024. With a capacity of over 100 megawatts, it is the world’s largest electrolysis plant for the generation of green hydrogen.

• GreenHydroChem project

Hydrogen from biogenic sources

Biogenic residues and waste are another potential source of green hydrogen. Fraunhofer UMSICHT has developed a process for generating hydrogen from feedstocks based on biomass. TCR^® is a thermo-chemical conversion process that yields an extremely hydrogen-rich synthesis gas. Moreover, the stable, carbonized solid that is produced in this process can also be gasified in order to generate hydrogen. The TCR^® process is currently being demonstrated in the EU project ToSynFuel, which has a throughput of 12 metric tons of residue a day.

Fraunhofer UMSICHT, Institutsteil Sulzbach-Rosenberg

• The Demonstration of Waste Biomass to Synthetic Fuels and Green Hydrogen project (TO-SYN-FUEL)