How ethanol is made, where it is used, and whether it can replace petrol and cooking gas in the years ahead.
A renewable fuel made from plants
Ethanol (chemical formula C₂H₅OH) is a clear, flammable alcohol produced by fermenting the sugars in plants. Because the crops that make it grow back every season, it is called a renewable fuel. When fuel-grade ethanol is made, a small amount of denaturant is added so that it cannot be drunk.
A growing plant absorbs CO₂ from the air. When ethanol is burned, roughly that same carbon returns to the air, and new plants absorb it again. Petrol, in contrast, releases carbon that was locked underground for millions of years. Overall, ethanol usually has a lower life-cycle carbon footprint than petrol, though the exact saving depends on the crop and the farming and factory methods used.
From field to fuel pump in six steps
Distillers' grain from grain plants is used as animal feed, bagasse (crushed cane fibre) burns to produce electricity for the factory, and captured CO₂ can be used in the food and beverage industry.
Much more than a petrol additive
Blended with petrol (E5, E10, E20) or used in high blends such as E85 in flex-fuel vehicles. Special ED95 ethanol buses run in some European cities.
A key ingredient in hand sanitisers, disinfectants, antiseptics, tinctures and many medicines.
Used as a solvent in paints, perfumes, inks and cosmetics, and as a raw material for acetic acid, ethyl acetate and bio-plastics.
Ethanol and ethanol gel stoves burn with little smoke and are used in parts of Africa, South Asia and Latin America as an alternative to firewood, kerosene and LPG.
Ethanol can be converted into sustainable aviation fuel through the alcohol-to-jet process, a growing area of research and early commercial use.
Used in some generators and studied as a hydrogen carrier for fuel cells.
The number after "E" is the percentage of ethanol
| Blend | Mix | Where it fits |
|---|---|---|
| E5 / E10 | 5–10% ethanol | Standard petrol in many countries; works in most modern petrol cars. |
| E20 | 20% ethanol | India's national blending target, rolled out across petrol pumps; best suited to vehicles built or certified for it. |
| E85 | 85% ethanol | For flex-fuel vehicles only (USA, Sweden, Brazil). |
| E100 | Pure ethanol | Sold at pumps in Brazil for flex-fuel cars. |
Ethanol has about two-thirds of the energy of petrol per litre, so mileage can fall slightly with higher blends. Its higher octane rating helps engines run smoothly.
Petrol, LPG and natural gas compared
This is the most realistic path. Blending already works at scale: Brazil runs on E27 and E100, the USA on E10 with some E15/E85, and India has moved from E10 to E20. Flex-fuel vehicles can use anything from petrol to high-ethanol blends, which lets countries raise the share step by step without changing the fuel network overnight.
Many countries import much of their LPG. Ethanol cooking stoves and ethanol gel can cut that dependence and give cleaner indoor air than wood or kerosene. Pilot projects in Africa and South Asia show promise, but the stoves, fuel supply and low-cost distribution must reach households before ethanol could replace LPG on a large scale.
Here ethanol is a smaller player. Natural gas and biogas (bio-CNG) are the more direct renewable gas options, while ethanol works best in liquid-fuel uses such as cars, buses, ships and aircraft.
| Fuel | Source | Main strength | Main limit |
|---|---|---|---|
| Petrol | Crude oil | High energy, huge network | Imported, high CO₂ |
| LPG | Oil and gas refining | Convenient cooking fuel | Largely imported in many countries |
| CNG / Natural gas | Gas fields | Cleaner than petrol | Needs pipelines and cylinders; still fossil |
| Ethanol | Plants and farm waste | Renewable, farm income, cleaner burn | Lower energy per litre, land and water needs |
In short: ethanol is likely to reduce petrol and some LPG use rather than replace them completely. It works best alongside electric vehicles, biogas, solar and hydrogen.
Making more fuel without taking food from the table
Enzymes break down farm waste such as paddy straw, corn stalks, bagasse and wood chips (cellulose) into sugars, which are then fermented. This can turn stubble that is often burnt into fuel, reducing air pollution and giving farmers extra income. India has started 2G ethanol plants using paddy straw.
Blending targets, production figures and policies change over time. Check the latest official sources before quoting exact numbers.