This mod adds mineable sulfur ore to the map. Intended to supplement your production of sulfuric acid by enabling mining of sulfur deposits produced long ago by ancient volcanism.
So, I assumed that this mod would supplement sulfur production as the description says, however, it seems to REPLACE production, as I lose the original sulfur from petroleum gas recipe in chemical plants when the mod is installed, making it hard to add to an existing game. May want to update your description to note that it replaces the base production, not supplements it.
It should be supplement. I have not made any changes to the other recipes.
Check to make sure you do not have other mods that are interfering.
This mod only adds sulfur as a spawnable resource. It makes no changes to recipes, your petroleum gas recipe should still be there provided other mods have not changed it.