The two companies’ vision is to supply the integrated steelworks in Salzgitter with so-called turquoise hydrogen produced in Central Germany through a pipeline. The first step initially involved assessing the economic viability based on a feasibility study conducted jointly with the Fraunhofer Research Institution for Energy Infrastructures and Geothermal Systems IEG and the Fraunhofer Institute for Systems and Innovation Research ISI. The emphasis was placed on the potential deployment of pyrolysis technology for producing hydrogen.

“Based on the tested scenarios, the cost of producing hydrogen from the pyrolysis procedure could be competitive compared with electrolysis and the process helpful in securing low emission hydrogen supplies. A prerequisite is, however, that the technological challenges of pyrolysis are surmounted in a timely fashion, that good application possibilities for the associated carbon are found, and that methane emissions along the entire process chain can be plausibly limited,” says Prof. Mario Ragwitz who heads up the Fraunhofer Research Institution for Energy Infrastructures and Geothermal Systems IEG (IEG) headquartered in Cottbus.

Economic viability of pyrolysis technology

The economic viability of using pyrolysis technology on an industrial scale while taking account of the various political framework conditions and necessary investments for the pyrolysis facilities, transport routes and the use of storage were the subject of the investigations. These scenarios differ depending on the price of CO2, electricity, and gas and the use of biogas. In addition, a comparison was made with the use of pure natural gas or the deployment of the electrolysis method for producing hydrogen with electricity generated in Germany. Moreover, anchoring Salzgitter in a future hydrogen grid also played a role.

“Our investigations have shown that supplying the Salzgitter site with green gases is technically and economically possible despite the anticipated high requirements for hydrogen,” says Cornelia Müller-Pagel, head of Green Gas at VNG AG based in Leipzig. “As far as economic viability is concerned, we nevertheless need even greater openness to technology in developing a hydrogen energy economy in the short and medium term, also in terms of funding policy. Along with green hydrogen, blue and turquoise hydrogen are also to play an equally important role in the future.” In order to compare the various methods of producing hydrogen in the future with regard to their environmental compatibility, Müller-Pagel is advocating a monitoring and certification system that is as holistic as possible to be deployed across the entire EU.

Investigating the future use of hydrogen in production goes hand in hand at Salzgitter AG with an analysis of cutting-edge methods and innovative procedural technologies aimed at significantly reducing CO2 emissions: Under the project name of SALCOS (Salzgitter Low CO2 Steelmaking), a concept for decarbonizing steel production was developed back in 2015. The first steps in implementing this concept consisted of the PEM electrolysis with an output of 2.5 MW with installation currently under way and a high-temperature electrolyzer with a 720 kW output on the site in order to cover current requirements for hydrogen in annealing processes, as well as the building of seven wind turbines.

The partners now intend to define a successor project with further possible steps, thus paving the way for the joint implementation of the project idea.

Source: Heat processing www.heat-processing.com