Describe the basic steps in bioethanol production from corn.

Bioethanol production from corn involves: 1) Milling - corn kernels are ground into flour or meal to increase surface area for enzymatic access. 2) Liquefaction - starch slurry is heated with alpha-amylase enzyme to break down starch into dextrins. 3) Saccharification - glucoamylase converts dextrins into fermentable glucose at lower temperature. 4) Fermentation - yeast (Saccharomyces cerevisiae) converts glucose to ethanol and CO2 over 48-72 hours; typically achieves 10-15% ethanol concentration. 5) Distillation - fermented mash is distilled to separate ethanol (boiling point 78C) from water; produces 95% ethanol. 6) Dehydration - molecular sieves remove remaining water to produce anhydrous ethanol (>99.5%) suitable for fuel blending. Co-products include distillers dried grains with solubles (DDGS) used as animal feed and CO2 for beverage industry.