Recycling Plants are found in Production Assignments where unwanted or unnecessary atoms and/or molecules will be an unavoidable by-product of a reaction. They allow the by-products to be safely removed from the Pipeline through 3 pipes that can be linked to a reactor output.
A Recycling Plant (de: Recycler) has 3 inputs. You may use 0 to 3 by connecting it with a pipeline.
This is great to get rid of any unwanted amount or any unwanted type of by-products (molecules/atoms).