The performance and emission characteristics of C₁-C₅ alcohol-gasoline blends with matched oxygen content in a single-cylinder spark ignition engine

Abstract

Alcohols with carbon numbers ranging from C1 to C5 were individually blended with unleaded test gasoline. All the alcohol-gasoline blends had the same oxygen mass content. The performance characteristics of the blends were quantified using a single-cylinder spark ignition engine. The knock-limiting spark timing was determined by analysis of the third derivative of the measured in-cylinder gas pressure versus crank angle. The engine operating conditions were optimized for each (C1-C5) blend with two different values of matched oxygen mass content (2.5 and 5.0 per cent). Emission mass rates of carbon monoxide (CO), nitric oxides (NOx), total unburned hydrocarbons (THCs), alcohols and aldehydes were quantified. The brake power specific rate emissions were compared with that of neat gasoline. Adding lower alcohols (C1, C2 and C3) to gasoline improved the knock resistance. Further improvement was achieved by increasing the oxygen content of the fuel blend. Blends with higher alcohols (C4 and C5) showed degraded knock resistance when compared with neat gasoline. Generally, all alcohol-gasoline blends showed reduction in CO emissions. Higher alcohol-gasoline blends with an oxygen mass content of 5.0 per cent showed a pronounced increase in NOx emission rates when operating at high compression ratios and 5° before top dead centre timing. This is attributed to their lower enthalpy of vaporization and higher flame temperature. All blends tested at optimized operating conditions showed reduction in THC emission rates. Unburned alcohol emission rates were higher for blends with higher content of alcohol, and aldehyde emissions were higher for all blends with formaldehyde as the main constituent.

Performance and Emission Characteristics of Spark Ignition Engine Fuelled with Ethanol and Methanol Gasoline Blended Fuels

“…The maximum improvement occured at 10% ethanol/90% gasoline fuel blend. Yacoub et al (1998) quantified the performance and exhaust gas emissions for an engine optimized to operate on C1-C5 alcohol/gasoline blends with matched oxygen content. The performance and exhaust gas emissions characteristics of the blends were quantified by using a singlecylinder spark ignition engine.…”

Evaluation of Butanol–Gasoline Blends in a Port Fuel-injection, Spark-Ignition Engine

“…Alcohol addition, however, can increase power for a given engine displacement and compression ratio, thereby reducing fossil-fuel consumption and CO 2 emissions [1][2][3]. Ethanol and butanol are two alcohols or oxygenated fuels that can be blended with gasoline to reduce fossil-fuel consumption and are often associated with a possible decrease in pollutant emissions.…”

“…Les principaux résultats : 1) un mélange de 40 % butanol et 60 % essence (B40) par volume diminue les émissions de HC ; 2) aucun effet significatif sur les émissions de NOx n'a été observé à l'exception du mélange 80% butanol/20 % essence ; 3) l'ajout de butanol améliore la stabilité de combustion ; 4) l'ajout de butanol réduit le délai d'inflammation, quantifié par la durée pour consommer 10% de masse de gaz frais; et 5) la consommation spécifique de carburant pour un mélange stoechiométrique de B40 est 10% supérieure à celle de l'essence. [0][1][2][3][4][5][6][7][8][9][10] …”

Perspectives of Biobutanol Production and Use

“…The total miscibility with hydrocarbons, boiling point, flash point and other properties allow mixing butanol with gasoline in wide range of concentrations and combustion in common spark ignition engines. In comparison to other alcohols in the range of C 1 to C 5 mixed to gasoline in concentrations matching fuel oxygen content, butanol does not differ significantly in its effect on the emissions of regulated pollutants (Yacoub et al, 1998). The emissions of total hydrocarbons decrease, while significant increase takes place in the emissions of aldehydes, whose main constituent was formaldehyde.…”