The butter press operated by a hydraulic jack has been around for a while. I saw my first one in Venezuela in 2006 and I recently met the guy who designed and fabricated them. Right now, the political situation in Venezuela makes it difficult to work with people there.
What you can't see here is that there is a tap hole drilled in the plate of the piston/plunger and there is a plastic tube attached to this tap hole. The cocoa butter is expressed through this hole. The plunger/plate is to the right of the press.
These are simple and relatively inexpensive to make and do not have any means to heat the pot that contains the cocoa liquor.
Sorry, the main nuance that the research team is shooting for, is that the whole system be 40 lbs. or less, minus the jack, so that they can put it into a suitcase and take it with them on flights to Africa, in order to help the farmers directly.
I tried to get one of these jack systems built here in Honduras, but the simplest design would cost $450, and that was cast iron, not steel. When I did a little math, cast iron was woefully inadequate to reach pressures needed to get a good yield. So, I went with this $200 screw press solution, for now. It's not great, but it makes chocolate possible.
It is very expensive for what you can produce.
What is very expensive for what you can produce? Cacao Cucina? We've moved off of the original topic of this post.