PTFE is not really produced from petrocarbons, at least not directly. Its made by polymerization of tetrafluoroethylene, which appears to be made from chlorofor

PTFE is not really produced from petrocarbons, at least not directly. Its made by polymerization of tetrafluoroethylene, which appears to be made from chloroform + HF, the former is made from petrocarbons (methane/methanol + HCl/Cl), the latter from minerals. PTFE is quite expensive (compared to most other polymers). I suspect PP or PE could work just fine in this application. I'm just saying that you could simply eat insoluble fiber (from plants or other source) instead of ground up plastics, which will also create a massive source of microplastic pollution and contamination as it comes out the other end. You can easily store insoluble fiber (cellulose/chitin, etc), in vast quantities in dried form without any major issues, I can't imagine ground up PTFE being significantly better in that regard.