Prewash and bubble with aquarium pump

[imilet1]

Dear all,

I am new here on this forum and I produce bio for my hobby and car also:) Usually my process goes like this:
1.heat 100 l Wvo to 60 C
2.add 15% methoxide
3.mix 1 hour
4. 7% prewash5
5. bubble 2 days with aquarium pump in open barrel without cover (open top)

I worried because of evaporation of methanol, after having poured fuel from the reactor into an open barrel without cover. Maybe you know how much methanol is in the 7% prewash bio? Is method bubble with an aquarium pump safe enough because of methanol evaporation? How much methanol is actually in bio after the 7% prewash? I can smell meth 2 days, sometimes even more...

Have a nice day:)

[Tony]

Welcome to the forum.  The tail end of my process involves heating the bio to 90C or so to condense out the methanol (GL style) then pump into open topped drums and bubble.  I'm just careful not to breath any fumes that comes off.

Are you sure you're smelling methanol and not just hot bio?  I would have thought that the 7% prewash would take a lot of Methanol with it.

I would quite like to make my settle/bubble drums vented to the outside but not quite got around to that yet

[imilet1]

hm, I dont demeth my fuel. My reactor is just vented to the air and doesn t have methanol recovery. So I prewash it and drain glyc, then in open barrel and bubble for 2 days...

[Julian]

Welcome to the wiki and forum.

What processor do you have?

It sounds like it may be a commercial produced unit.

[dgs]

Hi imilet,
nice to see you on here.

I also bubble to de-meth and don't have any venting of the methanol. I don't do the pre-wash (glycerol+water) so I have to leave the bio room while the methanol is evaporating. There is a door at both ends and these are open. I use a compressor to drive off the methanol at around 50 degs and after 2 hours or so it is mostly gone.

[Tony]

after 2 hours or so it is mostly gone.

Here's a question - how do you know?

I often wonder this with my bio.  Heat to 65C and see if it bubbles?  Sounds a bit risky!

[dgs]

Tony, I don't know!
The thing is I need to shift most of the residual methanol so most of the glyc/soap drops. This ensures that the soap/glyc level is such that it will not emulsify with an aggressive compressor wash(190 litres of bio + 10 litres of water)

 Until a few months ago I didn't try to get rid of the residual methanol, I just washed the mix with pure glycerine which got rid of most of the soap(even with methanol present)

On the few occasions that I have just settled (which I must say I don't like doing for reasons of residual glyc, mono's) I then carry on with a gentle bubble for a couple of days then let it stand for a week.

[imilet1]

I also bubble to de-meth and don't have any venting of the methanol. I don't do the pre-wash (glycerol+water) so I have to leave the bio room while the methanol is evaporating

That s interesting, how much methanol is in unwashed bio? 3-5 % or even more? I think that s a little dangerous to air bubble near open window:)

Maybe 2 or 3 static washing can reduce methanol...

My reactor is the same like these  http://www.threedeadflies.com/reactor.asp

[dgs]

Jamesrl is the one to answer that question, he recovers methanol from the bio only.

[Julian]

My reactor is the same like these  http://www.threedeadflies.com/reactor.asp

Ah, an apple seed type design.  It may pay you to install a venturi and condenser.  It would make the processor far more flexible in what it can do.

Incidentally, out of interest, roughly where are you located?