NH3-cracking is very different from NH3-synthesis and any ranking of materials regarding resistance against NH3-cracking is almost unknown, because of the higher temperatures (600-900°C) and much higher nitriding potentials. This project aims describe the nitriding effects - and what can be done to prevent/delay those - in 100% NH3 (with and without 0,2% water) during the cracking process in the reactor.
Nitriding experiments under pressurized conditions (10-50 bar) shall be undertaken to determine the resistance of various alloys. Pre-oxidation and its effective parameters as a mitigation towards nitriding will be part of the test plan. The objectives are to rank alloys for nitriding resistance - nickel or iron-based, Al- or Cr-oxide forming alloys, coatings like CVD-aluminizing or intentional CrN layers.
