Biopowered - vegetable oil and biodiesel forum
Biodiesel => Chemistry and process => Topic started by: Vijay on August 02, 2022, 08:30:06 PM
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Hoping someone can shine some light on the worst lot of batches I've ever had. I'm on the third lot without actually making a batch ::)
The problem seems to point to glyc washing but no idea why. This lot of oil has had 4-5 pre glyc washes and still titrated at 12. I have also condensed it for 12 hours at 90c, settled for 3 days and then dropped the bottom lot to make sure there was no water.
Because of the 2 previous nightmare batches, Yesterday I did a Dr P sample using 17g of sodium to 220ml meth and let it settle all day. I had some glyc drop and some bio on the top - but loads of soap :(
So today I did another Dr p with 9g sodium and 220ml meth. Straight away it went like a soft jelly. It has settled all day and no glyc drop.
Anyone ever had this sort of thing and any idea what I can do to save this batch?
Pic attached of the 2 sample batches
Cheers
Vijay
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the other thing I have noticed in the previous failed batches, is the less sodium I have used in test samples, the more jelly it makes - how???
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Can you blend it with a much better lower titrating oil?
One thing I have done with really crappy oil is give it 2 or 3 glyc washes but add around a liter of meth with 1g/l caustic after the glyc has gone in, that helped massively to help the oil convert, though with high titrating oil you will not have a high conversion rate.
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I blended the second lot with much better (very clean) oil then did glyc pre washes and had the same issue. That is now sitting in containers to be dealt with at a later date :(
I did 4-5 glyc washes as I always do. Do you mean add a litre of meth and 1g per litre of oil after each glyc wash?
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I blended the second lot with much better (very clean) oil then did glyc pre washes and had the same issue. That is now sitting in containers to be dealt with at a later date :(
I did 4-5 glyc washes as I always do. Do you mean add a litre of meth and 1g per litre of oil after each glyc wash?
Hi Vijay. I think Richard means to add the chemicals to the glyc wash as it is going. This method "enhanced glycerol pre wash" was something I came up with years ago. As the chemical reaction with high titrating oil yields quite a lot of water the answer is to neutralise the oil in the presence of glycerol which has a massive affinity for water, So after the glycerol is removed
the oil is left neutral and dry.
Looking at your 1st post you have glyc washed 4 to 5 times and still your oil titrates at 12 Gosh that means your oil originally titrated at probably over 20 with sodium, thats bloody high.
Suggestion, add the correct chemicals to nuetralise the oil (use a minimum of methanol) to the glycerol you are going to use for the wash. That should leave the oil dry and neutral. I think you would be better off using potassium for the whole method, using sodium for oil that titrates so high is bound to cause issues.
One last thought, from what you say if you titrated with potassium your level would be well over 30! Wow, no wonder you are having issues.
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right, so is it 1l of meth and 1g of sodium to each litre of oil with each glyc pre washes? (I normally do 4 or 5 which each wash being better glyc).
So you think start doing glyc washes again with it? I only have the same glyc I've used already on this oil. What would be the min of meth?
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Each gram of NaOH you add will create about 0.45g of water, but also 7.5g of soap (assumes oleic acid). So 12g of NaOH will give you 90g of soap. For reference, a bar of PalmOlive soap weighs 90g!
It is worth titrating the oil just to be sure of how bad it is. The cost of the chemicals to just make the oil usable may be more than it is worth to you. How much of this oil do you have?
If you are willing to experiment further, you could try an acid then base approach. Treat the oil with Methanol/Sulphuric acid to esterify the FFA, followed by the normal transesterification. The esterifcation process with Sulphuric acid is quite slow but wil convert the FFA to Bio allowing the Base method to convert the oil to Bio without all the reagents being used up neutralising the FFA.
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Each gram of NaOH you add will create about 0.45g of water, but also 7.5g of soap (assumes oleic acid). So 12g of NaOH will give you 90g of soap. For reference, a bar of PalmOlive soap weighs 90g!
It is worth titrating the oil just to be sure of how bad it is. The cost of the chemicals to just make the oil usable may be more than it is worth to you. How much of this oil do you have?
If you are willing to experiment further, you could try an acid then base approach. Treat the oil with Methanol/Sulphuric acid to esterify the FFA, followed by the normal transesterification. The esterifcation process with Sulphuric acid is quite slow but wil convert the FFA to Bio allowing the Base method to convert the oil to Bio without all the reagents being used up neutralising the FFA.
Got to be honest, haven't got the time or head to start messing with acid at the moment, so got to rule that out.
So why am I getting so much soap, I've done glyc washes and even ran the condensor at 90c for 12 hours to remove water. Is it just bad oil = soap regardless?
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oh and I did titrate it which was 12
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oh and I did titrate it which was 12
But didn't you say the 12 titration was after glyc washing. Have you titrated the oil before ie as is. It would give you a better idea of how bad it really is.
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I didn't mate. But what I did do was a test sample with the same good oil (after Nigel's heads up) and it titrated at 5. So somehow (and I have no idea how) the glyc washes have made my oil worse????
Just had a thought, would 5% petrol help clean this oil?
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I didn't mate. But what I did do was a test sample with the same good oil (after Nigel's heads up) and it titrated at 5. So somehow (and I have no idea how) the glyc washes have made my oil worse????
Just had a thought, would 5% petrol help clean this oil?
What can I say, has someone pranked you with a little sulphuric in your glyc?
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Each gram of NaOH you add will create about 0.45g of water, but also 7.5g of soap (assumes oleic acid). So 12g of NaOH will give you 90g of soap. For reference, a bar of PalmOlive soap weighs 90g!
It is worth titrating the oil just to be sure of how bad it is. The cost of the chemicals to just make the oil usable may be more than it is worth to you. How much of this oil do you have?
If you are willing to experiment further, you could try an acid then base approach. Treat the oil with Methanol/Sulphuric acid to esterify the FFA, followed by the normal transesterification. The esterifcation process with Sulphuric acid is quite slow but wil convert the FFA to Bio allowing the Base method to convert the oil to Bio without all the reagents being used up neutralising the FFA.
Got to be honest, haven't got the time or head to start messing with acid at the moment, so got to rule that out.
So why am I getting so much soap, I've done glyc washes and even ran the condensor at 90c for 12 hours to remove water. Is it just bad oil = soap regardless?
Not entirely surprised about your decision to avoid the acid step, it is not for the faint hearted, but I thought it ought to be at least mentioned.
Blowing air through the oil at 90C for 12 hours would result in some oxidation and creation of more FFA - how much is difficult to say without titrating it before hand and afterwards.
If the oil titrates at 12 then 10% of the oil will appear as soap, that is plenty to give you a jelly unfortunately. If you are using 17g/L of NaOH then you will have 8g/L of water present so that will catalyse more soap formation than the simple 90g from neutralising the FFA present.
I think you need to check all components again, is the solution you are using for titrating fresh and correct strength? Is the caustic soda still god and not ben left open to the air so it could absorb water/CO2? As Dave sugestscould anyone have tampered with the Glycerol?
You could check the amount of caustic left in the glycerol with a back titration. Titrate some acid (say 0.1*ml vinegar) and see what that comes out at (likely quite a high figure). Mix 1ml of glyc with 0.1*ml of the vineger and then titrate with your normal caustic solution the difference between the two sorts of titration will give you a value for the glycerol. If it turns out to be acidic then you have a problem.
*Not sure what quantity of vinegar you would need, or what quantity you can measure, so you may need 1ml diluted to 10 to get 1ml with the 0.1 you need, you may even need 0.01ml.
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Each gram of NaOH you add will create about 0.45g of water, but also 7.5g of soap (assumes oleic acid). So 12g of NaOH will give you 90g of soap. For reference, a bar of PalmOlive soap weighs 90g!
It is worth titrating the oil just to be sure of how bad it is. The cost of the chemicals to just make the oil usable may be more than it is worth to you. How much of this oil do you have?
If you are willing to experiment further, you could try an acid then base approach. Treat the oil with Methanol/Sulphuric acid to esterify the FFA, followed by the normal transesterification. The esterifcation process with Sulphuric acid is quite slow but wil convert the FFA to Bio allowing the Base method to convert the oil to Bio without all the reagents being used up neutralising the FFA.
Got to be honest, haven't got the time or head to start messing with acid at the moment, so got to rule that out.
So why am I getting so much soap, I've done glyc washes and even ran the condensor at 90c for 12 hours to remove water. Is it just bad oil = soap regardless?
Not entirely surprised about your decision to avoid the acid step, it is not for the faint hearted, but I thought it ought to be at least mentioned.
Blowing air through the oil at 90C for 12 hours would result in some oxidation and creation of more FFA - how much is difficult to say without titrating it before hand and afterwards.
If the oil titrates at 12 then 10% of the oil will appear as soap, that is plenty to give you a jelly unfortunately. If you are using 17g/L of NaOH then you will have 8g/L of water present so that will catalyse more soap formation than the simple 90g from neutralising the FFA present.
I think you need to check all components again, is the solution you are using for titrating fresh and correct strength? Is the caustic soda still god and not ben left open to the air so it could absorb water/CO2? As Dave sugestscould anyone have tampered with the Glycerol?
You could check the amount of caustic left in the glycerol with a back titration. Titrate some acid (say 0.1*ml vinegar) and see what that comes out at (likely quite a high figure). Mix 1ml of glyc with 0.1*ml of the vineger and then titrate with your normal caustic solution the difference between the two sorts of titration will give you a value for the glycerol. If it turns out to be acidic then you have a problem.
*Not sure what quantity of vinegar you would need, or what quantity you can measure, so you may need 1ml diluted to 10 to get 1ml with the 0.1 you need, you may even need 0.01ml.
I renewed the titratinsolution and got the same results as the old. Caustic is a new bag (but had the same sort of issues with the end of the old stuff which has always been in a small clip top container). Glycerol is left in sealed containers in the garden and doubt very much anyone has gone near it.
So if I forget about the glycerol, what can be done with 85l of this oil in the processor that's titrating at 12, what are my options? 2 stage process? https://biopowered.co.uk/wiki/Two_stage_process
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I suspect the glycerol you are using has no caustic left in it, as a result it will remove water but will not neutralise any of the FFA so the titration figure will remain at 12 unless you add some more reagent (see option 3).
I see a few options:
1) Get rid and cut your losses (Ebay?)
2) Mix it with good oil (I would suggest <25%), even with very good oil that will still give you a titration figure of 3. You could then process the mix normally.
3) Follow Dave's suggestion to reduce the level of FFA, that is mix some methoxide with the glycerol and use the mix to wash the oil. Repeat several times to get the titration down to below a reasonable figure (I woud sugget a titration below 3).
4) Try a 2 stage process, but I suspect this will be troublesome given how high the oil titrates. If using 17 g/L NaOH you are adding a lot of water and producing alot of soap, as a result I would not be in the least surprised if you end up with Jelly (as you have already experienced).
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I'd like to try option 3 as I'd love to see this batch through and learn.
So for 85l of this oil mix, if I add 20l of glycerol at a time, how much sodium and meth would I mix for the methoxide? Should I do some 1l samples of this or do the 85l in the processor?
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I would definitely do some Dr Pepper experiments rather than jump in at the deep end with the whole batch.
Follow Dave's suggestion of adding enough caustic to neutralise the FFA in the minimum amount of methanol you can get away with.
For 1 1L test, I would try 12g of NaOH (or 16g KOH if you have it) and I would start with 50ml methanol. Be warned adding 12g NaOH to 50ml methanol in one go may make the methanol boil so add 3-4g at a time and check how warm the solution is once dissolve then allow it time to cool. Mixing the methoxide dont use a PET container (soft drink bottle), use an HDPE/MDPE/LDPE one or glass as methoxde will dissolve its way through!
One treated and the glyc removed, you should be able to use 5g NaOH/200ml methanol to process the test -youmay need a second step with the processing to remove the last of any dropout.
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"For 1 1L test, I would try 12g of NaOH (or 16g KOH if you have it) and I would start with 50ml methanol. Be warned adding 12g NaOH to 50ml methanol in one go may make the methanol boil so add 3-4g at a time and check how warm the solution is once dissolve then allow it time to cool. Mixing the methoxide dont use a PET container (soft drink bottle), use an HDPE/MDPE/LDPE one or glass as methoxde will dissolve its way through!"
so mix 12g/50ml with how much glyc to do a glyc wash?
I do have some pot, so recommend using that over sodium?
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"For 1 1L test, I would try 12g of NaOH (or 16g KOH if you have it) and I would start with 50ml methanol. "
so mix 12g/50ml with how much glyc to do a glyc wash?
I do have some potassium, so recommend using that over sodium for high titration?
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As Dave says I did mean 1g/l in a liter of meth once the glyc was in and washing. I've only had to do this on a few batches some years ago when I had some real crappy oil that titrated around 7 with sodium. Any soapproduced would have come out with the glyc and they processed well afterwards, thought the final volume was a bit lower than normal.
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As Dave says I did mean 1g/l in a liter of meth once the glyc was in and washing. I've only had to do this on a few batches some years ago when I had some real crappy oil that titrated around 7 with sodium. Any soapproduced would have come out with the glyc and they processed well afterwards, thought the final volume was a bit lower than normal.
Sorry guys but I'm confused with the numbers. So 1g sodium for every litre of oil (so 85g of sodium) mixed with 1l of methanol. Once the glyc is in and washing, pour the methoxide in? How long should it be mixed for?
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I think we have 2 different approachs here.
For the Dr Pepper, if adding the 12g NaOH /50ml Methanol, I would try half a litre of glyc. If you have some KOH that would require 16g, but if only 90% then 18g. I was following Dave's coment "Suggestion, add the correct chemicals to nuetralise the oil (use a minimum of methanol) to the glycerol you are going to use for the wash. That should leave the oil dry and neutral. I think you would be better off using potassium for the whole method, using sodium for oil that titrates so high is bound to cause issues."
I think Richard is refering to what he used for a batch of his oil previously. We know yours titrates at 12, so just using 1g/L means you would have to repeat the process 12 times. My guess is that Richards glyc also had a significant caustic content, and his oil only titrated at 7.
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Doing 12g sodium to 50ml meth and 17g pot to 50ml meth at the moment. Not easy mixing that amount of chemicals to the meth though................
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Doing 12g sodium to 50ml meth and 17g pot to 50ml meth at the moment. Not easy mixing that amount of chemicals to the meth though................
Difficult, and the possibility of over cooking, which is why I suggested 3-4g at a time... so make sure you do it safely
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Doing 12g sodium to 50ml meth and 17g pot to 50ml meth at the moment. Not easy mixing that amount of chemicals to the meth though................
Difficult, and the possibility of over cooking, which is why I suggested 3-4g at a time... so make sure you do it safely
I thought you meant add 3-4g of sodium at a time to the 50ml of meth which is what I've done (or trying to lol)
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Doing 12g sodium to 50ml meth and 17g pot to 50ml meth at the moment. Not easy mixing that amount of chemicals to the meth though................
Difficult, and the possibility of over cooking, which is why I suggested 3-4g at a time... so make sure you do it safely
I thought you meant add 3-4g of sodium at a time to the 50ml of meth which is what I've done (or trying to lol)
Yes I did. What did you think I meant out of curiosity?
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when you asked again I wondered if you meant say 4g of meth into 50ml meth x 3 times. I've done it once (so 12g into 50ml)
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when you asked again I wondered if you meant say 4g of meth into 50ml meth x 3 times. I've done it once (so 12g into 50ml)
Ah, yes I can see that it could be interpreted that way, but I did mean 12g into 50ml.
Has it all dissolved yet?
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potassium did and sodium mostly lol
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Got very dark oil - thought there was no glycerol drop but using a torch behind the sample bottles, I can see the glyc dropped. I'll leave it overnight and titrate both samples in the morning.
I could be wrong, but it looks like the potassium sample oil is slightly lighter than the sodium one
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What stage are you at? Have you removed the glyc from the enhanced prewash and processed, or is it the glyc of the prewash you are lokking at?
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Only at the glyc prewash stage (the 12g and 50ml stuff to 1l of oil). Will let that settle overnight and then do a titration
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Good luck.
I won't be around until late afternoon tomorrow.
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I'm totally impressed guys. Sodium is now titrating at 6 and potassium at 4 - can't believe it worked soooo well :)
So should I upscale and go with potassium - for 85l =1445g potassium and 4.25l meth?
Gonna be a lot of chemicals in all by the time I process though isn't it..................
Or do I just process it as normal with 1445g of POTASSIUM and 18l meth?
Just did a test sample of 17g pot and 220ml meth and I'm pretty sure I have glyc drop - but the top bio layer is very dark. I can only tell the drop out by using a torch behind the bottle. Can bio be dark as I've never had that before?
Also there seems to be no soap made with the potassium sample where there was loads with the sodium sample
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One disavantage of potassium soap is that it can take a long time to drop out compared to sodium, as a result often a mixture is used part NaOH and part KOH to get the benefits of both.
As your oil is still titrating quite high (6 or 4), I would be tempted to try with a little more NaOH/KOH and see if you can get that titration level down further, maybe only 5g of NaOH, or 3g KOH (if you have the samples left). The reason being that when you add alot of caustic (soda or potash) there will be a certain amout of neutralisation, but also an amount of direct saponification where the oil is turned directly to soap. The presence of the glycerol should help reduce this, but given the titration values you now quote it does appear that is happening.
If you remove the glyc, the oil will still contain some soap so trying to transesterify immediatey is likely to produce yet more soap and also give a very incomplete reaction. The problem with an incomplete reaction is that it can result in soap/methanol remaining in the oil/bio and maybe not dropping out at all. More likely to happen with KOH as that tends to take longer anyway.
Due to the high amount of caustic used wit the oil, it is quite likely to go dark, most should drop out with the glyc, but the presence of pattially reacted oil in the form of mono and di glycerides will tend to keep lots of things from dropping. As you get closer to a pass, you should find the glyc drops quicker and the bio gets lighter. The final bio is still likely to be darker that you are used to though.
PS.
I went upto Father's on Teeside as planned and only been there 20 mins before getting a phone that our 10yo had collapsed and an ambulance called - he is home and seems to be none the worse - but I obviously had a change of plan and returned early.
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Is your ten year old ok, what happened bud??
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Should have been clearer in my earlier post, when I said "Just did a test sample of 17g pot and 220ml meth and I'm pretty sure I have glyc drop - but the top bio layer is very dark. I can only tell the drop out by using a torch behind the bottle. Can bio be dark as I've never had that before?" I should have said that is with the oil in my processor, NOT one of the earlier samples with the glyc wash.
I've also done a 3/27 test on that bio and it has stayed cloudy but absolutely no dropout. So a pass yes?
So what would happen if I tried to process it with 1445g pot and 18l of meth? I do demeth using a condenser which I believe will help let soaps drop when I settle?
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10yo seems fine, he spent quite some time in the swiming pool and had problems when he got out, the ambulance medics think he got too hot in the pool and lost blood pressure when he got out. An hour after he collapsed he was chatting to everyone and appeared fine, and when I got home he was back to normal - Dad can ou fix...
A cloudy 3/27 test can be due to mono and di glycerides being present so I would not class it as a pass. Continue processing for a while longer, or drop teh glyc and reprocess with a small amount of reagents.
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really glad he's fine, what a worry to get that sort of phone call...................
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10yo seems fine, he spent quite some time in the swiming pool and had problems when he got out, the ambulance medics think he got too hot in the pool and lost blood pressure when he got out. An hour after he collapsed he was chatting to everyone and appeared fine, and when I got home he was back to normal - Dad can ou fix...
A cloudy 3/27 test can be due to mono and di glycerides being present so I would not class it as a pass. Continue processing for a while longer, or drop teh glyc and reprocess with a small amount of reagents.
This was only a 1l sample but I'm tempted to process the whole lot in one go with all the chemicals on Monday and see how it comes out................
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Been following Paul, pleased your little one is ok.
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Thanks Vijay and Dave, he is fine now, doesn't like getting up in the morning so he seems back to his usual self
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so glad to hear that Paul :)
Well the batch didn't work, didn't get any glyc dropping in hours - not sure whether to laugh or cry right now lol
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gonna try some sample tests I guess, maybe 2g potassium with 50ml meth?
Well no glyc droped, so up the potassium or meth or both?
Tried 5g pot and 50ml meth and got a small amount of bio on top (like maybe 5%). Any idea which ingredient to change?
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Titrate the "oil" and see what figure you get. If the oil is already akaline then I would assume enough caustic is present and add just methanol - probably another 50m.l If it comes out as still acidic then treat as fresh oil with that titration figure. There may be an area in the middle where it is caustic but not enough to react - in this case I would add 50mlf methanol with 5g of KOH.
Potassium is well known for taking longer to settle out you may have to leave it a few days (though the warm weather may help).
If you have lots of soap it may also take longer for the glyc to drop - one possible approach is to add more glyc to see if that triggers better separation.
Others may give you better directions as I have not used KOH for bio.
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I've tried 5g and 50ml and got about5% bio on top.
I thought it was soaps that took a while to drop with KOH, didn't realise it was for glycerol too
I'm currently trying 5g and 50ml. I'll titrate after seeing how that works ;)
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How much oil is in this test Vijay?
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How much oil is in this test Vijay?
1l sample tests
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No Wonder there was no reaction on stage 1 with only 2gms of KOH. If your oil was average titration (say 3 to 4) then you would need a total of 11 to 12gms of KOH to achieve full conversion. Base for KOH is 8.
Also why the shortfall of Methanol, you have only used 5% You need at least 14% in stage 1 to get anywhere.
Why don't you try another litre of oil and add 10 gms KOH in 140mls of methanol, bet you get good conversion then and glyc will drop a lot sooner.
Wish I was there with you, I'de soon sort out that lot for you.
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No Wonder there was no reaction on stage 1 with only 2gms of KOH. If your oil was average titration (say 3 to 4) then you would need a total of 11 to 12gms of KOH to achieve full conversion. Base for KOH is 8.
Also why the shortfall of Methanol, you have only used 5% You need at least 14% in stage 1 to get anywhere.
Why don't you try another litre of oil and add 10 gms KOH in 140mls of methanol, bet you get good conversion then and glyc will drop a lot sooner.
Wish I was there with you, I'de soon sort out that lot for you.
This is 85l of oil I've already tried to process with 1360g koh and 18l meth. The gylc didn't drop. So today I have been trying to get 1l samples to convert by adding methoxide of different mixes
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Ah, ok with you now. Sounds as though your batch needs 'seeding' with more glycerol. Heat it and add more glyc as you are pumping it , usually works ok.
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Ah, ok with you now. Sounds as though your batch needs 'seeding' with more glycerol. Heat it and add more glyc as you are pumping it , usually works ok.
I can try that tomorrow. How much glyc to 85l would you suggest bud and pump for how long??
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Heat it to 50ish, add as much glyc as you can, mix for half an hour, let it settle and see what you get out.
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on now and will let it settle overnight
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on now and will let it settle overnight
Good lad!
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I put some of the glycerol mixed batch into some bottles last night and it looks like the glycerol has dropped and left semi dark bio on top. Will do a 27/3 test shortly and hopefully be able to drop the glyc in the processor
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slight dropout on the 27/3 test but I'm not worried about that as the car is a veg runner anyway.
Separating the glycerol has been a little fun with dark bio but the main thing is I have bio - happy days!!! :)
So how did you know adding old glycerol would drag down the new glycerol, just experience?
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Both experience and logic! The main reason for the glycerol not to drop is likely to be the presence of soap basically not allowing enough small globules of glycerol to amalgamate and drop. Adding more glycerol and mixing for a while will result in more globules which amalgamate with each other and dropout bringing the soap with them - at least thats my theory.
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did you just make that up lol it's a good theory and it seems to have worked for me :) :) :) It's actually a good easy thing to try though and something I'll no doubt try when I attack the other failed batches ;)
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did you just make that up lol it's a good theory and it seems to have worked for me :) :) :) It's actually a good easy thing to try though and something I'll no doubt try when I attack the other failed batches ;)
Not entirely, I remember from my undergrad days that changing the zeta potential can result in precipitation within colloidal chemistry. It has also been disscussed, quite a while back, that applying a high voltage across the bio diesel mix can significant accelerate the glycerine drop out. Whilst not the same situation it sems a reasonable analogy
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I seem to remember a post about electricity and making bio......
I just love the knowledge on here! :)
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slight dropout on the 27/3 test but I'm not worried about that as the car is a veg runner anyway.
Separating the glycerol has been a little fun with dark bio but the main thing is I have bio - happy days!!! :)
So how did you know adding old glycerol would drag down the new glycerol, just experience?
Yes, I've recovered lots of batches for people using glycerol.
Look at this one; a quote from someone on the facebook group.
It worked! You're a bloody genius! I used 20 litres of good stage 2 glycerol, and got around 35 litres back out 😁 going to bubble it for a couple of days. Thank you David
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Massive thank you to everyone who helped me get through this batch. Got just under 60l of bio out of an 85l batch in the end, so I'm happy.
Bit more of crappy oil to get through but fingers crossed it'll be easier
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Thats great, well done.
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Moved back onto the previous batch that went wrong. IIRC it titrated at 8 so added 1200g Naoh and 18l meth. No glycerol dropped. So today I got everything back into the processor with extra glycerol, mixed for 30 mins at 50c and took a sample. No glyc has dropped. Where do I go from here with this batch?
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I would titrate what you have in your processor and see whether it still appears acidic or is now alkaline. Assuming the latter, take a 1L sample and try a dr pepper test on it. I assume it was an 85L batch and base of 6 so 14g/L of NaOH.
Have you any more glycerine you could add and how much did you add?
You should try a 27/3 test even if the glyc has not dropped, that way the amout of conversion can be estimated and if very low gives an idea of what has gone wrong.
For the Dr pepper I would try 50g NaOH and 100ml Methanol - but I suggest posting the details of your glycerine first.
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Moved back onto the previous batch that went wrong. IIRC it titrated at 8 so added 1200g Naoh and 18l meth. No glycerol dropped. So today I got everything back into the processor with extra glycerol, mixed for 30 mins at 50c and took a sample. No glyc has dropped. Where do I go from here with this batch?
How much extra glycerol did you add.
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Just titrated at 3.
I added approx 40l of old glycerol back in. Yes I have more.
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Just titrated at 3.
I added approx 40l of old glycerol back in. Yes I have more.
Strange, you have run off more glycerol than you added proving some reaction has taken place. Yet your resultant mix is still acidic.
If I were you I would do an accurate 10/90 to see exactly how much chemical to add.
Have we established that you have a 10/90 tube, if not i can give you details of how to meke one out of an old syringe and a 500ml coke bottle.
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done a 27/3 test but only got a straight graduated flask. Funnily enough I was just trying to find the name of the graduated cone ones that I've seen some of you guys use. What are they called?
Happy to knock one up if you tell me how
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done a 27/3 test but only got a straight graduated flask. Funnily enough I was just trying to find the name of the graduated cone ones that I've seen some of you guys use. What are they called?
Happy to knock one up if you tell me how
i do keep the proper astm tibes in stock but a poor mans version is ----
glue the body of a 5ml or 10ml syringe into the top of a 500 ml coke bottle or similar. Block up the syringe tip outlet. mark 300mls on the side of the bottle with it upright. To use, measure 30 mls of sample into the bottle, top up to 300mls with methanol. Screw on the top, give it a good shake and retutn to its upside down position, wait for the result, residue will appear in calibrated portion of syringe body. test is 30/270 ratio so 10 times more accurate than 3/27/
https://imakebiodiesel.webs.com/apps/photos/album?albumid=13499644
Look at conversion tester on the photo's.
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how much are they mate?
I only have 3 or 60ml syringes so will look at making something up with that
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On the titration I did earlier, it went clear after a while, so I added more fluid and it stayed purple at 5
No dropout on the 27/3 test earlier and the later 270/30 test
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How old is your titration solution? Did you blank the solvent before adding the oil/bio? A titration of 3 is very strange especially as the conversion appears nearly complete - or totally incomplete if there is a colourless layer above the oil!
Under normal circumstances if you leave a titrated sample alone it will slowly saponify using up the NaOH so the solution might go clear depending on the indicator you used.
The bio in the samples does not appear completly clear, is that just due to the photographs or does it appear cloudy when viewed directy?
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Titration fluid is only a few weeks old
Blank the solvent??
The earlier 27/3 test does appear cloudy, but I had this with the ones I did on the previous nightmare batch, which went clear later on.
On the 270/30, the mix in the bottle part looks cloudy but the syringe is clear, I can read the markings easily through the syringe
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Titration fluid is only a few weeks old
Blank the solvent??
The earlier 27/3 test does appear cloudy, but I had this with the ones I did on the previous nightmare batch, which went clear later on.
On the 270/30, the mix in the bottle part looks cloudy but the syringe is clear, I can read the markings easily through the syringe
Leave it until the methanol phase is clear, then check it. Tubes are £38
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If you are using IPA as the solvent for titration it canbe acidic. Normal practice is to therefore put the solvent in the container to be used for the titration, add the indicator and titrate untl you just get a colour change that way you know there is no acid left from the solvent. You then add the oil which will normally change the colour back before carrying out the titration of the oil.
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Titration fluid is only a few weeks old
Blank the solvent??
The earlier 27/3 test does appear cloudy, but I had this with the ones I did on the previous nightmare batch, which went clear later on.
On the 270/30, the mix in the bottle part looks cloudy but the syringe is clear, I can read the markings easily through the syringe
Leave it until the methanol phase is clear, then check it. Tubes are £38
Will do.
What size are they? Do they do 90/10 or larger?
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If you are using IPA as the solvent for titration it canbe acidic. Normal practice is to therefore put the solvent in the container to be used for the titration, add the indicator and titrate untl you just get a colour change that way you know there is no acid left from the solvent. You then add the oil which will normally change the colour back before carrying out the titration of the oil.
I do use IPA but have never blanked the solvent in the past but can do if you think it would help?
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You can get separating funnels that are larger but they don't have the graduations where we need them, so 10/90 is what we use.
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If you are using IPA as the solvent for titration it canbe acidic. Normal practice is to therefore put the solvent in the container to be used for the titration, add the indicator and titrate untl you just get a colour change that way you know there is no acid left from the solvent. You then add the oil which will normally change the colour back before carrying out the titration of the oil.
Why would putting the ipa in the container to be used for the titration make it go alkaline Paul. Unless we make it alkaline we can't titrate to blank it?
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If you are using IPA as the solvent for titration it canbe acidic. Normal practice is to therefore put the solvent in the container to be used for the titration, add the indicator and titrate untl you just get a colour change that way you know there is no acid left from the solvent. You then add the oil which will normally change the colour back before carrying out the titration of the oil.
Why would putting the ipa in the container to be used for the titration make it go alkaline Paul. Unless we make it alkaline we can't titrate to blank it?
Maybe a confusing use of the word container. I normaly use a concical flask for titrations, but I thought that may not be used by everone. Just putting the IPA in the container would not make it go alkaline (unless it was contaminated).
What I meant was put the IPA you normally use into the conical flask (or whatever you use) add the indicator and then neutralise any acid present in the IPA by adding alkali as similar to normal when titrating. As soon as the indicator changes colour stop then add the oil and titrate as normal, much as suggested: https://biopowered.co.uk/wiki/Titration
I was merely highlighting that IPA can often be acidic so neutralising it before adding the oil will give a more accurate titration figure for the oil.
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Left the 270/30 test overnight but found that some of the unconverted oil was kinda sitting in the lid (where I wouldn't get it in a proper coned flask). I kept tapping it and gently turning the bottle allowing anything to hopefully sink into the syringe. So it looks like I've ended up with 0.3ml at the bottom. I'd assume this is a good conversion, so how come no glyc?
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Left the 270/30 test overnight but found that some of the unconverted oil was kinda sitting in the lid (where I wouldn't get it in a proper coned flask). I kept tapping it and gently turning the bottle allowing anything to hopefully sink into the syringe. So it looks like I've ended up with 0.3ml at the bottom. I'd assume this is a good conversion, so how come no glyc?
besause you have used biodiesel so although there will be glyc (a small amount, max about 0.3%) in the bio it dissolves in the methanol so invisible to the test.
Yes, well done its a good conversion.
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Left the 270/30 test overnight but found that some of the unconverted oil was kinda sitting in the lid (where I wouldn't get it in a proper coned flask). I kept tapping it and gently turning the bottle allowing anything to hopefully sink into the syringe. So it looks like I've ended up with 0.3ml at the bottom. I'd assume this is a good conversion, so how come no glyc?
besause you have used biodiesel so although there will be glyc (a small amount, max about 0.3%) in the bio it dissolves in the methanol so invisible to the test.
Yes, well done its a good conversion.
Great :) So where's all the glyc and how do I get it out lol No glyc dropped when I did the batch and then I added an extra 40l or so more glycerol - but nothing has dropped.....................
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I'm confused here, on post No 56 you reported that the glyc had dropped.
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I'm confused here, on post No 56 you reported that the glyc had dropped.
Post 64 mate lol "Moved back onto the previous batch that went wrong. IIRC it titrated at 8 so added 1200g Naoh and 18l meth. No glycerol dropped. So today I got everything back into the processor with extra glycerol, mixed for 30 mins at 50c and took a sample. No glyc has dropped. Where do I go from here with this batch?"
As the advice worked for the batch I posted about, I tried the same advice for the previous batch that had failed (no glyc dropped). The 27/3 and 270/30 test pictures I posted are from this batch which I have not been able to drop glyc from.
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So just to make sure we all have the correct understanding, this is the last but one batch that went wrong. You had 85L of oil that titrated at 8 so added 1200g Naoh and 18l meth. There was not glycerol dropout you you added 40L more glycerol and still not dropout but testing it gives what you are showing in you home made 10/90 or 30/270 tube?
If so that makes very little sense to me. You basically have about 80L of bio that should have about 60L of glycerol in it, yet there is next to nothing in the tube but no glycerol has dropped out?
Are you sure you added the oil from the failed batch and not the bio from the last batch? Are you sure you tested the mix from the failed batch and not the bio from the successful batch? Sorry for the questions, but the evidence doesn't all appear consistent to me.
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So just to make sure we all have the correct understanding, this is the last but one batch that went wrong. You had 85L of oil that titrated at 8 so added 1200g Naoh and 18l meth. There was not glycerol dropout you you added 40L more glycerol and still not dropout but testing it gives what you are showing in you home made 10/90 or 30/270 tube?
If so that makes very little sense to me. You basically have about 80L of bio that should have about 60L of glycerol in it, yet there is next to nothing in the tube but no glycerol has dropped out?
Are you sure you added the oil from the failed batch and not the bio from the last batch? Are you sure you tested the mix from the failed batch and not the bio from the successful batch? Sorry for the questions, but the evidence doesn't all appear consistent to me.
Yep absolutely correct.
I'm 100% certain that it's the batch I made in the last but one. It was labelled up and put in a shed out of the way when I removed it from my processor.
100% certain it's not the bio I made in the last batch. That is sitting in a settling tank
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is it worth trying more glyc? maybe do a sample with more glyc?
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I think a sample test is the best way to proceed. Since the mix you have should be about 4:3 bio to gylc, I would start with 1L mix and add 100ml glyc, if nothing happens try adding another 100ml.
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I think a sample test is the best way to proceed. Since the mix you have should be about 4:3 bio to gylc, I would start with 1L mix and add 100ml glyc, if nothing happens try adding another 100ml.
Doing 1l with 100ml right now. Does it make a difference how much glyc goes in though or is it just what I can get in the processor? I just wondered if there is a "too much" as wouldn't it just drop? (hopefully lol)
After half hour, I've a small amount of bio settled on top. Happy to leave it settling or more glyc?
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If glyc does drop out when you add 100ml to 1L of mix, check how much. If you only get about 100ml of glyc out then that would suggest that there is not much more in there. If you get 400ml out, then you know theres enough to cause almost all the glyc to dropout, if yu get no dropout, we will have figure what is happening...
If you leave the dropped glyc to settle further you will usually find a layer of bio forms on top, this can continue over a period of weeks or even months!
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this is after about half hour
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I have a horrible suspicion that the initial processing has resulted in a significant amount of you oil being converted to soap and glycerol and that whay little bio you produced has been kept in the glycerol as a result the glycerol has not appeared to drop because there was so little bio free to form the top layer. Adding the extra glycerol now has pushed things a little further in terms of freeing the bio from the soap and allowing a layer to clearly form on the top.
I would give it a few hours to settle further and see if the bio layer becomes much larger.
Normal rules suggest you added 18L of methanol and you would get out about 18L of glcyerol. You added 40L of glycerol do you would have roughtly 80L oil/Bio and 60L glycerol. So roughly 560ml Bio and 420ml glycerol in the 1L sample to which you added 100ml glycerol so 560ml Bio and 520ml glycerol. Given the titration figures of 8 would have resulted in soap plus losses from saponification of some oil/bio due to water etc. you are probably looking for a 50/50 split between bio and glycerol at best.
So far I think you have 12-15% bio.
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it's looking like you could be correct. Unless there's anything else I can try, guess all I can do with this is separate it out by adding more glyc, then keep the bio and demeth it with my next batch.
So would this have been caused by water in the oil or too much catalyst? Are there are any other reasons for excess soap?
It was the not very nice oil but I did about 4-5 glyc washes on it and thought it would be ok. What could I do better for next time, dewater though the condensor? Use Koh?
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If this titrated very high after the glyc wash then the presence of the FFA would cause the formation of soap and water.
Each 1g of NaOH would give about 0.5g of water, so if it was an 80L batch titrating at 8 you would get 320g of water.
Each 1g of NaOH would also produce about 8g of soap, so it 80L batch at 8 would give you about 5 Kg of soap !!!
This is why the glyc wash and in the case where there is insufficient glyc to neutralise all the FFA, Dave's enhanced glyc wash (with added caustic) is so beneficial as it neutralises the FFA, and absorbs the water and soap into the glyc. You are then just reacting the good oil with the base amount of caustic and not worrying about the excess soap/water created causing severe problems.
The glyc you have will probably be hold a significant amount of bio, you could try a few experiments to see if anything can free that bio.
I suggest:
1) 1L glyc and add say 250ml water
2) 1L glyc and add say 100l glyc
2) 1L glyc and add say 50ml methanol
3) 1L glyc and add say 50ml good clean veg oil
See if any of those cause any bio (or bio/oil) to be released, I've suggested quanties to add to the glyc, but these are pure guesses, you might want to try doubling or even quadrupling the quantities so see if anything works.
Heating the glyc up to distill off all the methanol and water might also work to release some bio but is obviously somewhat more hazardous and it might not work!
Dave or someone else might have some other suggestions.
PS
I've assumed your none too keen on messing with sulpuric acid.
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The best way to extract tied up bio and chems in the glycerol is to glyc wash with it. the bio certainly stays with the oil in preference to staying with the glyc. each 20 litre cubie of glycerol (with a 'normal' process ) contains about 5 litres of bio. Reclaiming this is the main reason why we see the increase in volume of the oil after glyc washing. For every litre of soap made whilst processing it takes 2 litres of bio with it into the glycerol. The soap level in the glycerol is around 15%
just going back to the enhanced glycerol prewash method. Some years ago on here someone was using oil that titrated at 10. They were getting 68 litres of bio from 100 litres of oil. I outlined the method to them which they tried, the result was 88 litres of bio.
I've found the old thread in my bookmarks, look at post No 16 to save you time.https://biopowered.co.uk/forum/index.php?topic=2409.0
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Just been re-reading this with enthusiasm and wanted to chime in and say thanks!
Trying to get my process more efficient so learning all I can about the enhanced glyc wash.
I've already managed to get my glyc down by about 20% by enhancing with about 2g/l on my 5.5 titrating oil (using koh)