An experimental investigation was conducted to determine the emissions characteristics of higher alcohols and gasoline (UTG96) blends. While lower alcohols (methanol and ethanol) have been ...

Combustion characteristics of higher-alcohol/gasoline blends

NOx Emission from a spark ignition engine using 30% Iso-butanol–gasoline blend: Part 1—Preheating inlet air

Comparative testing of pure methanol, methanol/water blends and isooctane in single-cylinder engines has demonstrated that through proper utilization of methanol's fuel-lean combustion characteristics it may be possible to reach CO emissions of the order of 0.1% and NO/sub x/ emission levels of less than 100 ppM in the raw (undiluted) exhaust. Exhaust treatment to remove unburned methanol and partial oxidation products might be required. Concomitant with decreased emissions are specific energy consumption improvements estimated to be in the range of 26 to 45% better than achievable with current gasolines and the associated low compression ratio engines and emission control systems. These energy consumption improvements are obtained by virtue of efficient lean operation and by utilizing the high octane values of methanol/water blends at high compression ratios. Despite these potential end-use technical advantages for methanol, its large scale use as an automotive fuel is precluded for at least one to two decades because of inadequate supply, the need for immense capital expenditures to increase supply and the need for special engine and fuel control designs.

Single-Cylinder Engine Evaluation of Methanol - Improved Energy Economy and Reduced NOx

NOx, NMHC and CO emissions from biomass derived gasoline extenders

Methanol's potential as a gasoline extender has been evaluated, with data being obtained in the areas of fuel economy, exhaust emissions, and driveability. The results of tests with three cars, having carburetion spanning the range normally encountered in the existing car population, showed that methanol's effect on fuel economy and emissions could be directly related to its leaning effect on carburetion. The data suggest that any benefits in these two areas would only be significant for older, rich-operating cars. A 13-car driveability study indicated that the large increase in fuel volatility which occurs with the addition of methanol to gasoline could pose serious problems. A marked increase in vapor locking tendency was observed when no front-end volatility adjustments were made to the methanol blends. Stretchiness, a lack of expected response to throttle movement, was also found with the methanol blends. This operational characteristic, being related to excessively lean operation, was more pronounced with the newer cars tested. Phase separation is also a potential problem with methanol-gasoline blends. Data are presented which show the effect of including higher molecular weight alcohols along with the methanol. Phase separation still occurred in the presence of less than 1% water. Taken as a whole,more » the data suggest that, if it becomes available in large quantities, the use of methanol in applications other than in motor gasoline would be preferred.« less

Methanol as a gasoline extender: fuel economy, emissions, and high temperature driveability

Operating characteristics of a single-cylinder, spark-ignition engine fueled by both methanol and isooctane were determined. Engine output, indicated specific fuel consumption, and specific emissions of hydrocarbon, carbon monoxide, nitric oxide, and aldehydes were measured for both fuels and compared using the performance maps. The engine output comparisons showed that lean misfire limits occurred at leaner mixtures with methanol than with isooctane and that maximum engine output levels were nearly equal for both fuels. Comparison of the specific parameters of each fuel at equivalent power levels obtained with maximum power spark timing permits the following conclusions: use of methanol results in higher indicated specific fuel consumption, greater emission of aldehydes, but lower emissions of hydrocarbon and nitric oxide; the two fuels showed similar trends of carbon monoxide emission.

F. S. Manning

Papers

Engine performance and exhaust emissions: methanol versus isooctane