How to Make Your Own Biofuel From Used Cooking Oil

How to Make Your Own Biofuel From Used Cooking Oil

How to Make Your Own Biofuel From Used Cooking Oil


Turning used cooking oil into biofuel is a great way to recycle waste and produce your own renewable fuel. With some simple equipment and homemade recipes, anyone can transform this common household item into usable biodiesel or vegetable oil fuel.

Making biofuel at home has many benefits:

  • It reduces your environmental impact by reusing waste cooking oil.
  • It saves you money by replacing traditional fuel.
  • It provides energy independence by producing your own fuel supply.

In this guide, I’ll walk you through the entire process, from collecting used oil to running your vehicle on homemade biofuel. With a few inexpensive materials and basic mechanical skills, you’ll be making earth-friendly fuel at home in no time!

Collecting Used Cooking Oil

The first step is gathering a sufficient amount of waste vegetable oil (WVO). Here are some tips for amassing this yellow gold:

  • Ask friends and family to save their oil after cooking. Offer to collect it yourself.
  • Check with local restaurants, cafeterias, or food trucks. Many are happy to give away their used oil.
  • Watch for community oil collection events. Some towns host periodic WVO drives.
  • Strain any debris through a fine mesh sieve. Cheesecloth also works well.
  • Allow particles to settle, then pour or siphon the clarified oil into a storage container.
  • Aim to collect 5-10 gallons to get started. The more oil you have, the more fuel you can produce.

Make sure to only collect pure vegetable oil. Avoid animal fats or grease contaminated with water or solids.

Pretreating the Oil

Before making biodiesel, the WVO needs to be pretreated to remove impurities:

  • Heat the oil to 130°F to drive off residual water. Use a cooking thermometer to monitor temperature.
  • Mix in a solution of 3% hydrogen peroxide and 1% sulfuric acid to degum the oil. Stir thoroughly.
  • Let the mixture sit for at least 30 minutes so gums form and precipitate out.
  • Filter the oil through a 5-micron filter to remove particulates.
  • Repeat as needed until the oil pours clear.
  • Store pretreated oil in clean 5-gallon buckets with tight lids.

Proper pretreatment prevents downstream issues with catalyst poisoning and poor fuel performance. Take the time to thoroughly cleanse the WVO.

Making Biodiesel through Transesterification

Biodiesel is produced by a chemical reaction called transesterification. This process converts the vegetable oil into fatty acid methyl esters, which closely resemble petroleum diesel.

Here’s how to transesterify WVO into biodiesel at home:

Gather Ingredients

  • Refined vegetable oil (pretreated WVO)
  • Methanol (also called methyl alcohol)
  • Catalyst, such as lye or sodium hydroxide (NaOH)
  • Glycerin (byproduct of the reaction)

Combine and Mix Chemicals

  • Pour the oil into a reactor vessel (e.g. large metal tank).
  • Add the methanol and catalyst in the correct proportions.
  • Use an electric mixer to combine ingredients for at least 30 minutes.
  • Let settle for 8 hours so glycerin layer separates.

Wash and Dry

  • Draw off the glycerin for use in soaps.
  • Wash the fuel 3 times with soft water to remove impurities.
  • Allow biodiesel to dry completely before use.

With some patience and safety precautions, you can make quality biodiesel fuel at home.

Converting WVO to Vegetable Oil Fuel

For a simpler biofuel, WVO can be filtered and used to power a diesel vehicle without conversion. Here’s how:

  • Strain oil through filters to remove food particles.
  • Use centrifugation to separate water and impurities.
  • Add stabilizing agents to improve viscosity. Consider alcohol, transmission fluid, or chemicals like oxo-degradable diesel fuel additive.
  • Dispense oil into vehicle’s tank in 5% blend with regular diesel.
  • Gradually increase blend percentage as engine acclimates. Up to 100% WVO is possible.
  • Change filters more frequently to prevent clogging from remnants.

Though not as pure a fuel as biodiesel, WVO oil requires less processing and can provide major cost savings.

Running a Vehicle on Straight Vegetable Oil (SVO)

For maximum use of biofuel, a vehicle can be converted to run on straight vegetable oil (SVO). This requires installing an auxiliary fuel system with heaters.

To successfully switch to SVO:

  • Add a secondary fuel tank in the trunk or bed to hold vegetable oil.
  • Install fuel heaters along the lines to decrease oil viscosity for flow.
  • Modify fuel injectors and pumps to handle the thicker fuel.
  • Initially start on diesel fuel before switching to SVO once warm.
  • Drain and flush Vegetable oil from lines before turning off to prevent clogging.

With the right engine adaptations, SVO enables relyance on renewable homemade biofuel.

Disposing of Waste Glycerin and Oil

Caution should be taken when disposing of byproducts from biofuel production:

  • Glycerin has many household uses, such as soap making. Otherwise dilute and add to a compost pile.
  • Waste oil should be recycled or disposed of responsibly. Many municipalities accept WVO at transfer stations.
  • Never pour fats or oils down drains. They can clog pipes!

Following eco-friendly disposal methods ensures the whole biofuel process remains environmentally sustainable.


Making your own biofuel from waste vegetable oil is rewarding, economical, and ecologically friendly. With minimal equipment and effort, anyone can transform this overlooked resource into usable fuel. Test batches first before ramping up production. And be sure to perform all steps safely! Homebrewed biodiesel is an excellent way to minimize your carbon footprint and achieve energy independence.