Final answer:
The two main processes for synthesizing ethanol are fermentation and distillation. Fermentation occurs in an anaerobic environment converting sugars to ethanol and CO2, followed by distillation to purify the ethanol.
Step-by-step explanation:
The two main processes used for synthesizing ethanol are fermentation and distillation. During the process of alcohol fermentation, sugars are converted into ethanol and carbon dioxide. This process is anaerobic, which means it does not require oxygen. The initial steps involve the conversion of pyruvic acid to CO2 and acetaldehyde, followed by the reduction of acetaldehyde to ethanol while oxidizing NADH to NAD+.
Once fermentation is complete, distillation is typically used to purify the ethanol, increasing its concentration by removing water and other components. Distillation exploits the differing boiling points of water and ethanol to separate them through selective evaporation and condensation.