Zero – dimensional modelling of electrochemical hydrogen compressors: an open tool to maximize efficiency

In this study an open zero-dimensional steady-state MATLAB model is validated against experimental data. It is used to investigate the effect of current density, pressure ratio, temperature, voltage, and number of compression steps on the EHC efficiency, considering the cell overpotentials, the membrane water management and the hydrogen back diffusion. Moreover, once target hydrogen flow rate and pressure are known, a study is presented to find the appropriate number of compression steps. The results indicate that the EHC efficiency is maximized at low current density, low pressure ratio, and low temperature, defining the optimal operation of EHC in low hydrogen flow rates and with multi-stage configuration to efficiently realize high compression ratios. When high target flow rates are required, the optimal number of compression steps decreases. The study fills a knowledge gap in supporting the model-guided industrial use of EHCs, and it provides an open simulation tool as supplementary material.