Abstract
Formic acid (FA) is a potential hydrogen energy carrier and low-carbon fuel by reversing the decomposition products, CO2 and H2, back to restore FA without additional carbon release. However, FA-air mixtures feature high ignition energy and low flame speed; hence stabilizing FA-air flames in combustion devices is challenging. This study experimentally investigates the flame stability and emission of swirl flames fueled with pre-vaporized formic acid-methane blends over a wide range of formic acid fuel fractions. Results show that by using a swirl combustor, the premixed formic acid-methane-air flames could be stabilized over a wide range of FA fuel fractions, Reynolds numbers, and swirl numbers. The addition of formic acid increases the equivalence ratios at which the flashback and lean blowout occur. When Reynolds number increases, the equivalence ratio at the flashback limit increases, but that decreases at the lean blowout limit. Increasing the swirl number has a non-monotonic effect on stability limits variation because increasing the swirl number changes the axial velocity on the centerline of the burner throat non-monotonically. In addition, emission characteristics were investigated using a gas analyzer. The CO and NO concentrations were below 20 ppm for all tested conditions, which is comparable to that seen with traditional hydrocarbon fuels, which is in favor of future practical applications with formic acid.
Original language | English (US) |
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Journal | International Journal of Hydrogen Energy |
DOIs | |
State | Published - Dec 5 2022 |
Bibliographical note
KAUST Repository Item: Exported on 2022-12-08Acknowledged KAUST grant number(s): BAS/1/1370-01-01
Acknowledgements: This work is supported by Saudi Aramco Research and Development Center under research agreement number RGC/3/3837-01-01 and by the King Abdullah University of Science and Technology under grant number BAS/1/1370-01-01.
ASJC Scopus subject areas
- Energy Engineering and Power Technology
- Condensed Matter Physics
- Fuel Technology
- Renewable Energy, Sustainability and the Environment