I have a box or two of just scrap PLA because they said it was recyclable/biodegradable. Not much about just how specific the conditions needed to be.
It can't be that hard to homebrew some sort of extruder to remake the filament, can it? Who needs tolerances?
1, pla melts at about the same temperature as paraffin, people have used candle making kits to cast skulls or whatever. Seems neat to me.
2, similar trick, put the pla between two cookie sheets with weights. Heat to melting. This gives panels you can cut and incorporate into projects. Drawer bottom or robot body , that kinda stuff.
Very cool project though.
OK, it can still be disposed of cleanly. As in, dump laundry basket of PLA scraps into washer, add magic PLA enzyme detergent, push "PLA Dispose" button, and all of it stays out of a landfill.