Abstract
Ammonia has received in recent years significant attention as potential carbon free fuel. However, its combustion properties limit its direct application for both providing heat and in power generation through gas turbines. Ammonia cracking is one potential solution to circumvent the problem by producing hydrogen. When using the ammonia in gas turbines, it is possible to heat integrate the endothermic decomposition reaction with the exhaust gas from the gas turbine. Thermodynamic and kinetic limitations have however a major impact on the achievable ammonia conversion. Based on the consideration of these limitations, this paper presents a detailed investigation of key design parameters affecting the overall process efficiency utilizing both an equilibrium reactor model and a reactor model based on detailed kinetics and heat transfer. Ammonia decomposition should occur at sufficiently high pressure to avoid a) the com-pression energy demand for achieving the pressure of the combustion chamber and b) to reduce equipment size although the increased pressure results in a reduced conversion when considering an equilibrium reactor. It is crucial for the energy efficient integration of ammonia decomposition with gas turbines to avoid a partial combustion of the decomposed ammonia even as an increased temperature of the reactor results in an increased ammonia conversion. Furthermore, it is beneficial to operate the compression stages without intercooling to reduce the required fuel flow to the gas turbine.