Seminars Archive

Two joint seminars on Metallurgy: 1-The potential of cryogenic treatment for materials used in the current and future energy sector 2-Ammonia based direct reduction: Prospects, challenges and open questions

1-Patricia Jovičević-Klug, 2-Matic Jovičević-Klug
Max-Planck-Institute for iron Research Düsseldorf, Germany 1-Group of Corrosion 2-Department of Microstructure Physics and Alloy Design

Abstract
1-In the last 5 years, the process known as cryogenic treatment (green technology) has become widely used in the heat treatment of various ferrous and non-ferrous alloys, providing improvements in various properties. Cryogenic treatment fundamentally changes the material properties (hardness, toughness, strength, corrosion and wear resistance, etc.) through the main mechanisms of austenite transformation into martensite and increased carbide precipitation. Various studies have shown that there is great potential for using various cryogenic treatments to improve materials, however till no was not considered to be applied in energy sector (including fusion). If you would like to know more about cryogenic processing and its applications in the current and future energy sector, you are welcome to join me. 2-In recent years the development of sustainable production of iron and steel has become a high priority objective of today’s world in order to meet the CO2 reduction for counteracting global warming. The iron- and steelmaking sector is responsible for the release of 7-8% of all global CO2 emissions, primarily originating from the use of fossil carbon carriers for the reduction of iron ores. The hydrogen-based reduction processes are arising as a feasible alternative that have the potential to cut CO2 emissions significantly. The primary pathway is to use hydrogen gas as a reducing agent to generate only water as a by-product during solid state iron oxide reduction. However, hydrogen is hard to transport and its transportation is energy intensive. This creates a highly challenging integration of such novel processes on a global scale, as most efficient local production of hydrogen might not overlap with steel production sites. As an alternative ammonia is considered as a hydrogen carrier for such reduction process due to its ease of transportation and existing transportation infrastructure. However, the ammonia reduction brings many differences in the reduction process compared to when pure hydrogen gas is utilized. The differences range from simultaneous nitriding, the need for catalytic cracking of ammonia gas during the process to modification of the progress of the solid-state reduction. In this presentation I will show you the differences, benefits, challenges and opportunities of using ammonia as a novel reducing agent for iron oxides that propels a new line of research to answer many unknowns of such a process.