Old Flaxseed Oil
Blue Bins & Chutes
Freecycle / Give Away
Offer in online groups like Art Don't throw or in platforms like Olio. Even when rancid, this can be repurposed.
Online Freecycle Groups
Art Don't Throw
Linseed has special properties which make it the top choice for seasoning cast iron pans and also as the base for many oil based paints.
While technically recyclable into bio-gas, the volumes of flaxseed oil make it unsuitable for recycling.