Review of Fuel Cell Technologies with CO₂ Capture for the Power Sector

Publication Overview

DOOSAN U.K. was commissioned by IEAGHG to provide a comprehensive techno-economic review on MCFCs and SOFCs for the power sector. The objectives of this technical study were:

Publication Summary

• This study aims to provide a techno-economic overview of the most promising fuel cells (FCs) for the power sector. It also identifies future research areas to enhance their performance and describes barriers and challenges to achieve commercial deployment
• The fuel cells assessed are SOFCs (Solid Oxide Fuel Cells) and MCFCs (Molten Carbonate Fuel Cells) with and without further CO₂ capture/purification, in Supercritical Pulverised Coal (PC), Natural Gas Combined Cycle (NGCC, also known as CCGT, Combined Cycle Gas Turbine) and Integrated Gasification Combined Cycle (IGCC) power plants
• The identified typical CO₂ capture/purification systems to use in combination with FCs are: cryogenic CO₂ separation, oxy-combustion, oxidation[1], condensation[2], membrane separation and physical absorption
• Two generations of SOFCs are identified, with the second generation offering promising cost reductions, although they are currently at low TRL (Technology Readiness Level) and therefore require an initial higher investment. For MCFCs, the general practice is to use those as an “active CO₂ concentrator” in combined cycles
• To facilitate the comparison of the costs reported in the literature, those are homogenised by currency, year, plant size and location. The results are compared with reference costs from cases without and with a benchmark CO₂ capture system (chemical absorption with Cansolv solvent)
• After homogenisation, SOFCs and MCFCs are shown as competitive systems for CO₂ capture in power plants
• The lowest CO₂ avoidance cost is showed by the MCFC case operating at atmospheric pressure in a NGCC (Natural Gas Combined Cycle) plant, with a CO₂ capture system using oxy-combustion followed by condensation.
• The lowest LCOE (levelized cost of electricity[3]) is shown by the MCFC case operating at atmospheric pressure in an integrated NGCC with CO₂ purification with cryogenic separation. This case represents a reduction of the LCOE by 24% compared to the use of the benchmark CO₂ capture system.
• The dependency of the LCOE on the fuel cells key parameters was assessed through a sensitivity analysis in the case of a NGCC with a MCFC operating at atmospheric pressure. The fuel cell investment was found to have the highest impact on the LCOE. Degradation[4] is identified in the literature as key parameter and it is studied as a variation on the stack life. However, in this study, its effect was less significant
• Challenges and barriers for the commercial deployment of fuel cells technologies with CO₂ capture can be divided into manufacturing and materials, operation, public policies and the need for large-scale projects.