Cracking of ammonia into hydrogen for gas turbines

Ammonia can be cracked into hydrogen and nitrogen (by a thermal and catalytic decomposition), so that the produced mixture of hydrogen and nitrogen is burnt in the combustor of the gas turbine. The heat required for decomposing (or cracking) the ammonia at temperature levels of 600-1000°C, depending on the catalyst, can be partially supplied by the hot gas turbine exhaust gases (550-650°C) when it is operated in simple cycle. In combined cycle mode, the energy supplied for decomposition would slightly reduce the electricity generation efficiency of the overall process. To minimize the energy demand for cracking, partial cracking of ammonia is possible where the fuel mixture is composed of hydrogen, nitrogen and ammonia.
Already small amounts (few %) of residual ammonia in the cracking product gas can lead to excessively high NOx emissions (few hundred ppm) if current state-of-the-art lean premixed combustion technology is applied.