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I have a closed tank. How can I remove acid/methanol solution if it goes to the top without draining the tank? I'd like to transesterify in the same tank, but I don't know how to remove the acid layer if it goes to the top.
 
Registered: January 04, 2007Reply With QuoteReport This Post
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-If T is less than 15 KOH there is no need for any draining. I have been doing AE for 6 years and the only time I saw the methanol on top was in a test sample that was allowed to cool, once the sample cooled no amount of mixing would keep the methanol mixed in, but on the other hand the sample that was kept hot had NO methanol floating on top.
-DD or DKenny can provide you with the molar formala that if followed will ensure the by product sinks ( thats too hard for this old brain Big Grin)
-Good luck on the AE treatment, be sure your wvo passes the hot pan or spoon test with NO bubbles. 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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I don't get no need for draining if T is less than 15KOH. Are you saying leave it in and pass it along to transesterification. I'm a little green to all this. Thanks David
 
Registered: January 04, 2007Reply With QuoteReport This Post
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David
-yes that is correct, after AE is complete check T, this will give you sufficient caustic to neutralize the acid as well as complete the base reaction. My oil T's at about 8 Naoh, and after ae/base/water wash the yied is 95 - 98 % 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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Sweet I'll give er a try.
 
Registered: January 04, 2007Reply With QuoteReport This Post
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please share the results..

good or bad..

-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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quote:
Originally posted by David Fryman:
I don't get no need for draining if T is less than 15KOH. Are you saying leave it in and pass it along to transesterification. I'm a little green to all this. Thanks David


Now I am a little confused also. I hope we didn't jump the rail in the middle of this. You started out the thread talking about methanol on top and draining it off. Which, BTW, I am at a loss to help you as I have never had it go up. Then you end by saying that draining is not necessary.

As a point of clarification, I would submit that it is ALWAYS necessary to drain some off the bottom after setting and before restarting the mixing pump to obtain your ending T. I just finished a 100 gallon (380L) load that started at T 6 KOH added 380ml sulfuric and got about a liter of watery residue off the bottom. If this isn't removed by draining you are going to remove it with catalyst and make soap, and possibly suffer an incomplete conversion.

Norman
 
Location: Lincoln, NE | Registered: April 10, 2006Reply With QuoteReport This Post
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Norman
-probably a good habit to get into, then you have to replace this amount with new methanol as you go into the base stage. There is no doubt, that the higher the T of the wvo the more water effected drainage you will see. If the wvo is very dry going into AE, then the drainage will be very black, and if you swerl say 1/2 a cup in the bottom of a pail you my see a slight water trace. If on the other hand the wvo was not dry enough you will see a creamy black drainage once the wet suff is drained the drainage will be jet black.
-the base stage is more tolerant of water than AE, and for those using AE if you start with dry oil, less that 500ppm water, the water added by the ae process will still leave you with dryer oil going into the base stage than most have who just do base stage processing. There is a formula for calculating how much water is created in the ae process, and also how much water is created when the acid is neutralized be the caustic material. I will leave that for the chemist to explain, much to hard for my old brain! 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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If it's on the bottom, it's high in water (and usually sulfuric acid) and should be drained. If it's on the top, and the reaction has not come to completion, the layer often contains high amounts of FFA as methanol actually "extracts" FFA due to solubility priciples. If it's on the top and the reaction has come to completion, many people leave it in without bad results.

My general belief is that it's good to remove it either way. Once removed you can distill it and purifying the methanol before re-use. Your equipment (and budget) may be the deciding factor on what you do.
 
Location: CO, CA, KS, or FL | Registered: January 17, 2009Reply With QuoteReport This Post
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I agree with the draining, but keep in mind the starting titration.

why..if I have T5 oil and it drops to T1..why drain?
if i have T18 oil..and it drops to T2 should I drain..YES why more water was created!! this reduces the yield. and its known the mix will sink not float.

sure the water in the T5 also reduces the yield, but not much. just guessing but maybe 1/2%..is it worth the extra time waiting for it to settle..while the whole time kept around 130F..yes strange things happens with it cools..

just some 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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Methanol, Sulfuric, and Water are completely miscible. I did some testing a while back and came to the determination that there is no stratification that occurs between the three. I thought that sulfuric may be more hydroscopic than methanol and pull the water layer with it but that proved to be untrue. The hydroscopy of methanol and sulfuric appears to be of equal strength.
 
Location: central virginia | Registered: March 13, 2008Reply With QuoteReport This Post
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DD
-that said, then should we assume that since methanol and sulfuric acid are not miscible in wvo that there will be phase seperation if the mix is allowed to sit? what did you see in your tests? last spring when all the AE testing was going on, the samples that where mixed hot then left to cool had a noticable clear layer on top. on the other hand the samples that where mixed and kept hot with no further mixing had no seperation. i am at a loss to explan this situation, all the wvo/ acid/methanol mix was drawn from the same 160 ltr batch. 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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Biotom,

I don't think so..

hot might change where the layer occurred..
I think there is always a layer..but where is happens?
heat?
water content?
acid content?
methanol content?
these change the where not if a layer happens..

or am I loosing it here..??

-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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quote:
Originally posted by dkenny:
sure the water in the T5 also reduces the yield, but not much. just guessing but maybe 1/2%..is it worth the extra time waiting for it to settle..while the whole time kept around 130F..yes strange things happens with it cools..dkenny


I must assume we are using different processes. Are you still stirring throughout the AE process?

I thought Tom broke everybody of that habit. Big Grin Mine is settled as it sets waiting for the acid to do it's job. Time element is less than a minute, and I always get water or sludge or both.

Norman
 
Location: Lincoln, NE | Registered: April 10, 2006Reply With QuoteReport This Post
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Dave
-are you loosing it? think your too young for that! I have no idea why that happened but it did, I was just wondering why it happened this way. such a differance in a sample that was allowed to cool and one that was kept hot.
-Yes, heat mix and sit is the way to go that allows the crud to drop to the bottom and you end up with a lower T. and the crud /water /acud is ready for draining at the end of the process. I assume that is one reson that T is lowered, the acid is not as concentrated it the mix. 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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Hey guys I'm still here. I feel like I'm in class. I was going to name myself clueless but I'll wait till class is over and decide. Lots of info. Thanks David
 
Registered: January 04, 2007Reply With QuoteReport This Post
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Biotom,

you should know the density of the layers determine where they occur..

methanol floats in oil

oil floats on water

water/acid/methanol(WAM) like each other more than oil..

now if the density of the oil is less than the water/acid/methanol the oil layer floats.

if the WAM layer has the same density of the oil..they stay mixed..no layers

if the WAM layer is less dense than the oil it floats.

make sense?

-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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DK
-your theory seems correct, but in this case the oil/methanol/acid mix came from the same AE batch so it seems there is something else at play. 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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DK

quote:
so it seems there is something else at play.

Or not, Dave is the answer to this almost year long question in your previous post! Big Grin WAM the sample that was left to cool had very little ffa conversion so there would be very little water created. the sample that was kept hot, final T was 1 so all ffa where converted which means more water was created in the hot sample, "WAM" no phase seperation. 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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