Stability, Lubricity, Viscosity, and Cold-Flow Properties of Alcohol−Diesel Blends

Abstract

Alcohols have an interesting potential as blending components for diesel fuels because of their capacity to reduce soot formation. Because they have increasing routes for their production from renewable sources, they could contribute toward increasing the renewable fraction of these fuels and, therefore, toward reducing the impact of diesel transportation on the global warming effect. To increase the knowledge about the implications of the use of short- and long-chain alcohols/diesel fuel blends in diesel engines, the stability, lubricity, viscosity, and cold filter plugging point (CFPP) have been tested. Blends of methanol, ethanol, propanol, butanol, and pentanol with diesel fuel have been analyzed at 1, 2.5, 7.7, 17, 50, 75, and 90% in volume [including 95% (v/v) in the case of CFPP]. Results have shown that short-chain alcohols depict poor blending stability and low viscosity (mainly for concentrations of ethanol and propanol in diesel fuel blends beyond 22 and 45%, respectively). A synergistic effect was observed in viscosity when moderate concentrations of butanol and pentanol were mixed with diesel fuel. The lubricity of the blends decreases with the alcohol content, but this effect is partially compensated by the alcohol volatility. The blends with the highest restriction of use are those containing pentanol, which should be limited to concentrations below 10% (v/v), because its volatility does not compensate for its lubricating capacity. The use of alcohol/winter diesel fuel blends provides a substantial benefit only when high alcohol concentrations are used. It can be concluded that alcohols can be blended with diesel fuel under low and high concentrations, although to improve the blending stability of short-chain alcohols in medium concentrations, the use of additives or fatty acid esters would be necessary.

Puffing and Micro-Explosion Behavior in Combustion of Butanol/Jet A-1 and Acetone-Butanol-Ethanol (A-B-E)/Jet A-1 Fuel Droplets

“…Properties of acetone are from Ref. [33,34] c Properties of ethanol and butanol are from Ref. [33,35].…”

“…[33,34] c Properties of ethanol and butanol are from Ref. [33,35]. Table 2 Composition and nomenclature of fuel blends Composition of fuel blends (volume basis) Designated nomenclature 10% butanol, 90% Jet A-1 B10 30% butanol, 70% Jet A-1 B30 50% butanol, 50% Jet A-1 B50 30% acetone, 60% butanol, 10% ethanol…”

A Review on Spray Characteristics of Bioethanol and Its Blended Fuels in CI Engines

“…The effect of ethanol addition and temperature on the dynamic viscosity of ethanol-diesel blend fuel was investigated by Chen et al (25) The experimental results for E0, E10, E20 and E30 showed that an increase in ethanol fraction and temperature resulted in the decrease of viscosity of the blends. The kinematic viscosity of the e-diesel blends for 0 to 90% in volume was measured at 40 o C by Lapuerta et al (26) With regard to the diesel quality norm EN 590, blends with more than 22% (v/v) ethanol would not satisfied the requirement of viscosities above 2 cSt. Those results are in accordance with the previous work (24) .…”

Effect of Ethanol on Performance and Durability of a Diesel Common Rail High Pressure Fuel Pump

“…Additionally, in this range, increasing temperatures led to improved lubricities as a consequence of the ethanol evaporation from the lubricating layer. It was also estimated, that the lubricity of the blends decreases with the alcohol content, but this effect is partially compensated by the alcohol volatility (Lapuerta et al 2010b). Torres-Jimenez et al (2011b) research results presents that the addition of ethanol to diesel fuel slightly improves lubricity, as the wear scar is lower.…”