Monday, 31 January 2011

Washing Problematic Bio Diesel At Home

Washing your bio diesel is a very important part of the process when you are making biofuel. The washing process removes excess Sodium Hydroxide and Methanol from the fuel meaning that it will burn clean in your engine!

Some of the waste vegetable oil I collected was a mixture of two different oils and probably had some water in it. I had to separate the two different oils and wash them before I could put the finished bio diesel in my car!

When I added the distilled water to the unwashed biofuel the water seemed to be clear at the bottom, however when I agitated the mixture it went cloudy and needed to be left to separate out.

The liquid looks very murky and the water has not separated from the diesel yet. Bio Diesel is Hydrophobic which means it separates from the Water (Hydrogen Dioxide) quite quickly on a molecular level.

In this close up you can see that the very bottom of the bottle contains water after leaving the bottle to stand for an hour or so the mixture looked like this.

A clear separation has occurred. The Sodium Hydroxide and methanol are hydrophillic and so they are dissolved in the water. The washing process has to be repeated until the water is totally clear. The water will appear clear at all times when the Sodium Hydroxide and Methanol have been removed. Effectively washed out of the bio diesel.

Here are the two different oils being washed together you can see that the darker oil has absorbed more methanol and sodium hydroxide than the lighter oil and will therefore take longer to wash!

When the two samples are stood next to each other you can clearly see that the darker of the two bio fuels has turned the water a milky colour. You will see over the next few photographs that the darker sample turns progressively lighter with each wash until both batches of biodiesel are the same colour.

First Wash

Second Wash

Third Wash

The bio diesel is then filtered again and left to "dry" overnight any excess water will evaporate overnight. After leaving the fuel to stand overnight I always filter it again before storing it.

For a complete guide to how you can make biodiesel at home from scratch this is a great book, it contains all the instructions on how you can easily make your own bio diesel processor that you can use to process 100 litres of biofuel a day!

Problems Making Bio Diesel At Home - Mixed Oils & Water

If you have been searching for information on how to make biodiesel at home you will have seen many recipe's and video's. This post is concerned with when things go wrong!

Problems can occur if you have water in your oil - Heating the waste vegetable oil removes this problem, however if you are making small amounts of bio fuel in coke bottles you can end up with a soapy jelly mix like this!

Don't give up! Don't throw your fuel away - all is not lost! After all you probably spent money on methanol and other ingredients! There is a very simple way to save the biodiesel that is caught up in this jelly.

You need to wash and filter your bio fuel to remove the jelly, this is quite a time consuming process however you will see at the end the results are good clean, green bio diesel that you started out to make!

So how do we go from the horrible mess to the clean fuel? Here is a step by step guide to the problems of making bio diesel at home, it involves a lot of washing!

First I took one of the bottles and poured in distilled water like so my reaction vessel looked like this!

You can see at the top of the bottle that there is a lighter coloured liquid starting to separate out from the jelly, I turned this bottle upside down and let it stand for a few hours so the different substances had time to separate out.

We now have 3 substances in the bottle, a dark liquid at the bottom (which I now know is unwashed biofuel as well), a semi solid layer and the unwashed bio diesel layer at the top.

The two layers are two different oils that were mixed together they can both be washed and turned into bio fuel - I think the layer in the middle is soap!

First I poured off the top layer into a filter to remove any of the solid particles after filtering the problematic biofuel I put it into a fresh container to wash.

The filtered liquid is looks a great colour and does not have any solid particles floating about in it, so it is safe to wash the fuel to remove any methanol and Sodium Hydroxide from the bio diesel.

Now we are left with the stuff below the dark layer and the jelly like gunk! There were about 4 or 5 litres that I did as a test batch that came out similar to this!

The bottle was then turned upside down and the dark layer was drained off the bottom and left to stand for a while so that the mixture of liquids separated out again.

Now we have two different coloured unwashed bio diesel liquids and all that needs to be done is the wash and dry, as you would for a normal batch that did not contain jelly like gunk!

Sunday, 23 January 2011

How To Make Bio Diesel At Home - Video Tutorial

Once you have filtered your waste vegtable oil you will need to react it with methoxide to seperate the glycerine from the rest of the oil. Here is a short video which demonstrates the process.

To Make Bio Diesel At Home You Will Need

  1. Filtered Waste Vegtable Oil
  2. Sodium Hydroxide (NaOH) Found in Drain Cleaner
  3. Methanol
  4. Eye Protectors
  5. Rubber Gloves
  6. Jam Jar
  7. Funnels
  8. Coffee Filter Papers
  9. Distilled (boiled) Water
  10. Coke Bottles

Filtering Waste Vegtable Oil To Make Bio Diesel

A Basic Filtration System For Waste Vegetable Oil Made From 2 Litre Coke Bottles

Here is a basic 2 stage filter that is made from 2 litre Coke bottles, you can get these anywhere in the world, recycling Coke bottles as a filter for waste vegetable oil is a good way to make BioDiesel on a tight budget.

You need 3 bottles to make this first filter.

Cut the bottom from two of the bottles and the top from the other bottle then assemble the bottles as in the photo above, using an old Tshirt as the first filter for your waste vegetable oil then an old pair of tights to remove any food debris that may have slipped through the T Shirt filter.

The filtered oil is collected at the bottom ready to be turned into BioDiesel that you can run your car or bucky on. It is very easy to make Bio Diesel using Coke bottles for the whole process. Africa should be ahead of the rest of the world when it comes to producing first generation Bio Fuel like Bio Diesel made from waste vegetable oil.

I paid about R100 for 20 litres of oil at the Woodcutters and it was reasonable non hydrogenated oil this is enough to produce about 22 litres of fuel.