Graham did you remove the methanol in your test
and yes it does smell nice.

plugly

hello all
looks like you guys are haveing some fun!
i havent made a lot of bio yet but i have a question/concern regarding the high voltage separation method ive done some reading on hydrogen and what i am wondering is this are you perhaps liberating hydrogen and creating a potentially explosive environment? i dont remember exactly whether hydrogen production involves both high current and amperage or what
anyhow im sure you guys thought of this already
as you seem pretty solid as far as technical expertise goes
keep up the good work!

andrew stegman

Liberating hydrogen from where? Electrolisys (pardon my spelling) is a definate possibility when you are talking about water. It will break into hydrogen and oxygen. I don't think I have ever heard of breaking apart oil.

This would be a great reason to not use the 5% prewash if you are going to do electrostatic settling.

-Jim

Would an electric fence energizer work for this? It is high voltage and low amps and I believe DC, but I am not positive about that.

Thanks for any thoughts.

Hi, I'm a little late in answering a few of you, so, here's a start...

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Hi Plugly,
All the methanol was present for the glycerol separation, but all was removed for the soap separation.
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Hi Andrew,
There is no electrolytic action, so no gas is given off. Even if the liquid were salty water, the current is limited to 0.0001A , which would liberate a truly insignificant amounts of gas, even if left for many, many hours.
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Hi Jim
The 5% prewash seems not to make much difference to the conductivity. Most of the water seems to end up in the glycerol, and the little remaining in the biodiesel, after glycerol has been removed, is so widely dispersed it should be safe to exclude hydrogen as being a risk. Especially so if the current is limited to 0.0001A.
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Hi JustATrader,
Sounds suitable for an experiment. The thing to do would be to measure the DC voltage, which I seem to recall was around 600V on some fence-guards I repaired many years ago. If it is somewhere in the range 250 to 1500V, I'd expect you to be able to see the effects of electrostatic separation.

To add a safety limit on the current, I'd suggest you connect 10 Megohms in series. Do so with 10 x 1 Megohm resistors, all connected in a series string, rather than 1 x 10 Megohm resistor, to reduce voltage stress across each resistor.

quote:

I believe DC, but I am not positive about that.

hehehe!

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I was planning to run a full batch this weekend, but the oil I picked up was very wet and it is still drying off in the heater. Sometime in the next few days I'll run the batch and see how well or badly the electric field idea works for real.

any progress to report on the 'for real' test? Or the electric fence energiser?

Hi Ant

The 'for real' test was a success.

The glycerol separated as far as it would go within 25 minutes, which was longer than I'd expected, but still a good improvement.

I used a homebrew conductivity dip stick to monitor the progress of the BD / Glycerol interface level.

I'd used a 4% prewash.

The soap content was 'very low' - I wish I'd measured it with my BPB, but I didn't expect it to be of interest - the soap removal stage was swift, with little soap residue.

The biodiesel passed Jan Warnqvist test, with no dropout.

I'm making a new high voltage generator. If any of the UK group want to borrow it, I'd be pleased to loan it out on rotation. It's reasonably safe, current limited, fully insulated, sealed in resin.

Perhaps handover at the convention?

Cheers for now,

we'd be very much up for doing some experiments with or without your kit, graham.

regarding electric fence energisers, the ones i've been looking at run something like 8kv...would that be too high? they're also pulsed...not sure if that would make a difference...at the very least it would mean much less on-time and presumably the whole process would therefore take longer. on the other hand i guess one could rip out the pulsing circuit...though i suppose the components may not be rated for continuous service. otherwise i need to get hold of a megger i suppose. most of the ones i can find are battery operated...i want a nice benchtop psu like yours.

incidentally we tried an experiment using our 20v dc supply. nothing at first, and when we got the gap down to about 2mm a tiny hair of ?soap? bridged it. need more volts!

Graham,
This is great news! I spoke with a friend who does electroplating for the microchip industry. He's a electrical/chemical engineer. Your results line up with his comments on the glycerin settling. He indicated it would take longer to settle with a larger batch using the same voltage. At a specific voltage the bioD will become electrically saturated and additional voltage will not increase the settling time. This voltage saturation is dependent on the amount of bioD in the electrical field. This may explain why there wasn't a large difference in the test experiments from 300 to 1000volts because the smaller sample was probably close to saturation at 300v. Of course the risk may go up, but we may see faster settling times with larger batches as voltage increases.
I'm roughly 2 weeks out before I can experiment, but can we do a graduated test as a community? Here's my proposal: Everyone conduct tests with a specific quantity of bioD. We could do 5, 10, 20, 30, 40 gallon batches and compare the results. Ideally one person would work with the same quantity…say 10 gallons at a time. Keep the quantity the same, but increase the voltage each time and record the amount of time it takes for settling. This would give us an electrical saturation point for a given quantity of product. We could then extrapolate this to larger batches and have an idea of proper voltage. This way we can limit the voltage to only what is really needed. Also, please indicate if you are using NaOH or KOH. There will probably be a difference between the two.
Also, he said the soap removal is essentially electroplating. You probably know this already. It may be as simple as introduction a positively charged rod into the bioD so all the soap clings to the rod. If done correctly, the rod could be easily removed, wiped off and replaced for the next batch.
Thanks to Graham, it sounds like this is something worth investing a lot of time and energy into so we can nail down specifics. I’m looking forward to experimenting and hearing what everyone else comes up with!

Kind Regards,
Martin

some fence energisers are continuous.

Got a circuit we could copy Graham?

I'm interested in what would work for a standard IBC as they are widely available to everyone relatively cheaply for the size.

am I the only person who hates to see this thread drop off the first page? combined with meth removal this seems like a great dry wash method to me with only a small amount of electicity as a consumable. Less time. Less resources. we win. the environment wins. Thats good.

Hi Ant,

The circuit I used is based on the one at the top of the page mentioned here, but with a few tweaks to suit the components I had on hand.

Regards,

I hate to see it drop off, but it is a method that requires more skill and dedication than I have right now. Especially as I am 800 miles away from my process right now.

-Jim

quote:

Originally posted by Ant:
am I the only person who hates to see this thread drop off the first page? combined with meth removal this seems like a great dry wash method to me with only a small amount of electicity as a consumable. Less time. Less resources. we win. the environment wins. Thats good.

Okay, so by way of keeping it up top, and to request a summary of benefits:

In order for this to replace common wash methods (water washing or Magnesol or GL's *other* method whose name I can't recall), electroshock therapy would have to remove soaps, glycerides, and other polar (?) impurities that regular wash methods remove. Does it do so?

...oh, and water. Does it dry the product? Is that really necessary if...

Does one *have* to remove the methanol for this to work? As (IIRC) Ant has pointed out, methanol is decent fuel itself, and having a small amount of it remain in the biodiesel may not be a bad thing.

I just ordered a negative ion generator from Electronic Goldmine, to experiment with EFP. 120vac input, 7.5kv DC output, $10.95.

Graham,

Thanks for posting the HiVoltage circuit page (and for coming up with all this). I saw that you were using a homebrew conductivity dip stick. You wouldn't happen to have a link to the circuit for that would you? I wonder if you could use it for monitoring water level when dewatering as well as.

Keith

not sure if this is along the lines we are talking about here

http://news.thomasnet.com/fullstory/467542/1344

http://www.oilkleen.com/oilkleen-products/index.php
http://www.oilkleen.com/oilkleen-products/system-specifications.php

plugly

Hi Keith,

This is the circuit I use...
Glycerol/water detector

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Hi plugly,

There you go! Looks like what we're doing. Except the biggest benefit with the least effort, for us, seems to be the glycerol settling.

Has anyone successfully opened the video I posted at the top of page 5? I know some folks have reported it doesn't open every time.

This message has been edited. Last edited by: GrahamLaming,

quote:

Originally posted by GrahamLaming:
(SNIP)Has anyone successfully opened the video I posted at the top of page 5? I know some folks have reported it doesn't open every time.

The video worked for me, Graham. Quite dramatic! I am a little puzzled, though: I use KOH, and I have separation of the glycerine in quite short order. Short enough, at least, that I wouldn't apply a few kV to anything to speed it up. If it removes the water, too, that might change the equation for me.

However, the possibility of removing soap and other impurities is very intriguing to me. Has anyone tried soap removal using high-voltage DC on KOH-based biodiesel?

quote:

Originally posted by greiswig:
The video worked for me, Graham. Quite dramatic! I am a little puzzled, though: I use KOH, and I have separation of the glycerine in quite short order. Short enough, at least, that I wouldn't apply a few kV to anything to speed it up. If it removes the water, too, that might change the equation for me.

However, the possibility of removing soap and other impurities is very intriguing to me. Has anyone tried soap removal using high-voltage DC on KOH-based biodiesel?

and...

quote:

Okay, so by way of keeping it up top, and to request a summary of benefits:

In order for this to replace common wash methods (water washing or Magnesol or GL's *other* method whose name I can't recall), electroshock therapy would have to remove soaps, glycerides, and other polar (?) impurities that regular wash methods remove. Does it do so?

...oh, and water. Does it dry the product? Is that really necessary if...

Does one *have* to remove the methanol for this to work? As (IIRC) Ant has pointed out, methanol is decent fuel itself, and having a small amount of it remain in the biodiesel may not be a bad thing.

What...no replies to EITHER of these? Have I offended? I thought I read the entire thread before I asked this...