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The use of biofuels has increased steadily in recent years, due to their importance in reducing the transportation and energy transition carbon footprint. They are of particular interest in sectors that are difficult to decarbonize, such as road freight transport and the maritime and aviation sectors. According to the European Environment Agency, the two most important plant-based fuels today are bioethanol and biodiesel. 

What is biodiesel?

Biodiesel is a natural, renewable, and clean fuel. Its use makes it possible to reduce greenhouse gas emissions, as it is produced from organic matter (mainly vegetable oils or animal fats). 

At present, it is mainly used as an automotive fuel to replace mineral-based diesel. Biodiesel can be blended with mineral diesel by up to 7%. It can also be used for domestic heating, in specific biodiesel boilers. It is obtained through a chemical process where the oil reacts with an alcohol when a catalyst is present.

Depending on the amount of biodiesel in a fuel's composition, a nomenclature is used using the letter B and a number, indicating the proportion of biodiesel in the blend with diesel obtained from oil. So, there can be anything from B2 (containing 2% biodiesel) to B100, which would be pure biofuel.

Advantages of biodiesel

The worldwide biodiesel boom can be explained by the fact that it's a clean and affordable fuel. Numerous studies have shown that its CO2, SO2, or CO emissions, among others, are lower than other fuels. In fact, institutions such as the U.S. EPA (Environmental Protection Agency) estimate that the CO2 reduction ranges between 57% and 86%. This makes it a very interesting alternative, but that’s not all:

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  • It is a renewable and environmentally-friendly fuel, as it comes from vegetable raw materials. The species used to generate it can be recultivated and, in the case of biodiesel produced from used oils, it allows waste to be given a new life, boosting the circular economy.
  • It can be used in most diesel engines without the need for any major mechanical modifications.
  • It does not contain sulfur, and therefore does not emit this greenhouse gas during combustion.
  • It can be produced locally, without the need to depend on imports.
  • It facilitates the use of soil with crops destined for its production, which in turn reduces erosion and deforestation.


Repsol and biodiesel

At Repsol, we have been incorporating biofuels into our automotive fuels for over two decades. Now, with the circular economy as one of the strategic pillars to accelerating the energy transition and achieving our goal of becoming a net zero emissions company by 2050, we will produce advanced biofuels from various types of waste (such as used cooking oils and waste from the agri-food industry). By doing so, we give this waste a second life and transform it into high value-added products. 

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First biofuels plant in Cartagena, Spain

Repsol’s goal is to produce two million tons of low-carbon fuels by 2030, which will avoid the emission of over seven million tons of CO2 a year. That’s why, we have already begun the construction of the first advanced biofuels plant in Spain, which will be located in Cartagena, Murcia, within the Cartagena Industrial Complex. 

Repsol will invest 200 million euros in this project, with the aim of producing 250,000 tons of advanced biofuels per year, such as biodiesel, bionaphtha, biojet, and biopropane, which can even be be used in transport that is difficult to decarbonize (such as planes, ships, or trucks) and will enable a reduction of 900,000 tons of CO2 per year.


In the words of Antonio Brufau, our Repsol chairman, "with this project, Cartagena will cement its role as a supply center for essential products for the present and for the future, serving as an example of Repsol's commitment to sustainable mobility." 

The facilities will begin operating in the first quarter of 2023. Its start-up is part of Repsol's transformation plan to decarbonize our processes and produce more sustainable products.

The new plant, according to Antonio Mestre, director of Repsol’s Cartagena refinery, "is a tangible example of circular economy that will allow us to offer sustainable mobility solutions to all sectors of society, and a hugely important step in the transformation of the industrial complex as a multi-energy hub." It will also contribute to the Fit for 55 target, which sets the use of sustainable aviation fuels at 63% by 2050.