Preparation of stable dieselwaste cooking oil microemulsion fuel using ionic liquid based benzimidazole derivatives: Fuel properties, particle size characteristics, and statistical investigation

• Published in: Fuel (Guildford) 2023-04, Vol.337, p.127217, Article 127217
• Main Authors: Nagy, H.A. El, El-Aziz Mohamed, Mahmoud Abd
• Format: Article
• Language: English
• Subjects: Emulsifier; Fuel blending; Ionic liquid; Microemulsion; Particle size; Synthesis; Waste cooking oil
• ISSN: 0016-2361
• DOI: 10.1016/j.fuel.2022.127217

•Two Ionic liquids are prepared based on benzimidazolium cation as emulsifiers for ethanol emulsification in diesel fuel/WCO blend.•The microemulsion fuels were characterized according to ASTM D975 minimal standards.•Particle size and size distribution of ethanol particles were indicated by dynamic light scattering (DLS) analyses.•In addition, statistical analyses were conducted to evaluate the prepared samples in order to choose the best sample in terms of particle size, homogeneity between particle sizes and the size distribution. Green microemulsions based on nontoxic oils and renewable components must be prepared and used because of the increasing demands of green chemistry and engineering. Fuel Microemulsions were prepared from ethanol in diesel/WCO blend (4:1) by using 2-heptadecyl-1,3-pentylbenzoimidazolium bromide (IL1) and 3-ethyl carboxylate-2-heptadecyl-1-pentylbenzoimidazolium chloride (IL2) ionic liquids as emulsifiers and 1-butanol as co-surfactant. Fuel Microemulsions were prepared as one hypothetical sample (Sh) and three alternative samples (S1, S2 and S3). Dynamic light scattering (DLS) analyses show that the ethanol mean particle size is 28 nm for Sh (IL1) microemulsion sample (up to 55 %) with a very narrow size distribution. The particle size of the prepared samples was noticed to be varied with the change in the microemulsion components percentage. The microemulsion fuels were characterized according to ASTM D975 minimal standards, and had properties close to that of the neat diesel. Distributions curves were studied by statistical analysis to determine the most appropriate mixing ratios between components based on the minimum particle size and the most homogeneity. The results show that the increasing diesel/WCO mixture causes the largest range with high variance of particle size distribution. The increasing of ethanol in sample makes the particle size become the largest among the other samples. Doubling the amount of IL1 or IL2 has low effect on the particle size. However, IL1 make the curve distribution more skew and kurtosis, on contrast, the IL2 has less skew and kurtosis compared with Sh samples of IL1 and IL2, respectively. The best results of the particle distribution obtained when the percentages of components are ethanol (7.4 %), co-surfactant (18.6 %) and the (diesel/WCO + IL1 or IL2) mixture (74 %). The mean particle size is 28 nm with a very narrow size distribution and high intensity up to 56 % for IL1 and 82 % for IL2.