Abstract
Yield Sooting Index (YSI) was determined for 13 oxygen-containing aromatic compounds by measuring line-of-sight spectral radiance (LSSR) in a laminar non-premixed methane/air flame doped with 1000 ppm of each compound. The compounds included anisole (methoxybenzene), other aromatic ethers, and phenols. The presence of oxygen greatly reduced soot formation in some cases, but increased it in others. Thus oxygenated aromatics are potentially valuable as fuel components with intrinsically low particulate emissions, but the specific structure is important. Compounds containing an aromatic ring with an adjacent oxygen atom tended to have a lower sooting tendency than did compounds with oxygen atoms elsewhere in the side chain. This observation was quantitatively explored using Density Functional Theory (DFT) calculations. The bond dissociation energies for nine aromatic hydrocarbons and oxygenates were calculated using GGA B3LYP density functions with 6-31G(d) basis sets. When possible, unimolecular dissociation to phenoxy radical was favored and resulted in much lower YSIs than similar compounds where the oxygen atom was not adjacent to the aromatic ring. Structures that dissociated to benzyl radical had much higher sooting tendencies, sometimes by over a factor of two in comparison to phenoxyforming compounds.
Original language | American English |
---|---|
Pages | 140-145 |
Number of pages | 6 |
State | Published - 2018 |
Event | Spring Technical Meeting of the Eastern States Section of the Combustion Institute 2018 - State College, Pennsylvania Duration: 4 Mar 2018 → 7 Mar 2018 |
Conference
Conference | Spring Technical Meeting of the Eastern States Section of the Combustion Institute 2018 |
---|---|
City | State College, Pennsylvania |
Period | 4/03/18 → 7/03/18 |
NREL Publication Number
- NREL/CP-2700-71631
Keywords
- aromatic compounds
- Density Functional Theory
- DFT
- hydrocarbons
- line-of-sight spectral radiance
- LSSR
- methane
- oxygenates
- phenoxyforming compounds
- soot
- Yield Sooting Index
- YSI