You know you can right click an item/fluid in FNEI and it will give you a list of all the recipes this item is used in, right?
Right clicking "Used lime filter" leads you directly to the "Acid gas" recipe which is made in liquifyers or chemical plants.
The locale does not make a difference in that regard: in English the recipe name does not mention lime filters either. In that sense it is just "as well hidden" in English.
[edit] So can you turn used filters into acid gas in liquifyers/chemplants, or is the recipe actually not there? The latter can happen when you add/remove mods for an existing save. Starting a new game of Angel's should have that recipe unlocked by Sulfur processing 3 β at least this is the case on my machine.