Biodiesel Veggie Oil Conversion

Waste oil is available from just about any fish and chip shop, takeaway, café, restaurant, or canteen.  I’ve collected from the local football club who were having to pay to get rid of it.  Every pub has a fryer and every town has a pub!

You are best off collecting oil that hasn’t been overused or used for fried chicken, as this has a higher fatty acid content and will gel at higher temperatures, meaning it will not remain liquid in cold weather.  

Waste oil is collected by tallow recyclers who come along and pick up the 200 litre drum out the back of the shop and replace it with an empty one.  They typically pay the shop up to 20 cents per litre.  They then take it to a tallow refiner who will pay them say 30 or 40 cents.  

This oil is often used to make biodiesel, sold for stock feed, or in Melbourne is used as a cooling fluid for a power station.  The rest  goes to China or India and is used for stockfeed or comes back as soap.  You can buy this oil from tallow refiners in most capital cities, but it is usually unfiltered, and you may have to buy at least 1000 litres at a time.

Most shops will either give the oil out the back to you for nothing or charge you up to 20 cents per litre.  You will find that the oil in the drum out the back is contaminated with very fine burnt crispy bits, and will contain some water.  The bottom of the barrel will be really sludgy.  To use this oil, you will have to purchase or create a filtration process, so I target shops that already utilise a quality filtration process in their day to day operation.

I collect from a high quality fish and chip shop.  When I approached them, I straight up offered more than they would have been getting from the oil collector to get them interested. The oil that they use is sunflower oil.  Check to make sure that your supplier uses a liquid vegetable oil, not animal fat or palm oil as it will go solid in your fuel tank.

This shop uses a 5 micron filter to filter their fryer oil every day.  Normally the oil would be at about 150°c when they filter it or dump it.  This of course would melt the plastic jerry cans, so they keep some cold waste vegetable oil in reserve to add the hot oil to, which then brings down the temperature to less than 80°c.  

They filter the oil directly into my jerry cans.  The illustration  shows the level of cold oil with the hot filtered oil starting to be added.

I have made the task as easy as possible for them by supplying light weight jerry cans, and picking up on a regular basis.  I pay them $5 per jerry can that I pick up, and have established a good rapport with the owners over time by being consistent, reliable and only picking up in off peak periods.

They have found that this system is better for OHS reasons than the way they were doing it in the past, as nobody is transporting heavy drums of hot oil around the shop.  They spend $50 a week on petrol getting to work, while I give them $20 for twice as much fuel!

I use 20 litre “water” jerry cans to collect my WVO because they are half the price of plastic diesel cans, quarter the price (and weight) of steel jerry cans, and the operator can see how much fluid is in the container, thereby not overfilling.

I then empty them at home into an old 100 gallon (450 litre) heating fuel tank that I collected off a hard waste collection.  I use this tank to settle out the oil (see Water in the fuel) before filling up the cars when required.  I have installed two taps onto the tank, one at the base for draining the waste, and one higher up for access to clean fuel.  This also means that I always have a set of empty jerry cans to swap at the fish and chip shop, and a good supply of  clean Vegetable Oil Fuel.

Oil spills dry quickly and are very difficult to wash off.  It comes off easily with caustic soda, but I have found a non caustic oven cleaner is a cheap and efficient product for keeping my containers and fuel filler area clean.

On a trip to NSW in September 2005, I picked up oil in this same manner at Nowra, Revesby and Forster.  All of these shops were filtering their oil to 5 or 10 microns.  I left my containers with them and picked them up full at a later date.  The car ran like a dream all the way home.

This of course is not always a suitable option and Vegiecars is developing a specialist portable filtration system that will allow you to tap into the 200 litre drum at the back of any fish and chip shop, fill your tank and keep driving, without having to come back a week later, or put the owners to any trouble.