Research Projects
Sustainable Synthesis of Materials Group

Hybrid hydrogen-based reduction of iron ores
Replacing carbon by hydrogen as the reducing agent in ironmaking offers a pathway to massively reduce the associated CO2 emissions. However, the production of hydrogen using renewable energy will remain as one of the bottlenecks at least in the next two decades. The underlying reasons are the low electrolysis productivity and the insufficient capacities in both renewable electricity and industrial infrastructures to produce sufficient amounts of green hydrogen, especially in view of the gigantic demand for currently 1.8 billion tons of steel being produced every year, with forecasts predicting 2.4 billion tons by the year 2040. We therefore demonstrate how the efficiency in hydrogen and energy consumption during iron ore reduction can be dramatically improved by the knowledge-based combination of two technologies: partially reducing the ore at low temperature via solid-state hydrogen-based direct reduction (HyDR) to a kinetically defined degree, and subsequently melting and completely transforming it to iron under a reducing plasma (i.e. via hydrogen plasma reduction, HPR) more
Hydrogen plasma-based reduction of iron ores
Iron- and steelmaking is the most staggering single source of CO2 emissions on the planet, accounting for ~7% of the global emissions. This fact challenges the current technologies to achieve carbon-lean steel production and reduce CO2 emissions by 80% until 2050. Among the sustainable alternatives for ironmaking, the hydrogen plasma reduction (HPR) is a promising route, as the associated by-product is water. In this process, a hydrogen plasma arc is ignited between an electrode and the ore in a conventional electrical arc furnace (EAF), Figure 1 (a). Thus, melting and reduction occur simultaneously, enabling the production of liquid iron in single step. The highly energetic hydrogen species existing in a reducing plasma also enable exothermic redox chemical reactions with enhanced kinetics, permitting energy savings.
Iron powder as metal fuel 
To successfully transition from fossil fuels to a sustainable carbon-free energy supply, a safe and stable energy storage technology is required. Recently, metallic powders, and particularly iron powder, have been proposed as a high energy density, easily storable, and commonly traded fuel. Energy production is obtained through the heat of oxidation, and the combusted products can then be reduced at the solid-state using hydrogen coming from sustainable energy sources, resulting in a complete CO2-free energy cycle. While the combustion of iron powders seems very promising in this regard, hardly anything is known about its in-process morphological, microstructural, and chemical evolution, which are critical for the circularity of the concept and the subsequent reduction process.
The HYDRI project: Multiscale and Operando Studies on the Role of Micro- and Nanostructures in Hydrogen-based Direct Reduction of Iron Oxides
The HYDRI project aims at disentangling the correlation between material micro-/nanostructures and the hydrogen-based direct reduction (HyDR) kinetics, to reveal the vital role of acquired defects in HyDR processes. A multiscale and time-resolved operando approach will be used to characterize micro-/nanostructures in HyDR. Gaining better insights into these effects enable improved access to the microstructure-based design of more efficient HyDR methods, with potentially high impact on the urgently needed decarbonization in the steel industry. more
Green Steel: The role of microstructure in Direct Reduction of Ores with Hydrogen
Direct reduction of iron ores with hydrogen is an attractive alternative to the common reduction with carbon, to eliminate the CO2 emissions in steel making. The kinetics of this process are not yet well understood, in particular during the wüstite reduction step. Microstructure, local chemistry and lattice defects are studied for better understanding the underlaying microscopic transport and reduction mechanisms and kinetics, aiming to open the perspective for a carbon-neutral iron production. more
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