What Is Biodiesel: An Alternative Fuel

November 3, 2021

Biodiesel is  an alternative fuel of natural origin, renewable and much cleaner than traditional diesel . Its production has aroused great interest in recent times, due to the increasing shortage of fossil fuels, in addition to the severity of climate change.

The product manufactured industrially by esterification and transesterification processes is applied in the preparation of total or partial substitutes for petroleum diesel or gas oil obtained from petroleum.

It is a synthetic fuel that combines diesel with a variable percentage of vegetable oils or animal fats obtained from natural components. Its current nomenclature uses the letter B, like the rest of diesel fuels, and the number that accompanies it indicates the percentage of oil in the mixture, with B5 being the one with the least amount of it.

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Types of biodiesel

As we have said, biodiesel is a fuel of natural origin. This can be manufactured from various renewable sources and, depending on that source, we classify it into one type or another. There are three main classes of biodiesel:

  • Biodiesel from crops. Such as soy, corn or rapeseed, whose oils are used for biofuel.
  • Biodiesel from trees. Such as palm or even pistachio, common in China. Again the oils of these plants are the product used.
  • Biodiesel from animal fats or waste oils. Like the ones we usually use at home or used by the food industry.


From these vegetable oils there are two traditional methods, direct mixing and micro emulsion. Alcohol and a catalyst are used in that mixture to create the biofuel.

Other more modern methods use the so-called transesterification,  a chemical reaction between the triglycerides of the oil and alcohol , which transforms the former and provides a reliable biodiesel with less inconvenience to be used in engines.

The manufacturing process has two stages: pretreatment and transesterification. In the pretreatment stage, the oil is subjected to physicochemical processes in order to eliminate the harmful components for the transesterification reaction and guarantee the final quality of the biodiesel.

Thus, it undergoes a degumming process, a bleaching process and, finally, a deodorization process. In transesterification, the chemical reaction between triglycerides and methanol is carried out to obtain biodiesel. In the reaction, glycerin is obtained as a by-product. Below is a schematic of the manufacturing process.

Advantages of Biodiesel

  • Conservation of the planet’s natural resources, as it is a renewable energy source.
  • Reduction of fuel imports, reduces dependence on fossil fuels.
  • Favor the development and fixation of rural populations that dedicate themselves to the production of this fuel.
  • Help reduce CO2 emissions into the atmosphere.
  • It does not contain sulfur, so it will eliminate the problem of acid rain
  • Reduce soil contamination as it is a biodegradable and non-toxic product.


  • It solidifies at low temperatures, which causes crystals to form that can clog fuel lines.
  • It loses part of its properties in the short term, something that does not happen with fossil fuels.
  • It is usually more expensive than gasoline, although this depends on its origin and how it is made.
  • It cannot be used in all engines on the market. Using biodiesel in an unprepared engine can cause different failures in the internal part of the engine.
Dr. Loony Davis5
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Born and raised in Brussels in an English family, I have always lived in a multicultural environment. After several work experiences in marketing and communication, I came to Smart Water Magazine, which I describe as the most exciting challenge of my career.
I am a person with great restlessness and curiosity to learn, discover what I do not know, as well as reinvent myself daily, someone who is curious about life and wants to know. I enjoy sharing knowledge.
This is my personal project but I also collaborate in other blogs, it is the case, the most important web on water currently exists in the US, if you are interested you can read my articles here.

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