Hi guys,
I have tried using the search engine to see if this is covered properly and I can't seem to find what I am looking for.

I have been having some mixed results trying to come up with the best washing method that is suitable for me, I don't have a lot of time as I work away from home during the week and am only home on weekends

I have been getting a good conversion of WVO to Bio but am struggling with the whole washing business.

The first wash using just fine mist sprayers seems to work ok but I have been trying to use the bubble wash method to get a better result. I have the aquarium pump on its lowest setting so it has nice small bubbles but I am getting an emulsion layer nearly every time.

I have found that by heating the emulsified bio to over 100 deg (boiling) that the emulsion seems to break and it comes out very clear, does this affect the quality of the fuel?

Sorry if this has been covered but I can't seem to find it.

Cheers
Mick

Try just bubble washing and save water. I also "spay wash" by pumping the bio onto a plate that allows the bio to "fan" back into the wash tank. I do this for about 4 hours than just bubble for a day or two. All the while I run an aquarium heater to keep the bio at about 34 deg C.

After a day of bubble washing I drain off the glycerol from the bottom of the wash tank and do this again when I have confirmed the batch is washed.

If I want to speed up the wash process I just "spray wash" longer.

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Maverick
Canberra

Try a dry bubble wash for a day or two to remove the bulk of the soap then a gentle mist for another day followed by bubble wash to finish.

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Joe Morgan
Brisbane Biodiesel Site Admin
http://www.brisbanebiodiesel.com

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Hi I saw on another site that pouring the by product into an emulsified batch of bio will break the emulsion!
Has anyone tried this.

OMG!!!!

Just think what can create an emolsion in the first place?????

I know, lets pump the bio and a small part of the byproduct into the wash tank. Add a heap of water and bubble away.

Great we now have a big whitish marsh mellow.

Daniel try it on a small scale. 50 ml bio 500 ml water and a teaspoon of byproduct in a coke bottle and shake. That should make a nice emolsion.

Now try adding more byproduct and see if you can get it to break that way. I am sure it will not.

Have a look at this Qwarla. Breaking Emulsions - Collaborative Biodiesel Tutorial Website

I did try it and got the results shown in the link. just a bit cautious about doing it to 80ltrs.

Quarla,
This technique does work!
While I have not researched the information I am recalling from about 5 - 6 years ago, I believe it is functionally correct. It was pioneered by HCII who is a member of this forum.

When an emulsion forms, usually a small amount of byproduct or soap in the biodiesel and the wash water, along with vigorous agitation, which is the cause.

Usually people use up to 50% water in each wash stage. Many use as little as 20% water by volume, some use up to 100% in each stage.

By adding back the total amount of byproduct which came from the batch process & stirring gently, you will break the emulsion. Less may also break the emulsion. It has been reported that 10% byproduct by volume, was sufficient for one biodiesel maker. Others will need to test the amount required for their particular emulsions. The amount of water in the mix is a variable which affects the effectiveness.

The disadvantages are that you now have a lot of watery byproduct and you need to start washing all over again.
This is a small price to pay for recovering a potential loss of all of the biodiesel from the batch.

Any attempt at emulsion breaking, or any other failure recovery method, should be tested on a small sample to determine the impact of the proposed remedy, on the emulsion. Not good to try adding 100 litres of water to a 100 litre batch if it is going to make things worse. Test first and be sure of the outcome.

Regards,

Tony

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Ok thanks Tony.
Interesting I must say. I see the problem here is that you would now have more stuff to wash out of the bio, or after adding the byproduct does it then settle out again or become part of the entire mixture?
If it becomes part of the mixture the washing has just become harder as you now have to wash all the added byproduct out as well as the original problem that caused the emolsion.

This is why I have always found the best cure is to use more water, and just wash the crap out of it carefully.

But hay there are more than one way to skin the cat!!!!

Quarla,
The byproduct takes the water out of the biodiesel and settles out, leaving the Biodiesel on top and the byproduct below.

The problem most people would have is that they would not have sufficient room for the 20% byproduct and the 20% water and the biodiesel in the washing tank.

Thue it would be bvest for them to add the byproduct to a sample, increasing the proportion gradually, while stirring, until the emulsion broke. This would give them the volume needed for their batch. They may need to drain off some of the batch to make room. This could be dealt wth later, after the majority has been recovered.

I hope this helps,
Tony

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