With Coal Liquification and Coal Filtration, using K2 or something that adds the recipe and Filtration Plant, enough productivity is easily reached so that more coal comes out than goes into the system.

The Coal Liquification recipe may need to be changes to require more coal. It feels like Voidcraft.

Thanks for the report! This is a balance interaction between K2's Coal Liquification/Filtration recipes and the plant's high base productivity — those recipes weren't designed for buildings with 50-200% base productivity on top of productivity modules.

A couple of options:
- You can lower the "Base productivity" setting (Startup settings → Unified Chemical Plant) to something that doesn't break the coal loop. Even 0-25% should prevent infinite generation while still giving a meaningful bonus.
- This is ultimately a recipe balance issue on K2's side — the coal conversion recipes would need higher input costs or a productivity cap to prevent positive feedback loops.

I don't want to hard-cap productivity for all recipes just because of one interaction, since that would hurt the general use case. But if more people run into this, I could look into adding a per-category productivity limit as an option.