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Advantages and Disadvantages of Biodiesel Fuel

Sunflower seeds

Mankind is moving towards cleaner sources of energy in order to reduce our impact on the environment.

One of the alternative fuels used to replace the conventional diesel fuel used daily in diesel engines is called ‘biodiesel’ and can be produced from natural sources of energy such as oil seeds and waste organic products (animal fats and used cooking oil).

Biodiesel – Definition

Biodiesel is a variety of ester-based oxygenated fuel produced from natural and renewable resources such as vegetable oils, animal fats and used cooking oil.

The original diesel engine created in the 1890s by the German inventor Rudolf Diesel initially ran on vegetable oil.

The changes in the design of the diesel engines over the years, required a different fuel with higher energy output and less gelling in colder weather conditions.

This way, petroleum-based diesel has become more popular than vegetable oil. However, due to the huge amount of air, soil and water pollution produced by diesel fuel, biodiesel is considered today a viable alternative to diesel fuel to reduce emissions.

How is Biodiesel Produced Today?

The main categories of feedstock used to produce biodiesel are mainly: vegetable oil, animal fats and used cooking oil.

Vegetable oil is produced by extracting oil from seeds using a seed press, animal fats are provided by the fat tissue of different animals such as: chicken, pigs, cows, horses, sheep, etc., and the used cooking oil is provided by households and restaurants.

The production process has different phases:

1. Removing impurities

To make biodiesel, we first thing to do is to remove the impurities from the animal fats or the used cooking oil.

2. Transesterification

To be used in conventional diesel engines, we need to change the viscosity of the oil to work smoothly without clogging up the fuel lines.

The viscosity changes through a chemical process called transesterification. This is a chemical reaction of the vegetable oil and alcohol mixed with a catalyst to speed the reaction.

The entire mixture consisting of vegetable oil, alcohol and catalyst is heated and agitated for a short period of time.

The result is a layer of biodiesel and a layer of glycerin. Glycerin drains through the bottom and is used later in the soap industry.

3. Removing contaminants

To clean the biodiesel obtained through transesterification a wash process using water will remove all the contaminants.

The biodiesel obtained this way can be used in diesel engines directly or blended with diesel fuel.

If you have an older vehicle with a diesel engine, you can use biodiesel obtained from used cooking oil, but from time to time you have to switch back to diesel fuel to clean the injectors.

The biodiesel should be used mainly during the summer, because in the winter, the biodiesel in your tank will turn into a gel, and your engine will not start.

Advantages of Biodiesel

Being and organic fuel produced from vegetable oil or waste products (animal fats and used cooking oil), biodiesel has many advantages over petroleum-based diesel.

1. Is a Renewable Source of Energy

Biodiesel can be produced from waste organic products such as animal fats and used cooking oil, but also from vegetable oil produced from oil seeds. As long as we have people and plants on the planet, used cooking oil and vegetable oil will always be available for biodiesel production.

This means that biodiesel is a renewable fuel because is produced from never-ending resources such as vegetable oil and used cooking oil.

2. Is An Environmentally Friendly Fuel

Biodiesel burns much cleaner than petroleum-based diesel because is nontoxic and a biodegradable fuel.

Using biodiesel in your diesel vehicle will release fewer emission such as particulates, carbon monoxide, hydrocarbons, sulfur dioxide, etc. Nitrogen oxide emissions (NOx) are slightly higher when burning biodiesel, but even so, biodiesel is much cleaner and friendly with the environment compared to diesel fuel produced from fossil fuels like petroleum.

3. Is an Alternative Fuel

Mankind moves towards a cleaner future where the environment will be much better protected than it is today.

To reduce the level of air, soil and water pollution on the planet, we have to replace the conventional sources of energy used today on a mass scale with alternative sources of energy, and biodiesel is one of them.

4. Can Reduce the Level of Greenhouse Gas Emissions Released by Diesel Engines

According to a recent EPA report, mixing only 20% of soybean-based biodiesel with 80% conventional diesel, reduces the emissions of the engine as follows: carbon monoxide by 11%, hydrocarbons by 21%, particulate matter by 10%, and only the nitrogen oxides are increased by 2%.


Soybeans a great feedstock for biodiesel production, image source:

5. Is a Flexible Fuel

Biodiesel can be used in diesel engines directly (B100 is diesel fuel containing 100% biodiesel) or mixed with diesel fuel in different percents. When mixing conventional diesel with biodiesel or using biodiesel directly (without conventional diesel) the engine will reduce its emissions, becoming this way less harmful for the environment.

B20 is a diesel fuel containing 20% biodiesel. Diesel fuels that contain up to 20% biodiesel work well in every diesel engine.

To use blends that contain more than 20% biodiesel, we have to make some changes to the diesel engine.

6. Can Be Used as Heating Fuel

Biodiesel can be used as fuel for residential and industrial heating. Using this alternative fuel for heating, will reduce the carbon footprint of the building.

7. Can Reduce the U.S. Dependence on Foreign Petroleum

Being a biofuel that can be produced locally from vegetable oil, animal fats and used cooking oil, biodiesel can replace the fuels based on petroleum, and this way can reduce the U.S. dependence on foreign oil imports.

8. Creates New Jobs

Biodiesel is a great asset for the U.S. economy because it creates new jobs in the sector (biofuels plants).

At the same time, biodiesel significantly reduces the U.S. dependency on the pricey imported oil market.

9. Does Not Contain Sulfur

Petroleum-based diesel fuel contains sulfur, which comes from the original crude oil used to produce the fuel. Sulfur is present in diesel fuel even after refining.

Biodiesel does not contain sulfur because is produced from waste organic products that are also biodegradable and not from petroleum.

Using biodiesel to run your diesel vehicle, will not reduce the performance of the engine, and will release a smaller amount of emissions.

10. Is a Great Lubricant for the Engine

High-quality biodiesel fuel has excellent cleaning properties for the diesel engine because it can dissolve the sediments accumulated over time.

This way, by switching to quality biodiesel, you are actually cleaning out your engine.

However, when residues are removed from the engine, they are deposited in the fuel filters, so when you decide to switch to biodiesel, your engine will be cleaner and well lubricated, but you will have to change the fuel filter more frequently.

When all the contaminants in your engine are removed, you can go back to a regular filter maintenance schedule.

Being a great lubricant for diesel engines, biodiesel can reduce engine wear, and improve the life of the components.

11. Provides Similar Performance

Biodiesel has a higher cetane level than regular diesel fuel and B20 (20% biodiesel and 80% diesel), provides similar fuel economy, horsepower and torque.

This alternative fuel has been used in trucks, passenger vehicles as well as construction and agricultural equipment with no noticeable difference in performance.

Disadvantages of Biodiesel

Like any other source of power, biodiesel has its own drawbacks.

1. Can Increase NOx Emissions

Switching to biodiesel does reduce the emissions of carbon monoxide, hydrocarbons and particulate matter of the engine, but at the same time, it slightly increases the emissions of nitrogen oxides.

Biodiesel only reduces air, water and soil pollution, but it can’t eliminate it completely.

2. Behaves Like a Solvent

Biodiesel is more hygroscopic or water absorbing than conventional diesel.
For maximum performance, biodiesel should be stored away from water and oxygen.

Contamination can occur through the distribution and storage network, and this is the reason why filtration should be implemented between all fuel transfers.

Water is the main contaminant, and can lead to many issues if not controlled properly.

3. Turns into a Gel in Cold Weather

Biodiesel is produced from natural organic products such as vegetable oils, animal fats and used cooking oil, and for this reason, in colder weather, this biofuel can turn into a gel.

Turned into a gel, biodiesel will not able to start the engine of your vehicle. To avoid this, we have to add antigel to the fuel to keep it flowing.

B100 (100% biodiesel), should be stored at temperatures between 5 and 10°F (higher than cloud point).

Blending biodiesel with conventional diesel will reduce the chance of turning into a gel.

4. Can Deteriorate Flexible Fuel Hoses

Older diesel tanks have a layer of sediment on the bottom that can be dissolved by biodiesel due to its excellent solvent ability.

After using biodiesel to run your diesel vehicle for a while, you should be prepared to replace the fuel filter if it becomes clogged.

You should also lift the hood more often to check your flexible fuel hoses, because biodiesel can deteriorate them quicker.


Biodiesel is an alternative fuel that should replace conventional diesel fuel in diesel vehicles to reduce emissions.

The same renewable fuel can be used for residential heating without the need of fossil fuels, which again will reduce the carbon footprint of your household.

Article written by:

I am a writer and reporter for the clean energy sector, I cover climate change issues, new clean technologies, sustainability and green cars. Danny Ovy

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