Whale Oil Tank is an item in Dishonored
When you meet Piero in Piero's Workshop, he asks you to fetch one of those tanks from the second floor and put it in the receptable, in the mission "Meet the Loyalists"
Walkthrough: How to place Whale Oil Tank in Receptable[edit]
After you have grabbed the Whale Oil Tank (its upstairs from where Piero is) climb back down and put it in the Whale Oil Tank Receptable. It should automatically be placed in the receptable when you approach it. Just get it near the receptable, magnetism will do the rest. But if it doesn't then try either dropping it near the receptable or throwing it onto the receptable.
Whale Oil Tank in Walls of Light[edit]
Removing a Whale Oil Tank from a Wall of Light disables the wall.
