Another question. Besides CC, what is everyone's level of success using this method?

I tried bubble drying for 24 hours after methanol recovery at 180F & down to 26"Hg and though the bio is crystal clear, soap is definitely present with no improvement from initial electrostatic settling.

Even after a week of settling in an open top 275 gal tote I still get cloudy water in a shake test.

I have no doubt that settling over the course of a couple of weeks works. I have seen it with my own two eyes. I can also believe that anything that drives off the methanol will shorten the amount of time before using the BD.

If you are settling your BD in 275 gal totes, I would guess that there isn't enough surface air above the BD to flash off the methanol. If you were using an open 55 gal drum it would probably happen faster.

The idea that letting BD settle for a few weeks open will let most soap settle seems to only work sometimes. On my tests after 1 month, I still usually get cloudy shakemup tests. Prior to test, the BD looks crystal clear.

Gday
I bubble air through the biodiesel using a 55 gallon open top drum and if i carry out a basic water shakem up test my water is crystal clear,
by the way the soap won't fall out of solution until the methanol has been driven off, also the settling period is important before carring out any soap test if you just turn your bubbler off and carry out a soap test your soap levels will be high but allow a couple of days of settling before carring out the soap test the reading will be generally about 220ppm my best is 60ppm

The tote is completely open, like a big tub and contains ~150 gallons of bio.

In addition to bubbling, I also circulated for around 3 hours at 12-15 gpm. Some serious surface agitation was going on.

Though anecdotal, the conflicting results are interesting. I don't have any bromo blue on hand, otherwise I'd have done soap tests at different intervals. As it stands I did shake'em ups after transferring, electrostatic settling, bubbling & settling, and circulating and settling.

But maybe I didn't bubble long enough...

I hear wood shavings and sawdust calling my name.

Captain_caveman - how do you measure the soap content to be able to define it in ppm? Is the equipment needed expensive or is there a 'home built' method.
Ron

Gday
You can buy a test kit or make your own just google it http://utahbiodieselsupply.com/soaptestkit.php
thanks caveman
PS. Gday westwinds

I was encouraged by your post as I can't afford the $$$ ion exchange towers being sold today so I tried the no-water bubble wash with one batch. I processed as normal, however, no pre-wash, 3/27 (25/225) test indicated a complete reaction. Bubbled for 4 days and let settle for 4 days at approx 100F. pH was 9+, did not bother with soap test since pH was so high. I took test sample from the top of the drum. Sounds good but my initial tests are discouraging.

Thoughts?

Dana

Chevy Duramax
3 VW TDI, wife and friends

Electrostatic settling? What exactly is that?

Dana

Chevy Duramax
3 VW TDI's wife and friends

Gday dckfly
I sometimes have that problem with particular batches i can't explain why but i just bubble for another day then settle again and problem solved , all my batches are done in open top 55 gallon drums larger batches may require longer bubbling. when the meth evaporates it reaches a point where the soap can no longer stay in suspension and falls to the bottom of the tank its similar to Graham lammings process without the methanol recovery
Thanks caveman

caveman,

once the soap has settled and the clean biodiesel has been removed what do you do with the settled soap?

thanks

Gday gpduxbak
Every two or three batches i pour off the last bit of bio by tipping the 55 gallon drum into another drum and then remove the soap which is almost solid.
Thanks caveman

quote:

once the soap has settled and the clean biodiesel has been removed what do you do with the settled soap?

I take the soap after several batches and scoop it out and dump it into a 35 gallon plastic drum. I then add about 25ml of sulfuric acid to 250ml methanol (adding the acid very slowly as it will spit back at you if you aren't careful while adding it) pour that into the plastic drum and stir the crap out of it with a canoe paddle. Visually inspect it again a day later. If it hasn't liquified yet, I will add some more methanol/acid solution to the drum and stir it up again. I don't know how to determine exactly how much acid it takes to do this, so you have to play it by ear.

Eventually you will end up with a bunch of gallons of FFA's that you can add to subsequent batches of oil and do an acid/base reaction to convert it all. As you get to the bottom of the drum you will encounter glycerin & brine. You can take that and some sawdust and make some firelogs for those cold nights when you need a fire.

Thanks for the replies,

I am giving it a shot. I have the typical water wash drum with a standpipe that I have been using. I already had a batch loaded into it so I just held my bubbler above the water level and let it eat. Caveman do you use a standpipe to move the finished Bio or pump it off the top? Also I don't have a soap test kit yet. Is clear water on shakem up sufficient?

thanks

Gday gpduxbak
I use a drum that has a fitting welded on the side about 4" up with a ball valve, a stand pipe would need a return so it dosent get blocked with soap settling to the bottom thats if your using NaoH,if your after astm standard fuel a shakem up test would'nt suffice, i do use a shakem up test as a rough indicator to see if a should keep bubbling. i havent acheived the 40ppm NaoH sodium level for astm fuel but i'm getting close.
thanks caveman

Bubbled for three days and even after only a few hours of settle time my shake test came out completely clear. Goodbye water washing. Thanks caveman.

quote:

Originally posted by greiswig:

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.

Are you saying you should bubble with compressed nitrogen instead of air?

Nitrogen will have less or no oxidative effect on the BD. That would be the only reason I can see for using nitrogen.

Gday gpduxbak
I'm glad i could help.
It looks like some people are still having trouble with it all i can say it works for me, if there's still methanol present you still have soap, try bubbling more vigorously i use two small air pumps now to speed things up and also start bubbling straight after processing which reduces bubbling time.
Thanks caveman