We have renewable production of non-metals from air, water, farming, oil and phosphorus cycling, but chlorine is missing from this list. After a while I figured out a potential source of renewable chlorine - Ghast Tears. The reasoning for this is a bit of a joke - Ghasts are always crying because their tears are made of tear gas. A simple Ghast Tear --> Chlorine recipe in the fluid extractor would do the trick, and provide the opportunity for a joke in a quest :)

I'm not sure how to add a fluid extractor recipe, but it was pretty easy to add an EnderIO vat recipe. Add the following to config\enderio\recipes\user\user_recipes.xml in your Omnifactory instance folder:

<recipe name="Chlorine" required="true">
  <fermenting energy="10000">
    <inputgroup>
      <input name="minecraft:ghast_tear" multiplier="1.0" />
    </inputgroup>
    <inputfluid name="water" multiplier="1.0"/>
    <outputfluid name="chlorine"/>
  </fermenting>
</recipe>

This will convert one bucket of water into one bucket of chlorine, using one ghast tear and 10000 RF. I have no idea if that's well-balanced or not.

Oops, duplicate of #70