I have wrote an article before about using waste vegetable oil as fuel on a small scale before, but now that I have a Land Rover that has a vegetable oil conversion, I have had to up scale my processing capability as I can now use more of it.
I now use a 2 stage filter process that I have set up in my garage. Its still a fairly manual way of doing it, but it suits my needs at the moment. So lets have a look how I do it.
Stage 1 – Filtering into a holding tank
I purchased a “Mighty White” mesh filter off eBay that can handle a lot of vegetable oil in one go. The filter will hold approx 15 litres of waste oil and has been constructed with a very fine stainless steel mesh. I have the filter suspended over the water butt, and I pour my waste vegetable oil straight into it. This way I can leave it to filter through overnight.
The “Mighty White” filters the oil down to 77 microns, and removes all the old bits of fish & chips, and anything else they have been frying in the oil! The filter is re-usable, and can be cleaned out with hot soapy water and a soft brush.
Now the oil is in the holding tank, I can use the drain tap at the bottom to decant vegetable oil into a bucket when it is needed for the second stage filtering.
Stage 2 – The final filtering
Now that the oil is in the storage tank, I can use the drain tap in the bottom to decant the oil into a bucket and then pour it straight into a second set of filters. These are bag filters, and I have 3 of them, one inside the other.
This is my current sock filter set up
- 1st filter: 100 microns
- 2nd filter: 25 microns
- 3rd filter: 1 micron
Even though the vegetable oil has been filtered down to 77 microns when it went into the tank, the reason I use a 100 micron filter again is to catch anything that might have entered the oil while in the storage tank (water butt).
Filtering vegetable oil down to 1 micron is more than good enough for use as fuel. Land Rover (and most car fuel filters) only filter down to about 5 microns anyway, so 1 micron is good enough for me! You can mix up your sock filters if you want, in the past I have used 100, 25, 5 – as long as you filter down to at least 5 microns you will be ok.
Once the oil has passed through the 3 filters, it collects in a big bin. From there I can just pour it out into a jerry can or a clean plastic container for storage until I need it.
From here I just tip it in the tank when I need it! Easy.
Even then, I always run some diesel mixed with the vegetable oil in the main tank. I never go higher than 80% vegetable oil mix in the summer, and much less than that in the winter (30-50%). I will never run 100% vegetable oil even with a heat exchanger – Thanks to Trailerfitter in the comments below for jogging my memory to add this to the article!
Not all Land Rover engines are suitable for using vegetable oil. Generally, if your engine is running the Bosch fuel injection pump then you are in the clear. (200/300tdi)
If its a Lucas/CAV pump (Series 2.25/Defender 2.5NA and TD) then you will have to fit a heat exchanger and twin tank set up, otherwise you risk ruining your injection pump.
Note: It is not recommended to use vegetable oil in the Land Rover TD5 or latest “Puma” TDCI engines.
- Series/Defender 2.25 – Lucas/CAV pump – use heat exchanger/twin tanks
- Defender 2.5NA/TD – Lucas/CAV pump – use heat exchanger/twin tanks
- Defender/Discovery/Range Rover 200Tdi – Bosch Pump
- Defender/Discovery 300Tdi – Bosch Pump
- Range Rover DT/DSE/DHSE (6 cylinder BMW engine) – Bosch Pump