Heat recovery within Na-O-H thermochemical cycle for hydrogen production

Hydrogen is a green energy carrier capable of storingenergy in chemical form in order to meet industrialand energy demands. Hydrogen is very reactive,cannot be found purely in nature, and needs to beproduced using special methods. In this paper, a Na-O-H thermochemical water splitting cycle forhydrogen production was investigated. The Na-O-Hcycle was modelled in Aspen Plus for the productionof ۱ kg/s of hydrogen, and then stream results wereused for heat exchanger network design and heatrecovery within the cycle. A designed network usingpinch logic can reduce the external heat requirementof cycle streams by ۸۳.۸۶% and the cooling load by۸۶.۷%. The total external energy requirement wasreduced by ۸۵.۳۴%. This reduction can make theNAOH cycle more feasible by reducing itsdependence on external heating and cooling loads.

Keywords:

Hydrogen production , Thermochemicalwater splitting , Pinch analysis , Heat exchangernetwork design