Energetic evaluation of high pressure PEM electrolyzer systems for intermediate storage of renewable energies

verfasst von

B. Bensmann, R. Hanke-Rauschenbach, I. K. Peña Arias, K. Sundmacher

Abstract

Three pathways for high pressure hydrogen production by means of water electrolysis are energetically compared. Besides the two classic paths, comprising either the pressurization of the product gas (path I) or the mechanical pressurization of the feed water (path II), a third path is discussed. It involves the electrochemical co-compression during the electrolysis. The energetic evaluation is based on a uniform model description of the different hydrogen production pathways. It consists of integral, steady-state balances for energy, entropy and mass as well as a modern equation of state. From this the reversible energy demand is used to identify the inherent thermodynamic drawbacks of the pathways. The additional consideration of irreversibilities allows for the determination of efficiency losses due to device specific characteristics. For hydrogen delivery pressures of up to 40 bar the classical pathways are out-performed by path III. Since the hydrogen is already produced at elevated pressure this eliminates the need for an energy consuming mechanical hydrogen compression and spares the additional energy demand due to the oxygen pressurization. However, with increasing pressure differences the hydrogen back-diffusion strongly decreases the Faradaic efficiency of the asymmetric electrolyzer that has to be compensated by an additional energy supply.

Externe Organisation(en)

Max-Planck-Institut für Dynamik komplexer technischer Systeme
Otto-von-Guericke-Universität Magdeburg

Typ

Artikel

Journal

Electrochimica acta

Band

110

Seiten

570-580

Anzahl der Seiten

11

ISSN

0013-4686

Publikationsdatum

2013

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Allgemeine chemische Verfahrenstechnik, Elektrochemie

Ziele für nachhaltige Entwicklung

SDG 7 – Erschwingliche und saubere Energie

Elektronische Version(en)

https://doi.org/10.1016/j.electacta.2013.05.102 (Zugang: Unbekannt)