SPP Vs Scrubbers on a short column

[Capt-Cudellez]

Hi. Yesterday and today I had a bit of time on my hands.

I had some high proof from an all heads run back in April that I wasn't happy with.
I had added lots and lots of calcium carbonate to my heads to try and help neutralize some of the esters and make the product more neutral. What I ended up with was 9L of 95.6% hearts that had a slight taste of calcium carbonate
At least I have plenty of junkahol for any new builds - or it might clean up with filtering.

So I decided to charge the small still with some of this and run the stumpy VM with SPP then with stainless scrubbers on the same power settings, to see what the difference in performance would be.

I have been running this stumpy VM with a bubble plate on the keg boiler for white rum, with SPP I was unable to shift it off of azeotrope, so had switched back to scrubbers.
Before yesterday I had not ran it without the bubble plate.

here is the still (it's way off plumb in this pic, It was sorted before the boiler was warmed up)


Saturdays run -
15L in the boiler @ 30%
Column packed with 3" of copper mesh and 9" of SPP
Power approx 1500W (I have trouble measuring the actual power due to the type of controller I'm using, but it was the same setting for both runs)

Sundays run -
15L in the boiler @ 30%
Column packed with 3" of copper mesh and 9" of scubbers - really densely packed.


The comparison. (I took product off at different take off speeds for comparison) SPP were measured at 21oC and it was cooler today so the scrubbers were measured at 19.5oC
All the measurements were taken with a narrow rage 90-100% alcometer, so are pretty accurate.

With SPP I was able to achieve 95.7% (@21oc) running 800ml/h

Below are the other results matched up with the closest take off rates.

SPP 95.5% @ 930ml/h SS - 93.7% @ 900ml/h
SPP 95.3% @ 1100ml/h SS - 92.7% @ 1110ml/h , 92.5% @ 1140ml/h
SPP 95.1% @ 1350ml/h SS - 92.7% @ 1410ml/h


So it looks like azeotrope is achievable somewhere between 800 and 930ml with the SPP, I couldn't get anywhere near it with the scrubbers.
And at other take off rates the SPP looks to be good for about an additional 2% ABV with this very short column.

[Phantom]

Was just thinking from the thread title that my money would be on the SSP.

I keep reading about it and when I finally manage to extract the digit I'm gonna order some to use in my T500 instead of the ceramics.....

If I've worked it out right, instead of the usual 94% I get, it should do azeotrope.......

[Capt-Cudellez]

I'm confident you would be able to hit azeotrope with a T500, the column is plenty long enough.

With the full length column I cant push in 2kw without it flooding, it does such a good job of holding onto the liquid. Not sure if you would have this issue with a shorter column.
But the T500 may require some sort of power controller to drop the power down.

[Phantom]

I'm confident you would be able to hit azeotrope with a T500, the column is plenty long enough.

With the full length column I cant push in 2kw without it flooding, it does such a good job of holding onto the liquid. Not sure if you would have this issue with a shorter column.
But the T500 may require some sort of power controller to drop the power down.

Was gonna wait on asking that when I'd got the structured packing.....

I built a power controller for my super reflux so it should be too much effort.

But gotta wait anyway, the bloody builders won't have finished for another 6 to 7 weeks plus its nearly wine grape season.......

[googe]

Have you tried lava rock captain?, very cheap compared to spp. Ive had a couple of goes on my 3 plate column but couldn't achieve over 90%. But on a strip run with lower abv it jumped around 20%.ive heard it works well with a long packed column.

[Capt-Cudellez]

Have you tried lava rock captain?

No I haven't - I wouldn't know where to buy such a thing, but it sounds interesting.

[FullySilenced]

Landscaping stores its called scoria here in the US... mostly red looking porous lava rock here it costs $5.00 US for a 50lb bag