Today, it is impossible to imagine any modern application without steel. It is inextricably linked with modern life. At the same time, steel also plays a significant role in the fight against climate change. On the one hand, as the material of choice to solve existing problems, and on the other hand, the steel industry is also involved in the current situation through the process-inherent emissions of greenhouse gases (GHG). The implementation of GHG-free steelmaking processes is of undisputed importance for the future. One of the most promising concepts for future GHG-free steelmaking is the hydrogen plasma smelting reduction (HPSR) process. This work deals with the determination of fundamental parameters for the Scale-up of the mentioned process. In addition to the theoretical principles required for this purpose, the work takes a closer look at the topics of the arc system, the refractory lining of the reactor, and the thermodynamic simulation of the process. Based on these investigations, it was possible to create a dimensionless number system for describing the arc stability and quality. The numbers shown describe the stability and quality of the arc in predefined ranges utilizing arc stability fields (Zs) and arc stability indices (ASId and ASIt). Concerning the refractory concept of the plant, a draft of the possible process management of the slag was adapted to the conditions in the process and presented. Furthermore, the suitability of MA spinel crucibles for the application in the HPSR process was investigated. To simplify the definition of design parameters for future plants, the results of the thermodynamic calculation model are also presented in the course of this work and compared with versions from previous work. The work�s results define a sound foundation for the scale-up of a HPSR-process. A base stone towards emission-free steel production has been laid.