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Have another AE batch but titration won't change
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I have another 40 gallon AE batch that titrated at 9. Actually it titrated at 12 but after doing a glycerin pre-treat it went to 9. Anyway, after 12 hours of heat at 120 -140F its still at 9. I used 5 gallons of methanol with 160 cc. of acid. From the last batch I tried where I used 300 cc of acid I learn it was too much acid, so I used half. I'm not sure if 160 cc is still to much ,or if I should add more? Could there be an agitation problem? I saw something where some brewers made a type of zig-zag baffle to aid it stirring thing up. My set-up just pump circulates without any type of restriction.
 
Location: western new york | Registered: November 19, 2008Reply With QuoteReport This Post
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heatbeater
-there is no easy way to do acid esterfication following a byproduct treatment!!!! When you do the byproduct treatment you add much caustic to the mix and this will simply neutralize the acid. For this batch you could keep adding acid in small amounts until the mix becomes acidic enough for AE to work, around ph 1 - ph 2.5 OR do several byproduct treatments until you achieve a workable titration. Tom


" I don't know what I don't know until I know"
1994 GMC 6.5 Tubo 2005 Dodge ram 3500, 3 VW's 2000, 2002, 2005.
 
Location: Manitoba Canada | Registered: March 24, 2009Reply With QuoteReport This Post
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For this batch you could keep adding acid in small amounts

What would be a small amount? 50 cc ? 100 cc ? I'll try 100 cc. of acid and see which way the titration goes. If it rises over 9 than my guess is to do some more glycerin treatment to help it drop.
 
Location: western new york | Registered: November 19, 2008Reply With QuoteReport This Post
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How long does it take to get the titration to an exceptable level? depends on temp?
 
Location: western new york | Registered: November 19, 2008Reply With QuoteReport This Post
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heatbeater
-don't get yourself into the vicious cycle of adding acid to neautralize the caustic then adding caustic to neutralize the acid, stick to one or the other. Yes try 100 ml of acid first, when I think back it took me almost 500 ml of 93% acid to neutralize 160 ltr of biodiesel after the byproduct was removed Tom


" I don't know what I don't know until I know"
1994 GMC 6.5 Tubo 2005 Dodge ram 3500, 3 VW's 2000, 2002, 2005.
 
Location: Manitoba Canada | Registered: March 24, 2009Reply With QuoteReport This Post
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If you are going to do a glycerin pretreatment heatbeater don't do it in the same tank as the AE. That or make SURE you remove it all before moving on to the AE stage. If you are using a recirculation pump I wouldn't do the glycerin pretreatment at all unless you can be sure you clean all the glycerin out of the pump lines, which is easier said than done.

That being said glycerin pretreatment does work wonders for an AE stage by removing the water and some of the other gunk. As Tom said though it's dangerous (product wise) in that it's really easy to screw up.
 
Registered: February 25, 2010Reply With QuoteReport This Post



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BWilder
-the only way you could follow a byproduct treatment with AE is if you where to neutralize the whole batch first, this may work. Even if you move the entire batch to another tank, the caustic contamination from the pre treatment will be in the oil and the AE will not work. Tom


" I don't know what I don't know until I know"
1994 GMC 6.5 Tubo 2005 Dodge ram 3500, 3 VW's 2000, 2002, 2005.
 
Location: Manitoba Canada | Registered: March 24, 2009Reply With QuoteReport This Post
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Hi Tom
I can only speak from experience. I've done a glycerin pretreatment using demethed glycerin and then removed the glycerin and done an AE with really good results.

I don't think what you are finding is caustic contamination. The caustic will combine with any FFA in the oil really quickly and make soap which should end up in the glycerin, maybe if the glycerin was already really soapy? It's hard to say without knowing the particulars of a persons glycerin but this has almost always improved my AE. The only time it didn't was once when I tried to use partially neutralized glycerin, I ended up with a lot of soap suspended in my oil, that didn't settle into the glycerin, and when I did the AE the salt dropped out and I had to add more acid to neutralize the soaps. I'm actually not 100% sure why this was a problem while the non-neutralized one wasn't
 
Registered: February 25, 2010Reply With QuoteReport This Post
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BWilder
-very interesring result, the only thing different in the process for me was the byproduct was not demethed. I am very open minded on this, so if you can let me know exatly the steps you used ei how long the treatment lasted, time mix,no mix,settle time, ect I will run a batch on Tues. Always willing to learn a new trick Big Grin Tom


" I don't know what I don't know until I know"
1994 GMC 6.5 Tubo 2005 Dodge ram 3500, 3 VW's 2000, 2002, 2005.
 
Location: Manitoba Canada | Registered: March 24, 2009Reply With QuoteReport This Post
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Ahh that's probably why. The glycerin MUST be demethed at least partially to allow it to absorb more material. Most of the glycerin we get from the bottoms is fairly saturated with material so it probably just added more soap to your mix too.

My pretreatment goes
check water and titration
Add 10% by weight of demethed glycerin
mix GENTLY for 10 mins
settle 3 hours
drain glycerin
check water and titration (should have dropped on both accounts)
proceed with AE

edit: I actually am wondering if there's a limit to how much soap glycerin can absorb though. My glycerin was from canola oil that had 1.4 titration and 0.1% water. I don't want to give you some advice that turns horribly wrong if your glycerin is already really soapy
 
Registered: February 25, 2010Reply With QuoteReport This Post
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BWilder
-this is the first I read that the byproduct has to be demethed for this treatment to work Confused I don't have my still set up yet, but will giver a go any way. the worst that can happen is it doesn't work, in that case I will go straight to base reaction and take my lumps on yield. I'll let you know how it turns out.
-my byproduct is from ae/base process and the T between 1.5 and 2.5 so soap concentration should not be too high.
-using the byproduct pre treatment places the bound biodiesl back into the wvo, I think if anything this is where the extra caustic comes from, and the more biodiesel that is transfered to the wvo the more neative the impact will be on the following acid stage. Tom


" I don't know what I don't know until I know"
1994 GMC 6.5 Tubo 2005 Dodge ram 3500, 3 VW's 2000, 2002, 2005.
 
Location: Manitoba Canada | Registered: March 24, 2009Reply With QuoteReport This Post
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The glycerin MUST be demethed at least partially to allow it to absorb more material.

I thought that by doing glycerin pre-treatment it was benefical to have the methanol in the glycerin ,why would you want to de-meth it? Plus I would think the methanol would help pull out any water. Another thing is ,should you expect to get the some amount of glycerin back that was put in? I got about 2/3 's the amount which I thought was odd, unless there was alot of bio that stayed with the wvo. The glycerin was from a batch of bio made a few days before.
 
Location: western new york | Registered: November 19, 2008Reply With QuoteReport This Post



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I'll try 100 cc. of acid and see which way the titration goes

I added 100 cc. at 7 pm and now titrates 7, so its dropping . Tempted to add another 50- 100 cc. more.
 
Location: western new york | Registered: November 19, 2008Reply With QuoteReport This Post
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if you have time go with the smaller amount first..you can always add more acid but to subtract you'd need to add caustic, but this creates water.

-dkenny


'84 bluebird school bus, DD8.2L turbo( 4/2011, the bus tranny has died..Frown 8.23.11 bus driven to scrap yard Frown )
2006 Jeep Liberty CRD Smile - the wife's
99 dodge 2500 5.9l 24v..-mine Smile
everything run B100 when its warm enough Smile
 
Location: RTP, North Carolina | Registered: December 15, 2004Reply With QuoteReport This Post
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Originally posted by heatbeater:

I thought that by doing glycerin pre-treatment it was benefical to have the methanol in the glycerin ,why would you want to de-meth it? Plus I would think the methanol would help pull out any water. Another thing is ,should you expect to get the some amount of glycerin back that was put in? I got about 2/3 's the amount which I thought was odd, unless there was alot of bio that stayed with the wvo. The glycerin was from a batch of bio made a few days before.


True but the way I'm looking at it is that the methanol will help dissolve water. The problem is that more methanol can stay in the oil than water. So by adding glycerin with methanol to the oil you are really dissolving methanol (and anything that was dissolved in the methanol) back into the oil. The other way I'm looking at it is that there is only a limited amount of 'space' in the glycerin for dissolved stuff. By removing the methanol you are freeing up more 'space' to suck stuff out of the oil. The BD in the glycerin shouldn't matter since even if you demeth it it will still be there and will still go back into the oil at least partially. Probably less so than if you didn't demeth I'm thinking, but it's a trade off with the other impurities (that harm the AE)

And did you mean you are going to use un-demethed glycerin Tom or are you going to demeth it too? Confirmation of my theory or debunking it would be nice Razz
 
Registered: February 25, 2010Reply With QuoteReport This Post
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Originally posted by heatbeater:
quote:
The glycerin MUST be demethed at least partially to allow it to absorb more material.

I thought that by doing glycerin pre-treatment it was benefical to have the methanol in the glycerin ,why would you want to de-meth it? Plus I would think the methanol would help pull out any water. Another thing is ,should you expect to get the some amount of glycerin back that was put in? I got about 2/3 's the amount which I thought was odd, unless there was alot of bio that stayed with the wvo. The glycerin was from a batch of bio made a few days before.


Heatbeater,
Acid stages and base stages are both esterification stages with the only difference being the type of catalyst that is used. When most people speak of using a "glycerin pretreatment" there referring to a glycerin pretreatment for base catalyzed reactions. In that case, using glycerin that contains methanol, some of the methanol is transferred back into the oil saving some of the methanol. The down side is that there is a bit of soap that is also transferred at the same time do to the solubility of soap in methanol. The soap that is transferred is not as much of a problem for base catalyzed reactions as it is for Acid catalyzed reactions. In an acid catalyzed reaction, the acid will be consumed by reacting with the soap.

In a base catalyzed reation, the soap that is present (from the glycerin pretreat) cannot consume anymore of your base producing more soap.
In an acid catalyzed reaction, the soap that is present (from the glycerin pretreat) can neutralize your acid leaving no acid left to act as a catalyst.
 
Location: central virginia | Registered: March 13, 2008Reply With QuoteReport This Post
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BWilder
-I will have to use byproduct with the methanol in so I will be following more what heat has done, but I have done this before with the same results that he is having on this batch. As you can see he only reclaims 2/3 of the byproduct, and to me that leaves more than enough caustic in the batch to produce the results that he has. without the methanol the soaps should fall out with the byproduct, and in theory that should greatly reduce the causic load passed to the wvo. and as you say draw the water out as well. I look forward to trying your method as well once I get my still in place this summer. I will contact you by PM to continue this conversation and if we hit pay dirt we can bring the good info back to the board. Tom


" I don't know what I don't know until I know"
1994 GMC 6.5 Tubo 2005 Dodge ram 3500, 3 VW's 2000, 2002, 2005.
 
Location: Manitoba Canada | Registered: March 24, 2009Reply With QuoteReport This Post
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Beautiful description DD much clearer than mine.

Tom isn't the definition of insanity doing things the same way and expecting different results each time :P
 
Registered: February 25, 2010Reply With QuoteReport This Post



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it would be my suggestion to decide if your going to use glycerin pretreatment or AE for processing the oil. Then don't mix the 2 methods. why? you might ask?
well consider
the soap left behind -> mixed with acid produces water. bad for AE
methanol left behind -> are we sure about this..oil and methanol don't mix..so I don't think much if any is left.

is water in the glycerin..this might create more soap from the FFA. reduces the oil volume that could be made into biodiesel. I don't use caustic stripping for this reason

depending on the setup how do you know with to stop drain the glycerin from the oil?

you might get some the biodiesel that in the glycerin to stay in the oil..this would be good

Heatbeater..how's the batch going?

just some early morning thoughts

-dkenny


'84 bluebird school bus, DD8.2L turbo( 4/2011, the bus tranny has died..Frown 8.23.11 bus driven to scrap yard Frown )
2006 Jeep Liberty CRD Smile - the wife's
99 dodge 2500 5.9l 24v..-mine Smile
everything run B100 when its warm enough Smile
 
Location: RTP, North Carolina | Registered: December 15, 2004Reply With QuoteReport This Post
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In an acid catalyzed reaction, the soap that is present (from the glycerin pretreat) can neutralize your acid leaving no acid left to act as a catalyst.

-and thats why we don't do byproduct treatment prior to ae. If we new the amount of caustic that was being added then an extra amount of acid could be used, but we all know the down side to adding too much acid.
-BWilders pretreatment is unlike the normal byproduct treament I read about here and have tried with the same result as heatbeater, and many others here .
-Insanity EH! Big Grin Big Grin Big Grin that remark made me change my mind, I will do a test batch after cooking off the methanol!!! Red Face
-the other question I have, what is the purpose of doing a byproduct pretreatment prior to AE if the pretreatment takes care of the ffa (that cost in yield) and what then is the AE for? Tom


" I don't know what I don't know until I know"
1994 GMC 6.5 Tubo 2005 Dodge ram 3500, 3 VW's 2000, 2002, 2005.
 
Location: Manitoba Canada | Registered: March 24, 2009Reply With QuoteReport This Post
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