Decarbonizing the chemical industry with PEM electrolysis

The BASF factory in Ludwigshafen is a city in itself: With about 33,000 people working there, it is the largest integrated chemical complex in the world, stretching 5 kilometers along the river Rhine. Here, in the Southwest of Germany, BASF produces petrochemicals like ethylene and propylene, various acids, alcohols, dispersions, resins and electronic materials for coatings, construction, transportation and other industries. And 160 years after its establishment, the site is still the place where bold steps towards innovation are taken. 

In an inconspicuous factory hall, Germany’s largest PEM electrolyzer (Proton Exchange Membrane) with a power demand of 54 megawatts, producing green hydrogen, was recently commissioned. The plant with 72 electrolysis stacks of the Hy4Chem project, delivered by Siemens Energy, is calmly humming on this late season afternoon – producing one ton of green hydrogen per hour – a potential of roughly 8,000 tons per year. 

Peter Schwab of BASF, in charge of Hy4Chem, recalls the year 2021, when BASF was closely examining all branches of its production in order to reach its own climate goal: net-zero greenhouse gas emissions by 2050. “Sustainability is in the DNA of BASF, and as a frontrunner in the chemical industry we develop new technologies from the very beginning and try to be the first ones to implement them subject to a positive business case,” says Schwab. With the electrolyzer running at full capacity, BASF can save up to 72,000 tons of CO₂ per year.

The choice fell on Siemens Energy’s PEM technology as it is more ecological and space saving than conventional methods. Space was a crucial issue on the BASF ground, its ten square kilometers being densely packed with industrial plants, pipelines and roads. The idea to integrate the electrolyzer into an existing production and infrastructure network fits well into the company’s “Verbund” network idea: Production facilities, energy flow, logistics and infrastructure are networked together intelligently in the Verbund. In this system, chemical processes can run in a resource-efficient way with lower energy consumption and higher yields.

The decision to build Hy4Chem was a bold step, but facilitated by financial support of €124.3 million from the local government and the European Union’s IPCEI H₂ program (“Important Project of Common European Interest”). After its commissioning, although hard to find on BASF’s site, the visibility of the project is huge: Visitors, from politics as well as from the industry, regularly come to inspect the facility, says Schwab. “And our employees are proud to have this plant here on site.” Schwab himself recalls how, as a child, he used to experiment with electrolysis using his Kosmos chemistry set: “Now, toward the end of my professional career, to see it again at industrial scale is something truly special.”

The scope of use for the green hydrogen produced in Ludwigshafen is huge. It can be utilized in the production of ammonia, vitamins, methanol, and specialty products such as neopentyl glycol, in other words: wherever hydrogenation is required in the chemical process. Apart from that, there are plans to use it for the public transport fleet of the city. A green hydrogen filling station already exists next to the BASF plant. 

“This project showcases that it is absolutely possible to produce green hydrogen at a large scale,” says Siemens Energy’s Lydia Thelen. “Our message is: the technology is there, and we are ready.” In several European countries, the construction of electrolyzers is under way. For example, two plants with Siemens Energy’s electrolyzer technology for the production of green hydrogen, one with a capacity of 100 megawatts, the other more than the double, are under construction in the North of Germany. And Germany is building a Hydrogen Core Network, with roughly 9,700 kilometers of hydrogen pipeline coming into operation across the country from 2025 to 2027. 

But for a full ramp-up of a green hydrogen economy, Germany and Europe need supportive regulation, both Schwab and Thelen agree. “The role of green hydrogen in the chemical industry can ramp up to a significant volume demand, but this is all subject to regulation, which is not there at the moment. Even more, it is dependent on the willingness of customers to pay slightly higher prices for greener products,” says Schwab. 

So far, BASF is using the flexible mass balance approach, co-feeding the green hydrogen into the grid along with conventionally generated hydrogen recounts Schwab: “The ramp-up of green hydrogen at our site is relatively slow, and we can adjust the needs for green hydrogen with our production of fossil-based hydrogen production.” An important trait of the plant in this regard is its high flexibility: If there’s a lot of wind and the windmills are producing enough green energy, the electrolyzer can be ramped up quickly – and the other way round. 

And the cooperation continues: Employees of both companies are regularly sharing data and experience of the site, helping shape the future of water electrolysis technologies for green hydrogen production across Europe and beyond.  “We work together in order to improve the plant – and to learn for future projects,” says Thelen.