What Is the Process That Turns Sugar Cane Into Ethanol?

The biggest producer of sugarcane ethanol in the world is Brazil. Brazil makes its ethanol exclusively with sugarcane, the most efficient ethanol feedstock. The process of making sugarcane into ethanol is threefold: harvesting, milling and refining, and fermentation-distillation.

Harvest

• Sugarcane is harvested industrially, using heavy machinery combined with manual laborers to grade and wrap. It is then shipped from the field to a cane mill.

Refine

• Cane is chopped and washed mechanically, and then the cane is milled by rolling it between massive stone or steel rollers to squeeze out the juice. It is further refined by winnowing out the bagasse, the fibrous leftover stalks. The juice is then pasteurized, partially evaporated and centrifuged into syrup, or molasses.

Distill

• Yeast is added to the syrup to begin fermentation. Fermentation creates "wine," or alcohol that is still mixed with solids. The "wine" is then centrifuged to separate the solids and distilled to separate the remaining water from the remaining alcohol. The alcohol is ethanol.