Modeling and multi-objective optimization of electrified ammonia decomposition: Improvement of performance and thermal behavior

Process electrification is one of the most viable solutions to overcoming the perpetual dependency on depleting carbon-based fossil fuels. In this study, hydrogen production via electrically heated ammonia decomposition was numerically modeled and analyzed. Aiming to improve the reaction performance, a novel design in which an in -situ electric heater is embedded amid the catalyst (i.e., EH-AD) was proposed. This design was compared with traditional configurations where heat is supplied via a wall-adjacent heater (WAH-AD) and a case where the reaction has externally supplied heat (NGH-AT). An optimization approach was conducted to further enhance the novel configuration to find the optimal operating conditions and heater position. In terms of ammonia conversion and thermal behavior, the reactor performance of EH-AD was significantly improved compared to the WAH-AD and the NGH-AD cases. The optimal EH-AD showed a significant increase in the hydrogen yield by up to 61% compared with that of WAH-AD, and the conversion nearly reached 100%, while compared to the optimized NGH-AD, the hydrogen yield increased to 70.8% with 17.9% higher conversion.