Bioethanol is a bio-based alcohol (C₂H₅OH) produced through the biological fermentation of carbohydrates derived from renewable agricultural feedstocks. It serves as a low-carbon substitute for fossil-based gasoline and as a versatile industrial alcohol. Due to its oxygen content, bioethanol improves combustion efficiency and reduces harmful exhaust emissions.
Feedstocks & Raw Materials
Sugar-Based Feedstocks
Sugarcane, sugar beet, molasses
Starch-Based Feedstocks
Corn (maize), wheat, cassava, sorghum
Cellulosic / Advanced Feedstocks (2G Ethanol)
Agricultural residues, bagasse, corn cobs, forestry waste, energy crops
Cellulosic bioethanol improves sustainability by avoiding food-versus-fuel conflicts.
Manufacturing Process
Feedstock Preparation
Crushing, milling, liquefaction, hydrolysis
Fermentation
Yeast converts sugars into ethanol and CO₂
30–35°C | 24–72 hours
Distillation
Produces ~95% hydrous ethanol
Dehydration
Molecular sieves, vacuum or azeotropic distillation
Final purity: 99.5–99.9% anhydrous ethanol
Grades & Specifications
Fuel Grade Bioethanol
Purity ≥ 99.5% | Petrol blending
Industrial Grade Bioethanol
Purity 95–99.9% | Chemicals, inks, coatings
Extra Neutral Alcohol (ENA)
Highly purified | Beverages & pharmaceuticals
Physical & Chemical Properties
Chemical Formula: C₂H₅OH
Density: ~0.789 g/cm³ (20°C)
Boiling Point: ~78.37°C
Flash Point: ~13°C
Energy Content: ~21–23 MJ/L
Octane Number: 108–110 (RON)
Performance Characteristics
Cleaner combustion due to oxygen content
High octane reduces engine knock
Improved throttle response in high-compression engines
Environmental & Sustainability Benefits
Up to 60–90% lower lifecycle CO₂ emissions
Reduced CO, HC, and particulate emissions
Carbon-neutral lifecycle
Rapid biodegradability
Blending Standards & Applications
E5, E10, E20, E85, E100 fuel blends
Automotive gasoline blending
Flex-fuel vehicles and generators
Industrial & Commercial Applications
Chemical solvents and intermediates
Pharmaceuticals and healthcare
Personal care and FMCG products
Storage & Handling
Stored in stainless or carbon steel tanks
Moisture-free environment required
Highly flammable – Class 3 liquid
Regulatory & Policy Landscape (India)
National Bio-Energy Mission
Ethanol Blended Petrol Programme (E20 target)
Supports energy security and farmer income
Advantages vs Limitations
Advantages
Renewable, cleaner combustion, high octane
Limitations
Lower calorific value than petrol
Hygroscopic nature
Requires compatible engines at higher blends