Ok, here is the update.

1) Still not sure abut why I am creating so much soap. I will run a batch on Thursday and pull samples to test.


AMAZING NEWS THOUGH. Wood chips are not all the same. I mean radically different. I have two batches of bio. One was like 1600 and the other 3600ppm. Last week I circulated the 1600ppm bio through hardwood wood chip shaving I got from hardwood milling place. For the life of me, I couldn't get the soup count below 1000. I also had a batch of bio (34 gallons) that was reading about ~3600 ppm soap. I had no faith in the wood chips anymore so I decided to do a number of 5% washes on this batch. I dumped in 2 gallons of water on top, let settle for about an hour and then drained about .5 gallons of water and a whole LOT of emulsion - another 3-4 gallons or so. I repeated this 5 times over the course of the day and let last water wash sit in overnight. Drained it again this morning. Soap tested - came up at 2100ppm. Ughh, this was working but oh my at this rate, it will take forever. So I dumped a second bag of Shredded decorative Redwood Bark I had let sit out in the sun to dry. (I got this from Anawalt Lumber - $5.99 a bag - not sure if its by weight or volume, but that size of the bag was one you sling over your shoulder.) So now in the wood chipper barrel, there is hardwood chips that fill the bottom third - these currently are either soap saturated or do little - I think the the latter. Then on top of these, 2 bags of redwood bark. Guess what? After 3 hours so circulating 35 gallons over the bark and other chips, I am at around 90 ppm!

I guess the lesson here is test your chips first. From Graydon over at Utah Bio wrote that its actually the sawdust that does most of the absorbing and not the bigger shavings. I had sifted out my shavings and dumped out the finer sawdust, so could this be the issue as well. Oh well. Next time I collect the sawdust/shavings, I will test this theory out. But the redwood bark works, and works well. (well unless someone tells me that is all Tannins and all I have done is make by bio acidic.... no....)


Doug

Chug and all,

I'm running another batch with the WBD method.

My batch size is 29 gallons of WVO which titrated at 2.0.

I used 6.5 gallons of methanol, 1 gallon or so came from the recovery of the batch before. I mixed in 990 grams of NaOH and dosed it in over 30 minutes.

The whole batch temp started at 140F and stayed there. After dosing in the methoxide, I mixed the batch for 3 hours. Passed the 3/27 test with flying colors.

Now I'm demething and I want to make sure that I don't pull too much methanol out and get a reverse reaction. Am I safe to pull out 3.5 gallons? Help me with the math here.

Thanks.

[QUOTE]Originally posted by PwrStrk6spd:

Now I'm demething and I want to make sure that I don't pull too much methanol out and get a reverse reaction. Am I safe to pull out 3.5 gallons? Help me with the math here.

_______________________________________________________________________________________________________


NO, according to the numbers that Chug provided, your recoverable meth would be 2.8 gallons.

You should stop 500ml short of that.

This message has been edited. Last edited by: oceanflyer,

PwrStrk6spd.
I built a spreadsheet and it tells me you should recover 8.28 liters. 2.1 gallons. Hopefully Chug or someone will verify that.
My sheet takes Volume of oil+volume of meth for total batch. Time 12.5% for Methanol consumed in the reaction. I subtract that amount from the methanol put in originally.
Hope thia helps. Tom2

I better check my numbers and read up it sounds like.
oops.
Thank you Oceanflyer. My bad. I fouled up a formula. 2.8 it is.
Oops again. now I'm back down at 2.2. My brain is too tired I guess. Don't trust me.

For me it's a lot simpler to do an acid titration and neutralize any remaining catalyst, that way you are not relying on any theoretical recovery amounts.

Fabricator,

Are you Acid Titrating the glycerine? Could you post a link or tell us how you are creating your titration solution and then how do you calculate amount of acid to add?

Thanks
Doug

agree with fabricator.. much easier and less risky imo..

quote:

Originally posted by Reece123:
agree with fabricator.. much easier and less risky imo..

Reese,

I'd really like to know what you use to neutralize the excess caustic and what your procedure is. Please tell...

Thanks.

i will use any acid i have it really doesn't matter.. usually sulfuric cos thats laying around.

take a sample from your reactor.. using phenol red as an indicator (or pH meter) measure how much acid is required to bring that size of your sample down to ph 7 or get the phenol red to change from red back to yellow. then just multiply the amount of acid u used by the same as your batch size.

eg: 0.5mL of acid required to neutralize 1L of fluid. Multiply 0.5mL by your batch size.. lets say you do batches of 150L.. 2mL*150 = 75mL of your chosen acid to be added very slowly back to reactor.

I made a solution of one liter of distilled water with one ml of sulfuric acid in it, I draw a sample while processing and keep shaking it so the glyc cant settle out, then just add a one ml sample to ten ml of iso four drops of my turmeric solution then titrate with the acid solution from red to yellow, basically the reverse of the titration to determine how much koh/naoh to use, say it takes one ml to go yellow that means it will take one ml per liter to neutralize any left over catalyst.

PwrStrk6spd,
I posted a link earlier in this thread to a nice acid titration technique Johno came up with in GL's push/pull thread. There is allot of discussion their about neutralizing as that is part of the push/pull method.
I find I need to reduce the amount of acid I actually add to the batch compared to the titrated amount due to the bio being slightly acidic after the recovery. If my acid titration comes out to 150ml I will add 100ml and end up with no acid number with the finished product, see the push/pull thread for all the details...
Jon

Hi guys,

just catchin up here, I've been quite busy lately (for a change),

I find I get less soap in the bio as more of it drops out in the glyc with WBD, and this sees to be the general consensus.

If you have an instant clear and bright 3/27 and no dreaded white stuff(DWS) showing up at the interface of the water and bio from MG's, DG's in a 50/50 shake em up test (I shake the hell out of it for a minute), then I think that is a pretty good sign of no back reaction, But it would still be nice to get some GC testing done to confirm or refute this.

The first two batches of WBD I ever did I just kept recovering until methanol stopped dripping and both had DWS at the bio/water interface, that is when/why I progressed to only recovering down to stoich.

I've only tried reprocessing one sample of bio after WBD and that gave no extra glyc so I'm happy with it. Bio samples I have from WBD going back to March still look as bright and clear as the day they were made.

I've added the link to the recoverable amounts again,

http://www.biofuel-uk.net/recoverable%20methanol.doc

but I now use 25% methanol as it means the math is easy and I just recover half of the starting amount.

One or two of the guys from the UK who have problems with soap and didn't like leaving out the 5% prewash are now doing WBD, then a 5% prewash, then settle and drain glyc and this seems to work with their wvo.

I've done four 300 gallon batches now with the wbd, there has definitely been less soap in the bio after demeth than with the regular method, I have also had a definite reduction in yield, around 7-8%.
The time and energy savings I get with this method are worth the reduction in yield.

I gotta chime in on this one. Chug, you are really onto something with this WBD. I've done the last 3 batches doing a methanol recovery and the results have been awesome to say the least.

I can't use my vacuum venturi when things get above 75C as internal vapor pressure wants to force fluid out the venturi port, but the recovery condenser doesn't seem to mind.

The biodiesel gained passes 3/27 with flying colors and has an excellent cloud point temperature as well, around 35F.

I've been recovering methanol at about 98.5% purity now that I've got all the bugs worked out of the methanol condenser.

Chug, and whoever collaborated with you, the beers are on me.

I'm curious to ask...

Neutralizing lye with acid during a water wash...

Of you guys that are doing WBD without Acid, how many of you are water washing? Of those guys, have you seen any different behavior from your water washing?

My latest batch of 28 gallons of oil titrated at 2.0. I put in 990g of lye total. My biodiesel passed 3/27 and 5/27 and 12/27 with no clouding. But water washing has been a bear for this batch. I've been getting emulsions and the last bottom 5 gallons of biodiesel next to the water was very slow to separate. So here's what I did. I transferred if from the standpipe wash tank to to a small poly cone bottom tank for more precise separation. The crud just didn't want to completely break. I mixed a bucket of hot tap water and splash of pool acid. Poured it in and WHAMMO! It broke immediately and completely.

I'm wondering if adding a touch of acid to my wash water would make the bio/water separation faster and with less washings. So here's my thought. If I don't neutralize the excess lye before demething the biodiesel and glycerine, I'm thinking that I'll benefit from neutralizing the lye when I'm washing. Has anyone tried this?

Another question, has anyone tried WBD with acid and then without acid and noticed a washing performance difference?

Thanks guys.

Pwr
-I have done several batches , neutralizing with sulfuric acid prior to water wash, nothing but trouble for me!!!. Three batches went to the boiler,and used them the heat. Prior to the whole batch acid neutralizing, I used 7ml of vinigar/ltr of wash water and found that to be much superior to the latter process, mybe I was doing something wrong? I know I wasn't the only one having wash problems after neutralizing. Tom

I've never resorted to using acid or water so I'm not qualified to answer.

I just demeth and recover half the methanol I put in then settle and drain glyc, pump to settling tank, bubble with air overnight, settle min 24 hrs and then filter and use.

But the reason I developed this method was to simplify things and get away from acid and water and save time and energy, and to that end it works brilliant for me.

Ok, since I made a mess of this thread, let me clean it up a bit.

BACKSTORY
Without making ever making biodiesel before, I started reading threads here and came across Graham's Push Pull. So that is the system I built - first - ever. Looking back it probably was a bit more than I could handle out of the gate. I had problems with the separate oil heated venturi system as designed, couldn't get the acid indicator to flash in the sight tube as I added acid, added WAY TOO MUCH acid, then tried to titrate with acid outside of the processor to try to calculate an acid amount - met with some limited success. Adding to the problems was that I was using KOH and soap never visibly dropped out like in Graham's pictures. So I gave up on all of this and about a year ago, started doing WBD. I didn't report on it because I was also doing dry washing.... which also wasn't working for me because now I was having WAY TOO MUCH soap. Plus my wood chips were not the right ones.... blah, blah, blah. blah blah.


Ok now I am 2 years more experienced, can test for Water, Soap, % Quality of methanol, rough test for methanol content in the bio, and can pull a good vacuum, AND I have new methanol from a reliable source. I am currently doing what I said I would do earlier and pull samples in the beginning and as I demethed. Bottom line so far in the soap area it is working wonders.


START:
130 Liters Oil
Water: 610ppm
20% methanol added: 26 Liters 99% pure.
2.5 Koh Titration.
Used 10+2.5=12.5 or 1625 Grahams of KOH.


PROCESS
Oil Temp got to 135.
Added ~80% Methoxide. Let mix for 90 minutes.
Let mixture sit for 20 minutes.
Drained ~4.25 gallons of Glycerol. (covered the bucket to prevent methanol evaporating)
Added the other 20% and let mix for 120 minutes.
Let the batch sit overnight. (55F ambient Temp)

Next morning:
Drained another 3 gallons of Glycerol from the processor.


TESTS:
Before any demeth: Took 2 samples, 1 from the bottom (bio & Glyc) and another from the middle (more or less pure bio)

27/3: Both samples passed great. Clear mixing with the 27ml meth.
Soap: Top sample tested at 8.6ml or 2753 ppm soap. Strangely after a few hours, same sample tested at 6 ml or 1920 ppm

Water Test: 580ppm


METHANOL REMOVAL:
First I used the vacuum, to suck up the Glycerol back into the bottom of my tank. (I didn't want to completely remix it with the bio.)

Also, now I am only taking samples from the middle. Samples are very warm when tested for soap.

At -20hg and 150F and 90 minutes
After removing a total of 2 L of methanol:
Soap Test: 4ml or 1280. Sample @ 140F
Methanol purity removed 99% (.797)

At -20hg going down to -10hg and 150F and 7 hours
Removed another of 200 ml of methanol: (2.2L removed)
No sample or test taken.

At -20hg going down to -10hg and 165F and 9 hours
Removed another of 500 ml of methanol: (2.75L removed)
Soap Test: 2.5ml or 800ppm. Sample at 160F.
Methanol that was additionally removed (.500ml)is 97%pure. .802

(I am now seeming to have a very small vacuum leak so...methanol removal is taking a lot longer than in prior batches). However, I will just keep going with it for now as I do not have to time to repair it.

I should be able to recover about 9.75 Liters of methanol. Lets see.

Doug

Doug,

I'm struggling with your KOH calculation for your reaction. The base amount of KOH (assuming 90% KOH purity), should be 7.7g per liter plus 2.5g per liter for titration.

7.7g x 130 = 1001g for base amount
2.5g x 130 = 325 for titration
Total = 1326g for your batch.

By my calculation, you're overdosing your KOH by 300g!! Correct me if I'm wrong here.

Just like you, I bit off more than I could chew. I started with a GL-1Day Eco processor with venturi and condenser as my first and current rig.

I first distilled methanol from bio after draining glycerin. Now I'm demething the whole thing.

Here's a suggestion. Try using NaOH instead of KOH. Your reaction will require less. Probably 880g of NaOH for the same batch. The NaOH glycerin will drop out and the soap will drop out. KOH tends to make snowflakes and doesn't drop out easily.

I started with KOH but switched and I really like the result. That's my opinion. Others may differ.