The oxygenates ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol (isobutanol), 1-pentanol, 3-methyl-1-butanol (isopentanol), methyl levulinate, ethyl levulinate, butyl levulinate, 2-methyltetrahydrofuran (MTHF), 2-methylfuran (MF), and 2,5-dimethylfuran (DMF) were blended in three gasoline blendstocks for oxygenate blending (BOBs) at levels up to 3.7 wt % oxygen. Chemical and physical properties of the blends were compared to the requirements of ASTM specification D4814 for spark-ignited engine fuels to determine their utility as gasoline extenders. Vapor pressure, vapor lock protection, distillation, density, octane rating, viscosity, and potential for extraction into water were measured. Blending of ethanol at 3.7% oxygen increased vapor pressure by 5–7 kPa as expected. 2-Propanol slightly increased vapor pressure in the lowest-volatility BOB, while all other oxygenates caused a reduction in vapor pressure of up to 10 kPa. Coefficients for the Wilson equation were fitted to the measured vapor pressure data and were shown to adequately predict the vapor pressure of oxygenate–gasoline blends for five individual alcohols and MTHF in different gasolines. Higher alcohols and other oxygenates generally improved vapor lock protection. Butyl levulinate blended at 2.7% oxygen caused the distillation end point to exceed 225 °C, thus failing the specification. Distillation parameters were within specification limits for the other oxygenates tested. Other than ethanol, MF, and DMF, the oxygenates examined will not produce blends with satisfactory octane ratings at these blend levels when blended into lower-octane blendstocks designed for ethanol blending. However, all oxygenates tested except 1-pentanol and MTHF produced an increase in octane rating. For ethanol, the propanol isomers, and methyl levulinate, 20 wt % or more of the oxygenate could be extracted into water in a room-temperature water tolerance experiment. For the butanol isomers and ethyl levulinate, the percent extracted ranged from about 4% to 8%. Extraction for other oxygenates was 2% or lower. Methyl levulinate separates from gasoline as a separate liquid phase at temperatures below 0 °C.

This is a three part thesis regarding the regulated emissions from in-use heavy duty diesel vehicles. The first part of the thesis involves the collection and analysis of emissions from 21 vehicles. Emissions of particulate matter (PM), nitrogen oxides (NO x ), carbon monoxide (CO), total hydrocarbon (THC) and PM sulfate fraction were measured as well as smoke opacity. The vehicles were tested on three different driving cycles. This study found that when emissions were converted to a g/gallon basis, the effect of driving cycle was eliminated for NO x and reduced for PM. Sulfate comprised less than 1% of the emitted PM. Smoke opacity was not well correlated with mass emissions of any of the regulated pollutants. Multivariate regression analysis indicated that in-use NO x emissions did not decrease for this fleet during the years 1986 to 1995 while engine certification standards dropped sharply during that time. A review of all inuse emissions data in the scientific literature supported this result. The review also showed that PM emissions were widely variable among vehicles certified under identical standards. The variability was attributed to environmental factors, inertial weight, test cycle, driver variability and vehicle condition, but the relative importance of these factors could not be determined based on previously collected data. The wide variability in PM emissions within model years and the uniformity of NOx results despite the change in engine standards showed that engine certification was not an accurate tool to predict and iv control emissions from vehicles. To better understand the relationship between engine and chassis test results, a computer model was developed that estimates engine speed and load from vehicle speed. Using this model it was possible to detect the use of electronic controls which operate the engine in a different mode during engine testing and other more typical types of operation. The model also showed that the engine certification test generated consistently less PM than the vehicle tests when the model was used to put the engine and chassis emissions on a consistent basis. A good correlation was found between rate of HP increase integrated over the test cycle and PM emissions for both the chassis and engine tests. The engine test procedure includes engine behaviors that cannot be duplicated in in-use operation, and appears to favor lower rates of acceleration than typical chassis operation. The model also showed how small changes in vehicle speeds (+/-2 mph) due to driver variability can lead to a doubling of load on the engine.v

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