when //Lawnmower dead

Your commune rubbish dump will take it.
Just look up the details from whatever commune you reside in.
Or put it on: https://groups.freecycle.org/group/Brussels_Freecycle/posts/all someone might want it for parts

Put it on ebay website or on the Koopjeskrant website http://www.koopjeskrant.be/.

Somebody might take it as it is and get it working and use it for themselves!