Abstract
Conventional hydrogen separations from reformed hydrocarbons often deploy a water gas shift (WGS) reactor to convert CO to CO2, followed by adsorption processes to achieve pure hydrogen. The purified hydrogen is then fed to a compressor to deliver hydrogen at high pressures. Electrochemical hydrogen pumps (EHPs) featuring proton-selective polymer electrolyte membranes (PEMs) represent an alternative separation platform with fewer unit operations because they can simultaneously separate and compress hydrogen continuously. In this work, a high-temperature PEM (HT-PEM) EHP purified hydrogen to 99.3%, with greater than 85% hydrogen recovery for feed mixtures containing 25-40% CO. The ion-pair HT-PEM and phosphonic acid ionomer binder enabled the EHP to be operated in the temperature range from 160 to 220 degrees C. The ability to operate the EHP at an elevated temperature allowed the EHP to purify hydrogen from gas feeds with large CO contents at 1 A cm-2. Finally, the EHP with the said materials displayed a small performance loss of 12 uV h-1 for purifying hydrogen from syngas for 100 h at 200 degrees C.
Original language | American English |
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Pages (from-to) | 1322-1329 |
Number of pages | 8 |
Journal | ACS Energy Letters |
Volume | 7 |
Issue number | 4 |
DOIs | |
State | Published - 2022 |
NREL Publication Number
- NREL/JA-5900-82544
Keywords
- adsorption process
- electrochemical pumping
- electrochemicals
- high pressure
- high temperature polymer electrolyte membranes
- hydrogen pump
- hydrogen recovery
- hydrogen separation
- polymer electrolyte membranes
- water gas shift reactors