Make Diesel From Waste Oil: Walk With Us Through The Steps

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The amount of waste oil that accumulates daily around the world is growing rapidly, making its incorrect disposal an increasingly pressing problem.

Waste oil is not only harmful for the environment, when disposed of, it is also a missed opportunity for companies looking for alternative fuel sources.

This blogpost aims to give a comprehensive understanding of the process of how to make diesel from waste oil and the benefits and challenges that come with it, while exploring the different faces of waste oil and which ones are more suitable for fuel production. 

A post by Alice Frassin

Table of Contents

Unleashing the Potential of Waste Oil: Why Companies are Turning to Diesel Fuel

As the demand for eco-friendly options keeps growing, many organizations from different industries are turning to alternative fuel sources to reduce their dependence on traditional fossil fuels.

Waste oil recycling offers a unique opportunity to turn a problem into a solution. By making diesel from waste oil, companies can reduce their carbon footprint, while also saving energy and reducing costs.

When diesel fuel is obtained through waste oil recycling, the final product is generally less expensive than conventional diesel, making it a cost-effective option. Furthermore, it has higher energy density and lower carbon emissions compared to traditional fossil fuels, which increases the value of its use as an alternative fuel source.

Companies that know how to turn waste oil into diesel fuel also provides them with greater energy independence: when they are able to obtain their own fuel directly from the waste they generate, they can reduce the dependence on foreign oil and stabilize energy costs.

While the process might require some initial investment in equipment and infrastructure, the long-term benefits usually outweigh the costs.

Thanks to the increasing need for renewable energy sources, it is likely that the trend of turning waste oil into diesel fuel will only keep gaining popularity and momentum.

Turn Waste Oil into Diesel: Different Forms and Characteristics

Waste oil is a term that encompasses a variety of oils that can no longer be used for their original purposes.

Knowing the distinctive characteristics of each type of waste oil is crucial for determining the best method for disposal, recycling and fuel generation. In this section, we will delve into the different types of waste oil, their unique properties, and the industries that generate them.

There are four main categories of waste oil usually implemented in the production of diesel: used lubricant & motor oil, hydraulic oil cooking oil and waste fuel oils.

Used lubricant & motor oil

Used lubricant (or industrial lubricants) and motor oil are part of the most common forms of waste oil generated by automobiles and other vehicles as they are used to reduce friction in machinery.

They can be either synthetic or mineral-based (also called conventional or petroleum-based) and they contain various additives, chemicals and impurities, making them more difficult to recycle than other waste oils.

Used hydraulic oil

Another common form of waste oil is hydraulic oil, which is employed in hydraulic systems for power transfer.

This type of oil can also be either synthetic or mineral-based, with high viscosity and the presence of contaminants like water and particulate matter. Because of its importance in many industries, it is frequently recycled or re-refined.

Used cooking oil

Industrial lubricants, which are used to reduce friction in machinery, constitute another type of waste oil that is typically recycled.

Lubricant oils can also be either synthetic or mineral-based (also called conventional or petroleum-based) and they contain various additives and impurities, making them more difficult to recycle than other waste oils.

Waste fuel oils

Waste fuel oils are generally defined as those mineral or synthetic oils that can no longer perform their intended use, as they are or have been contaminated.

These oils could be sludge, petrol, kerosene, diesel and heating oil and they are typically used as energy sources in various applications, such as transportation, heating, and electricity generation.

Understanding the different types of waste oil and their properties is a vital aspect of managing and disposing of these materials responsibly and finding out if they can be turned into fuel sources.

From Waste to Wealth: Which Oils Can Be Turned into Diesel?

When it comes to turning waste oil into diesel, selecting the right waste oils with the right criteria is a must.

Not all waste oils are suitable for conversion into diesel: contaminants, like water and dirt, can seriously damage the oil’s quality, making it unsuitable for fuel production. Furthermore, some oils contain higher levels of impurities that can negatively affect fuel performance.

A good distinction to also understand if your waste oil is worth recycling, is between synthetic oils, vegetable oils and mineral oils: all the waste oils listed above are part of one or two of these categories.

Let’s take a closer look at which can be turned into diesel and what qualities they need to have.

Vegetable oils

Vegetable oils are plant-based oils that are typically implemented in the cooking process and because of their organic nature, they are perfect to be recycled into biodiesel. Despite that, they don’t make the best candidate for diesel production.

Due to the fact that vegetable oil it’s not originally made for use in the industrial sector, it can deteriorate faster than other oils, like mineral or synthetic oils, which means it might need to be changed more frequently and not work as desired.

On top of that, since the production of vegetable oil competes with the manufacturing of food, producing it in large quantities may not be a sustainable option.

Synthetic oils

Synthetic oils are human-made oils, chemically engineered and designed to have specific properties and characteristics for a variety of applications, including in high-performance engines and industrial machinery.

One of the benefits of synthetic oils is their durability. Since they are designed to provide superior performance, synthetic oils can often go longer between oil changes, which means that you will need to purchase less oil over the life of your engine or machine.

However, synthetic oils can be very expensive, which can be a disadvantage for some companies. Because of their higher cost and more limited use, they may be less commonly recycled and have a higher environmental impact.

Mineral oils

Mineral oils are petroleum-based oils originated from crude oil, which is a naturally occurring fossil fuel. They are most commonly used as lubricants for engines, hydraulic systems, and industrial machinery.

They can be recycled into diesel fuel, as they are typically less expensive than synthetic oils and more readily available in many regions, making them a more accessible and cost-effective feedstock option for diesel production.

Additionally, because they are derived from a natural resource, they have a lower environmental impact compared to synthetic oils.

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Did you know? In general, when it comes to recycling waste oil, mineral oils are more commonly recycled as they are good candidates for high-quality end products, with more stability and consistency than other oils, which makes them easier to process.

Ultimately, the choice of mineral oil, synthetic oil or vegetable oil for diesel production will depend on the specific needs of the system or application in question, as well as local availability and pricing.

Other factors that might influence the choice can include the desired performance characteristics and environmental considerations, depending on the specific circumstances.

At Biofabrik, for example, we specialize in the recycling of waste mineral oils and feedstocks to clean and purify them to obtain in-spec reusable fuels as end products.

The WASTX Oil & Turning Waste Oil into Diesel: A Step-by-Step Guide to Fuel Creation

The WASTX Oil is the right solution for companies or organizations that generate a significant amount of waste oil as a byproduct of their operations – such as industrial facilities, oil refineries, transportation companies, or waste management companies – and are interested in reducing their environmental impact by recycling their waste oil and turning it into a reusable and valuable fuel source, as well as reducing their disposal costs associated with traditional methods of waste oil disposal.

If you are looking for compact and efficient solution for cleaning and recycling a variety of mineral oil-based feedstocks, the WASTX Oil technology can potentially fit your business case, especially if your waste streams include diesel, heating oils, petrol, kerosene, lubricating oils, generator oils and marine sludge.

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Waste oils

Diesel, Heating Oils, Petrol, Kerosene, Lubricating Oils, Generator Oils, Marine Sludge

Fractionating distillation process

Transforms up to 3.000 kg per day to a valuable output

Valuable recycling oil

The oil meets quality requirements of various offtake partners

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Depending on the specific feedstock and capacity needs, the technology is available in two different configurations – the smaller WASTX Oil GO2 and the larger WASTX Oil X3.

The GO2 specializes in gasoil applications and the X3 is used for recycling heavier contaminated waste oils.

Both technologies are a compact and beneficial way of making diesel from waste oil through the use of a fractionating vacuum distillation process. However, they can process a variety of other mineral waste oils, too.

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Remember! It is important to point out that the quality of the recycled oil strictly depends on the quality of the input material: to obtain a high-quality diesel as output, the input material feedstock has to be homogeneous and there might be the need of additional steps to clean it efficiently.

In any case, before learning how to turn waste oil into diesel, we always recommend analyzing your waste streams to understand if your waste oil is worth recycling: this will make you feel more confident about implementing any recycling processes and technologies. If you would like to find out the value and recycling potential of your waste oil, get in touch with us for an individual analysis of your feedstock.

That said, let’s now have a look at the two technologies.


As mentioned before, the WASTX Oil GO2 is most suitable for gasoil applications, for instance petrol, kerosene, diesel and heating oil recycling.

The process consists of one distillation unit of 4 main steps to obtain gasoil, clean diesel & petrol:

  1. Evaporation reactor: the process starts in the evaporation reactor, where the feedstock is indirectly heated with a heat transfer medium to around 300°C and mostly converted to gas.

  2. Condensation column: the gas phase is then purified and condensed back to liquid in the condensation column.

  3. Separator: in the next step, the separator collects and discharges any remaining materials that did not convert to gas, to be then properly stored and disposed of.

  4. Cooling system: the cooling system with condensers and coolers extracts the heat of condensation and releases it to the ambient air, ensuring all vapors are reliably returned to the liquid state. This way, there are no gaseous byproducts.
The WASTX Oil X3

The WASTX Oil X3 is implemented to recycle marine sludge, petrol, diesel & heating oil, lubricating oils, generator oils, kerosene and, depending on feedstock, the output can be marine diesel, VLSFO, Naphtha, Flux oils, middle distillates and similar.

While the GO2 and the X3 still constitute two separate products, the latter has the same distillation unit of the former, with an addition of 3 initial steps to ensure the processability of more heavily contaminated waste oils:

  1. Input oil dewatering: to remove water from oil, the input material is first heated and dried at 120-150°C in a controlled container. An auxiliary heater helps in heating the material and evaporating the water, which is then condensed and removed. Once the oil is preheated and dewatered, it is automatically transferred to the next process step.

  2. Detox system: the Detox System removes impurities from the feedstock using sodium kerosene that reacts with contaminants such as sulfur. The material and sodium kerosene are circulated in a tubular reactor under heat, and the process time depends on the level of contamination.

  3. Buffer tank: the buffer tank stores the feedstock between the detox system and the distillation unit, ensuring a continuous process. The input pump of the distillation unit is supplied from this tank.

  4. Distillation unit: The feedstock material goes then through the four steps mentioned above for the GO2 technology.


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