Optimal configurations of ammonia decomposition reactor with minimum power consumption and minimum heat transfer rate

Abstract

Ammonia decomposition reactor is an important component in process of ammonia hydrogen energy conversion technology where ammonia is the storage and transportation medium for hydrogen. In this research, a tubular ammonia decomposition reactor is modeled according to finite-time thermodynamics. With a fixed hydrogen yield, heat transfer rate and power consumption are taken as optimization targets, and the corresponding optimal temperature distributions outside the tube, that is, the optimal configurations, are obtained through a nonlinear programming method. In addition, the optimized reactor is also analyzed for three parameters: reactant initial temperature, reactant initial pressure, and reaction tube length. The results indicate that heat transfer rate of the optimal reactor with the minimum heat transfer rate and power consumption of the optimal reactor with the minimum power consumption are reduced by 10.5% and 17.26% compared to the reference reactor, respectively. The optimum parameters of the reactor are obtained as a tube length of 8 m, reactant inlet temperature of 450 K, and reactant inlet pressure of 8 bar. The findings of this research are instructive towards the optimal design and operation of ammonia decomposition reactors.