APPLICATIONS OF TECHNOLOGY:
- Hydrogen production
BENEFITS:
- Large scale, CO2-free production of hydrogen
- High H2 selectivity
- Higher conversion rate than state-of-the-art catalysts
- Lower activation energy than solid catalysts
- Wider range and lower operating temperatures than solid catalysts: 450 oC to 1200 oC
- Co-produces carbon powder
BACKGROUND:
- Hydrogen has been proposed as a potential clean energy solution to transition away from the use of fossil fuels. Currently, most hydrogen is still produced from fossil fuels in a process which still generates CO2, limiting the efficacy of hydrogen technology for emissions reduction. Methane pyrolysis is more energy efficient (consuming 37.5 kJ of energy to produce 1 mole of H2) than water electrolysis (286 kJ/molH2) and breaks methane down into hydrogen and solid carbon, producing hydrogen gas without any CO2 emissions and presents a promising source of clean hydrogen if a high performing catalyst (especially under low reaction temperature) can be identified.
TECHNOLOGY OVERVIEW:
Berkeley Lab researchers have developed a homogeneous multiple-element liquid metal catalyst that presents a number of advantages over the more common solid catalysts used for methane pyrolysis. Solid catalysts can suffer from deactivation by the buildup of carbon and other byproducts of the reaction, which limits their performance for hydrogen production. A liquid metal catalyst presents the advantage of easy separation of carbon, as they would simply float to the surface of the liquid metal, where they could be easily separated.
The liquid metal catalyst, which includes nickel (Ni) and bismuth (Bi) and an additional element, performed well at the laboratory scale, demonstrating a high H2 generation efficiency of 4 mL H2 /g Ni / min, which is an order of magnitude higher than state-of-the-art binary liquid Ni-Bi catalysts. The liquid metal catalyst displayed an activation energy of 81 kJ/mol, which is much lower than the binary liquid Ni-Bi catalyst (Ea of 208 kJ/mol) and very close in performance to common solid metal catalysts. Additionally, no partial dehydrogenation byproducts (such as acetylene and ethylene) were formed, leading to higher generation efficiency and reduced buildup of contaminants (such as aromatics fouling) in the reactor. Furthermore, the liquid metal catalyst displayed a good activity under lower operating temperatures (450 – 800 oC).
DEVELOPMENT STAGE: Performance validated at laboratory scale
PRINCIPAL INVESTIGATORS:
- Ji Su
- Luning Chen
STATUS: Patent pending.
OPPORTUNITIES: Available for licensing or collaborative research.