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Title: Bioblendstocks that Enable High Efficiency Engine Designs

Abstract

The past decade has seen a high level of innovation in production of biofuels from sugar, lipid, and lignocellulose feedstocks. As discussed in several talks at this workshop, ethanol blends in the E25 to E50 range could enable more highly efficient spark-ignited (SI) engines. This is because of their knock resistance properties that include not only high research octane number (RON), but also charge cooling from high heat of vaporization, and high flame speed. Emerging alcohol fuels such as isobutanol or mixed alcohols have desirable properties such as reduced gasoline blend vapor pressure, but also have lower RON than ethanol. These fuels may be able to achieve the same knock resistance benefits, but likely will require higher blend levels or higher RON hydrocarbon blendstocks. A group of very high RON (>150) oxygenates such as dimethyl furan, methyl anisole, and related compounds are also produced from biomass. While providing no increase in charge cooling, their very high octane numbers may provide adequate knock resistance for future highly efficient SI engines. Given this range of options for highly knock resistant fuels there appears to be a critical need for a fuel knock resistance metric that includes effects of octane number, heat ofmore » vaporization, and potentially flame speed. Emerging diesel fuels include highly branched long-chain alkanes from hydroprocessing of fats and oils, as well as sugar-derived terpenoids. These have relatively high cetane number (CN), which may have some benefits in designing more efficient CI engines. Fast pyrolysis of biomass can produce diesel boiling range streams that are high in aromatic, oxygen and acid contents. Hydroprocessing can be applied to remove oxygen and consequently reduce acidity, however there are strong economic incentives to leave up to 2 wt% oxygen in the product. This oxygen will primarily be present as low CN alkyl phenols and aryl ethers. While these have high heating value, their presence in diesel fuel at significant volume percentage will require higher CN blendstocks or the use of cetane improving additives.« less

Authors:
; ; ; ;
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)
OSTI Identifier:
1337921
Report Number(s):
PR-5400-67629
DOE Contract Number:
AC36-08GO28308
Resource Type:
Conference
Resource Relation:
Conference: Presented at the 2nd Coordinating Research Council (CRC) Advanced Fuels and Engine Efficiency Workshop, 1-3 November 2016, Livermore, California
Country of Publication:
United States
Language:
English
Subject:
09 BIOMASS FUELS; biofuels; spark ignition; compression ignition; co-optimization

Citation Formats

McCormick, Robert L., Fioroni, Gina M., Ratcliff, Matthew A., Zigler, Bradley T., and Farrell, John. Bioblendstocks that Enable High Efficiency Engine Designs. United States: N. p., 2016. Web.
McCormick, Robert L., Fioroni, Gina M., Ratcliff, Matthew A., Zigler, Bradley T., & Farrell, John. Bioblendstocks that Enable High Efficiency Engine Designs. United States.
McCormick, Robert L., Fioroni, Gina M., Ratcliff, Matthew A., Zigler, Bradley T., and Farrell, John. Thu . "Bioblendstocks that Enable High Efficiency Engine Designs". United States. doi:. https://www.osti.gov/servlets/purl/1337921.
@article{osti_1337921,
title = {Bioblendstocks that Enable High Efficiency Engine Designs},
author = {McCormick, Robert L. and Fioroni, Gina M. and Ratcliff, Matthew A. and Zigler, Bradley T. and Farrell, John},
abstractNote = {The past decade has seen a high level of innovation in production of biofuels from sugar, lipid, and lignocellulose feedstocks. As discussed in several talks at this workshop, ethanol blends in the E25 to E50 range could enable more highly efficient spark-ignited (SI) engines. This is because of their knock resistance properties that include not only high research octane number (RON), but also charge cooling from high heat of vaporization, and high flame speed. Emerging alcohol fuels such as isobutanol or mixed alcohols have desirable properties such as reduced gasoline blend vapor pressure, but also have lower RON than ethanol. These fuels may be able to achieve the same knock resistance benefits, but likely will require higher blend levels or higher RON hydrocarbon blendstocks. A group of very high RON (>150) oxygenates such as dimethyl furan, methyl anisole, and related compounds are also produced from biomass. While providing no increase in charge cooling, their very high octane numbers may provide adequate knock resistance for future highly efficient SI engines. Given this range of options for highly knock resistant fuels there appears to be a critical need for a fuel knock resistance metric that includes effects of octane number, heat of vaporization, and potentially flame speed. Emerging diesel fuels include highly branched long-chain alkanes from hydroprocessing of fats and oils, as well as sugar-derived terpenoids. These have relatively high cetane number (CN), which may have some benefits in designing more efficient CI engines. Fast pyrolysis of biomass can produce diesel boiling range streams that are high in aromatic, oxygen and acid contents. Hydroprocessing can be applied to remove oxygen and consequently reduce acidity, however there are strong economic incentives to leave up to 2 wt% oxygen in the product. This oxygen will primarily be present as low CN alkyl phenols and aryl ethers. While these have high heating value, their presence in diesel fuel at significant volume percentage will require higher CN blendstocks or the use of cetane improving additives.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Nov 03 00:00:00 EDT 2016},
month = {Thu Nov 03 00:00:00 EDT 2016}
}

Conference:
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