Effects of iso-octane/ethanol blend ratios on the observance of negative temperature coefficient behavior within the Ignition Quality Tester
Abstract
Here, an ignition delay study investigating the reduction in low temperature heat release (LTHR) and negative temperature coefficient (NTC) region with increasing ethanol concentration in binary blends of ethanol/isooctane was conducted in the Ignition Quality Tester (IQT). The IQT is advantageous for studying multi-component fuels such as iso-octane/ethanol which are difficult to study at lower temperatures covering the NTC region in traditional systems (e.g., shock tubes, rapid compression machines, etc.). The high octane numbers and concomitant long ignition delay times of ethanol and iso-octane are ideal for study in the IQT allowing the system to reach a quasi-homogeneous mixture; allowing the effect of fuel chemistry on ignition delay to be investigated with minimal impact from the fuel spray due to the relatively long ignition times. NTC behavior from iso-octane/ethanol blends was observed for the first time using an IQT. Temperature sweeps of iso-octane/ethanol volumetric blends (100/0, 90/10, 80/20, 50/50, and 0/100) were conducted from 623 to 993 K at 0.5, 1.0 and 1.5 MPa and global equivalence ratios ranging from 0.7 to 1.0. Ignition of the iso-octane/ethanol blends in the IQT was also modeled using a 0-D homogeneous batch reactor model. Significant observations include: (1) NTC behavior was observed formore »
- Authors:
-
- Colorado School of Mines, Golden, CO (United States)
- National Renewable Energy Lab. (NREL), Golden, CO (United States)
- Publication Date:
- Research Org.:
- National Renewable Energy Lab. (NREL), Golden, CO (United States)
- Sponsoring Org.:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE), Vehicle Technologies Office (EE-3V); USDOE Office of Energy Efficiency and Renewable Energy (EERE), Sustainable Transportation Office. Bioenergy Technologies Office
- OSTI Identifier:
- 1329461
- Alternate Identifier(s):
- OSTI ID: 1399040
- Report Number(s):
- NREL/JA-5400-66816
Journal ID: ISSN 0016-2361
- Grant/Contract Number:
- AC36-08GO28308; AC36-08-GO28308
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Fuel
- Additional Journal Information:
- Journal Volume: 186; Journal ID: ISSN 0016-2361
- Publisher:
- Elsevier
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 09 BIOMASS FUELS; IQT; iso-octane; ethanol; ignition; NTC; fuel blends
Citation Formats
Bogin, Jr., Gregory E., Luecke, Jon, Ratcliff, Matthew A., Osecky, Eric, and Zigler, Bradley T. Effects of iso-octane/ethanol blend ratios on the observance of negative temperature coefficient behavior within the Ignition Quality Tester. United States: N. p., 2016.
Web. doi:10.1016/j.fuel.2016.08.021.
Bogin, Jr., Gregory E., Luecke, Jon, Ratcliff, Matthew A., Osecky, Eric, & Zigler, Bradley T. Effects of iso-octane/ethanol blend ratios on the observance of negative temperature coefficient behavior within the Ignition Quality Tester. United States. https://doi.org/10.1016/j.fuel.2016.08.021
Bogin, Jr., Gregory E., Luecke, Jon, Ratcliff, Matthew A., Osecky, Eric, and Zigler, Bradley T. Sun .
"Effects of iso-octane/ethanol blend ratios on the observance of negative temperature coefficient behavior within the Ignition Quality Tester". United States. https://doi.org/10.1016/j.fuel.2016.08.021. https://www.osti.gov/servlets/purl/1329461.
@article{osti_1329461,
title = {Effects of iso-octane/ethanol blend ratios on the observance of negative temperature coefficient behavior within the Ignition Quality Tester},
author = {Bogin, Jr., Gregory E. and Luecke, Jon and Ratcliff, Matthew A. and Osecky, Eric and Zigler, Bradley T.},
abstractNote = {Here, an ignition delay study investigating the reduction in low temperature heat release (LTHR) and negative temperature coefficient (NTC) region with increasing ethanol concentration in binary blends of ethanol/isooctane was conducted in the Ignition Quality Tester (IQT). The IQT is advantageous for studying multi-component fuels such as iso-octane/ethanol which are difficult to study at lower temperatures covering the NTC region in traditional systems (e.g., shock tubes, rapid compression machines, etc.). The high octane numbers and concomitant long ignition delay times of ethanol and iso-octane are ideal for study in the IQT allowing the system to reach a quasi-homogeneous mixture; allowing the effect of fuel chemistry on ignition delay to be investigated with minimal impact from the fuel spray due to the relatively long ignition times. NTC behavior from iso-octane/ethanol blends was observed for the first time using an IQT. Temperature sweeps of iso-octane/ethanol volumetric blends (100/0, 90/10, 80/20, 50/50, and 0/100) were conducted from 623 to 993 K at 0.5, 1.0 and 1.5 MPa and global equivalence ratios ranging from 0.7 to 1.0. Ignition of the iso-octane/ethanol blends in the IQT was also modeled using a 0-D homogeneous batch reactor model. Significant observations include: (1) NTC behavior was observed for ethanol/iso-octane fuel blends up to 20% ethanol. (2) Ethanol produced shorter ignition delay times than iso-octane in the high temperature region. (3) The initial increase in ethanol from 0% to 10% had a lesser impact on ignition delay than increasing ethanol from 10% to 20%. (4) The 0-D model predicts that at 0.5 and 1.0 MPa ethanol produces the shortest ignition time in the high-temperature regime, as seen experimentally.},
doi = {10.1016/j.fuel.2016.08.021},
journal = {Fuel},
number = ,
volume = 186,
place = {United States},
year = {2016},
month = {8}
}
Web of Science