Ceramic Material Selection for Toroidal Jet-Stirred Reactors in Ammonia Combustion for Aviation Fuel Research

As the constant use of hydrocarbon fuels in everyday human activities raises environmental concerns, society must shift towards non-carbon fuels; one of these is ammonia. One experimental campaign aims to study ammonia combustion inside a toroidal jet-stirred reactor and utilizes a ceramic reactor in the center where the ammonia-hydrogen flame will stabilize. This paper aims to discuss options for the ceramic used in manufacturing the reactor. Considered ceramics must withstand thermal shock and high temperatures without any breakage. The materials discussed are yttria-stabilized tetragonal zirconia polycrystal, magnesia-stabilized zirconia, alumina, calcium-stabilized zirconia, and nickel alloy Inconel 625. Generally, ceramics are preferred for this application over metal because they have a lower heat transfer coefficient, reducing heat loss through the reactor. However, metal is less likely to crack from thermal shock but rather to melt. It would need a ceramic thermal barrier coating to protect from melting and minimize heat loss. This research will analyze which material would work best for more efficient experimental runs.