as an aside, was boiling sap this weekend for maple syrup, and came across
some really neat 15 gallon drums (half of a 30) labeled "dr. pepper", a semi
popular soft drinks in these parts. complete with bungs and everything a 30
or 55 would have.
Steve Spence
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[EMAIL PROTECTED]
- Original Message -
From: "Darryl McMahon" <[EMAIL PROTECTED]>
To:
Sent: Sunday, March 23, 2003 10:03 PM
Subject: [biofuel] One Litre Line
> I hope some of you can help explain to me what I have seen of late.
>
> I am a biodiesel novice and no chemist. I have spent a couple of months
now
> building my one-litre biodiesel processing "plant". This is intended to
model my
> plans for a larger 100-150 litre setup to come later. But I want to keep
my early
> mistakes small (and I make plenty to learn from).
>
> The reactor is a scavenged slow cooker, which does a reasonable job of
keeping the
> mixture at about 50 degrees C at the lowest setting. Agitation is
provided by a
> discarded mix master with one beater that is lowered into the cooker while
attached
> to a plexiglas splatter shield. The settling tank is a 1.8 litre glass
jar, and
> the washing tank is a 2-litre glass jar with 2 small air stones, a
5-gallon
> aquarium pump, plastic tubing and a large steel washer as a weight.
>
> The first batch was done with fresh vegetable oil. I made the methoxide
using 200
> ml of methanol and 3.5 grams of lye. The titration results were bizarre
the first
> time, and closer to the expected result the second time. I went with Mike
Pelly's
> recommended recipe for the one-litre test batch. I put the oil into the
reactor,
> then the methoxide. All went as expected from my reading. I allowed the
mixing to
> go for about an hour, then drained the lot into the settling tank.
>
> The separation began quite quickly, and after a couple of days there was a
creamy
> coloured precipitate layer at the bottom, but less than I expected. I
estimate a
> bit less than 10% of the total volume (say about 100 ml). Does this make
sense
> given it was fresh oil instead of waste oil?
>
> I let the batch settle for about 2 weeks, and then transferred the oil to
the
> washing tank, drawing the oil off from the top. I noticed at this time
that there
> seemed to be some "dendritic" material, almost like wisps of white cotton
candy,
> growing up from the sediment layer. Any ideas on what that is?
>
> Onto the washing. I set up the washer with the stones at the bottom of
the jar,
> then added about 500 ml of tap water, more or less the Idaho method, as I
> understand it anyway. Then I added the oil, a little over a litre, so
presumably
> containing some methanol/methoxide. Before I started the bubbling, there
was a
> significant white layer above the water and below the oil. Reminded me of
> mayonnaise. I suspect a water/methoxide reaction, as I see no visible
reaction
> when I mixed methanol and water for comparison.
>
> Oh, no vinegar used. When I was finally set to go tonight, not a drop to
be found
> in the house. I'll be sure to correct that before the next washing.
>
> After I started the bubbling, the "mayonnaise" came to look more like
white
> aquarium stone or rock salt. Anyway, the wash is under way now. Bubbling
froth at
> the top was ferocious initially, but after 20 minutes it has subsided a
lot. The
> mix is quite opaque and a dark cream colour now. I have had to stop the
bubbling a
> little after an hour, as one of the air stones has disintegrated (12 hours
was
> recommended). It is starting to settle out again, looks like there will
be a good
> pile of whitish precipitate once settling is done.
>
> The second batch was made from lightly used vegetable oil (to deep fry a
turkey),
> but has been stored for some time since then. Titration indicated 1.5 ml,
so I
> used 5 grams of lye (1.5 + 3.5) and 200 ml methanol.
>
> This batch frothed some during the stirring phase, which I did not notice
with the
> first batch (fresh oil). The separation started slower, but there is much
more
> precipitate this time (at least 25%). However, there are a few of the
"dendritic"
> white threads suspended in the clearer oil, apparently due to having
trapped some
> bubbles which are keeping them buoyant. I'm sure they'll filter out in
the next
> transfer.
>
> So, now that I actually have some experiences to report, I would also like
to thank
> Tom Leue for putting up with us for an afternoon last November when we
brought the
> snow to Massachusetts. His tour of the facility and advice were, and are,
much
> appreciated.
>
