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Title: Reactant gas composition for fuel cell potential control

Abstract

A fuel cell (10) system in which a nitrogen (N.sub.2) gas is used on the anode section (11) and a nitrogen/oxygen (N.sub.2 /O.sub.2) gaseous mix is used on the cathode section (12) to maintain the cathode at an acceptable voltage potential during adverse conditions occurring particularly during off-power conditions, for example, during power plant shutdown, start-up and hot holds. During power plant shutdown, the cathode section is purged with a gaseous mixture of, for example, one-half percent (0.5%) oxygen (O.sub.2) and ninety-nine and a half percent (99.5%) nitrogen (N.sub.2) supplied from an ejector (21) bleeding in air (24/28) into a high pressure stream (27) of nitrogen (N.sub.2) as the primary or majority gas. Thereafter the fuel gas in the fuel processor (31) and the anode section (11) is purged with nitrogen gas to prevent nickel (Ni) carbonyl from forming from the shift catalyst. A switched dummy electrical load (30) is used to bring the cathode potential down rapidly during the start of the purges. The 0.5%/99.5% O.sub.2 /N.sub.2 mixture maintains the cathode potential between 0.3 and 0.7 volts, and this is sufficient to maintain the cathode potential at 0.3 volts for the case of H.sub.2 diffusing to the cathode throughmore » a 2 mil thick electrolyte filled matrix and below 0.8 volts for no diffusion at open circuit conditions. The same high pressure gas source (20) is used via a "T" juncture ("T") to purge the anode section and its associated fuel processor (31).« less

Inventors:
 [1];  [2]
  1. Glastonbury, CT
  2. Tolland, CT
Issue Date:
Research Org.:
INTERNATIONAL FUEL CELLS CORP
OSTI Identifier:
867966
Patent Number(s):
5045414
Assignee:
International Fuel Cells Corporation (South Windsor, CT) [*] Notice: portion of term of this patent subsequent to May 7, 2008 has been disclaimed.
Patent Classifications (CPCs):
H - ELECTRICITY H01 - BASIC ELECTRIC ELEMENTS H01M - PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
Y - NEW / CROSS SECTIONAL TECHNOLOGIES Y02 - TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE Y02E - REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
DOE Contract Number:  
AC21-82MC24222
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
reactant; gas; composition; fuel; cell; potential; control; 10; nitrogen; anode; section; 11; oxygen; gaseous; mix; cathode; 12; maintain; acceptable; voltage; adverse; conditions; occurring; particularly; off-power; example; power; plant; shutdown; start-up; hot; holds; purged; mixture; one-half; percent; ninety-nine; half; 99; supplied; ejector; 21; bleeding; air; 24; 28; pressure; stream; 27; primary; majority; thereafter; processor; 31; prevent; nickel; carbonyl; forming; shift; catalyst; switched; dummy; electrical; load; 30; bring; rapidly; start; purges; maintains; volts; sufficient; diffusing; mil; thick; electrolyte; filled; matrix; below; diffusion; circuit; source; 20; via; juncture; purge; associated; voltage potential; nitrogen gas; gas composition; fuel cell; pressure gas; gaseous mixture; fuel gas; power plant; reactant gas; gas source; electrical load; mil thick; anode section; electrolyte fill; associated fuel; cell potential; circuit condition; fuel processor; shift catalyst; /429/

Citation Formats

Bushnell, Calvin L, and Davis, Christopher L. Reactant gas composition for fuel cell potential control. United States: N. p., 1991. Web.
Bushnell, Calvin L, & Davis, Christopher L. Reactant gas composition for fuel cell potential control. United States.
Bushnell, Calvin L, and Davis, Christopher L. Tue . "Reactant gas composition for fuel cell potential control". United States. https://www.osti.gov/servlets/purl/867966.
@article{osti_867966,
title = {Reactant gas composition for fuel cell potential control},
author = {Bushnell, Calvin L and Davis, Christopher L},
abstractNote = {A fuel cell (10) system in which a nitrogen (N.sub.2) gas is used on the anode section (11) and a nitrogen/oxygen (N.sub.2 /O.sub.2) gaseous mix is used on the cathode section (12) to maintain the cathode at an acceptable voltage potential during adverse conditions occurring particularly during off-power conditions, for example, during power plant shutdown, start-up and hot holds. During power plant shutdown, the cathode section is purged with a gaseous mixture of, for example, one-half percent (0.5%) oxygen (O.sub.2) and ninety-nine and a half percent (99.5%) nitrogen (N.sub.2) supplied from an ejector (21) bleeding in air (24/28) into a high pressure stream (27) of nitrogen (N.sub.2) as the primary or majority gas. Thereafter the fuel gas in the fuel processor (31) and the anode section (11) is purged with nitrogen gas to prevent nickel (Ni) carbonyl from forming from the shift catalyst. A switched dummy electrical load (30) is used to bring the cathode potential down rapidly during the start of the purges. The 0.5%/99.5% O.sub.2 /N.sub.2 mixture maintains the cathode potential between 0.3 and 0.7 volts, and this is sufficient to maintain the cathode potential at 0.3 volts for the case of H.sub.2 diffusing to the cathode through a 2 mil thick electrolyte filled matrix and below 0.8 volts for no diffusion at open circuit conditions. The same high pressure gas source (20) is used via a "T" juncture ("T") to purge the anode section and its associated fuel processor (31).},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1991},
month = {1}
}

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