Realistic simulation in a single stage hydrogen compressor based on AB2 alloys

• The simulation evidenced the need for realistic behavior of P-c-T curves in a single stage compressor.
• The effect of some real equation of state on the compressor simulation is addressed.
• The ideal model presents problems in the P-c-T determination at some extreme situations.

A simulation analysis was performed to study the thermodynamic behavior of a realistic single stage hydride compressor, taking into account real H2 gas behavior by implementing several H2 equations of state, as well as realistic features in the hydrogen sorption properties of the hydride, like sloping plateau and hysteresis. The model was validated with experimental data from two different AB2 hydride systems, a low pressure Ti0.9Zr0.1Mn1.34V0.3 and a high pressure Ti0.9Zr0.1Mn1.47Cr0.4V0.2 alloys. The materials were characterized by X-ray powder diffraction (XRPD), Scanning Electron Microscopy (SEM) and Energy Dispersion X-ray spectroscopy (EDX). The numerical study was divided in three main parts: the effect of implementing real/ideal hydrogen gas models, a study of how the equations of state affect the Pressure composition Isotherm (P-c-T) determination and the influence of each model and realistic features of the P-c-T on the compressor simulation. Among all the models tested, Hemmes and Joubert real models give the more confident values for the compression ratio and final moles in the system volume at a final temperature of 353 K and pressures <50 bar.