Temperature & ABV charts, product ABV calculator (pot/plates)

[tmitsi]

Inspired from viewtopic.php?t=10158, I made a calculator that I have been using for some time. All calculations are performed using the formulas given in the wiki section https://homedistiller.org/wiki/htm/calcs/calcs_calc.htm.

I've decided to put the code online, so here is the repo: https://github.com/tmitsi/distillation-tools, go to the only folder there. It's in octave (it should run in matlab too), usage is kinda easy if you know basic octave/matlab or if you have experience with other programming languages.

Features:

• Generates the ABV/Temperature diagram
• Calculates the expected product ABV from a given wash ABV assuming no plates, i.e., pot-still with no reflux
• Calculates the expected product ABV from a given wash ABV assuming a specific number of theoretical plates (integers only)

If you have any suggestions, let me know.

I hope it will be helpful. BTW, would an excel version be helpful too for the non-programmers?

Screenshots:

[Renhoekk]

Very nice, tmitsi. Your stepped phase diagram is more user-friendly than the one I recently linked to in another thread. The topic was "how do I get the last 3%", and it's very useful I think to see just how hard it is to go from 93% to 96%. You can go from 40% to 93% relatively easily with a basic reflux setup, and then it takes at least double the plates (or HETP) again to get to 96%.

[MooseMan]

Very nice, tmitsi. Your stepped phase diagram is more user-friendly than the one I recently linked to in another thread. The topic was "how do I get the last 3%", and it's very useful I think to see just how hard it is to go from 93% to 96%. You can go from 40% to 93% relatively easily with a basic reflux setup, and then it takes at least double the plates (or HETP) again to get to 96%.

That was me, and I thank you for your input Renhoekk.

Tmitsi nice work!

[higgins]

Very nice, smooth graphs.

As with all the other similar ones that I've seen, it seems this is only useful for those who are at sea level as there is no correction for elevation. I'm at 3200 ft elevation and my water boils at ~206F (96.7C), so my effective temp scale is 32 to 206 rather than 32 to 212. When my VT is 206 my abv is 0, not 20.5.

Since these are app-generated graphs, would it be very difficult to include an elevation factor, and adjust the graphs accordingly? That would allow people to generate a graph that applies to their situation.

I've created a vapor temp correction list to show me ABV for MY vapor temp. I 'compressed' the graph by adjusting it such that 206 correlates to 212, and 32 still correlated to 32. Of course, it is only pertinent for ranges of about 167F to 206F, but applying the same factor (206/212) to each temp I get a new temp for that ABV. I'm not sure this is exactly correct, but the corrected values seem to correlate more with reality for me. Here is a clip to show it:

I'd love to have an Excel version. Although I was a software developer for years, I've been retired for 8 years and have not dabbled in it since.

[bluefish_dist]

Nice work. As Higgins suggested any way to do it by absolute pressure? That would also take into account changes due to weather as well as elevation.

[higgins]

In the thread that inspired tmitsi I found this post that contains a formula that includes altitude correction.

With what I learned over the last few days I think this is the equation to use.

V=1.00234870142762+0.00448539174680633*(T+A*F)^2/((T+A*F)^2-76.8192824761981^2)+0.167549870972697*(T+A*F)^2/((T+A*F)^2-107.95147196715^2)


T=Temp in °C
V=%ABV of vapour
A=Altitude in metres
F=fudge factor (%0.34 for water or %0.31 for azeotrope, depends which end of the scale to you want more accurate) Just leave at 0m for no effect.

If you don’t want altitude, just leave out A&F.
This equation gives 100°C as exactly 0% and 78.1°C as 95.6% and it is derived from the original Perry data set so hasn’t been washed down along the way.

If anyone has better data I could go further but I think this is the end of the line.

So this formula calculates ABV when given a vapor temperature (C), altitude (m), and fudge factor.

I've put that into excel and use 975m (3200ft) as my altitude (note that I had to include the fudge factor [.31%] to make it use altitude). I regenerated my list, converted to °F and it correlates fairly well with my adjusted list. 206.56°F = 0% ABV, 167.15°F = 95.6% ABV

This is certainly close enough for me without including atmospheric pressure.

[tmitsi]

Nice feedback, many thanks.

So, a few points (and some priorities to set):

I don't have MS Excel handy, but played a little with LibreOffice's Calc. Working with speadsheets was a pain but I can generate the diagram. But Excel cannot read the file correctly, the diagram is messed up. I'll see if I can find a computer with Excel to correct the file and upload both .ods and .xls versions.

Now, about atmospheric pressure:
The vapor ABV calculation would be straightforward using Jacksonbrown's equations (thanks higgins, I overlooked that). But here is the problem, any idea what happens with the liquid phase? As far as I can see, the liquid phase would determine the temperature, and this temperature will be subsequently used to calculate the vapor ABV.

[tmitsi]

Quick update:
Maybe correcting the boiling temperature by subtracting A*F (t = t - A * F) does the job?
If that is correct, the diagram seems kinda ok, and the two curves don't differ that much. Both are using the new boiling temperature though.