DNA Explainer: What is ethanol blended petrol, how useful or harmful it is for vehicles

Jun 08,2022

In India, an alternative to fossil fuels is being looked up to amid rising petrol and diesel prices in the country and international market. Recently, Union Road Transport and Highways Minister Nitin Gadkari has also indicated that soon ethanol-containing fuel vehicles will start running in the country. At present, 5 to 10% ethanol blended petrol are being used in the country.

Ethanol fuel is ethyl alcohol, the same type of alcohol found in alcoholic beverages, used as fuel. It is most often used as a motor fuel, mainly as a biofuel additive for gasoline. Hardeep Singh Puri, Union minister for petroleum and natural gas, on Monday said 20% ethanol blended petrol may be available at select petrol pumps in the country ahead of the April 2023 target.

Earlier, Prime Minister Narendra Modi announced that India has achieved 10% ethanol blended petrol around five months ahead of the November 2022 deadline. Today, we try to understand what is ethanol blended petrol and what are its advantages and disadvantages.

What is ethanol?
Ethanol is an organic compound, ethyl alcohol, which is a fuel made from biomass. It is used in alcoholic beverages like alcohol. It has a higher octane number than gasoline, hence improves the petrol octane number. Ethanol has insignificant amount of water in it.

Although ethanol can be fully used for the fuel of vehicles, but for this some changes will have to be made in the engine and some parts of the vehicles. But for the time being by mixing it in the current petrol, it can be used effectively. Ethanol blended petrol is already in use within the country.

This blending of ethanol with petrol is being done by the oil marketing companies in their terminals and is not something new and is being used the world-over. It will not have any effect. Since ethanol contains oxygen, it is supposed to help in complete combustion of fuel, resulting in lower emissions.

Does it affect the vehicle?
It is said that adding ethanol to petrol does not have any effect in the current vehicle. Since ethanol contains oxygen, it helps in more complete combustion of the fuel, reduces emissions and makes it a much better fuel for the environment. But there are some changes in its effectiveness.

Ethanol in India is obtained primarily from sugarcane via a fermentation process. It can be mixed with fuel in different quantities and can help reduce vehicular emissions. Also, since it is plant-based, it is considered to be a renewable fuel.

How much ethanol in petrol
At present, ethanol is being mixed in petrol in the amount of 5 to 10% in many places in the country. It started with one or two percent, but now it is being taken towards the target of 10%. The cost of ethanol is around Rs 61 per litre. Mixing it with the expensive petrol at present can bring down the price.

There is however no change in the price of petrol or motor spirit, as it is called, due to ethanol blending. The consumer pays for a litre of petrol only. The price of ethanol containing petrol is dependent on petrol and many other factors. For this, a separate arrangement has to be made in the petrol pump. 

Its delivery machine is also different. In such a situation, due to this, there may be an extra load on the petrol pump owners, but it is not an excessive or uncontrollable expenditure. It can also be controlled with proper planning. At present, its price has been kept the same as the current petrol.

What about water complaints
There have been incidents of vehicle owners questioning water in the petrol, specially down south. Ethanol has an insignificant amount of water in it and if the mix is as stipulated it does not do any harm. Since ethanol is blended in the terminal itself, there is no chance that it will separate from the petrol.

In normal petrol vehicles, when water is mixed with petrol, it is considered harmful to the engine and its other parts. But there is very little water in petrol containing ethanol. Efforts are also been made to eliminate the possibility of mixing water with ethanol blended petrol. Petroleum dealers have been asked to adhere to quality checks as stipulated by oil companies for the fuel they receive and store. 

Ethanol cannot be separated from petrol. In this, the same standards are used which are happening in other countries of the world. At present, ethanol cannot be considered as an alternative to petrol, for this many changes will have to be made in the vehicles and engines and many practical challenges have to be faced.