Reversible Molten Carbonate Fuel Cells Integrated in Biomass Gasification
Time: Fri 2026-05-22 10.00
Location: Kollegiesalen, Brinellvägen 8, Stockholm
Video link: https://kth-se.zoom.us/webinar/register/WN_i6ljr1aCQ5OR3EKVrYhR_g
Language: English
Subject area: Chemical Engineering
Doctoral student: Deniz Björkén , Tillämpad elektrokemi
Opponent: Professor Armelle Ringuedé, CNRS - French National Centre of Scientific Research, Chimie ParisTech, Frankrike
Supervisor: Professor Carina Lagergren, Tillämpad elektrokemi; Professor Klas Engvall, Processteknologi
QC 20260423
Abstract
Reversible molten carbonate fuel cells (RMCFCs) are promising for integration with biomass gasification systems, enabling flexible electricity generation and chemical energy storage, thereby enhancing grid stability and energy security. However, biomass-derived product gases introduce gas-phase reactions coupled with electrochemistry, and their impact on RMCFC performance remains insufficiently understood.
This thesis aims to investigate the effect of product gases on RMCFC operation through lab-scale button-cell experiments, electrode-level kinetic analysis, and numerical modelling. Stable and reversible operation is demonstrated with complex gas mixtures representing different gasification routes over operating conditions of 600–650 °C and 20–40 % inlet humidity.
Electrode-level analysis identifies exchange current densities and reaction orders, showing that apparent kinetics are governed by local gas compositions modified by steam reforming and water–gas shift reactions, rather than inlet compositions alone. The electrochemical reactions at the Ni hydrogen electrode remain reversible under these conditions.
The results show that performance is strongly condition-dependent. Increasing temperature and humidity enhance hydrogen availability through gas-phase reactions, supporting electrochemical conversion, while at lower temperatures or limited humidity insufficient reforming leads to depletion of electroactive species and increased transport limitations.
A modelling framework predicts outlet gas compositions, showing that temperature, humidity, and current density control gas-phase equilibria and enable tuning towards electricity generation, hydrogen production, and syngas conditioning.
Overall, this thesis establishes a mechanistic understanding of RMCFC operation with complex gas mixtures and identifies the coupled electrochemical–thermochemical processes governing performance.