Fusel oil, a byproduct of ethanol fermentation, contains higher alcohols such as isoamyl alcohol, isobutanol, and propanol. Fusel oil separation technology typically employs distillation, decantation, and liquid‑liquid extraction to recover these valuable components. A common approach uses a multi‑column distillation system to concentrate fusel oil from the fermentation beer, followed by a refining column to separate individual alcohols. Advanced processes integrate extractive distillation or membrane pervaporation to enhance purity and yield. The recovered alcohols serve as solvents, flavorings, or precursors for chemical synthesis. Efficient fusel oil separation improves overall economics and reduces waste in bioethanol plants.