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what size reflux tube for recovery?
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I have been reading a few other post where people are talking about the recovery purity form 40% to 98% pure methanol that they recover. I assume allot of that is just like moonshine purity and depends on your specific setup so here the question.

Using these for base factors; reactor tanks being 60" tall and 24" diameter, maintained temp at top of reactor tank of 148 degrees , using a small diameter 2" pipe for a reflux tube. How long/tall would it need to be to effectively recover around 98% pure methanol ? (not the condenser coil just the reflux tube)
 
Location: SE Florida | Registered: March 13, 2011Reply With QuoteReport This Post
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When we built ours we used 3" pipe and made it as long as we had room for, around 3'. Works awesome. Go as long as you can. First we had it filled with marbles but when we took it apart after almost a year the marbles were pitted so when we put it back together we used some stainless steel shavings from a machine shop- they are essentially long curly cues of steel and we just hung them in the column.



 
Registered: April 28, 2008Reply With QuoteReport This Post
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ok thanks 3"x3' or taller gives me a good base line of what works. My bio system is on a wheeled frame so it can be stored on the screen porch or garage when not in use but moved outside when I am using it so the reflux tube will have to be removable to fit through the door so I can go pretty much any length
 
Location: SE Florida | Registered: March 13, 2011Reply With QuoteReport This Post
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Thanks for posting your thoughts on my thread about what sized tank I may have. You could always start with 3' and add a fitting to add another amount of height or just go for it inthe beginning. If you expiriment let us know the outcomes of your purity to height ratios. The pitting that occures in the marbles would add additional surface area I believe.
 
Location: Chicopee, MA | Registered: February 28, 2011Reply With QuoteReport This Post
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its not the size that matters..

can you control the temps at the top of the column?

if not..you never get 99+ % pure..

stats..

80 gallon water heater..electric..
I inject air into the pot
I control the temps at the top of the column..152F..+-1F
column 2" dia 5' tall most packed with stainless scrubbies..

purity out..good enough for 27/3 testing..or 99.5% or better

-dkenny

ps I control the temps at the head..not the pot..


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Location: RTP, North Carolina | Registered: December 15, 2004Reply With QuoteReport This Post
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quote:
I assume allot of that is just like moonshine purity and depends on your specific setup so here the question.

Not quite, with methanol you can get 100% purity since unlike ethanol there is no azeotrope concerns with water. A reflux column is not necessary for methanol if your only contaminate is water (in theory).
I use a 3/4" piece of black pipe about 40" long, its on about a 45 degree angle from the top of my reactor to the top of the condenser. I have nothing in it other than a small piece of steel wool jammed into the union at the tank connection, I stuck the steel wool in there just to break up any foam or bubbles that may get into it, I dont think it does squat though.
I do WBD or push/pull batches so I have to keep the pot to a maximum of 175F, the PID for my processor heater maintains the pot at 175F. I then have a heat tape wrapped around the 3/4" pipe mentioned above thats controlled by a separate PID with the TC at the top of the pipe before it turns down into the condenser, that PID keeps the pipe temp at 150F for methanol recovery and about 175F for dewatering. I get between 99 and 100% methanol recovered with this setup.
Here is a crappy picture of the pipe with the heat tape on it before it was wrapped in insulation. You can see the wire leading to the TC that is clamped to the 90 at the end of the pipe before the condenser, and the white heat tape going up either side of the pipe, I will be using the exact same setup on my new 500 gallon reactor since it works so well.
cheers,
Jon
 
Location: Wellington County, Ontario Canada | Registered: February 07, 2008Reply With QuoteReport This Post



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I forgot to mention a very important point! I use vacuum for recovery.
Also, it does not seem to matter how long I let the recovery go, I let it recover until the methanol slows to a slow drip and I always get very pure methanol.
Cheers,
Jon
 
Location: Wellington County, Ontario Canada | Registered: February 07, 2008Reply With QuoteReport This Post
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I want to ask a "reflux column" question. Once I reach 146F headtemp on my short reflux column I get good recovery for awhile. Usually as I reach the theoretical amount for recovery my headtemp will drop to 133F or so, and of course output stops. I am still adding heat via a 4500 watt heater and the pot temp is 180 to 190F. I thought the "normal" thing would be a temp rise and the capture of water vapor rather than a cooling and stopping of the distilling.
jim
 
Location: Saint Paul, MN. | Registered: September 17, 2007Reply With QuoteReport This Post
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My head temp (pot still) is a steady 150-152F and the pot itself gets up to 260F +/- sustained until the flow is down to a very slow drip.

I do not reuse the full amount of methanol in follow up batches but rather limit it to about 25% recovered to 75% fresh.

HTH



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Location: :-) Great White North eh ? | Registered: December 10, 2004Reply With QuoteReport This Post
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quote:
Originally posted by Legal Eagle:
My head temp (pot still) is a steady 150-152F and the pot itself gets up to 260F +/- sustained until the flow is down to a very slow drip.

I do not reuse the full amount of methanol in follow up batches but rather limit it to about 25% recovered to 75% fresh.

HTH


Mine works the same, although I had to put a gable vent and fan in my garage last week because it was so hot in there that it stopped working properly. Outside temp was almost 100F and in the garage it must have been 150F in the top where the top of the reflux column is. It was flowing good but then stopped flowing because with the temp so high the thermostat was not calling for heat from the pot.



 
Registered: April 28, 2008Reply With QuoteReport This Post
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