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I have been slowly converting to Acid/Base from Base/Base process. Out of curiosity I made a little spread sheet to determine my break even point cost wise. I found that If I use the same amount of "New" methanol (99% pure) it is always cheaper to do the acid/base mainly due to the increased yield. However, I have been hesitant to us all my recovered methanol that I would use in a base/base process in the acid/base process (to reduce the new methanol consumption) due to the introduction of extra water. The Methanol I recover from the BD is ~97% pure typically, which I use. The methanol I get from my glycerol recovery is only ~90% pure, which I have not used yet. This makes the acid/base more expensive (ignoring the ability to process a greater range of oils). For the base/base I manage this by limiting my total water indroduction to less than .75% quite sucessfully.

Since the Acid/base process is more water sensitive does anyone know a similar limit or has anyone developed a corrilation between amount of acid used to water created of which I can attempt to apply the same limit. Goal is to begin using some of my glycerol recovered methanol.

I understand that about titration of 15 I have to pull the water out and do a second acid stage. Perhaps at this point I hit the 1% limit where making BD get troublesome. So assuming a straight line from that amount of acid to zero I can assume that at say T-7 I have introduced .5% water?

Brent
 
Location: Annapolis MD | Registered: September 26, 2005Reply With QuoteReport This Post
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Why not run your recovered meth through some zeolite to remove the warer? 10lb will last a lifetime. To re-activate it just spread the zeolite on a steel cake sheet and put your oven on self clean.


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Location: lakewood, Co. | Registered: February 15, 2008Reply With QuoteReport This Post
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Applehead

-use the new methanol for acid esterfication, and the recovered stuff for the next base or base/base stage. the ae process is much more sensative to water than the base process. the ae process creates water, but this has little effect on the process. so be sure your oil is bone dry before proceeding I put the wvo through the same process as I use for drying the finished bio.
-no need to drain anything after the ae treatment unless the wvo T's more that 15KOH. If your wvo is dry, and T's aroud 10, >75ml acid/ltr of wvo should give you a finnal T of 1 or less. I've had T as low as .75KOH thats the amount needed to neutralize the acid. If you need any help with this process, PM me, I'd be glad to help. every batch i process has the ae treatment first
-Think safety first, put methanol into the wvo mix for 20 min then add the acid and mix for a further 10-20 min. wvo must be heated above 130f. treatment can take about 12- 16 hrs, heat on, just let it sit hot until it's done. Tom


" I don't know what I don't know until I know"
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Location: Manitoba Canada | Registered: March 24, 2009Reply With QuoteReport This Post
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jdfoxinc
The zeolite may be a good option, but I need to do some more homework on it. I have read some mixed reviews, and also that I should not dry in the oven since it makes a very bad smell during the drying process.

Biotom
I agree, If I do a A/B/B process I will use the lower grade methanol on the second base stage. However, the goal is to not have to do that and use it in the first base stage which stll has the acid/water in it.

I was following the thread "Call for BD producers using acid" and thought I got a good understanding of the process. I thought I read that water was a by product of the AE process. If the titration is to high the process created enough water to impact making BD and a second acid stage is needed. Or is it that the titration will stop dropping at some point and require a second acid stage to get the titration low, not impact the base stage. I thought the reason was water creation, is this incorrect? If this is so than I can use the less pure methnol in the base stage and be fine?

Brent

This message has been edited. Last edited by: applhead,
 
Location: Annapolis MD | Registered: September 26, 2005Reply With QuoteReport This Post
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applhead

-the base stage is of course sensitive to water, but not to the same degree as acid esterfication. And yes the AE treatment makes a small amount of h2o. Hence the need to start with extremely dry wvo!
-5% water by weight, has been shown to decrease ffa conversion to 5%, so one can’t emphasize enough the need to start out dry.
-as far as acidic methanol? I’m not sure why this is a concern Yes the entire mix is acidic after the AE process, this is neutralized during the first base stage. The normal ph on a T sample with a T of 8-9 is 6.3 after AE the ph will be about 1.3, depending on how much acid you use.
-If the T is higher than 15, it is not likely that you can bring it down to 1 in one ae treatment, the water produced stops the reaction, a lose of heat will also stop the reaction regardless of the starting T. To restart the reaction of the higher T wvo, you have to settle and drain some by-product the redo the acid process. The by-product you drain will be of course very acidic, handle it with care. As a rule of thumb, I drain about 3 ltrs after every ae process, to minimize the effect of water on the base/base process. If the wvo T’s above 15, then drain ½ the volume of methanol that you added for the treatment. Extra methanol will be required to replace this for the next stage.
-Well as you can see I could go on and on here but not sure what info is pertinent to your situation. If I’m leaving you short , just ask 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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First to adjust, T NaOH of 1 = T KOH of 1.4. Meaning critical value of NaOH is near 10 not 15 as for KOH.

Not concerned about acidic methanol. Simply concerned about to much water is created in the acid stage to prevent complete processing. If I can predict the amount of water created I can add a calcualted amount of XX% purity methanol to the base stage and not impact the process.

Some amount of water is created during the acid stage.

At some point (~T=15 KOH, T=10 NaOH) the amount of water does one of 3 things

1) prevents the acid stage from proceeding and reducing my titration
2) prevents the base stage from completing as it would if I have to much water (~1%) in a normal base process
3) Both 1 and 2

Goal is to estimate the amount of water created during the AE process so I can maximuze my use of lower purity methanol and not impact the process. I am attempting to develop my process so I can complete with only a single base stage. I understand if I pass the titration threashold I will be forced into drain off and a second base stage.

My guess is I can assume a linear relationship. at T=0 water addition =0 At T=15 water addition is 1%. NO room for less than pure methanol. If T=7.5 I can add up to .5% water (from the less than pure methanol. Of course this assumes that the oil is completly dry.

Brent
 
Location: Annapolis MD | Registered: September 26, 2005Reply With QuoteReport This Post



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Brent

-don't make this more difficult that it is. the process works extremely well if you start with very dry wvo. you will find that the bio from base/base is much more reacted than single base if your concerned about quality. As I said before, I have serveral years experiance with this process,and feel this quanative water number your looking for is really a non issue. I'm not saying this to sound harsh, just to provide you with the insight to geter done 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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I seem to remember hearing/reading somewhere that for 3 every moles of FFA 1 mole of water is created.

I would worry about the difference between 97 and 99%..I'd also suggest using the 90% stuff for the 2nd base stage not the first. the more water in the first base stage the more soap you'll create.

work the conversion the other way.

15NaOH is 21 KOH..well into draining and maybe requiring 2 acid stages. besure to drain after the first stage, remix and then titrate..you might find that you don't need the 2nd acid stage. another thought is you might try using more methanol in the acid stage say 14% instead of 12%. if you have to drain you'll need more than 20% to get the job done. don't throw away the drained mix after the first acid stage. it contains mostly methanol.

the biggest question that's not answered is how water much can be tolerated? 0.1% ,1% or more?

-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
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Location: RTP, North Carolina | Registered: December 15, 2004Reply With QuoteReport This Post
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It looks like there is no data showing what the water limits are.

Tomorrow I'm picking up a second batch of oil from the same place and I think it titrates at about 8 (NaOH). So I should have enough for 3 batches from the same source. So I'll proceess each with a different amount of water resulting from my methanol I get 97% from my BD recovered, and about 90% from my glycerol recovery. I'll accurarly track the amount of water added from the methanol and see if there is a difference. Unfortunatly I only do 1 batch per week at most and the first will not be until first weekend in July, so it'll be slow going

Brent
 
Location: Annapolis MD | Registered: September 26, 2005Reply With QuoteReport This Post
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Dave

-if your talking about how much water the acid stage can take, check the ISU report the graph there shows a very steep decline in the ffa's converted as the water is increased 5% water by weight = 5% of the ffa's converted in other words, at 5% water ae process doesn't work. at 2% water, ffa conversion = 50% at 1% water ffa conversion = 80%. Eek 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'll have to go read the report again. I also wonder if the changed the acid qty/methanol qty then compared to the amount of 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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Dave
-they show conversion with added water to 5% by weight and conversion based on the water produced by the treatment seperately. 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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Where would I get a copy of the ISU report?
 
Location: Annapolis MD | Registered: September 26, 2005Reply With QuoteReport This Post
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applhead
-google ISU biodiesel 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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Tom

Thanks I got it. However, it has been long time since I took chemisrty. DO you know where I could get some basic conversions into biodiesel speak

% FFA = ?? mL of KOH/NaOH titration (1g lye/L distilled water)
5 wt% H2SO4 the FFA = ?? mL/L H2SO4 for oil titrating at XX mL
Acid value of XX mg (KOH or NaOH)/g = titration value ??

Thanks
Brent
 
Location: Annapolis MD | Registered: September 26, 2005Reply With QuoteReport This Post
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applehead

-1%ffa = 2mg koh/g
-for the amount of acid to use, DON'T follow the amounts used in the ISU report they use away too much, but where trying to have esterfication within a short period of time. it's best to let it sit with the heat on until the goal is reached. The higher the T the more acid you need dkenny has an acid calculator on CBT If you use that, use a multiplier of 1 - 1.5 .
-for how much caustic you need, it's base plus 1 gr for each T # ie T8 = 8gr plus base. Tom

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" 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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Here is a good post by Neutral about conversions to homebrew titrations.http://biodiesel.infopop.cc/ev...=846105159#846105159
 
Location: central virginia | Registered: March 13, 2008Reply With QuoteReport This Post
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