An analytical multiphase flow model for parallel plate electrolyzers

Research output: Contribution to journalArticleScientificpeer-review

13 Downloads (Pure)

Abstract

Membraneless parallel-plate electrolyzers use electrolyte flow to avoid product crossover. Using a mixture model neglecting inertia, and assuming an exponential gas fraction profile, we derive approximate analytical expressions for the velocity profile and pressure drop for thin plumes. We verify these expressions using numerical solutions obtained with COMSOL and validate them using experimental data from the literature. We find that the wall gas fraction increases rapidly at small heights, but becomes fairly constant at larger heights. These expressions serve as a guiding framework for designing a membraneless parallel-plate electrolyzer by quantifying the maximum possible height. We find that buoyancy driven membraneless parallel-plate electrolyzers with a 3 mm gap can be designed with a maximum height of around 7.6 cm at 1000 A/m2 for operation with 98% product purity at atmospheric pressure. For a forced flow at Re=1000, the same electrolyzer can be made around 17.6 cm tall at 1000 A/m2. These limits can be further improved with smaller bubbles or higher pressure.

Original languageEnglish
Article number117823
Number of pages14
JournalChemical Engineering Science
Volume260
DOIs
Publication statusPublished - 2022

Keywords

  • Analytical solution
  • Membraneless
  • Multiphase flow
  • Parallel plate electrolyzer
  • Water electrolysis

Fingerprint

Dive into the research topics of 'An analytical multiphase flow model for parallel plate electrolyzers'. Together they form a unique fingerprint.

Cite this