So you want to turn used cooking oil into biodiesel?

Biodiesel is a renewable, clean-burning fuel. It’s made through a chemical reaction that relies on animal fats or vegetable oils and an alcohol. The technical term for this process is transesterification.

Biodiesel is said to degrade as fast as sugar and is less toxic than table salt. It can be used by itself or blended with petroleum for a more environmentally friendly fuel alternative.

You can use biodiesel to run a variety of fuel-reliant machinery, including generators, posho mills, tractors and combine harvesters. Technically, any vehicle that runs on diesel fuel can use biodiesel.

The trouble is, since the process of making biodiesel almost mimics that of making soap, some biodiesels can corrode engines after resulting in the formation of soap.

Here’s a basic guide on making your own biodiesel. You can carry out further research to refine the process. Ensure you work within Energy Regulation 1009 on Biodiesel Licensing, which regulates the production and commercialisation of biodiesel in Kenya.

What you’ll need

1. The ingredients

You don’t need technical knowledge to make biodiesel. But it’s important to understand the fundamentals of transesterification, which you can learn through YouTube tutorials.

The ingredients and equipment you need to make your first batch of biodiesel are:

– Used cooking oil, which you can source for from individuals, fast-food joints or restaurants

– Methanol or methyl alcohol, which you can get from chemical industries, such as those along Nairobi’s Kirinyaga Road or Industrial Area

– Potassium hydroxide or sodium hydroxide (also known as caustic soda or lye), which you can get from the same firms dealing with chemicals

– A catalyst, from the chemicals firm

– A funnel

– Methanol-measuring equipment

– A pan for heating oil

– Thermometer

– Mixing container or mason jar

– Protective gear so the chemicals don’t get into contact with your skin

2. The process

Step 1: Start small for the first batch, so measure 500ml of oil and pour it into the pan, turn on the heat and put your thermometer in; wait for the oil to heat up to 130oC.

Step 2: Measure out 100ml of methanol.

Step 3: Weigh 3.5 grammes of potassium hydroxide or 2.8 grammes of sodium hydroxide.

Step 4: Add 0.5 grammes of the catalyst into the methanol and slowly stir until it gets dissolved. This should take about 15 minutes.

Step 5: Check the oil temperature and if it has reached 130oC, remove it from the fire.

Step 6: Pour the heated oil into a mixing container or mason jar.

Step 7: Pour the methanol and catalyst into the heated oil and seal the container tightly. Shake vigorously for about five minutes and then let it sit for 24 hours.

Step 8: After 24 hours, check the mixture for separation. There should be a layer with glycerin (which can be filtered and turned into a degreaser) and then the biodiesel. Remove the glycerin and give the biodiesel time to clear up slowly.

3. The business

After creating a sample product, test it. You can use the biodiesel on a generator or posho mill. Check how the machinery runs and adjust anything that corrodes the engine before you market the finished product.

Once you’ve ironed out all the kinks, you can go fully commercial. Make sure you comply with the law and get your product certified before you go into commercial production. Biodiesel can be used by smallholder farmers to run irrigation generators, posho mills, tractors and so on.

In the process of making your biodiesel, you can also make soap, which uses similar ingredients. You’d just need to adjust how much lye you use, and mix in fragrances to add appeal.

Biodiesel can also be made from waste animal or vegetable fat, or from plant oils like soybean, cottonseed or canola.