Interaction of coal-derived synthesis gas impurities with solid oxide fuel cell metallic components

Olga A. Marina, Larry R. Pederson, Christopher A. Coyle, Danny J. Edwards, Yeong Shyung Chou, Carolyn N. Cramer

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Oxidation-resistant alloys find use as interconnect materials, heat exchangers, and gas supply tubing in solid oxide fuel cell (SOFC) systems, especially when operated at temperatures below ∼800 °C. If fueled with synthesis gas derived from coal or biomass, such metallic components could be exposed to impurities contained in those fuel sources. In this study, coupons of ferritic stainless steels Crofer 22 APU and SS 441, austenitic nickel-chromium superalloy Inconel 600, and an alumina-forming high nickel alloy alumel were exposed to synthesis gas containing ≤2 ppm phosphorus, arsenic and antimony, and reaction products were tested. Crofer 22 APU coupons coated with a (Mn,Co)3O4 protective layer were also evaluated. Phosphorus was found to be the most reactive. On Crofer 22 APU, the (Mn,Cr) 3O4 passivation layer reacted to form an Mn-P-O product, predicted to be manganese phosphate from thermochemical calculations, and Cr2O3. On SS 441, reaction of phosphorus with (Mn,Cr) 3O4 led to the formation of manganese phosphate as well as an Fe-P product, predicted from thermochemical calculations to be Fe 3P. Minimal interactions with antimony or arsenic in synthesis gas were limited to Fe-Sb and Fe-As solid solution formation. Though not intended for use on the anode side, a (Mn,Co)3O4 spinel coating on Crofer 22 APU reacted with phosphorus in synthesis gas to produce products consistent with Mn3(PO4)2 and Co2P. A thin Cr2O3 passivation layer on Inconel 600 did not prevent the formation of nickel phosphides and arsenides and of iron phosphides and arsenides, though no reaction with Cr2O3 was apparent. On alumel, an Al2O3 passivation layer rich in Ni did not prevent the formation of nickel phosphides, arsenides, and antimonides, though no reaction with Al2O3 occurred. This work shows that unprotected metallic components of an SOFC stack and system can provide a sink for P, As and Sb impurities that may be present in fuel gases, and thus complicate experimental studies of impurity interactions with the anode.

Original languageEnglish
Pages (from-to)636-643
Number of pages8
JournalJournal of Power Sources
Volume196
Issue number2
DOIs
Publication statusPublished - 15 Jan 2011
Externally publishedYes

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Keywords

  • Chromia-forming alloys
  • Coal and biomass
  • Impurities
  • Metallic interconnect
  • Passivation layer
  • SOFC

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Energy Engineering and Power Technology
  • Renewable Energy, Sustainability and the Environment
  • Physical and Theoretical Chemistry

Cite this

Marina, O. A., Pederson, L. R., Coyle, C. A., Edwards, D. J., Chou, Y. S., & Cramer, C. N. (2011). Interaction of coal-derived synthesis gas impurities with solid oxide fuel cell metallic components. Journal of Power Sources, 196(2), 636-643. https://doi.org/10.1016/j.jpowsour.2010.07.081