The present work is aimed at analysing the compositions of the water, ethanol, and gasoline which has Research Octane Number/RON was 88 forming a stable emulsion (one phase) employing a ternary graph. When the mixture process, the blended fuels consisted of water-ethanol-gasoline were successfully prepared in which they were formed in one phase. Ethanol was derived from Arenga pinnata liquor which is locally called cap tikus using a home-made reflux distillation filled by packing materials. Ethanol obtained were differing their concentration that depended on the column temperature set. It was found that the purities were ranged from 80 to 96% and the higher column temperature was chosen the lower concentration was obtained. Each aqueous ethanol was blended with gasoline to obtain a homogenous solution. For ethanol 80%, compositions of water, pure ethanol, and gasoline were observed at 18, 74, and 8 (%v/v), and 22, 70, and 7 (%w/w). While ethanol 96%, the compositions ratios were 1:22:77 (%v/v) and 1:23:76 (%w/w). The ranges of pure ethanol, gasoline, and water in which they formed one phase solution were recorded at 23-70%, 7-76%, and 1-22%. The work found that substance was in one phase if the wet ethanol keeps being added. When the ethanol composition has decreased the substance was separated into wet ethanol and gasoline. The minimum ethanol dissolved completely into gasoline was of 80%.

This study investigates the composition and fuel parameters of a fuel blend of aqueous ethanol and gasoline, with RONs (Research Octane Numbers) of 90 and 92, called pertalite and pertamax in Indonesia, respectively. The emulsion fuel blend of gasoline and ethanol was prepared successfully, and the concentrations ranged from 80 to 98% (v/v). The steps employed in this work are as follows: first, the fermentation of sugar tapped from a palm tree (Arenga pinnata). The obtained liquor containing ethanol was distilled using a reflux still to separate ethanol and water. The purity of the ethanol obtained from the reflux process ranged from 80 to 96%, depending on the column temperature set. Ethanol solutions of 97 and 98% purities were obtained through an absorption method employing lime particles. Subsequently, aqueous ethanol was blended with gasoline manually inside a flask. It was discovered that the minimum ethanol concentration, which could be blended with pertalite to form a single-phase substance, was 80%. By using 80% ethanol in the blending process, the composition ratio of pertalite, pure ethanol, and water was recorded as 1:11.65:2.91 (in volume unit), while this was not the case with pertamax. The minimum ethanol concentration that could be blended with pertamax to form a single-phase emulsion was 88%, with a composition ratio of 1:5.91:0.81. The composition proportions of the three components with 96% ethanol were 1:0.27:0.01 (RON 90) and 1:0.41:0.02 (RON 92). It was observed that the higher the ethanol concentration, the less the amount of ethanol required for the blending process with gasoline to form a single-phase emulsion.