Biopowered - vegetable oil and biodiesel forum
Biodiesel => Chemistry and process => Topic started by: neisel on September 23, 2013, 09:29:52 AM
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I haven't enough KOH to make a complete batch & have bought some NaOH from a helpful member.
Planning on making a batch today using the same no tit 2 stage / water wash/ spray dry method I would normally use & I will be using both catalysts, probably NaOH on the first stage followed by the last of my KOH on the second stage, but maybe the other way around depending on exactly how much KOH I have left.
Anyone foresee any problems doing this?
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There's no issues (that i have found) - just make sure you get the numbers right for each!
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You've done this?
End product the same or have you noticed any difference?
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Im fairly sure ive even mixed them on the same stage, but i dont remember details like that so well.
I thought that some people mixed them to try and maintain fluid glycerol also?
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Thinking about it...
Im sure anyone who has changed from sodium to potassium, or vice versa, would have done it.
It would either be "mix them" or "throw out the last of one" and most people here dont much like throwing stuff out! : )
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so if the batch is made up of a mix of catalysts, if i use the glyc as a wash on the next batch i make which catalyst should one use? or does one have to use a mix again????
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you can mix together in same batch with no problems I've found out as people keep giving me KOH so I use it but I prefer NaOH as the soap settles out much quicker, so using a mix gets rid of the KOH and still gives good soap settling time.
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ok that seems to make sense. not sure where i read that you shouldn't mix. and if you use a glyc wash on a new batch you should the same catalyst as was used to make glyc.
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I used KOH for the first stage & NaOH for the 7% unconverted. All went well & no problems.
Must say NaOH is a complete bastard to dissolve compared to KOH & I ended up with a hard lump that took ages to break up dissolve.
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used NaOH on my first few batches, poured the meth into a large funnel with theNaOH in the funnel whilst breaking it up with a stick.
have since seen a method where you place two large ball bearing in the carbody and with a large magnet pull the ball bearings to and fro from the outside
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This is how I mix mine.
http://www.youtube.com/watch?v=D3UxlfCxsIU
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Put some old wheel nuts / big bolts in the hdpe cubie with 1/4 of the meth you need, then top up later.
The exothermics and agitation help, as does kicking it about like Chug does.
You do need to vent it a few times, mind.
Some 25L cubies have bastard 'pockets' in the corners that agglomerated / undisolved catalyst like to hide in.
One needs to be thorough in this respect ...like I am (as if!)
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I mix all of mine the chug way too. It's most impressive on the lawn in winter as it steams in the wet grass :)
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Well I've solved the NaOH dissolving problem by introducing a handful of round, roughly 1" across stones from the banks of a local river. These seem to churn the stuff up well & it really takes no longer to dissolve the NAOH than it did the KOH.
Must say I think I'm going to convert to using NaOH all the time when I start making bio again in the Spring. Seems to be a lot less soap created & I can get a crystal clear 50/50 result with 4 or 5 water washes. Thanks go out to Julian for selling me some & convincing me to try it.
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Glad it worked OK for you. Try ASM and you may find it's better still.
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If you want to try some ASM Niesel give me a shout.
£44.50 for a 25lt at the mo and could well get some down to the cotswolds real soon. It's about time for a visit to Keith and Lorreta.
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Thanks, but until the Spring I'm done with bio making.
I'm not going to buy any new ingredients until I start up again in about 5 or 6 months.