Thermodynamic and chemical kinetic analysis of a gas turbine power plant using hydrogen from onsite ammonia cracking for low-emission power generation

The global shift away from fossil fuels has intensified interest in hydrogen as it is a carbon-free energy carrier. Hydrogen storage, transportation, and infrastructure limitations hinder its widespread adoption, while direct ammonia combustion faces challenges such as low reactivity, high ignition temperatures, and elevated emissions. Ammonia, with its high hydrogen content and ease of liquefaction, is a promising hydrogen carrier for catalytic cracking to produce hydrogen for efficient power generation. This study proposes an integrated gas turbine power cycle incorporating ammonia preheating and vaporization, a nickel-based cracking unit, hydrogen–nitrogen separation, a GE-LM2500 hydrogen-fueled gas turbine, and a heat recovery loop. The cycle is modeled using a combination of Ansys-CHEMKIN, GasTurb, and a MATLAB-based energy integration code. Results indicate that cracked hydrogen supports lean (φ = 0.56), stable combustion with reduced NOx formation and enhanced thermal efficiency. The ammonia–hydrogen cycle with on-site cracked ammonia achieves a thermal efficiency of 34%, higher than pure hydrogen (32%) and JP-10 (30.3%).The placement of the ammonia preheater and cracking unit was optimized within the high-temperature heat-recovery zone, resulting in improved waste-heat utilization and enhanced overall thermal efficiency. These findings affirm the potential of ammonia as a hydrogen carrier for low-emission power generation and offer a framework for advancing ammonia-integrated energy systems.