Biopowered - vegetable oil and biodiesel forum
Biodiesel => Chemistry and process => Topic started by: Tony on January 08, 2013, 11:46:22 PM
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This is a wild stab in the dark type experiment.
I've dried 80l of WVO, and added my accumulation of HMPEs this winter (45l) for a grand total of 125l (sucked in via Nige's very sucky venturi - though it took a little while!).
The whole lot has been heated to 100C and a sample taken shows nice clear liquid (all HMPEs melted). I'll keep this sample to cool and sit for a few days.
I also took a sample to do a 10/90 on using one of Nathanrobos fabulous centrifuge tubes, and it couldn't confirm things better if it tried - 6.4ml of dropout from a 10ml sample. Which is exactly the ratio of HMPEs to WVO. Interestingly, and I don't know if this is significant, the liquid above the dropout was quite cloudy. Monoglycerides?
So I'm going to react it with 16l Meth (20% of 80l) and 550g NaOH (based on how the WVO titrated plus a little for luck - it is all nice and dry)!
So anyone want to take a bet on the volume of HMPEs I'll get at the end of this?
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cloudy - only see thisn when clear oil is mixed with rough stuff via a pump, like emulisified, could get the same with pure fat and clear oil, not sure...
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The layer above the dropout is mostly Methanol with a little bit of ??? in it rather than fatty/high melt oil suspended in clearer oil so could be anything.
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cloudy - only see thisn when clear oil is mixed with rough stuff via a pump, like emulisified, could get the same with pure fat and clear oil, not sure...
This is cloudy meth in the 10/90 test above the dropout, are you referring to this or to cloudy oil ?
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This is a wild stab in the dark type experiment.
I've dried 80l of WVO, and added my accumulation of HMPEs this winter (45l) for a grand total of 125l (sucked in via Nige's very sucky venturi - though it took a little while!).
The whole lot has been heated to 100C and a sample taken shows nice clear liquid (all HMPEs melted). I'll keep this sample to cool and sit for a few days.
I also took a sample to do a 10/90 on using one of Nathanrobos fabulous centrifuge tubes, and it couldn't confirm things better if it tried - 6.4ml of dropout from a 10ml sample. Which is exactly the ratio of HMPEs to WVO. Interestingly, and I don't know if this is significant, the liquid above the dropout was quite cloudy. Monoglycerides?
So I'm going to react it with 16l Meth (20% of 80l) and 550g NaOH (based on how the WVO titrated plus a little for luck - it is all nice and dry)!
So anyone want to take a bet on the volume of HMPEs I'll get at the end of this?
I'm making a guess at 45l but it would be good if it turned out to be much less. We have been meaning to do a 10/90 on Hmpe's but your results have given the answer.
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cloudy - only see thisn when clear oil is mixed with rough stuff via a pump, like emulisified, could get the same with pure fat and clear oil, not sure...
This is cloudy meth in the 10/90 test above the dropout, are you referring to this or to cloudy oil ?
oil
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I melted a little less than 10ml of HMPEs and tried to dissolve in Meth (about 90ml) a while ago and most or all of it dropped out. Now I have some meth again, I'll try to repeat and post photos.
I'm not sure that what we are calling HMPEs are High Melting Point Esters. I'm not even convinced that what we are all referring to as HMPE's are all the same substance.
I've settle fuel for some weeks outside in steel drums and then pulled into my polishing tank and centrifuged. I seem to get a consistent sized cake each time:
(http://i1030.photobucket.com/albums/y363/nathanrobo/New%20fuel%20polisher%20additive%20mixing%20and%20dispense/HMPEcake_zps894fafac.jpg)
I've put these in a glass jar and melted on top of the wood burner, then left it to settle by the side of the burner and it's gone solid again (quite firm). I find this really strange! I know that what's pulled out is concentrated, but there's nothing in my process that is this solid, the glyc is fluid, the oil is fluid, full reaction, water washed , dried bla bla bla.
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That's what I thought, liquids in, solids out? Umm?
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This is just a quick idea -
Blends can alter melting points - eg when people blend palm etsers with rape esters to get better cold temp performance.
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Might that be the case with the triglycerides also? That the feedstock, although liquid, may actually be a blend, with the higher melting point fats being kept in suspension by the others?
If so, you could imagine a scenario where part of the feedstock 'blend' gets converted, whilst part of it remains as a triglyceride?
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Nathan -
Do you have enough from your centrifuge to run a dr pepper reaction?
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Nathan -
Do you have enough from your centrifuge to run a dr pepper reaction?
Got maybe 200 grams. Can try a Dr. Pepper tomorrow.
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5 days of settling so far, and a sample from this batch is showing only a very thin layer of HMPEs at the bottom. Not done waiting yet though, got some nice cold weather coming to properly chill it (very obliging of it)!
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5 days of settling so far, and a sample from this batch is showing only a very thin layer of HMPEs at the bottom. Not done waiting yet though, got some nice cold weather coming to properly chill it (very obliging of it)!
by observation, the fuel that produced the HMPEs in the picture had settled for some weeks, but didn't have detectable HMPE's. When I pulled the fuel out of it's drum and into my new polish / dispense tank, it got sucked in through about 20 feet of clear reinforced 3/4" hose. The hose pulled from the bottom of the tank and if there were HMPE's that had settled out it would have gone white or at least cloudy in appearance and then clear. This didn't happen, just clear (ish) fuel all the way through.
Seems to me that some of this stuff can form but then be suspended.
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I keep meaning to buy a flea for my magnetic stirrer - Tony has found that agitation in his car causes more fall-out from bio, and im wondering if gentle agitation may help flocculate hmpes when its cold also. Ie in keeping with your comment about this stuff forming, but remaining in suspension.
Ive wondered before if the water wash benefits im told of may also be due to the water giving somthing for the HMPEs to form on and then be removed.
Does anyone have any findings on how the titrated water wash possibly affects HMPEs yet?
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Initial mix was 45l creamy HMPEs and 80l WVO (36% HMPEs). Whole lot heated to 100C and melted to clear liquid.
I took a sample from this, which is currently showing about 20% HMPE formation (11 days on).
I made bio with this mix, and took a sample (after bubbling trace Methanol off). This shows about 3-4% HMPE formation tops (11 days on). The weather has been bitterly cold - plenty of thermal cycling!
I'm hoping this is representative of the 125l I've got standing - if so I'm definitely keeping all my HMPEs from this point forward for reprocessing.
I don't understand why, but it seems to work!
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Initial mix was 45l creamy HMPEs and 80l WVO (36% HMPEs). Whole lot heated to 100C and melted to clear liquid.
I took a sample from this, which is currently showing about 20% HMPE formation (11 days on).
I made bio with this mix, and took a sample (after bubbling trace Methanol off). This shows about 3-4% HMPE formation tops (11 days on). The weather has been bitterly cold - plenty of thermal cycling!
I'm hoping this is representative of the 125l I've got standing - if so I'm definitely keeping all my HMPEs from this point forward for reprocessing.
I don't understand why, but it seems to work!
That's really interesting results Tony, I for one would love to know exactly what HMPE's are.
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I have accumulated around 100L of HMPE's, so I'm very pleased to read your findings.
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I have accumulated around 100L of HMPE's, so I'm very pleased to read your findings.
What am I doing wrong, I only have about 400ml tops ? lol.
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I haven't got any, i feel left out >:( ,do you give lessons?
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Keith, Steve.
You're doing it wrong, try two stage non titration with NaOH, WBD, followed by bubble and settle.
Then you'll be able to join the HMPE club.
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Keith, Steve.
You're doing it wrong, try two stage non titration with NaOH, WBD, followed by bubble and settle.
Then you'll be able to join the HMPE club.
I Know tosser doesn't, but do you WBD Steve?
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The biggest producer of HMPE's is when you combine two stage non titration with WBD.
I stopped doing WBD for this reason alone.
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Keith, Steve.
You're doing it wrong, try two stage non titration with NaOH, WBD, followed by bubble and settle.
Then you'll be able to join the HMPE club.
I Know tosser doesn't, but do you WBD Steve?
Mr Soap Rich Bio Poor is grumpy tonight :)
Nige gave up WBD for the same reasons I believe
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Mr Soap Rich Bio Poor is grumpy tonight :)
Nice one kieth.
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Mr Soap Rich Bio Poor is grumpy tonight
He, he
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Keith, Steve.
You're doing it wrong, try two stage non titration with NaOH, WBD, followed by bubble and settle.
Then you'll be able to join the HMPE club.
I Know tosser doesn't, but do you WBD Steve?
No I was using the meth laden Glyc for pre treating my oil way before WBD came in and found the benefits of that far outweighed those of getting the Meth back from the Glyc.
I also think WBD Bio could do with EN testing ! I fear weird chemical changes may be going on.
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Right from the introduction of WBD there "appears" to be connection between WBD and increased HMPEs, but I don't think any one has done any meaningful tests to prove the point.
If anyone wants to prepair samples I'll happly run some chilling tests on them.
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Luckily with the ambient temperature staying low Fuging my bio is taking most if not all of them out, I have a sample in a jar sat outside in the snow and it is still crystal clear.
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Right from the introduction of WBD there "appears" to be connection between WBD and increased HMPEs, but I don't think any one has done any meaningful tests to prove the point.
I'd agree that there appears to be some connection, there was some speculation that maintaining high temperatures for prolonged periods (as part of Demething) caused it but I'm not sure. Certainly I did a batch without WBD a long time ago during winter and got comparable HMPEs. But that was just a single test.
I think I'll drywash my HMPE reprocess batch tonight, fingers crossed that the sample represents what's in the drum and there will be very little HMPEs left. If so, happy days - I'll be keeping all future HMPEs for reprocessing :)
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Delighted to report that the settled batch was even better than the sample! Only a light dusting of HMPEs at the bottom - the rest is all super usable biodiesel, despite having cycled through colder weather than the original HMPEs had - happy days!
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Is it me or does this suggest that HMPE's are a form of reverse reaction.
We know non titration followed by WBD produces an excess of HMPE's,
so does using less catalyst (non titration) produce a marginal reaction, that can be, to some extent,
reversed if then heating for extended time at high temp (WBD).
Could it be that the esters are not properly bonded together, so are easier to split the methanol molecule from them,
but still bonded enough to pass a 27/3 test.
I'm no chemist, so this is only what my simple mind has come up with.
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Given the (apparently) HMPE problems I had with the acetone batch that I did not WBD it will be interesting to see how the next one that I intend to WBD turns out.
Dick
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Is it me or does this suggest that HMPE's are a form of reverse reaction.
I mooted just that point quite some time ago.
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this is why i think we need to remove any remaining catalyst from the batch before we do wbd
it is still my theory that after we get a complete reaction and then go onto demeth that any remaining catalyst will carry on doing the job the we employed it to do which is to remove the alcohol from the fatty acid, when it has done this if there is any glyc remaining in the product then as there is three entry points on the glyc molecule then it is far easy er for the glycerin molecule to re-bond with the fatty acid. the product phase that has glycerin re-bonded will become much more hygroscopic which becomes a problem in cold weather.
if anyone out there does a 5% water wash after reaction and then goes onto wbd would you be interested in trying something to maybe help with this.
if so send me a message and i will send you something to try.
Paul
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this is why i think we need to remove any remaining catalyst from the batch before we do wbd
it is still my theory that after we get a complete reaction and then go onto demeth that any remaining catalyst will carry on doing the job the we employed it to do which is to remove the alcohol from the fatty acid, when it has done this if there is any glyc remaining in the product then as there is three entry points on the glyc molecule then it is far easy er for the glycerin molecule to re-bond with the fatty acid. the product phase that has glycerin re-bonded will become much more hygroscopic which becomes a problem in cold weather.
if anyone out there does a 5% water wash after reaction and then goes onto wbd would you be interested in trying something to maybe help with this.
if so send me a message and i will send you something to try.
Paul
You're brave, casting aspersions on the sacred WBD! I thought that questioning this process or making any suggestion that problems were connected with it was viewed as heresy or at least very taboo
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Not here it ain't ;D
Paul I don't think anyone does 5% water followed by WBD as that ruins the recovered Methanol purity.
Perhaps acid neutralisation prior to WBD would work, but how do we do that without adding water too?
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I've tried that. You add concentrated Sulphuric to Methanol to neutralise the soap, after which you go and change your underpants.
Seemed to work ok but I wasn't happy doing it!
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I've tried that. You add concentrated Sulphuric to Methanol to neutralise the soap, after which you go and change your underpants.
Surely taking a safety minded approach to the problem with the addition of the correct PPE would be best.
May I suggest the addition of Incontinence Pants, they'll take away the worry of sh!ting yourself during the process.
Be Prepared and safe out there.
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I've tried that. You add concentrated Sulphuric to Methanol to neutralise the soap, after which you go and change your underpants.
Surely taking a safety minded approach to the problem with the addition of the correct PPE would be best.
May I suggest the addition of Incontinence Pants, they'll take away the worry of sh!ting yourself during the process.
Be Prepared and safe out there.
He, he, like it.
Perhaps we should add IP to the acronyms list ... we could do a wiki page!
I was careful and did wear wraparound goggles. But I find working in rubber gloves more dangerous than without, you seem to have far less control over what you're doing (waiting for comments on that one).
PS ... Jim there's no swear filter on here. There's not really been a need, the odd bit of mild and controlled bad language hasn't raised any hackles ... yet!
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Incontinence pants? Talk about overcomplicating things, what's wrong with a cork?
It is curious that my attempts to water wash HMPEs have left a white band in the middle very similar to the band seen in Dick's photos of the cream from the top after using Acetone. I suspect they are the same thing.
Perhaps it's not HMPEs but soap somehow bound up with FAME?
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Don't think it is soap as it does not mix with water but separates out.
I did an experiment today that was interesting? I have a jar of old HMPE so I did a 50/50 and not surprisingly got a white layer over water. I then added acetone shook and the white layer got bigger! I intend to try some more tests but only have 1 test tube so I am waiting for some to be delivered.
Could it be mono or di glyc!
Dick
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I think you are right dick , I think it's made up of all mono's . This then suggest a back reaction or the 09/10 test isn't really big enough as the original test was 225/25.
I think for the near future I'm going back to 225/25 until we can prove that it's a back reaction
Paul
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That would make sense as they are great emulsifiers. And would therefore wash out.
But why would their melt point be up in the 50-60C range?
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Have a look at this link -
http://www.rikenvitamin.jp/int/emulsifier/spec/dmg.html
I have not looked at it much, but it certainly supports elevated melting points.
As a side note -
I deliberately overdose the 2nd stage of the 2stage no titration. I figure i can accept the extra soap from a 10% overdose on 10% (or whatever) of the batch. This, i assume, pushes things to a true 100% conversion, however, i have not yet concluded what may happen to the excess catalyst!
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Have a look at this link -
http://www.rikenvitamin.jp/int/emulsifier/spec/dmg.html
I have not looked at it much, but it certainly supports elevated melting points.
That's interesting...
If they are fats, why do they not convert in the process? If it's that we have a conversion of 99.XX% with the unconverted not detected by 10/90 there's no reason why it would all have a high melting point unless the following is the case:
1. There is oil present in the bio, which doesn't show up - but this stuff does due to it's higher melting point
2. Or if the fats are less likely or harder to reach 100% conversion (so if you have 95% oil for example and 5% fats in your feedstock, all of the oil goes over but only a % of the fats.
As Paul says it could be Mono's... If mono's do they have properties that would mean higher melting points.
Another question for consideration is... Are all of what we're referring to as HMPE's or waxing stuff, are they always the same or could there be a number of elements that appear to have the same properties.
Too many questions!
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Have a look at this link -
http://www.rikenvitamin.jp/int/emulsifier/spec/dmg.html
I have not looked at it much, but it certainly supports elevated melting points.
That's interesting...
If they are fats, why do they not convert in the process? If it's that we have a conversion of 99.XX% with the unconverted not detected by 10/90 there's no reason why it would all have a high melting point unless the following is the case:
1. There is oil present in the bio, which doesn't show up - but this stuff does due to it's higher melting point
2. Or if the fats are less likely or harder to reach 100% conversion (so if you have 95% oil for example and 5% fats in your feedstock, all of the oil goes over but only a % of the fats.
As Paul says it could be Mono's... If mono's do they have properties that would mean higher melting points.
Another question for consideration is... Are all of what we're referring to as HMPE's or waxing stuff, always the same or could there be a number of elements that appear to have the same properties.
Too many questions!