The structural formula of recycled waste ethanol is C2H5OH, commonly known as alcohol. It is a flammable and volatile colorless transparent liquid at room temperature and pressure. Its aqueous solution has a unique, pleasant aroma with a slight刺激性. Ethanol is used to produce acetic acid, beverages, perfumes, dyes, fuels, and more. In medicine, 70% to 75% ethanol by volume is commonly used as a disinfectant.

Ethanol's physical properties are mainly related to the characteristics of its low-carbon straight-chain alcohols. The hydroxyl group in its molecule can form hydrogen bonds, resulting in a high viscosity and less polarity compared to organic compounds with a similar relative molecular mass. At room temperature, ethanol is colorless and has a distinctive, aromatic volatile liquid.