Biopowered - vegetable oil and biodiesel forum
Biodiesel => Chemistry and process => Topic started by: Julian on November 23, 2012, 10:55:58 PM
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OK ... Think it's time to come out of the shadows and divulge one of the much speculated "secret" methods I've tried.
This is Paul's (Carrington's) idea so I take no credit for it's merit or otherwise.
I have to say at the outset that the process involves operations I consider potentially dangerous, and I'd recommend that it is not tried unless you are careful, knowledgeable of chemicals (especially acids) and use the required personal protection equipment.
I'm not putting myself forward as particularly careful and certainly not knowledgeable about chemistry, but I did seek third party advise from a friend who has a PhD in chemistry and survived to tell the tail.
The method is very similar to Paul's titrated acid wash method, except it uses no water. Paul believes that there is a chance this method may prevent the formation of HMPEs.
The sequence is as follows ...
Process normally to a 3/27 pass, by whatever method you choose.
Allow Glycerol at least 8 hours to settle then drain.
(By draining the lower pipe work I managed to settle over 24hrs, draining several times)
Titrate to quantify acid requirement ... probably a bit of a mix with the pump before hand will collect glycerine off the processor walls and give a more representative result. I believe a concentrated acid is required to eliminate as much water as possible.
Add acid to Methanol, the acid being circa 20% of Methanol quantity.
(This is the dangerous bit! I used roughly double the Methanol quantity, believing it to be slightly less hazardous. The reaction is highly exothermic and the acid should be added very slowly. I did so using a pipette, but even then an audible fizzing and gluping was noticed if more than a few drops were added at one time.
Add "Methacid" to processor and mix, say 20 mins
(My plan was to introduce the "Methacid" via the venturi, but again I had concerns about this. There were pockets where the "Methacid" could come into contact with copper and brass and not have a chance to get washed away by the bio. So I decanted bio from the sample point and added small quantities of the "Methacid" to the bio and entrained that into the processor via the venturi and all went well)
Demeth the bio.
( I usually WBD, but as the bio had cooled to around 20°C, the glycerin had been removed and there's the school of thought that WBD can promote HMPEs, I decided to bubble the Methanol out. So I added Coldflow, mixed and pumped out.)
Pump to settling tank.
(I bubbled for 24 hrs to remove Methanol)
Settle for X days as you see fit.
(After a week the bio was still cloudy, but gave the best 50/50 test I've ever seen. A test with litmus paper showed a pH of around 7. To remove the cloudiness I returned the bio to the processor and distilled out about 2 litres of Methanol ... unless for prolonged periods, bubbling is obviously only good at removing residual Methanol)
I've still to get a controller for the redundant freezer and run chilling tests, but I'll stick a sample in the kitchen freezer and report results.
I have to say that, having tried it, unless it returns startling results in the way of HMPE reduction, I'll not be trying the process again ... I found it rather scary! That said, many thanks to Paul for hitting on another variation of the process, these things have to be tried, let's hope it has some effect on HMPEs ... watch this space!
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The mixing sounds scary, I'm not doing another batch just yet but may well try this in conjunction with water washing.
I need to get some acid first though.
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Be very careful Mark. I couldn't bear it if any thing happened to you ... before you've returned my concrete mixer.
Unless it yields a reduction in HMPEs, there's little to be gained by this method and quite a lot to loose! I recon Paul's titrated acid wash is much safer, works brilliantly and we've proved water washing reduces HMPEs (some claim it eradicates them). If you haven't tried that yet it's well worth a go.
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Providing this method has some substance would it not be more prudent to add the acid directly into the methanol by having the tip of the pipette under the surface of the methanol instead of adding dropwise to the surface.
Nige
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Julian, I've been doing the titrated water wash for a while now and getting on very well with it.
But I'm happy to to do some testing if we can move things forward even further.
I'm using brick cleaner (34% hydrochloric) for the water washing but will need some 99% stuff for these tests.
Nige, I'm thinking of rigging up a small funnel and some small bore air line pipe,
this way the acid could be added from a safe distance and the end of the pipe can be below the surface of the meths.
Would there be a benefit from making up a large batch, say 10 or 15 Liters, and decanting the required amount for each reaction.
The acid could be added a small amount at a time over a few days allowing the mix to cool and stabilise between doses.
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It sounds like a lot of complication and feckin about to me, unless you can affect the structure of the chain length/carbon bonds to make shorter/bent chains then even with the best feedstock you are gonna get HMPE's when it gets near to, or drops below freezing.
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The idea of immersing the pipette or tube in the Methanol, doesn't sound like a good one to me.
If there's even a remote chance of the Methanol migrating up the tube, the reaction might be quite violent. I'm thinking about the issue of adding acid to water rather than the otherway round.
I know the acid is denser than Methanol but it's still a risk. One time when cleaning up after a titrated acid wash, I ran water from the tap into a very small amount of conc Sulfuric, thinking it was Methanol, and the reaction was quite startling. Luckily because it was running water from the tap, the volume quelled the reaction quite quickly, but it certainly taught me a lesson.
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The idea of immersing the pipette or tube in the Methanol, doesn't sound like a good one to me.
If there's even a remote chance of the Methanol migrating up the tube, the reaction might be quite violent. I'm thinking about the issue of adding acid to water rather than the otherway round.
I know the acid is denser than Methanol but it's still a risk. One time when cleaning up after a titrated acid wash, I ran water from the tap into a very small amount of conc Sulfuric, thinking it was Methanol, and the reaction was quite startling. Luckily because it was running water from the tap, the volume quelled the reaction quite quickly, but it certainly taught me a lesson.
Very good point Julian, if it did this with my idea it could spit acid out of the funnel.
But as long as the end of the pipe is above the meths level so it's drop feeds it should be ok, what do you think.
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The idea of immersing the pipette or tube in the Methanol, doesn't sound like a good one to me.
If there's even a remote chance of the Methanol migrating up the tube, the reaction might be quite violent. I'm thinking about the issue of adding acid to water rather than the otherway round.
I know the acid is denser than Methanol but it's still a risk. One time when cleaning up after a titrated acid wash, I ran water from the tap into a very small amount of conc Sulfuric, thinking it was Methanol, and the reaction was quite startling. Luckily because it was running water from the tap, the volume quelled the reaction quite quickly, but it certainly taught me a lesson.
Very good point Julian, if it did this with my idea it could spit acid out of the funnel.
But as long as the end of the pipe is above the meths level so it's drop feeds it should be ok, what do you think.
Just wish I'd paid more attention to Chemistry when at school! I know what I did worked, you just need to take things easy and carefully. I was using a 3ml pipette, adding two or three drops at a time and giving the flask a gentle mix to ensure the acid was dispersed.
I recon a small volume in a pipette is probably safer than the whole quantity in a funnel. If anything goes wrong, the whole volume dumping into the methanol at one time wouldn't be good!
Keep it simple and take your time.
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I never took any notice in chemistry either,
I know mixing acid and base wasn't good,
and phenolphthalein could give you serious runs,
but apart from that playing with bunson burners was fun.
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Would there be a benefit from making up a large batch, say 10 or 15 Liters, and decanting the required amount for each reaction.
The acid could be added a small amount at a time over a few days allowing the mix to cool and stabilise between doses.
Sorry, missed this bit! I'd say no. The concentration will vary batch to batch and it's nasty stuff to have hanging around. Probably better to keep the acid in a comparatively small glass container in a safe place.
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Julian, I've been doing the titrated water wash for a while now and getting on very well with it.
But I'm happy to to do some testing if we can move things forward even further.
I'm using brick cleaner (34% hydrochloric) for the water washing but will need some 99% stuff for these tests.
Nige, I'm thinking of rigging up a small funnel and some small bore air line pipe,
this way the acid could be added from a safe distance and the end of the pipe can be below the surface of the meths.
Would there be a benefit from making up a large batch, say 10 or 15 Liters, and decanting the required amount for each reaction.
The acid could be added a small amount at a time over a few days allowing the mix to cool and stabilise between doses.
34% is the highest concentration you can get with hydrochloric acid. any higher and it it is a gas, according to Wikipedia, just in case you thought i might know what i am talking about. :D
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Julian, I've been doing the titrated water wash for a while now and getting on very well with it.
But I'm happy to to do some testing if we can move things forward even further.
I'm using brick cleaner (34% hydrochloric) for the water washing but will need some 99% stuff for these tests.
Nige, I'm thinking of rigging up a small funnel and some small bore air line pipe,
this way the acid could be added from a safe distance and the end of the pipe can be below the surface of the meths.
Would there be a benefit from making up a large batch, say 10 or 15 Liters, and decanting the required amount for each reaction.
The acid could be added a small amount at a time over a few days allowing the mix to cool and stabilise between doses.
34% is the highest concentration you can get with hydrochloric acid. any higher and it it is a gas, according to Wikipedia, just in case you thought i might know what i am talking about. :D
That would explain why I get a vissable vapor gassing off when the container is opened,
it spooked me the first time I opened it.
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The only problem I see with adding Conc sulphuric (or hydrochloric) acid to methanol as opposed to water is that the boiling point of the methanol is much lower (65C as opposed to 100C) so the mixture is more prone to boiling and therefore spitting everywhere (and liberating flammable vapour as opposed to steam)
I quite happily add 500ml of 96% sulphuric acid to 20 litres of water in a 25 litre carboy for my acid washes with no problem. I just measure the acid into a plastic jug (from the 25 litre carboy I received it in) and then slowly pour that (via a plastic funnel) into the top of the water container.
Then I swill out the jug with some cold water and pour that in as well.
I would be quite happy to do the same with methanol personally, I just dont really see the point.
As it stands with the water method, after draining off the water from the washes you just need to dry the bio by your chosen means, liberating clouds of steam to the atmosphere (harmless) or condensing it into distilled water. Also the water is, depending on whether you have a meter or not, either free or very very cheap. Methanol is the best part of 50p per litre!
The method also means that any residual sodium sulphate (or the salt of whatever acid you happen to use) is washed out,
With the 'meth acid' process, you need to either drive off the methanol to the air (not very enviromentally friendly and potentially flammable) or condense it.
Also, you then need to settle the bio to let anything settle out (which hopefully the salts will but what if they dont?). That means an extra settling stage that is not needed with the water wash method.
Peronally, whilst I would be happy mixing the chemicals, I wont be trying this method as :
1. I am happy with the titrated water process
2. I have given away my condenser so could not condense the methanol and dont fancy wasting it to the air.
3. Dont have the room in my new layout for an extra settling tank of 300+ litre capacity
I am certainly not criticising Paul's work in any way, he really is a true pioneer and a gent for sharing his methods with us, I just dont think this is a particularly realistic process for home users.
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Hi all
A agree with all the comments about mixing the acid and meth and yes it does carry more hazards than the water wash.
The reason I used this way in the factory was so I could reclaim the meth and not have it contaminated with water. Also when going over to dry wash filter any sodium sulphate created is much easer to filter out or settle. This way I could go straight into filtering after de-meth and the filters would last many many times longer.
I look forward to see how this turns out but can understand why people may not choose to go down this route.
Paul
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I've finally got round to sticking the samples in the freezer. Not a scientific test at all as it's just one batch and not chilled in increments as I did for the HMPE water washing tests and there are no control samples.
BUT, the samples have been sitting for three days at -18°C and are still at least 50% liquid! I have to say that's the best cold weather fuel I've produced.
(http://www.palmergroup.co.uk/Bio/Methacid samples.JPG)
Sample on the right is straight bio, The one on the left has Cold Flow added.
They are thawing as I post ... I'll report any sediments (possible HMPEs) if they occur, but in my opinion the bio should be chilled slowly over a long period to be a fair test.
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Hi Julian
I can't see the pick's but will take your word for the quality of winter bio.
To make things easer to mix I'm getting some anhydrouse powdered sulphuric acid in January so will see how it mixes with meth and if it goes well I will send some out for trials.
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I've finally got round to sticking the samples in the freezer. Not a scientific test at all as it's just one batch and not chilled in increments as I did for the HMPE water washing tests and there are no control samples.
BUT, the samples have been sitting for three days at -18°C and are still at least 50% liquid! I have to say that's the best cold weather fuel I've produced.
(http://www.palmergroup.co.uk/Bio/Methacid samples.JPG)
Sample on the right is straight bio, The one on the left has Cold Flow added.
They are thawing as I post ... I'll report any sediments (possible HMPEs) if they occur, but in my opinion the bio should be chilled slowly over a long period to be a fair test.
Are you saying the one on the right which is more bio and less whites is the non treated fuel ?
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Hi Julian
I can't see the pick's but will take your word for the quality of winter bio.
To make things easer to mix I'm getting some anhydrouse powdered sulphuric acid in January so will see how it mixes with meth and if it goes well I will send some out for trials.
Strange you can't see the photo, try this link http://www.palmergroup.co.uk/Bio/Methacid%20samples.JPG
The powdered sulphuric sound interesting, but if it's equally as strong, won't it behave in the same way?
To make any tests meaningful, we really need samples from several people along with controls. If we can achieve that, I'll buy a controller for the freezer and replicate the chilling tests. I think it would be a good idea to try and run tests on your titrated acid wash too. Far more people are using that method and I'm sure most wouldn't mind mailing a sample or two.
The samples have thawed now. The non treated sample is clear with no apparent drop out. The Cold Flow sample has a very small amount of precipitate, but it went cloudy when treated. So I'm guessing the freezing has some how made the cloudiness drop out.
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I've finally got round to sticking the samples in the freezer. Not a scientific test at all as it's just one batch and not chilled in increments as I did for the HMPE water washing tests and there are no control samples.
BUT, the samples have been sitting for three days at -18°C and are still at least 50% liquid! I have to say that's the best cold weather fuel I've produced.
(http://www.palmergroup.co.uk/Bio/Methacid samples.JPG)
Sample on the right is straight bio, The one on the left has Cold Flow added.
They are thawing as I post ... I'll report any sediments (possible HMPEs) if they occur, but in my opinion the bio should be chilled slowly over a long period to be a fair test.
Are you saying the one on the right which is more bio and less whites is the non treated fuel ?
Yup. I think the photo might be a bit misleading, when they came out of the freezer, they looked pretty similar. The treated bio was slightly clearer when frozen (it wasn't at ambient).
For the first couple of days the wax dropout would move quite freely when the jars were tilted. I think they may have compacted slightly as they were fairly solid today.
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Carrington is probably using a mobile device. Julian's hosting breaks images for mobile devices. His avatar doesn't show either on my mobile for the same reason.
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Hi Julian
If I get the powder mixes well with the meth which I realy believe it will then I will see who wants to do the trials and send out the powder so we are all working with the same product , this should give us more accurate results and also make the procedure more straight forward in the future for all.
Still can't see the picks but in my head the one with the cold flow looks a bit grim and the one processed in the new crazy way looks fab (but I could be wrong).
I should take delivery of the powdered sulphuric on jan 4th so will get on it ASAP
Paul
Yes on mobile so this is why I'm not able to see picks
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I've just emailed you the photo ... sadly it's not quite what you were envisaging!
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Am I right in seeing that the pot with the coldflow, has got almost twice as much lard in the bottom as the pot without the coldflow???
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Am I right in seeing that the pot with the coldflow, has got almost twice as much lard in the bottom as the pot without the coldflow???
See my post above.
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Carrington is probably using a mobile device. Julian's hosting breaks images for mobile devices. His avatar doesn't show either on my mobile for the same reason.
Thanks, Tony. Not sure what "breaking images" is but is there anything I can do to change that in my hosting control panel?
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Cheers Julian just got the mail
So if I get this right the one on the left which looks to have more whites is the one with cold flow , but they where taken out from the freezer they both where about the same.
If this is right then maybe -18 is just to cold for both but as they warm the the untreated is returning to normal at a lower temp. Can I give you a ring tomorrow just so I can get things straight in my head
Paul
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Yes, no problem, but like I said I think the photo's misleading ... I had been tipping the jars to see how solid the wax was. I was more impressed with the clear bio above!
I'll put them back in the freezer for a couple of days and take more care with the photo.
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Julian
A big thanks for another great thread! That's what we're interested in, pushing the boundaries of what we currently think we know.
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Not my idea ... Paul (Carrington) should take any credit, I just followed instructions and, after a quick change of skiddies, wrote it up.
We really need more samples and controls to determin if there's any merit in the process.
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You want a litre of fuel down? My last batch was rushed a bit, cos a mate was coming to pick up my plant and take it up North to convert all of the oil he's stored up.
But it should be okay.
I could ship in a hdpe container, I could ship a litre from Steve, PJ, Andy and anyone else near that could get a litre to me. Would that help?
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Im not sending any, he takes the wee wee out of the posh bottles i bought!
Thinking about it, its better than him putting it in!
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You want a litre of fuel down? My last batch was rushed a bit, cos a mate was coming to pick up my plant and take it up North to convert all of the oil he's stored up.
But it should be okay.
I could ship in a hdpe container, I could ship a litre from Steve, PJ, Andy and anyone else near that could get a litre to me. Would that help?
Yes, very much but they would need to have made the bio with this "Methacid" method, taken a sample before adding the "Methacid" and demethed/washed (whatever their normal finishing method is) that separate to the main batch.
For shipping, you can get away with jam jars carefully wrapped on bubble wrap or just use the little "yuppie" water bottles.
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Im not sending any, he takes the wee wee out of the posh bottles i bought!
Thinking about it, its better than him putting it in!
I don't remember taking the urine ... sounds most unlike me. I do remember being surprised at you extravagance and deeply impressed by your seemingly immense wealth.
I even cleaned the labeling off and stored the things for several months returning them to you at Chugs ... there's gratitude for you!
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So would vinegar neutralised with 50 / 50 test - pump washed be up to the standard? If so, I could send a couple of samples in yuppie bottles.
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I think there would be a lot of merit in testing the titrated acid wash in due course, but currently we are looking to test the "Methacid" method which may be better at winterising.
I spoke to Paul this evening and he's looking at obtaining a dry chemical, which might be less onerous to use, but I'll leave him to fill in the details.
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No worries! Thanks mate, look forward to hearing from PC
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Hi all
I'm getting some dry acid in the new year that I think may mix better with methanol so if you are interested in testing the dry wash meth acid process let me know and I will get some out to you with instruction' of what we are hoping to achieve.
Paul
Ps will elaborate more when time allows
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I'd like to give it a go Paul.
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i would also like to give this a try to see the out come
willaim
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All good stuff, If we can get several people involved I'll run similar chill tests as I did before. The new temperature controller should be winging it's way from China right now!
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Morning all
Picked up my dry acid product yesterday so after I do some test to make sure it's easy to use I will be a le to send some out to people for trials.
Also got some acertone so will start doing some tests with that.
Paul
I may be snowed in the unit for sometime
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My temperature controller has been delivered, so all ready to go with chilling tests too.
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Cool let the games begin
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I hope that was intended to be a pun.
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Being a newbie to this Forum I've been catching up on old posts. Instead of adding acid to methanol, add the methanol to the oil, mix and while mixing slowly pour in the acid. It's a lot safer.
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No oil at this stage it's a method for neutralising soap in bio.
The methanol is used as a carrier for the acid. I'm not sufficiently knowledgeable to say if adding neat conc. acid to bio is safe, but the method I tried with the methanol, as suggested by PC, seemed to work.
I'm sure I've read neat acid on oil will carbonise it ... would that also be the case with bio?
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Hi Julian. I'm no chemist but I've been reading up on 2 stage reactions with conc Sulphuric acid as the first stage and adding the acid after mixing in the methanol seems to be acceptable.
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Ah, are you talking about acid esterifiucation?
Having made a heated stirrer, I've been intending to have a small scale play with that, but work keeps getting in the way!
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As I'm sure a lot of you know that I am not adversed to trying new things, so well done to Julian and the guy that first tried this.
However, I am not a great lover of acid washing. The question I ask myself is why convert an unknown amount of soap to FFA's, one of the things we are trying to remove from the oil in the first place.
I realise FFA's can be a good source of fuel in the right circumstances, but in an HDI engine?
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I'm not a sufficiently good chemist to know if it makes FFA, but the sole aim of this process was to neutralise the soap in biodiesel to "something" in order to get rid of it. I believe Paul said it converted to sodium sulfate, but don't quote me on that ... there may be more info on the wiki.
As stated above, converting FFAs to usable fuel is something totally different and an area I've yet to blunder my way into! Given time I'm sure I can add it to my list of heroic failures.
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I'm not a sufficiently good chemist to know if it makes FFA, but the sole aim of this process was to neutralise the soap in biodiesel to "something" in order to get rid of it. I believe Paul said it converted to sodium sulfate, but don't quote me on that ... there may be more info on the wiki.
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I am pretty sure the soap is converted to FFA's, but on any biodiesel spec sheets I cannot find a max for FFA's in finished fuel, does anyone know?
This is the way that ion exchange works, by replacing the Na or K ion at the end of the molecule with a H ion. The ion exchange beads are coated with an acid (from memory I think it is sulphonic acid)
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Found a couple of pages which agree with your statement ... soap + acid = FFA.
This methacid wash was just an experiment to keep the bio water free and obviate drying.
Logically though, wouldn't the same thing happen with an acid/water wash? If so, would the FFAs get washed away in the water or stay in the bio?
Perhaps the standards were drawn up before the common use of dry media, hence no FFA content limits.
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Yes, an acid wash does the same thing.
I'm reasonably sure that they stay with the bio.
Maybe its not really bad, I don't know, but if a batch had been really over-chemicaled ( i know thats not a proper word) the soap level could be sky high.
One of the most efficient ways I have found of getting rid of soap is to wash the bio with pure glycerine.
This can be done preferably after de-mething and whether you water wash or not. It's expensive, but can be used many times, until it gets towards saturation. I have had the soap level of non de-methed bio down to 10ppm in the processor by using this method.
Maybe the subject of a new thread sometime.
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So acid esterification, to get shot of FFAs without forming soap in the first place could, theoretically have it's merits.
I've tended to hear more bad things about acid esterification than good.
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One of the most efficient ways I have found of getting rid of soap is to wash the bio with pure glycerine.
This can be done preferably after de-mething and whether you water wash or not. It's expensive, but can be used many times, until it gets towards saturation. I have had the soap level of non de-methed bio down to 10ppm in the processor by using this method.
Maybe the subject of a new thread sometime.
It would be most interesting to have a thread on the subject, or even a wiki page it you fancy it.
To that end I've just given you wiki editing rights!
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Found a couple of pages which agree with your statement ... soap + acid = FFA.
This methacid wash was just an experiment to keep the bio water free and obviate drying.
Logically though, wouldn't the same thing happen with an acid/water wash? If so, would the FFAs get washed away in the water or stay in the bio?
Perhaps the standards were drawn up before the common use of dry media, hence no FFA content limits.
Yet Another Innovation to BioDiesel Process, YAIBP!
Yes--Soap neutralisation will form FFA'a....
But In the presence of Methanol--the (Remaining Acid not consumed in neutralisation) will act as Catalyst and Esterify the FFA into esters.....
--As an observation/experiment--Add approx 2.5-3.5mL Extra Acid in addition to your titrated quantity per L of Biodiesel--So there's sufficient left over to Esterify the FFA liberated, and Maybe increase the yield just slightly....
The Esterification stage--when done on raw oil though is a rather long time-consuming process stage--Maybe the extra heat during the De-meth after the 'methacid' stage is sufficient to shorten this into the usual de-meth time....