Abstract
A COX-free 1 kW-class hydrogen power pack fueled by liquid ammonia is presented. For applications in a practical-scale hydrogen production system in conjunction with a polymer electrolyte membrane fuel cell, Ru catalysts supported on La-doped alumina (Ru/La(x)-Al2O3) were pelletized by varying the lanthanum doping content (x mol%) to control catalytic activities. An optimized Ru(1.06 wt%)/La(20)-Al2O3 pellet catalyst presents a >99.7% conversion efficiency at 500 °C under a gas hourly space velocity of 5000 mL gcat −1 h−1. Various materials were screened to remove residual ammonia from the product stream, and the X zeolite was chosen as a highly capable adsorbent. Based on the synthesized catalyst and screened adsorbent, a power pack consisting of a dehydrogenation reactor, an adsorbent tower, and a 1 kW-class polymer electrolyte membrane fuel cell was designed and manufactured. The as-integrated system can convert 9 L min−1 of ammonia into 13.4 L min−1 of hydrogen, powering a 1 kW-class fuel-cell continuously for >2 h without any performance degradation. To achieve autothermal and COX-free operations, heat required for ammonia dehydrogenation was provided by unutilized hydrogen from the fuel cell, drastically increasing the overall efficiency of the system to >49% while removing the external heat source, isobutane. Finally, a drone tethered to the system was operated, demonstrating the feasibility of an elongated flight time of >4 h, much longer than 14 min with Li-polymer battery loaded on the drone. The system is expected to meet the United States Department of Energy's 2020 gravimetric and volumetric hydrogen storage targets of 4.5 wt% and 30 gH2 L−1 at system weights of 43 kg and 50 kg, respectively.
| Original language | English |
|---|---|
| Pages (from-to) | 194-204 |
| Number of pages | 11 |
| Journal | Applied Energy |
| Volume | 224 |
| DOIs | |
| Publication status | Published - 2018 Aug 15 |
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Keywords
- Ammonia dehydrogenation
- Carbon-free energy conversion
- Catalysis
- Energy storage
- Fuel-cell
- Hydrogen storage
ASJC Scopus subject areas
- Building and Construction
- Energy(all)
- Mechanical Engineering
- Management, Monitoring, Policy and Law
Cite this
Ammonia as an efficient COX-free hydrogen carrier : Fundamentals and feasibility analyses for fuel cell applications. / Cha, Junyoung; Jo, Young Suk; Jeong, Hyangsoo; Han, Jonghee; Nam, SukWoo; Song, Kwang Ho; Yoon, Chang Won.
In: Applied Energy, Vol. 224, 15.08.2018, p. 194-204.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Ammonia as an efficient COX-free hydrogen carrier
T2 - Fundamentals and feasibility analyses for fuel cell applications
AU - Cha, Junyoung
AU - Jo, Young Suk
AU - Jeong, Hyangsoo
AU - Han, Jonghee
AU - Nam, SukWoo
AU - Song, Kwang Ho
AU - Yoon, Chang Won
PY - 2018/8/15
Y1 - 2018/8/15
N2 - A COX-free 1 kW-class hydrogen power pack fueled by liquid ammonia is presented. For applications in a practical-scale hydrogen production system in conjunction with a polymer electrolyte membrane fuel cell, Ru catalysts supported on La-doped alumina (Ru/La(x)-Al2O3) were pelletized by varying the lanthanum doping content (x mol%) to control catalytic activities. An optimized Ru(1.06 wt%)/La(20)-Al2O3 pellet catalyst presents a >99.7% conversion efficiency at 500 °C under a gas hourly space velocity of 5000 mL gcat −1 h−1. Various materials were screened to remove residual ammonia from the product stream, and the X zeolite was chosen as a highly capable adsorbent. Based on the synthesized catalyst and screened adsorbent, a power pack consisting of a dehydrogenation reactor, an adsorbent tower, and a 1 kW-class polymer electrolyte membrane fuel cell was designed and manufactured. The as-integrated system can convert 9 L min−1 of ammonia into 13.4 L min−1 of hydrogen, powering a 1 kW-class fuel-cell continuously for >2 h without any performance degradation. To achieve autothermal and COX-free operations, heat required for ammonia dehydrogenation was provided by unutilized hydrogen from the fuel cell, drastically increasing the overall efficiency of the system to >49% while removing the external heat source, isobutane. Finally, a drone tethered to the system was operated, demonstrating the feasibility of an elongated flight time of >4 h, much longer than 14 min with Li-polymer battery loaded on the drone. The system is expected to meet the United States Department of Energy's 2020 gravimetric and volumetric hydrogen storage targets of 4.5 wt% and 30 gH2 L−1 at system weights of 43 kg and 50 kg, respectively.
AB - A COX-free 1 kW-class hydrogen power pack fueled by liquid ammonia is presented. For applications in a practical-scale hydrogen production system in conjunction with a polymer electrolyte membrane fuel cell, Ru catalysts supported on La-doped alumina (Ru/La(x)-Al2O3) were pelletized by varying the lanthanum doping content (x mol%) to control catalytic activities. An optimized Ru(1.06 wt%)/La(20)-Al2O3 pellet catalyst presents a >99.7% conversion efficiency at 500 °C under a gas hourly space velocity of 5000 mL gcat −1 h−1. Various materials were screened to remove residual ammonia from the product stream, and the X zeolite was chosen as a highly capable adsorbent. Based on the synthesized catalyst and screened adsorbent, a power pack consisting of a dehydrogenation reactor, an adsorbent tower, and a 1 kW-class polymer electrolyte membrane fuel cell was designed and manufactured. The as-integrated system can convert 9 L min−1 of ammonia into 13.4 L min−1 of hydrogen, powering a 1 kW-class fuel-cell continuously for >2 h without any performance degradation. To achieve autothermal and COX-free operations, heat required for ammonia dehydrogenation was provided by unutilized hydrogen from the fuel cell, drastically increasing the overall efficiency of the system to >49% while removing the external heat source, isobutane. Finally, a drone tethered to the system was operated, demonstrating the feasibility of an elongated flight time of >4 h, much longer than 14 min with Li-polymer battery loaded on the drone. The system is expected to meet the United States Department of Energy's 2020 gravimetric and volumetric hydrogen storage targets of 4.5 wt% and 30 gH2 L−1 at system weights of 43 kg and 50 kg, respectively.
KW - Ammonia dehydrogenation
KW - Carbon-free energy conversion
KW - Catalysis
KW - Energy storage
KW - Fuel-cell
KW - Hydrogen storage
UR - http://www.scopus.com/inward/record.url?scp=85046710403&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85046710403&partnerID=8YFLogxK
U2 - 10.1016/j.apenergy.2018.04.100
DO - 10.1016/j.apenergy.2018.04.100
M3 - Article
AN - SCOPUS:85046710403
VL - 224
SP - 194
EP - 204
JO - Applied Energy
JF - Applied Energy
SN - 0306-2619
ER -