Biopowered - vegetable oil and biodiesel forum
Biodiesel => Chemistry and process => Topic started by: Tony on September 17, 2012, 08:25:26 AM
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Hehe, seems to be one I follow more often than not during the summer months :)
The excess catalyst process is this:
- dry oil very well (heat to 105C and use condenser)
- titrate
- mix Methoxide using 5% too much catalyst
- single stage (usually a clear pass due to catalyst overdose)
- Whole Batch Demeth
- no water prewashing!
- settle soap out
Sure there may be extra soaps but who cares when it's that easy? I don't make jelly because there's no prewash water and I don't water wash so no emulsion to worry about either. And I've got enough feedstock that yeild isn't an issue (not that I've noticed a yeild reduction though).
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Looking at: http://www.biopowered.co.uk/wiki/Methoxide#A_note_on_soap
Does this also apply to excess NaOH? So 40g NaOH extra => 320g soap produced by whatever the mechanism of interaction is between NaOH and triglycerides?
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Heathen
Post it up on the VOD and see what happens :)
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Did I mention that I stir it all in a bucket with an old paddle? Can tell when it's done because it tastes right. ;)
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Complicated that bio lark isn't it?
My "process" is: tip oil through bed sheet, put it in car.
If it buggers the car up, I'll buy another £400 one. Happy days ;D
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Definitely the right attitude. If you can get from A to B by whatever means costs the least then it's a win-win situation.
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Complicated that bio lark isn't it?
My "process" is: tip oil through bed sheet, put it in car.
If it buggers the car up, I'll buy another £400 one. Happy days ;D
That's a bit posh innit? I just use a j cloth shaped like the inside of my funnel and stapled! hahahaha
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This has got me wondering... if there is no water presumably you won't make soap (which is why we don't see jelly batches until prewash water has been added). Since abandoning prewash, I've never had a jelly batch despite overdosing catalyst.
So I wonder what would happen with dry oil and a serious catalyst overdose (say, double that required). Presumably the water in the Methoxide mix will get used up make soap - but this would happen anyway?
Catalyst use is one of the lowest cost parts of the whole conversion process, so in that respect no problems using a bit more for ease of use.
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Why dont you give it a go and find out Tony - we promise not to laugh too loudly if you fill the processor with yellow yellow
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Got some WVO up to 105C with plenty of time on the condenser so I think it's pretty dry. Mixed Methoxide to titration amount plus 25% extra (on the total, not just titration) so we'll see how a single stage goes tomorrow. Hopefully lazy days on getting a clear pass :)
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So far so good, got 3/27 pass just demething now (WBD) :)
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Prepare for plenty of rock solid glyc I reckon ;)
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Hehe we'll see - nearly up to 90C and still a little Meth coming out. No sign of jelly/pump struggling noises - should be OK anyway unless water gets added.
Got a monster spider on the shed wall, I think he's keeping me company tonight!
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Got a monster spider on the shed wall, I think he's keeping me company tonight!
I got lots of them. I've even got a crane fly that's been through the Mono pump, loosing only one wing and two legs on the journey, who's now lodged in my transparent final filter.
Anyway I was thinking recently, people have been looking for Methanol alarms to test the shed atmosphere, but surely the shed wildlife could be to a bio maker as a canary is to a miner.
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I wouldn't bother using your little crane fly, they only live for two weeks anyway.
That could make you paranoid about meth levels.
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Here he is
(https://lh3.googleusercontent.com/-UhOnXSRwF7k/UG4AAFgY1zI/AAAAAAAABGs/SZ5AhI21f9E/s640/IMG_20121004_222021.jpg)
Anyway, onto a sample and it's 3/27 result - no sign of jelly:
(https://lh6.googleusercontent.com/-aaEaWLarFYc/UG3_wYC7R0I/AAAAAAAABGc/zf1fQKXQIMg/s640/IMG_20121004_222528.jpg)
(https://lh3.googleusercontent.com/-H-NfYY_10XI/UG3_7usPMtI/AAAAAAAABGk/u6a3VjXIX70/s512/IMG_20121004_222634.jpg)
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I wouldn't bother using your little crane fly, they only live for two weeks anyway.
That could make you paranoid about meth levels.
No, he or she, (the crane fly) committed suicide in one of my settling barrels and has been submerged in Bio, in the filter for many months. It would appear that Bio is quite a good preservative.
I was thinking about the live community of creepy crawlies.
Nice 3/27, Tony!
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Hmm .... ok then, if cockroaches are immune to radiation, maybe other creepy crawlies are immune to methanol vapours.
Further tests needed.
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Hmm .... ok then, if cockroaches are immune to radiation, maybe other creepy crawlies are immune to methanol vapours.
Further tests needed.
TONY ... stick that spider in a jar with some Methanol and report back. Insect lovers look away now!
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What and dilute my Meth with spider? Never I say!
Anyway, batch done, bubbling in the settle drum. Might be lower yeild but it's hard to say as I drained the Glyc super-fast and probably will find some bio sitting on top of that tomorrow.
Happy with getting a single stage clear pass so easily, I know it would've jellied if I added prewash water but because I haven't all is OK (so far!)
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Bubbled overnight, bio is now beautifully clear though soap test is cloudy; just needs to settle. No jelly signs at all.
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Got some WVO up to 105C with plenty of time on the condenser so I think it's pretty dry. Mixed Methoxide to titration amount plus 20% extra (on the total, not just titration) so we'll see how a single stage goes tomorrow. Hopefully lazy days on getting a clear pass :)
How are you heating up to 105c, have you modded your immersion heater?
I remember seeing a guide on it but can't find it anywhere.
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Graham Lambing details modifying an immersion heater thermostat on his site here ... http://www.graham-laming.com/bd/thermostat/thermostat.htm
Common practise now is to remove the thermostat and use a PID and SSR controller.
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Graham Lambing details modifying an immersion heater thermostat on his site here ... http://www.graham-laming.com/bd/thermostat/thermostat.htm
Common practise now is to remove the thermostat and use a PID and SSR controller.
Now I understand why you use them, cheers for the link :)
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Though I'm using a Burco capillary stat so the processor has an oven-style knob on it for temp :)
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Though I'm using a Burco capillary stat so the processor has an oven-style knob on it for temp :)
I've got an old burco, that's a brilliant idea
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Tony, does the 2nd graph down on this page ... http://www.sciencemadness.org/talk/viewthread.php?tid=1694 have any bearing on what you are doing. Seems to indicate that high levels of catalyst lead to a very quick reaction at the expense of soap ... I think!
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It's been a long time since I last saw that graph, you're really digging them up today Julian!
Their test seems to be with Sainsbury's Rapeseed.
Since 1l of Rapeseed weighs 910g;
0.5% w/w gives 4.55g KOH per litre
1% w/w gives 9.1g KOH per litre
2% gives 18.2g KOH per litre
4% gives 36.4g KOH per litre
Interesting to see the effects of concentrations over the 7g base many of us use. But yes, essentially that's what I'm trying to achieve - enough catalyst to get a quick and easy single stage 3/27 pass without creating too much soap. Which means using more than we'd normally expect to, on the provision the oil is nice and dry and we don't make things worse by adding water later in the process. So far all has worked well so I'll be trying the same again next batch. No titration single stage, the key is bone dry oil all the way through the process :)
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So am I right in thinking that the lazyman process seems to work fine and the upsides are
1] you don't need to titrate
2] you are almost guaranteed a 27/3 pass in one stage
but the downsides are
1] You have to spend extra time/money ensuring your oil is completely dry
2] Your yield is lower
3] You make more soap
4] you end up with more glyc to dispose of and it's rock hard
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So am I right in thinking that the lazyman process seems to work fine and the upsides are
1] you don't need to titrate
2] you are almost guaranteed a 27/3 pass in one stage
That's the plan, though I think it's good to have a rough idea of the oil's titration so the catalyst overdose isn't too massive.
but the downsides are
1] You have to spend extra time/money ensuring your oil is completely dry
2] Your yield is lower
3] You make more soap
4] you end up with more glyc to dispose of and it's rock hard
1] yes definitely - for my 125l batch I might use roughly an extra 4kWh to make sure it's toasty dry, which is somewhere between £0.50 to £1.00 depending on your tarrif (0.4-0.8 pence per litre). Although it consumes more time to do this, it's not hands on time, in keeping with the "lazy" part of the process :)
2] apparently it should be lower yeild though I've not done enough batches with a good 25% overdose to really judge this
3] I've not noticed extra soap yet but I'm waiting on settling to see
4] 24h after completing the batch the glyc was still liquid, though usually after WBD all of my glyc sets solid eventually. I'll check again next time I'm out both on the soap settling progress and the glyc solidity.
The way I look at it, the primary production cost is Methanol, which I'm recovering, so the cost of that part of the process won't change.
Sodium Hydroxide is about £25 per 25kg bag, and I'm using 200g over what I normally would (20 pence extra per batch or 0.16ppl).
So I'd say I'd be paying about 0.6 to 1ppl extra by this process, or 75p-£1.25 per 125l batch for the privilege of less effort.
I suppose I could mix up loads of Methoxide in advance since the same amount of catalyst would be used each time, that'd make life a little easier too.
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Sodium methylate might be worth trying with this process with it's higher yields and no water?
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I was just thinking that. Presumably with less water there would be less soap/yield loss.
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Liking the sound of this process, sounds ideal for Muppets like me.
Be interesting to try a "Carrington wash", comparing the amount of acid needed, compaired with a normal batch. Would that give an indication as to where the additional catalyst ends up?
Is the excess of catalyst likely to have an effect on the performance of Glogs?
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I've just realised that an extra 200g over the 800g I would usually use is actually 25% extra not 20% extra (though is is 20% of the final amount) so I've gone back and edited my previous posts to reflect this.
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Thought I'd chime in here.
Very similar to what I've been doing, except I don't even bother to titrate any more. I know my titration normally comes out at about 7g/litre, so I normally increase that to about 8g/litre, and just shove it in.
Very rarely get a fail, in which case I drop the glyc and do a 2 stage.
Given your findings Tony, I might increase that to 8.5g/litre.
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5 days of settling, Glyc is solid, 50:50 soap test is getting well towards being clear!
Having poured the floating bio from my hastily drained Glyc into the settle drum, the yield looks OK too.
Edit: just got in a post before me James, good to hear it! To think I used to be paranoid about going 0.1 over on titrations.
I take it you don't water prewash either?
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This must be at the opposite end of the spectrum from the 2 stage non titration
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Looks like titration is well out of vogue these days.
It'll be back, just like cheesecloth shirts and monkey boots. 8)
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The Lazy bug is catching...I'm done with 2am finishes (and not even finished)
With a 'suitable' heated / pumped wvo settle tank, at the end of the WBD, one could immediately use the hot glyc. to dewater the next load of wvo (already heated to 40 C). Maybe pump it about overnight. CH pumps will do the job and have such a small power consumption.
Just avoid any runs of pipe that solid glyc would block when cooled some time later. That would save some heating ... but, would it be as good as 105 C boiling off?
No use for really wet oil as the glyc from a same sized batch isn't enough but for good clear, low tit wvo, 20% glyc could be enough.
What does the panel think?
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A very good question. I guess any WBD process allows for the Glyc to be used straight after for drying, but how well it dries, I don't know. I think that would require experimenting using Keith's water test kit.
However, if you have damp oil I would imagine that Glyc only has a certain capacity for water extraction, so you couldn't be sure the oil was dry without testing. At least with heating over 105C you can be pretty sure there is minimal water left.
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Tested the bio for soap today and got a lovely clear 50:50 :) Will be doing another batch this way as soon as I've dewatered some more oil.
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Did another batch this way no problem. Nice clear 3/27 pass again after single staging. It's settling now. So easy, no titration and no faffing with two stage glyc.
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You'll all miss titrating when it's gone
I on the other hand have to titrate 5x per batch so I'll always be happy in the knolage that I'm not in the in crowd
Paul
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With a 'suitable' heated / pumped wvo settle tank, at the end of the WBD, one could immediately use the hot glyc. to dewater the next load of wvo (already heated to 40 C). Maybe pump it about overnight. CH pumps will do the job and have such a small power consumption.
Just avoid any runs of pipe that solid glyc would block when cooled some time later. That would save some heating ...
What does the panel think?
If you ran a reversed flow system (pumped from the top to the bottom) and had the outlet central in the drum and just above the settled gly level you wouldn't suffer from blocked pipes, just a big lump in the bottom if the pump stopped overnight.
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Well I've been doing this for months now, overdosing the catalyst. Not had a bad batch yet! Yield does not seem to be noticeably less, though my processing time is as I'm getting a clear pass with a single stage.
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Well I've been doing this for months now, overdosing the catalyst. Not had a bad batch yet! Yield does not seem to be noticeably less, though my processing time is as I'm getting a clear pass with a single stage.
I was under the impression we were doing just that BEFORE Titless arrived AND without over dosing the catalyst.
When you've got a crystal 10/90 in under 15mins single stage gissa shout, did that years ago.
HCII was doing 10k litres in approx 20mins.
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Catalyst, in the true sense, shouldn't be consumed by the process - so in theory the quantity shouldn't matter.
HCII was using more catalyst than conventional? Wish I'd know that years ago.
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I'm fully aware of what a catalyst is and how it works, it's only be consumed if water is present.
Over dosing, as you say, should make no difference to the finished product as it ends up in the glyc which would be advantageous when used in the next glyc wash, especially if the glyc is not demethed.
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I'm fully aware of what a catalyst is and how it works, it's only be consumed if water is present.
Which makes a good argument for using ASM this way.
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I'm fully aware of what a catalyst is and how it works, it's only be consumed if water is present.
Which makes a good argument for using ASM this way.
Correction to my last statement, Catalyst is consumed if FFA's and/or water is present.
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I've just given this method a try with ASM and I have to say I'm impressed ... well done Tony!
I didn't bother to titrate (well, if it's meant to be a lazy method), just added around 20% more ASM and another litre or so of methanol than usual and did a single stage. The oil was dried to 90°C using the condenser the day before. At the start of processing I did a lazy HPT ... switched on the heater and heard no popping or crackling (I normally hear it with undired oil).
I tried doing 10/90 tests instead of my usual 3/27s and at 16 minuets I got a 95% conversion. At 45 minuets, the drop out was barely visible so I recon around 99.5% conversion. Taking frequent samples, I didn't notice any of the jelly stages I've been using as guidance when skimping heavily on catalyst during the last dozen or so batches. Working on the principle that the remnants of oil would convert during the early stages of demeth if they were going to convert at all, I started demeth 50 minuets after starting the batch.
I tried a couple of pre-wash tests in jam jars and test tubes. Way too much water resulted in respectable looking bio and glycerin, but it had a light coloured intermediate layer which I'm guessing could be the start of an emulsion. Smaller tests with the correct amount of water showed a separation between bio and glycerin, but the glycerin was a strange light colour.
I then tried an acid titration on centrifuged bio. The acid required was only roughly double that of my previous method (although my previous method included a 7% pre-wash which would have removed much of the unused catalyst), so I've drained the glycerin and will continue with a titrated acid wash and subsequent washes over the next few days.
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Julian old chap,
A clear 10/90 only indicates a 96.5% conversion has been achieved so you're guessing at 99.5% of 96.5%.
There could be inexcess of 3.5% triglycerides floating about in the batch.
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Julian old chap,
A clear 10/90 only indicates a 96.5% conversion has been achieved so you're guessing at 99.5% of 96.5%.
There could be inexcess of 3.5% triglycerides floating about in the batch.
Complete news to me !!!!
Where did that revelation come from? It wasn't mentioned by Jan Warnqvist when he first published the method.
Anyhow, it had several hours demething so I'm hoping that I got a slightly better conversion.
This being my first 10/90, I also noticed that there appears to be two phases of settling occurring ... a clear oil looking layer with a cloudy and deeper layer on top.
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It wasn't mentioned by Jan Warnqvist when he first published the method.
Strange, 'cause that's where I got the info from, it's not written in those words but that's what he was saying.
He said that the test, 25/225, indicated that the conversion had met the minimum requirements (ASTM) to be classed as Biodiesel.
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Quote ...
------------------------------------
From: "Jan Warnqvist" <EMAIL PROTECTED>
Reply-To: Biofuel@sustainablelists.org
To: <Biofuel@sustainablelists.org>
Subject: Re: Biofuel Quality Test
Date: Thu, 11 Aug 2005 18:51:02 +0200
Hello Jeffery.
The test method that you are using seems to me highly dubious, since there are a number of pre-assumptions that has to be met. For a further check I´d suggest this:
Take exactly 25 ml of biodiesel and dissolve it in exactly 225 ml of methanol in a measuring glass. Now: The biodiesel should be fully soluble in the methanol forming a clear bright phase. If not, there is pollution in the biodiesel causing you trouble with the water test. Each ml of undissolved material is corresponding to 4% by volume. Are there any undissolved material at the bottom of the measuring glass ?
If there is, your reaction is not complete and this is causing you trouble with the water test. This method does not cover every aspect of quality, but it gives a hint though........
Good luck to you
Jan Warnqvist
AGERATEC AB
--------------------------
... Unquote
No mention of the ASTM test!
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I'm absolutely sure the discussion continued for quite a while and the figures were mentioned somewhere along the line, I don't think I made it up, why would I.
I'm far from having the right knowledge to draw those conclusions meself.
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I'm absolutely sure the discussion continued for quite a while and the figures were mentioned somewhere along the line, I don't think I made it up, why would I.
I'm far from having the right knowledge to draw those conclusions meself.
I know you wouldn't make it up ... but at your age ... well, you know, the mind plays funny tricks! Have those voices come back after since you started the new medication?
But seriously (quite a feat for me) I did an awful lot of digging around to get back to the earliest mention of the test to stick it on the wiki and I don't remember any mention of the ASTM test in any posts. There's a link to the thread on the wiki, so I'll go back and have another read.
I too know nothing of the chemistry involved but it would seem logical that if nothing drops out, it's all dissolved in the methanol ... so I don't logically see how could that equate to 69.5%.
I've had other thoughts on the 3/27 test today so I'll start another thread on the subject.
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Oh, to answer a question raised earlier in this thread ... glogs made from this glycerin burn perfectly well, ones flaming away nicely in the log burner as I type.
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The accuracy of the Jan Warnqvist test is reduced as the sample size decreases from 100/900 down to 25/225 down through 10/90 to 3/27. It depends how readable or measureable the drop is.
At 1ml of dropout in the 25/225 test is 4% unconverted, at 10/90 its 10%. Whats the smallest amount of dropout you can accurately measure or estimate by observation? That's the limit of your accuracy in claiming an achieved conversion value.
A claim of 99.5% conversion with a 10/90 test suggests that you measured or estimated the dropout at 0.05ml.
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The accuracy of the Jan Warnqvist test is reduced as the sample size decreases from 100/900 down to 25/225 down through 10/90 to 3/27. It depends how readable or measureable the drop is.
At 1ml of dropout in the 25/225 test is 4% unconverted, at 10/90 its 10%. Whats the smallest amount of dropout you can accurately measure or estimate by observation? That's the limit of your accuracy in claiming an achieved conversion value.
A claim of 99.5% conversion with a 10/90 test suggests that you measured or estimated the dropout at 0.05ml.
Exactly that, my conical centrifuge tube starts with 0.05ml graduations.
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Just to throw a spanner or two in the works, what percentage of your test sample is methanol, soap, free and suspended glyc all soluble in methanol?
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Just to throw a spanner or two in the works, what percentage of your test sample is methanol, soap, free and suspended glyc all soluble in methanol?
You know I can't answer that!
All I can say is that the sample was given a very good human centrifuging before I ran the test (as I always do).
I'll start the other thread as this discussion is probably more pertinent to that. The point I was trying to make in stating the 99.5% was that I got, as near as damn it, full conversion with a single stage in 45 minutes, (not the fastest but far faster than I normally manage to achieve with a two stage process) ... all credit to Tony's experimentation.
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Hehe don't worry, the process works.
Jim just had trouble with ideas that aren't his own working out ;)
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Hehe don't worry, the process works.
Jim just had trouble with ideas that aren't his own working out ;)
Nah, that ain't not true 'cause as I says earlier, peeps was doin' it years ago sunshine.
I don't think there's anything out there that hasn't been tried by someone.
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I did read. . Somewhere. . a long time ago... that 100% conversion cannot be achieved in a single stage ! something along the lines that 100% conversion cannot be achieved while the glycerol is still present.
Hence the reason that 2 stage was so successful because once the stage one glyc was dropped stage two should be almost instantaneous if the correct doses are used.
This is not my own opinion but something I recall reading... way way back.. and I am not in anyway dissing anyone's findings but just throwing it back out there.
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I did read. . Somewhere. . a long time ago... that 100% conversion cannot be achieved in a single stage ! something along the lines that 100% conversion cannot be achieved while the glycerol is still present.
Hence the reason that 2 stage was so successful because once the stage one glyc was dropped stage two should be almost instantaneous if the correct doses are used.
This is not my own opinion but something I recall reading... way way back.. and I am not in anyway dissing anyone's findings but just throwing it back out there.
You could well be right. I know I got very close to a full conversion before I started demething. However, if you take your statement to extremes, surely the glycerol produced in stage two, all be it a smaller quantity, would, to a degree, inhibit that stage too, but that's probably being pedantic!
The acid wash went OK. I did another titration and that showed just slightly less than double the normal quantity of acid. Once it's dried I'll do another 3/27 and post the result.
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I did read. . Somewhere. . a long time ago... that 100% conversion cannot be achieved in a single stage ! something along the lines that 100% conversion cannot be achieved while the glycerol is still present.
Hence the reason that 2 stage was so successful because once the stage one glyc was dropped stage two should be almost instantaneous if the correct doses are used.
This is not my own opinion but something I recall reading... way way back.. and I am not in anyway dissing anyone's findings but just throwing it back out there.
You could well be right. I know I got very close to a full conversion before I started demething. However, if you take
your statement to extremes, surely the glycerol produced in stage two, all be it a smaller quantity, would, to a degree, inhibit that stage too, but that's probably being pedantic!
The acid wash went OK. I did another titration and that showed just slightly less than double the normal quantity of acid. Once it's dried I'll do another 3/27 and post the result.
Steve's statement is true and known about in the 30's.
The bio researchers of yesteryear were well aware that multi staging with removal of byproducts between was the most effective way of achieving maximum conversion.
There was also mention of lower chemical costs, as we've found.
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No doubt about it, two stage uses the minimal chemicals to achieve complete conversion.
I guess there is a curve between minimum process cost and minimum effort though, and I'm quite interested in a balance of the two.
As far as I can tell, single stage overdose is pretty minimum effort and combined with WBD pretty cost effective on chemicals too. The only thing it uses more of is catalyst, which adds very little overall cost to production.
Despite the glycerol balanced reaction argument I'm getting nice clear 3/27 passes, which is good enough for me - just finished another batch today in fact :)
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Just to put it on record ... don't know if it's any thing to do with the overdose, but this batch has been a devil to dry after washing.
Normal drying time and temperature in the processor plus an overnight bubble still left dirty orange juice which has taken most of today to clear using a bubbler and a Tosser Tube to reheat to 60°C.
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Interesting, I wonder why?
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Don't think I can pin it down. No 7% prewash, obviously more soap hence more acid and sodium sulphate and I did use more water than normal for each wash.
Even so it's still strange it didn't dry in the processor at 80+°C.
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Don't think I can pin it down. No 7% prewash, obviously more soap hence more acid and sodium sulphate and I did use more water than normal for each wash.
Even so it's still strange it didn't dry in the processor at 80+°C.
Aha! That'll be the wetter water then, adding soap to water makes it much wetter ya know, so the wetter the water the more drying required.
There it is in a nutshell.
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Water is not wet.
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I know I aint been online as much as previous years but I don't know how the feck I managed to miss this thread :-[
And I'm almost cursing Bev and hubby right now as I did many tests with overdosing, amongst many other tests, but left the test samples behind at Bev's BB, I let her know asap and she saved them for months but they got thrown away in the messy divorce!
Anyway, if I recall correctly I had to go up to nearly 40% extra NaOH to get jelly.
As Jim said I got the idea to test from HCII saying he used 6g when everyone else had only just moved up to 5g from 3.5g.
My process from then on was almost as James-reckless eng outlines ie approx 8g per litre, except I never weigh it I just know the rough amount after using the same tub to measure it in for years...ha ha
I only went to two stage to get quicker, higher conversion (although I think with a bigger flow pump single stage would have been as quick) my process is still the same now.
Well it's almost the same I now add methoxide as soon as wvo is roughly mixed, ie a few mins after pump is turned on, then it's starting to react as its coming up to temp and reduces my overall time a bit, and of course I now always wbd.
EDIT:
Whilst searching for Tony from west Oz for the new VOD member from Oz I came across an old thread talking about this.
http://www.vegetableoildiesel.co.uk/forum/viewthread.php?tid=7267
P.S The graphs I mentioned in that thread are these
(http://www.wastevegoildacorum.co.uk/catalyst.gif)
(http://www.wastevegoildacorum.co.uk/methanol.gif)
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For the record, I've just done a 10/90 on the finished bio and, despite the additional catalyst being added before demeth, the result is the same as the previous test.
So, not withstanding the speed of over dosing, I think I'll go back to a two stage process.
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Interesting, Chug. Do you know how residual methanol was measured?
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Interesting, Chug. Do you know how residual methanol was measured?
Residual/dissolved glycol would need a GC I'd have thought.
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For the record, I've just done a 10/90 on the finished bio and, despite the additional catalyst being added before demeth, the result is the same as the previous test.
So, not withstanding the speed of over dosing, I think I'll go back to a two stage process.
At least you now know why it was hard to dry.
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Interesting, Chug. Do you know how residual methanol was measured?
It was done by Frank (neutral on infopop) and he used GC test results and Sam Ley turned it into the graphs.
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Hi just come across this thread and found it interesting as the the last 2 batches I've done (80 litre) I've used 8 instead of 7 grams of KOH for the first stage no titration after glycerol prewashing and have only had 0.5% dropout so first stage 12.8 litre methanol 640 grams koh second stage 0.8 litre methanol 32 grams koh.I then water wash through a misting nozzle and overflow system usually overnight then drain the rest of the water and dry through a spray bar which usually only takes about 1 hour at 75 degrees get clear 50/50 test and its been giving clear full conversion on the 10/90 test.maybe if I up the methanol to say 14 litres and koh at 8.5 grammes it'll go clear on the first dropout test think I'll try it next batch.
Tony Deli's are quite tolerant of slight amounts of unreacted oil anyway considered leaving it at first stage with .5 dropout what's you thoughts about that?
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5% dropout has never cause me any problems,a nd is not a level I would worry about.
The way I see it is this, triglycerides are funny shaped molecules that like to tangle and gum because of their three arms. Fatty Acid Methyl Esters are like a pile of bent sticks, not much chance of tangling them. But if you have a few three armed molecules in a sea of sticks, they're also unlikely to tangle either.
I think this is the premice by which blending with diesel/petrol works too. So if you think your engine would be happy on 95% diesel and 5% veg then it should be happy enough with 95% converted bio.
On the other hand, if you have a sensitive fuel system this might not be acceptable.
Given some people run them on 90% veg (I used to run mine on 30% SVO) I wouldn't sweat it!
The only catch is moisture, if there are mono/diglycerides present from partial conversion, this is more of an issue as emulsions can form. On the other hand, if you water wash this kind of fuel these will get flushed away anyway.