Biopowered - vegetable oil and biodiesel forum
Biodiesel => Biodiesel equipment => Topic started by: PD1 on January 12, 2021, 10:42:56 PM
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Hi again I hope you are all keeping well ,
I’m going to have a go a the interval mixing process , I’m just wondering that during the rest period of 1hr I assume some glyc settles , I’m just concerned that the pump will struggle with the glyc , I use KOH so not as bad as NaOH, but still I the past my pump does t seem to like it , I’m going to put some heat into the process just because it’s so cold at the mo , if only to about 20 degrees it I guess this should help the pump , Would I be right to do 5 minute cycles every hour for 5 hours?
Also did a glyc wash on my oil , used glyc from a previous batch , ran it for 30 mins at 60degrees but even after a week no glyc has dropped , what shall I do now ?
Thank you all
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First things first...you need to get that glyc out.
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Ok thanks Nigel , how ? Add more glycerine I have about 5litres still ?
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You'll need to get it all blended up again to ensure even distribution of the glyc and whatever is preventing it from splitting. Drop 10lts into a bucket and stsrt experimenting on 500ml at a time in a 1 lt jug.
Its never happened to me before but you could try adding small amounts of methanol to encourage it. I would hope that one of our members may have a different view and be able to assist.
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Thanks , good idea about experimenting with small batches
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Its as scientifuc as you can get. Once it starts to split do the same on another sample to prove it off. Scale the results up to whatever the volume is in your reactor inclusive of the glyc in there.
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As a rule of thumb...never experiment with the entire batch.
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How much money are you saving by not warming your batch up? You have to weigh up whether saving 50p or £1 or £3 or whatever it is per batch is worth the hassle & extra time of doing this at ambient temps in the dead of winter.
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How much glyc did you put in to do the glyc wash?
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How much money are you saving by not warming your batch up? You have to weigh up whether saving 50p or £1 or £3 or whatever it is per batch is worth the hassle & extra time of doing this at ambient temps in the dead of winter.
Hi Neil I’m going to heat up the oil but just thought that heating it to 20 degrees Instead of 55degress would be ambient temperature during the summer , when you do your processing , it’s a fair point though about how much in reality it actually saves
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How much money are you saving by not warming your batch up? You have to weigh up whether saving 50p or £1 or £3 or whatever it is per batch is worth the hassle & extra time of doing this at ambient temps in the dead of winter.
Next summer I will make up enough to get me through the winter , as you do, however for now I’ve got to process in the dead of winter !
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How much glyc did you put in to do the glyc wash?
I must admit I only put in 5 litres into a 140 litre batch ! I had 10 litres spare but halved it so I could add some warm oil to it to make it a bit easier on the pump , problem is this took it to the max so I do t have enough room to add the other 5 litres !
I’ll drain some off and add the remaining 5 litres if you think this would help
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Can’t wait until the warmer weather when things should be easier !
Thanks for the replies chaps
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How much glyc did you put in to do the glyc wash?
I must admit I only put in 5 litres into a 140 litre batch ! I had 10 litres spare but halved it so I could add some warm oil to it to make it a bit easier on the pump , problem is this took it to the max so I do t have enough room to add the other 5 litres !
I’ll drain some off and add the remaining 5 litres if you think this would help
Hells Bells Paul, 5lts in 140, no wonder it didn't split. Get a load more in there, as much as you can. The norm is about 20% of batch volume but the more the better.
Don't worry about the glyc dropping when you do the intermittant method, you need to mix it in again. You only drop it after you've mixed it several times, then the reaction has reached an equilibrium between conversion and residual chemicals left in the glycerol.
Re intermittant and ambient methods; 52 mins mixing saved per stage at 1.5kw's is a good saving I would say, plus the time to heat 200 litres from 20 to 50 degs with a 3kw heater.
Paul, Run some of your mix out of the processor so you can get the rest of your glyc in.
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That's why I asked. TBH I thought you had loads in there..not 5lts. I'm with Dave. Get it all in...as much as you've got.
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Ok thanks , I didn’t realise it should be at least 20% ,
Any way all good now , have managed to get my first stage done today too , I did run it initially for longer but then went for the 5 minutes per hour and glycerine was dropping each time before I mixed it up again , the pump seemed to struggle a bit , but still pumped the glyc but it did seem happier when the bio came through !
Will drain glyc in the morning and see where I’m at with a 10/90 , I have been doing a glyc wash at the end of the final stage , can’t remember off the top of my head how much glyc I put in but think it was 7% water , I’m assuming that this glyc will be no good for drying the oil of the next batch as it’s full of water !
I want to try bubble washing this time as opposed to mist washing , As I think it’s something that I can just leave running without the need to keep an eye on it , roughly how long would I need to bubble wash a 125litre batch and do I need to change the water at all
Thanks again guys , I really appreciate you replying
Paul
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It normally takes me a couple of days and 4-5 water changes to bubble wash my 150lt batches. I use 10lts at a time. I change the water last thing at night and first thing in the morning. Be careful of the type of stone you use. It should be ceramic not one of the blue aquarium types. The glue that holds them together isnt bio compatable.
I'm a bit if a dinosaur and totaly trust my methods but some bubblers have moved to pump washing. Could be worth looking up.
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Thanks Nigel , I’ve got a wooden air stone as I’ve read about the aquarium ones , I think I’ll give it a go , just to try different methods , all done at ambient temperature I assume?
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Yep..ambient washing. I some times do a hot wash at the end. Heat the bio to drying temps and add another 10lts. Not much heat lost but it can drag that last bit of soap out. I pump wash the hot wash though.