Chemistry – Organic chemistry - Alcohols | e-Consult

The manufacture of ethanol by fermentation is an anaerobic process carried out by yeast (typically Saccharomyces cerevisiae). The process involves the breakdown of glucose in aqueous solution into ethanol and carbon dioxide.

Process:

• Glucose (C₆H₁₂O₆) in aqueous solution is supplied to a fermentation vessel.
• Yeast is added to the glucose solution.
• The vessel is kept at a temperature between 25-35°C, which is optimal for yeast activity.
• Oxygen is excluded from the vessel to ensure anaerobic conditions.
• The yeast enzymes catalyze the breakdown of glucose.

Reactants and Products:

• Reactant: Aqueous glucose (C₆H₁₂O₆)
• Products: Ethanol (C₂H₅OH) and Carbon Dioxide (CO₂)
• The chemical equation for the reaction is: C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂

Role of Yeast:

• Yeast contains enzymes that catalyze the fermentation process.
• These enzymes break down glucose into pyruvate.
• Pyruvate is then converted to ethanol and carbon dioxide through a series of enzymatic reactions.
• The carbon dioxide produced is released from the solution, causing the solution to bubble.