Engine oil 15ltr Drum - 5w-30 Fully Synthetic Premium oil (Necton PE37)

I have only used 5ltrs from this 20ltr Drum of Mannol 7908 ACEA C3 for my last car, now sold. The oil is no longer suitable for any of my vehicles so needs a good home. I don't want to poor this into the waste oil at the dump such a waste of around £60 of good oil.