Transformation of the Lower Saxony energy system (TEN.efzn)

The transformation of our energy system towards 100 % renewable energy requires good ideas and innovations from science in order to become increasingly efficient and ensure a reliable supply. Hydrogen from renewable sources (green hydrogen) plays a decisive role in the targeted decarbonisation and defossilisation of our energy and industrial system. In  current discussions, it is also becoming clear that other energy sources will play an important role alongside green hydrogen. Green ammonia (NH3) is particularly important in this context. It can be liquefied at low pressures, making it easy to transport and, due to its high hydrogen content, an efficient hydrogen carrier, especially for long-distance transport. In addition, ammonia is carbon-free and can therefore be produced anywhere in the world without an additional carbon source. In this way, ammonia can be synthesised from the ambient components water and air even in regions far away from Germany (Australia, South America, South Africa, etc.) and transported safely by ship. This means that ammonia will become very important for Germany and especially for the importing state of Lower Saxony in the future.

The Institute of Technical Combustion is conducting research on ammonia and ammonia/hydrogen flames under technically relevant conditions (increased pressure) in innovation area II of the ‘Direct utilisation of NH3 through combustion’ project. This gives rise to numerous research questions such as: combustion properties of the fuel mixture as a function of the H2 content, laminar and turbulent combustion velocity, flame stability limits and pollutant emissions. Further questions relate to experiments on the ignitability of H2-NH3 flames (in collaboration with PTB Braunschweig) with mixtures that are difficult to ignite, the measurement of very well-defined flames in order to validate new combustion models (in conjunction with TU Braunschweig), the measurement of emissions (in particular NOx) and the testing of staged combustion in order to minimise these (in conjunction with PTB Braunschweig). In addition, ‘impure’ NH3 flames are to be specifically measured (TU Clausthal) in order to find an optimised strategy for NH3 synthesis that may be able to manage with partial purities. Finally, research is to be carried out into the possibility of upstream partial conversion (‘cracking’) of NH3 to H2 in order to release hydrogen from the energy source ammonia for NH3/H2 mixed combustion in a decentralised manner (in conjunction with the University of Oldenburg).