Biopowered - vegetable oil and biodiesel forum
Biodiesel => Chemistry and process => Topic started by: Bio-boy on April 17, 2015, 11:01:21 AM
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How good is this process???
Is it comparable to a 2 stage titrated process???
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I can't remember the last time I titrated.
The titration is largely irrelevant. Once you throw in some catalyst and methanol it'll neutralise all the FFAs and partially convert. It's then just a 3/27 test to determine how much further it needs to go.
Truth be told - I didn't even bother pushing it to completion a lot of the time. The van and the landy are both pretty tolerant. I just ensured that the dropout was less than 0.5ml in 3 which is >80% conversion.
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Sounds like the way forward.
What quantities of KOH do you use for the 1st stage?
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Hi Bio-boy, welcome to the forum and wiki.
Just to give you an alternative view, I've been making bio for 7 years and need to produce reasonable quality bio as some finds it's way into a VW PD engine, and when that won't go, boy, do I get it in the neck!
I've tried most of the methods suggested over the years, and when not using ASM I stick to a simple two stage with titration.
I struggle to see why people are so anti titration. It really doesn't take long and you know exactly the quality of the oil you're dealing with. I find it far less hassle than the no titration method ... having to mix a second batch of methoxide etc, added to which the method has a flaw ... the 3/27 test doesn't give instant results. It can take several hours for all the fallout to occur.
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Welcome.
I've also not titrated for a long time and follow the two stage process to get a clear pass. Nothing wrong with titrating, just that I'm lazy, it's easy and it works.
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How good is this process???
Is it comparable to a 2 stage titrated process???
At the end of the day there is really no difference. With titration you work out your chemical requirements from the result of the titration. With no-titration you estimate the amount for the 1st reaction (usually from experiance) then from the result of a 10/90 dropout test will calculate the exact amount for the 2nd stage.
Both methods will require less chemicals than using a single stage.
Without trying to confuse you with too much information, it is more important that you do a glycerol pre-treatment than whichever of the two types of reactions you choose.
http://www.biopowered.co.uk/wiki/Glycerol_wash
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I'd hate to think of the last time I titrated, I don't reckon it's as accurate as peeps seem to think especially as most of us made up our own solutions.
Titless with glyc wash for me.
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With titration I always struggled to get a complete reaction.
I now do no titration, but as some have said it takes some time to get a true indication of dropout, so now I just give it 10 mins to dropout and add 10 to 20% more NaOH than calculated.
using this method I get a complete reaction every time with no fuss.
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With titration I always struggled to get a complete reaction.
I now do no titration, but as some have said it takes some time to get a true indication of dropout, so now I just give it 10 mins to dropout and add 10 to 20% more NaOH than calculated.
using this method I get a complete reaction every time with no fuss.
Indeed, the 10/90 dropout test is full of anamolies
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With titration I always struggled to get a complete reaction.
I now do no titration, but as some have said it takes some time to get a true indication of dropout, so now I just give it 10 mins to dropout and add 10 to 20% more NaOH than calculated.
using this method I get a complete reaction every time with no fuss.
Same here but 10% extra added to stage 2 sees me to a clear 10/90, I do use ASM though.
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Two stage non titration with ASM for me, quite often turns out to be a one stage anyway
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Really impressed with this process. 130 litres feedstock, 2 stage no titration, 100% conversion and only requiring 3 water washes. Yield 125 Litres!!! WOW. I can't believe its taken me so long to jump ship.
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Now try it with ASM. ;)
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ASM, I know its Anhydrous Sodium Methylate, but how do you use it, do you dilute it with methanol & what are the base amounts on new veg oil - SVO....?
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Hi SS069, yes, ASM is good stuff, just dilute it in methanol as you would a solid catalyst. You can deduct the volume of methanol you add in the ASM. The base is really 5.0 but some use down to 3.5 As it is 30% strength you should multiply the weight of the solid catalyst by 3.33 ( most round this up to 3.5)
Disadvantage is that ASM gives rise to solid glycerol, some (like me) use 50/50 KOH/ASM it works nearly as well, works out much cheaper and gives you liquid glyc for pre-treating.