Gday
I just bubble air through the biodiesel until the methanol evaporates and the soap just falls to the bottom no water no resin and im left with perfectly clear biodiesel
thanks caveman

What is your soap ppm after you do this?

Gday
Soap levels vary from 60 to 220 ppm it just depends how long you bubble and settle for also adding a little heat in colder climates would help the methanol to evaporate faster.
thanks caveman

Caveman,do you use KOH? Also, how long do you bubble the bio to get the lower soap levels?This sounds like it would be worth a try. Thanks,Jerry

Gday
I'm using NaOH but there's no problem using KOH i bubble for 3 to 4 days at 95 degrees fahrenheit and then settle for a few days before carring out a soap test the longer you bubble and settle for the lower the soap content also when you empty your tank dont suck the soap off the bottom of the tank.
thanks caveman

I sue the same method, wash water was becoming an issue to get rid of so I tried this method and it's been working well for me.

HELO I THINK THIS IS MY FIRST POST. I HAVE A QUSTION REGARDING THE BUBBLE WASH METHOD TO GET THE METHANOL OUT. WHEN DOING THE BUBBLE WASH WHERE IS THE METHANOL ALLOW TO GO . INTO THE AIR?. AND IF SO DO YOU HAVE SAFETY CONCERNS? I HAVE A WELL VENTED AREA IN MY SHED AND THINKING ABOUT TRYING THIS. DONT LIKE THE WATER WASHING. CAN YOU GIVE ME SOME SUGGESTIONS

TID, try using lower case letters and yes the methanol goes into the air.

hey thanks . notice i went to lower case.can you give me a suggestion on how long to bubble and then to settle out before rebubbleing. or maybe yet just tell me how you do your bubble wash. i have a 39 gallion batch in my reactor just waiting to be washed.

I can't tell you anything about dry or wet bubble washing since I wet wash only. I did try heating the raw bd last week to 130f then bubbling and blowing air on the surface. I only did it for one day and saw no improvement when I washed. I was hoping for a quicker wash and using less water for the wash. It seems if I try it again I'll have to bubble for a few days to see any result.

I had read some time ago that there was a posibility that with the introduction of air into the finished bio there was a risk of oxidation. Is this risk real or just a percieved problem when bubble washing was first introduced?
Dom

We cant change the winds but we can reset our sails.

quote:

Originally posted by Dom:
I had read some time ago that there was a posibility that with the introduction of air into the finished bio there was a risk of oxidation. Is this risk real or just a percieved problem when bubble washing was first introduced?
Dom

We cant change the winds but we can reset our sails.

Why take chances? A bottle of compressed nitrogen is cheap and goes a long way.

Gday
I'm not worried about oxidisation, my fuel isn't stored long enough,as for bubbling i just use a cheap 4 watt aquarium air pump with a bio- proof air stone and just bubble air through the bio for 3 to 4 days and settle for 2 days
thanks caveman

I use the same setup. I process as usual, do a 5% prewash. let it settle over night. next day, I drain the glycerine and mix the bio to 150 degrees and mix it for about an hour. then I turn off the pump and bubble for about 2 days. let it settle for 1 day and drain off the last bit of glycerine/soap, then I pump through a 2 micron filter into a storage tank, then polish it through a 1 micron filter for about an hour.

that's it.

I have driven about 15,000 miles on the same fuel filter with no problems.

Danny

Caveman,

Where do I find the proper BD compatible air pump and bubbler? I have a few air compressors and could easily pump air through my BD. Of course an aquarium pump would certainly use a lot less electricity. What is the best bubbler for the money?

I usually finish my processing in the evening, so I let it stand 1/2 - 3/4Hr then drain off the glycerol from the pre-wash.
Pump straight into a settling tank and bubble wash overnight, using a ceramic airstone and an aquarium pump.
In the morning I switch off the pump and settle for an hour or so, then pump slowly through ecopure and a 1 micron filter.
Crystal clear water after a wash test, can't check the ppm though.
Eliminating the water washing halved the production time and the bio wasn't as good as it contained more soap.

Gday
I just use a open drum with a ceramic airstone and clear air hose, the aquarium air pump uses very little energy so make sure you bubble for a minimum of 72 hours then allow 48 hours for settling,
The air pumps are avaliable at any aquarium shop or ebay for 10 to 15 bucks
thanks caveman

Gday,I am surprised that Girl Mark is not on the forum telling you that you are enviromental vandals putting that methanol into the atmosphere.I also agree that it is a great way to clean up bio.Captain i presume that you from the great southern land? regards westwinds

Dry washing by methanol removal and settling sounds great and GL's pictures look fab but I wonder how caustic the fuel still is, will the unused NaOH have settled out too or is it still in solution the Biodesel to eat your injection pump from the inside? I'd do a PH test on the water from a shake up test or test the oil directly with PH indicator. Don't forget Ion exchange resins activly absorbe the NaOH as part of their dry washing function. Somthing i don't think ecopure can do. I will experiment with sample from my next batch.

I was under the impression that the catalyst, NaOH, left solution with the soap & glycerin. Methanol is only partially consumed in the reaction when making FAME.

Under the assumption that resin tends to slightly acidify the BD. I guess if there was caustic present, there would also be a small reaction with the acid creating a byproduct of water & salt. Of course I am just making a guess on this.

I know that the macroporous resin is made of some type of polymer which has been treated with sulfonic acid. I know nothing about other resins.