RO question

[BCPP]

We have a mini pro evaporator that we run for demonstration purposes at our maple festival in March (it is one of several stations that shows the evolution of syrup making).

We can't do RO for several reasons but do talk about it. I'd like to have a visual aid and I'm thinking a used RO cartridge might work. However, I'm only familiar with RO in the pharmaceutical industry. Do maple RO cartridges have a finite life? Are they garbage at end of life? Would they be useful as a visual aid to explain RO? Thoughts on how to get a cartridge that's headed for the dumpster (if that's where they go!).

Any and all comments welcome!

[Urban Sugarmaker]

I'd say they do have a finite life although well-maintained membranes last a long time. I have seen other people re-purpose an old membrane for demonstration use by cutting away sections of it so people can see inside it. You could buy a small membrane for a household system and do a cutaway.

[maple flats]

A section would be good for demo purposes but even though I have an RO, I have never shown a membrane on any demo. I simply describe it as a super filter, that under pressure, pushes water thru the membrane while the sugar molecules are large enough that they won't got thru, thus I remove lots of the water from the sap, then I boil the remaining concentrate. I explain that typical sap has about 2% sugar (I wish it was that this season) and I remove enough water to get it to anywhere from 8% up to 12 or 13% sugar. Then the rest of the water is removed by boiling until I end up with syrup which I do to 66.9% sugar. Syrup can be anywhere from 66% up to slightly over 67% sugar depending on the requirements for that state or province. NY requires 66%, I do 66.9%, I think Vermont does 67%.