Do you not just shred them and send them to a scrap metal processor?
The newer pennies are not really worth the effort as they are mostly zinc.
Ironically if they are no longer illegal to melt down (IANAL but I would think this is true?) they actually would be more worth it to scrap because of the negated risk.
The practicalities of their illegality then comes down to enforcement. Given the current executive branch's behavior related to enforcement of laws, that can mean anything from "melt them all down", to "don't do it", to "if our friends start doing it, it'll be legal, if our enemies start doing it, we'll enforce".
They're still worth $1 per lb., and you have to destroy them, anyway.
because the cost of seperation from the copper is greater than simply sourcing other materials.
I think however the problem would be the trouble in seperating the zinc from the copper, I think you would likely operate at a loss still but this is just a guess.