Here in Brazil cars run on pure alcohol. Usually 96GL (or 92,8 INPM as it is calculated per weight here) but cars can run with alcohol as low as at 85GL. The remaining being water.
Crush so much cane to get 1000 - 1500 gallons and ferment that much mash is not the biggest issue really.
A man can cut up to 6 tons of cane per day
This used press (just an example among many other available) can produce 1200 gallons of juice per hour. There is a lot of equipment for sale all the time.
Tanks like this are used.
Now how such quantities can be considered a hobby? Despite the quantities it's still very amateur. It will be done in our small farm and it's a project to complete our income, we are far from an industry. In the same vein, I want to build, myself, a continuous still to avoid having to boil huge quantities of mash with huge losses both in alcohol and energy. I am definitely not in condition to buy a turnkey SS continuous still.
semi continuous column design
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Re: semi continuous column design
Please Deepsouth, how do you find out these dimensions?DeepSouth wrote:I think your biggest issue is fermentation. You'll need to process something like 1000-1500 gallons of fermented wash per day.
Your column will need probably need to be around 10 to 12" on diameter and maybe 15-20' tall.
Re: semi continuous column design
Simple math working backwards for the quantity of wash.
You said you wanted 360L/day of 90% ethanol. So thats about 330L/day of pure ethanol.
You COULD say, that you can ferment to 15% ABV in the mash/ferment. Yeast slows down as it goes higher, and its harder to dissolve all those sugars, taking disproportionately more time.
Thats 330L/0.15 for a total volume fermented of 2200L/day or dividing by 3.8 for Gallons, 580 Gallons/day - Obviously, lower ABV in the ferment, more total volume (1160G at 10% ABV and 1740G at 5% ABV)
For the column dimensions thats a bit trickier, the height is determined by 2 things,
stage efficiency or the technical term HETP (Height equivalent theoretical plates), to keep it simple, a tray is usually between 35 - 50% efficient, so as a rule of thumb you need 3 trays per theoretical stage.I haven't checked this because I'm away and not at work, but say you need 6 theoretical stages (which is about the minimum from memory for this duty), you'd need 18 trays, with a gap of say, at least 1 foot between them.
The second is reflux ratio, in short columns, you can still achieve very high purity using a high reflux ratio, the taller the column, the less reflux you need until you reach somewhere near the minimum (you will never get the actual minimum ratio, but I'm not going in to why thats the case here). Why is this important?! Well simply put, the higher your reflux ratio, the more cooling water you use and the more energy you use heating the still, as energy used to evaporate is used to condense the liquor.
So column height vs reflux is trading between Capital Cost and Variable Cost. Do the sums, and balance it based on that.
Column diameter is based on throughput and reflux ratio, higher the ratio, the wider the column, for some applications the difference is so negligible that it isn't worth mentioning, for others, it can be huge (for a fixed throughput)
Unfortunately I haven't the time today to go through sizing the column diameter, as I'd need to work out the traffic and then do the flood point calculations based on an assumed reflux ratio. Someone with more knowledge (deepsouth) can probably tell you how to arrive at that number based on rules of thumb or by eye based on experience. The numbers cited don't look too unreasonable though.
Hope that helps a bit, if it doesn't make sense I'll try and explain it a bit better when I get more time and I suggest doing a lot more reading prior to jumping in. If it makes sense, well good
Cheers,
GB
You said you wanted 360L/day of 90% ethanol. So thats about 330L/day of pure ethanol.
You COULD say, that you can ferment to 15% ABV in the mash/ferment. Yeast slows down as it goes higher, and its harder to dissolve all those sugars, taking disproportionately more time.
Thats 330L/0.15 for a total volume fermented of 2200L/day or dividing by 3.8 for Gallons, 580 Gallons/day - Obviously, lower ABV in the ferment, more total volume (1160G at 10% ABV and 1740G at 5% ABV)
For the column dimensions thats a bit trickier, the height is determined by 2 things,
stage efficiency or the technical term HETP (Height equivalent theoretical plates), to keep it simple, a tray is usually between 35 - 50% efficient, so as a rule of thumb you need 3 trays per theoretical stage.I haven't checked this because I'm away and not at work, but say you need 6 theoretical stages (which is about the minimum from memory for this duty), you'd need 18 trays, with a gap of say, at least 1 foot between them.
The second is reflux ratio, in short columns, you can still achieve very high purity using a high reflux ratio, the taller the column, the less reflux you need until you reach somewhere near the minimum (you will never get the actual minimum ratio, but I'm not going in to why thats the case here). Why is this important?! Well simply put, the higher your reflux ratio, the more cooling water you use and the more energy you use heating the still, as energy used to evaporate is used to condense the liquor.
So column height vs reflux is trading between Capital Cost and Variable Cost. Do the sums, and balance it based on that.
Column diameter is based on throughput and reflux ratio, higher the ratio, the wider the column, for some applications the difference is so negligible that it isn't worth mentioning, for others, it can be huge (for a fixed throughput)
Unfortunately I haven't the time today to go through sizing the column diameter, as I'd need to work out the traffic and then do the flood point calculations based on an assumed reflux ratio. Someone with more knowledge (deepsouth) can probably tell you how to arrive at that number based on rules of thumb or by eye based on experience. The numbers cited don't look too unreasonable though.
Hope that helps a bit, if it doesn't make sense I'll try and explain it a bit better when I get more time and I suggest doing a lot more reading prior to jumping in. If it makes sense, well good
Cheers,
GB
Re: semi continuous column design
Thank you so much.GinBob wrote:Simple math working backwards for the quantity of wash.
You said you wanted 360L/day of 90% ethanol. So thats about 330L/day of pure ethanol.
You COULD say, that you can ferment to 15% ABV in the mash/ferment. Yeast slows down as it goes higher, and its harder to dissolve all those sugars, taking disproportionately more time.
Thats 330L/0.15 for a total volume fermented of 2200L/day or dividing by 3.8 for Gallons, 580 Gallons/day - Obviously, lower ABV in the ferment, more total volume (1160G at 10% ABV and 1740G at 5% ABV)
For the column dimensions thats a bit trickier, the height is determined by 2 things,
stage efficiency or the technical term HETP (Height equivalent theoretical plates), to keep it simple, a tray is usually between 35 - 50% efficient, so as a rule of thumb you need 3 trays per theoretical stage.I haven't checked this because I'm away and not at work, but say you need 6 theoretical stages (which is about the minimum from memory for this duty), you'd need 18 trays, with a gap of say, at least 1 foot between them.
The second is reflux ratio, in short columns, you can still achieve very high purity using a high reflux ratio, the taller the column, the less reflux you need until you reach somewhere near the minimum (you will never get the actual minimum ratio, but I'm not going in to why thats the case here). Why is this important?! Well simply put, the higher your reflux ratio, the more cooling water you use and the more energy you use heating the still, as energy used to evaporate is used to condense the liquor.
So column height vs reflux is trading between Capital Cost and Variable Cost. Do the sums, and balance it based on that.
Column diameter is based on throughput and reflux ratio, higher the ratio, the wider the column, for some applications the difference is so negligible that it isn't worth mentioning, for others, it can be huge (for a fixed throughput)
Unfortunately I haven't the time today to go through sizing the column diameter, as I'd need to work out the traffic and then do the flood point calculations based on an assumed reflux ratio. Someone with more knowledge (deepsouth) can probably tell you how to arrive at that number based on rules of thumb or by eye based on experience. The numbers cited don't look too unreasonable though.
Hope that helps a bit, if it doesn't make sense I'll try and explain it a bit better when I get more time and I suggest doing a lot more reading prior to jumping in. If it makes sense, well good
Cheers,
GB
Re: semi continuous column design
Ginbob, deepsouth, let's consider that I changed my mind and want "only" 120 litres of ethanol per day instead of 360 of my previous example. And considering a 6" diameter column, knowing that the bottom half of the column will be full of marbles and the upper half will be packed with SS scrubbers, what would be the ideal height of that column?
I understood that the marbles need to be washed everyday otherwise the wash would soon clog the system, so there will be two 2" holes in the column to empty it and fill it with clean marbles.
Also I plan on using a 30 litres SS beerkeg boiler and I believe that the column and marbles inside will be heavy enough to be simply placed on top of a (thick) rubber gasket around the opening of the keg. It will be kept in position by side stabilizers but it won't be screwed or soldered on the keg. I would like the opinion of those who already operate with similar designs/dimensions/weights/temperatures to see if this idea is completely crazy or not.
Thanks in advance for your answers
I understood that the marbles need to be washed everyday otherwise the wash would soon clog the system, so there will be two 2" holes in the column to empty it and fill it with clean marbles.
Also I plan on using a 30 litres SS beerkeg boiler and I believe that the column and marbles inside will be heavy enough to be simply placed on top of a (thick) rubber gasket around the opening of the keg. It will be kept in position by side stabilizers but it won't be screwed or soldered on the keg. I would like the opinion of those who already operate with similar designs/dimensions/weights/temperatures to see if this idea is completely crazy or not.
Thanks in advance for your answers
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still_stirrin
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Re: semi continuous column design
Tsk..tsk..tsk. You’re gonna’ get spanked for that one!Seb wrote:...marbles inside will be heavy enough to be simply placed on top of a (thick) rubber gasket around the opening of the keg....
My LM/VM & Potstill: My build thread
My Cadco hotplate modification thread: Hotplate Build
My stock pot gin still: stock pot potstill
My 5-grain Bourbon recipe: Special K
My Cadco hotplate modification thread: Hotplate Build
My stock pot gin still: stock pot potstill
My 5-grain Bourbon recipe: Special K
Re: semi continuous column design
It's for fuel man, I think its fine
Re: semi continuous column design
Yes, and the column will be carbon steel.zapata wrote:It's for fuel man, I think its fine
Re: semi continuous column design
- vapor-management-reflux-still-design-VM-300x231.png (64.15 KiB) Viewed 2300 times
I've read that owners of similar designs (but with larger exits) actually open the product exit valve very little, less than 3/4". I also read something about the russians doing something similar but I can't get back to this thread.
And also for the reflux part I prefer to use a worm condenser. That way I can build two identical condensers. But it makes me put the reflux inlet lower in the column (than the one in the pic above) maybe 1/3 of the column downwards. Is it a problem? I can even put that inlet at the same level of the wash inlet so that I don't disturb the equilibrium upwards. What do you people think?
Just to clarify: below is the general design of the continuous still I plan to make but I will make it a VM head so that I can get azeo from the beginning - I aim 30 gallons of ethanol/day :
- cont_concept.gif (9.43 KiB) Viewed 2299 times