removing Methanol in a continuous still

[Woodpile]

Well, That was certainly a lot of references - which I will try to collect and read over time. If I understand correctly, my ignorance of the principles of continuous still operation are why I was curious about volatility levels. As the old-timers pointed out, that type of still causes the problem. I am glad I didn't make one of those - problem solved. I will continue learning to improve my cuts. And I assume I didn't read about continuous stills here because they are not practical for the normal intentions addressed on this site.

[Prairiepiss]

I as usual annum agreement with Rad on this subject. Yes I am intrigued by its use as a stripping still. No mater what anyone can say here will ever convene me there is a viable option for making a finished product. From a hobby scale continuous still. But my only hickup with the stripping setup is. The added space needed for the thing to work. And the fact that you will need a batch still to finish the job. Just doesn't make since to me. When the batch still could be used from the get go. I would love to see someone succeed in a good design. That actually did something to better the hobby. That wasn't overly complicated, expensive, or take up to much room.

The other problem I do have with a continuous still. I am one of the many that beleave you should man your still the whole time it is running. And don't like set it and forget it thinking. So how much time can you really save by using one?
I can strip and run a spirit run on 35 gal of wash in 12 hours with my keg boiler batch still. Without ever tearing it down. What would be the realistic numbers of a continuous running still. At a hobby level? Would it take up less space then what I have now? I just don't see it happening. But I've been wrong many times before.

[NZChris]

Did a bundle of research on this back when stillin was still illegal in NZ. Too many problems for this hobbiest. My design ended up with two columns because of the height I needed and even if I went to the trouble of building it, it still needed feeding with far more than I could reasonably expect to be able to brew ...... or drink ...... and my lawnmower was doing just fine on petrol.

Built a preheater utilizing the condensate instead. Saved a heap of time and energy costs.

[Hennie]

Hi, Guys
This is my first real post(apart from my intro!).
I really need advice! I just build my first Boka and are about to do my first runs so I'm a complete novice! I do have a scientific background,which does make a lot of things easier for me to understand.
I'm from Namibia and there is currently a massive ethanol shortage for hand sanitizers,,etc
We don't have many confirmed cases yet but this is Africa, we don't really have the capacity to test extensively and the situation could in reality be much worse. People are scared like everywhere else but we are a net importing country and our borders are shut except for critical services and products. Normally we would import ethanol from South Africa but most suppliers are already out of stock or they keep it in country.
The local government agencies has asked if I can produce on large scale; 250-500 gallons/week! All will be done quite legally of course!
Quality does not matter as long as its 80% or higher.
What advice can you offer me? Assuming funds are not a problem but everything has to be sourced locally!

I know many newbies ask silly questions but if I'm in a situation where I can help I have to.

Appreciate you advice.

[Corsaire]

I'm no expert, but a single column Coffey still comes to mind. It's what they use in Martinique, or so I'm told.
It's just the twin columns of a regular Coffey still stacked on top of each other, which simplifies plumbing. Live steam in in the bottom section, fresh wash enters in the middle of the column, product out at top plates, spent wash leaves at the bottom.

Since you only need 80% I don't think you'd need a whole lot of plates.

[Kareltje]

How about this:

Each day one of the submarines was filled with wort and fermentation was started.
When fermentation was finished, a copper helmet was placed and a fire was made under the submarine.
After distilling the vessel was cleaned and the cycle could start again.
With one stripping run each day you need only one stil for the spirit runs.

If the quality of the drink is not a issue, bad taste and/or some methanol from the wooden sides is not a problem.
I suppose you can think of the advantages of this system yourself.

[LWTCS]

Hennie,

If you had a still that could produce that volume within the time constraints, how will you feed it?
You'll need fermentation capacity.
You'll also need to fire the still.
Probably 500,000 BTUs to fire the still and about 17 tons of cooling.

Are you prepared for that? And likely a six month lead time to get everything manufactured.

[Birrofilo]

The local government agencies has asked if I can produce on large scale; 250-500 gallons/week! All will be done quite legally of course!
Quality does not matter as long as its 80% or higher.
What advice can you offer me? Assuming funds are not a problem but everything has to be sourced locally!

I am probably saying something incorrect, but for what I know, ethanol can be produced by purely chemical procedures, without involving yeast and without fermentation.
Starting from say natural gas, through a process of thermal cracking you obtain ethylene, C2H4, and from that you can obtain ethanol through a series of chemical reactions. I'm no chemist but I have always known that all alcohols for industrial purposes (be it ethanol, methanol as fuel, etc.) can be obtained through strictly chemical means rather than biologic.

I am quite surprised to read your text as, for what I know, I would expect a governement to pursue the chemical route, the refinery (unless, that is, there is no chemical plant able to produce it in the country) instead of the biological route, the still.

A chemical plant is able to produce those substances in huge quantities and much lower cost.

A Chinese firm can possibly come to Namibia and open an alcohol refinery in 20 days (OK maybe more, but you get the point) and that will produce huge amounts of ethanol. I must be missing some information.

Basically I think ethanol can be produced with the same kind of chemical transformations that are used to produce methanol for industrial purposes (as solvent, fuel etc.).

[Hennie]

Pot is only 165 litres but will get an upgrade if all works well!

Sorry, I have been away for a while and I've been buzy! Can not believe it is so difficult finding material and parts in a lock down!
Birrofilo, thanks but Namibia does not have a refinery and we are relying on Sasol in South Africa for our ethanol and isopropyl supply. They announced last week that they will no longer supply any raw material and will manufacture their own sanitiser! Many industries require these products apart from producing hand sanitiser but apparently that is not the focus at the moment!

I have found a much better market for my produce anyway! Won't say what!

My days work with my two helpers!

[drmiller100]

The members of this site are convinced methanol doesn't exist, or come out in rhe heads.

None the less, there are heads and fores which would be nice to separate if you are making drinking spirits.

I've made amd ran several small continuous FUEL stills, and I don't think you can separate the heads from the hearts in a continuous still without a lot of waste IN ONE PASS.
There is no way in the reflux to separate the heads out.

However, you could absolutely pull the heads from the 190 proof using s pot reflux still.

Or you could run the 190 proof through the continuous still amd get the heads. To do that,, run the continuous still in full reflux, amd pull the heads in spurts when you see the reflux Temps drop indicating a collection of heads at the top of the column

[DRHillier]

And I'm now following this thread for educational purposes as well as amusement and curiosity.

[LWTCS]

The members of this site are convinced methanol doesn't exist, or come out in rhe heads.

None the less, there are heads and fores which would be nice to separate if you are making drinking spirits.

I've made amd ran several small continuous FUEL stills, and I don't think you can separate the heads from the hearts in a continuous still without a lot of waste IN ONE PASS.
There is no way in the reflux to separate the heads out.

However, you could absolutely pull the heads from the 190 proof using s pot reflux still.

Or you could run the 190 proof through the continuous still amd get the heads. To do that,, run the continuous still in full reflux, amd pull the heads in spurts when you see the reflux Temps drop indicating a collection of heads at the top of the column

Hi Doug,
You can make (somewhat) of a heads cut if you pull product as liquid off of an actual plate.
In other words, you cannot collect / send vapor directly to the finished product condenser as all manner of beer constituents will be in the vapor.

Collection as liquid off of the plate will allow for lower boiling point constituents to re-vaporize and continue to the top of the apparatus.
In order for this to happen there needs to be a dephlegmator with ample knockdown power, precision cooling media flow control, and a dedicated cooling circuit. And you'll need a trap at the take off port to ensure vapor doesn't escape unless you install a slant plate or internal cup.

You can't really execute that with packing unless you install a dedicated collection cup ahla Liquid Management style.

[LWTCS]

You know what,, I take that slant plate / collection cup assertion back.

Without vapor passing through the liquid bed (as with bubble plates) there won't be enough heat to flash volatiles in the liquid bed of a more traditional LM styled slant plate.

[drmiller100]

You know what,, I take that slant plate / collection cup assertion back.

Without vapor passing through the liquid bed (as with bubble plates) there won't be enough heat to flash volatiles in the liquid bed of a more traditional LM styled slant plate.

Yeah, it took me a while to figure it out too.

I think you MIGHT be able to control the reflux coolant amd run the heads out the top as steam along with a bunch of etoh but not very efficient and I'm not sure it would really work.

[LWTCS]

It does work. That is to say it is working.

There is a very perceivable difference in the heads product take off vs the finished product take off.

The question is how much ethanol is in the heads product?

As far as whiskey goes, Usge always used to say ya gotta put it up a little dirty to make good whiskey haha.

[stevea]

You can remove "heads" in a continuous still, by adding additional plates above the distillate extraction plate, and then extracting and tossing some of the most volatile bits at the top. Another approach is to vent the distillate plate into another column where ethanol becomes "bottoms" and the higher volatile "heads" are the "tops". These are sometimes called "barbet" columns after their use in rum distillation.

But Edwin's comment from ~7ys ago is relevant. BP does NOT directly determine what is in the various cuts. Some molecules bind more tightly to others, so the behavior of the partial pressure of a pure compound is not representative is a mixure. Ethanol & Methanol have very similar VLE curves IN WATER. But MeOH & EtOH clign to each other and are much harder to separate well.

I'm increasingly unconvinced that "heads" exist in a grain wash. In Scotch manufacure lit', they attribute "foreshots" to washing fusel residue from the previous batch. So they put all the foreshots back into the subsequent batch! Then they immediately start collecting for the barrel once the demister test passes. They don't toss tails either! They stop collecting to barrel when the total ABV drops (~65-70% ABV) and then separately collect almost all the remaining "tails" alcohol for later batch re-distillation,

In US whiskey production, they run a continuous column at 100% reflux till stable (washes any residual fusel's down), then into a heated "doubler". The big guys will operate a column up to 11 months of the year 24x7. No heads removal to speak of.

Of course many sins are forgiven with a few years in a barrel.

[LWTCS]

Yeah nicely put Steve.
Also think about how Armagnac is distilled.

I'm also increasingly more convinced that there is some thermal degradation that occurs when reboiler bottoms get recirculated back into the beer circuit to be run back through the system.
I believe doing so has a transformative, softening effect on some of those constituents that would otherwise be viewed as undesirable.
I don't have any COAs however to verify any of my practical exposure to fresh made white dog off of the continuous still.

[LWTCS]

"Another approach is to vent the distillate plate into another column where ethanol becomes "bottoms" and the higher volatile "heads" are the "tops". These are sometimes called "barbet" columns after their use in rum distillation."

Yessir. The above simulation does just that.

[drmiller100]

Of course many sins are forgiven with a few years in a barrel.

For sure the heads leak out of the barrel first.

I am curious about your suggestion heads don't exist. I can taste them and smell them. They are nasty.

And you deny their existence??????

On edit. I lump heads and fores together in my mind as ickies at the beginning.

[LWTCS]

Doug I don't think Steve is saying that the constituents that make up a more typical heads cut don't exist. clearly they do.

To put into a different context, and notwithstanding grain bill, yeast, fermentation temps, barrel aging, and blending, it is ultimately it is the constituents found North or South of dead center that provide much of the complexity.

And as mentioned there are distilleries that make no cuts or recycle everything back into the circuit.

Just takes a bit more time to round out. 4 year old bourbon or better is kinda where ya wanna be for a mature whiskey.
Imo, Armagnac on the otherhand is still way too raw for my liking at 4 years as an example. But at 12 years,,oh yeah!!