All for One

To produce climate-neutral hydrogen, the raw material in strongest focus at the moment is water (H₂O). Electrolysis powered by green electricity splits it into hydrogen (H₂) and oxygen (O). But hydrogen is not just found in water. It is also a constituent of numerous hydrocarbon and nitrogen compounds in wastewater, slurry and gases. Berlin-based company Graforce wants to extract hydrogen from these residual materials: It has developed a plasma electrolysis (‘plasmalysis’) process where a high-frequency plasma field is generated using renewable energy. The plasma field splits the ammonia molecules (NH₃) in sewage, or methane molecules (CH₄) in natural gas or biogas, into their atomic constituents. “Water bonds H₂ more strongly than other chemical compounds. That is why methane plasmalysis can generate a given amount of hydrogen using only one-fifth of the electrical energy of water electrolysis,” Dr Jens Hanke, managing director of Graforce, explains. This cuts production costs considerably. Furthermore, putting methane through the plasmalysis process produces, in addition to hydrogen, solid carbon (carbon black) that finds uses in the construction and steel industries, for example. And with biomethane, CO₂ is not emitted from the process but actually extracted from the natural carbon cycle. Running the technology with natural gas as the methane source would be useful in the oil and gas industry, which could consequently avoid flaring off the gas and so achieve its climate targets. The modular Graforce plants are already market-ready. Endress+Hauser supplies the measurement technology for methane plasmalysis. “Plus points include our large portfolio, our application expertise, online technical documentation and the on-site support we can offer all over the world,” Mathias Christ, a technical sales employee of Endress+Hauser Germany, explains.

Hydrogen has a large part to play in the future of steel production. The idea is to use the gas in new production processes like direct reduction that will supplant the classic carbon-based blast furnace route. But blast furnaces have long investment cycles and direct reduction requires green hydrogen in very large amounts. So bridge technologies are needed on the road to carbon-neutral steel. “One possibility is to inject coke oven gas into the blast furnaces,” says Jens Hundrieser. Coke oven gas contains 55 percent hydrogen; this replaces coal as a reducing agent and energy carrier for the process. The benefit here is an immediate way for manufacturers to lower emissions while also laying the groundwork to operate their blast furnaces with green hydrogen in future. In Germany, Dillinger and Saarstahl have been using this new technology since 2020; the injection systems come from plant builder Paul Wurth. Longstanding, partnership-based customer relationships have led both companies to equip their plants with Endress+Hauser measurement technology, including 200 Cerabar pressure sensors.