Adding n‐butanol, n‐heptanol, and n‐octanol to improve vaporization, combustion, and emission characteristics of diesel/used frying oil biodiesel blends in DICI engine

Abstract

Diesel engines play a vital role in the transportation sector. Ternary blends of alcohol, biodiesel, and diesel have the potential to improve diesel engine combustion and emissions. In the current work, three different types of alcohols; n‐butanol, n‐heptanol, and n‐octanol were added to biodiesel/diesel blends to improve diesel engine performance, combustion, and emissions. The biodiesel was produced from used frying oil (UFO) by ultrasonic enhanced transesterification to achieve the highest yield, lowest viscosity, and minimum production time. Three ternary fuels containing 10 vol% (n‐butanol or n‐heptanol or n‐octanol), 10 vol% UFO biodiesel, and 80 vol% diesel were tested using diesel engine at 25%, 50%, and 75% load conditions. Thermogravimetric analysis of the ternary blends proved the enhancement in the vaporization characteristics compared with biodiesel and diesel fuels; the lighter the alcohol, the faster the vaporization rate but with longer ignition delay which enhanced the premixed burning mode. The specific fuel consumption increased by up to 6% with a slight reduction in thermal efficiency (≈1%) when n‐octanol was used while n‐butanol and n‐heptanol showed comparable values to neat diesel. Ternary blends showed a reduction in smoke opacity, NOx, CO, and CO2 by up to 38%, 11%, 35%, and 14% compared with diesel, while the lowest emissions were attained for the addition of n‐heptanol.

Critical Review on Effects of Alcohols and Nanoadditives on Performance and Emission in Low-Temperature Combustion Engines: Advances and Perspectives

“…Several research works evaluated the influence of a mass proportion of methanol/diesel mixtures. The HRR rose as the diffusive combustion duration was reduced based on the experimental outcomes. − …”

“…The increased heating value of n -octanol (LHV = 37.5–38.4 MJ/kg vs ethanol (21.4–26.9 MJ/kg) and butanol (26.9–36.0 MJ/kg) for CI engines is another key property. Because of its low solubility in water (4.6 g/L), n -octanol has higher pipeline compatibility than ethanol (miscible) and n -butanol (*77 g/L). − , El-Seesy et al investigated the effects of quaternary biodiesel/methanol/ n -octanol/DEE. The pure methanol/waste frying oil biodiesel mixes were stable at all temperatures.…”

“…DBOHep40 had the highest BTE of 30.1% and the lowest BSFC of 0.305 kg/kWh among the ternary blends. Nour et al investigated the combustion and performance of a CIDI engine running on 1-heptanol-diesel mixes in an experimental setting. Furthermore, Hep10–50 mixes created more heat than standard diesel in the premixed fast-burn mode.…”

Combustion characteristics of butanol‐ Jet A‐1 fuel blends in a swirl‐stabilized combustor under the influence of preheated swirling air

“…However, there are approaches available to estimate approximate fuel properties of blends as suggested by researchers. 11,37 The density and surface tension of butanol and Jet A-1 are almost the same, hence no variation is observed in the fuel blends. The viscosity of butanol is significantly greater than Jet A-1; therefore, the viscosity variation is evident in fuel blends.…”

“…Over time significant developments have been made in the use of biofuel fuels, as shown by the approval of seven types of biomass-derived alternative jet fuels in the ASTM D7566 standard and the many flight trials conducted using biofuels in the past decade. 10,11 Different types of biofuels either as single fuel or as a mixture/blend with conventional fuels have been studied for their fundamental combustion properties and emission characteristics in gas turbine burners. Attia et al 12 examined the combustion behavior of Jet A-1/Jojoba methyl ester (JOME) blend in a swirl-stabilized combustor and compared them with Jet A-1.…”