Browse Publications Technical Papers 2016-01-0705
2016-04-05

Knock Resistance and Fine Particle Emissions for Several Biomass-Derived Oxygenates in a Direct-Injection Spark-Ignition Engine 2016-01-0705

Several high octane number oxygenates that could be derived from biomass were blended with gasoline and examined for performance properties and their impact on knock resistance and fine particle emissions in a single cylinder direct-injection spark-ignition engine. The oxygenates included ethanol, isobutanol, anisole, 4-methylanisole, 2-phenylethanol, 2,5-dimethyl furan, and 2,4-xylenol. These were blended into a summertime blendstock for oxygenate blending at levels ranging from 10 to 50 percent by volume. The base gasoline, its blends with p-xylene and p-cymene, and high-octane racing gasoline were tested as controls. Relevant gasoline properties including research octane number (RON), motor octane number, distillation curve, and vapor pressure were measured. Detailed hydrocarbon analysis was used to estimate heat of vaporization and particulate matter index (PMI). Experiments were conducted to measure knock-limited spark advance and particulate matter (PM) emissions. The results show a range of knock resistances that correlate well with RON. Molecules with relatively low boiling point and high vapor pressure had little effect on PM emissions. In contrast, the aromatic oxygenates caused significant increases in PM emissions (factors of 2 to 5) relative to the base gasoline. Thus, any effect of their oxygen atom on increasing local air-fuel ratio was outweighed by their low vapor pressure and high double-bond equivalent values. For most fuels and oxygenate blend components, PMI was a good predictor of PM emissions. However, the high boiling point, low vapor pressure oxygenates 2-phenylethanol and 2,4-xylenol produced lower PM emissions than predicted by PMI. This was likely because they did not fully evaporate and combust, and instead were swept into the lube oil.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 18% off list price.
Login to see discount.
We also recommend:
TECHNICAL PAPER

The Effect of Direct Injection Timing and Pressure on Engine Performance in an Ethanol Direct Injection Plus Gasoline Port Injection (EDI+GPI) SI Engine

2013-01-0892

View Details

TECHNICAL PAPER

Investigations of Port Dual Injection (PDI) Strategies in Single Cylinder SI Engine Fueled with Ethanol/Gasoline Blends

2016-01-0573

View Details

JOURNAL ARTICLE

Experimental Investigation of the Influence of Boost on Combustion and Particulate Emissions in Optical and Metal SGDI-Engines Operated in Stratified Mode

2016-01-0714

View Details

X