In a fantasy world I'm developing the kingdom of Andalus is seeking a more potent propellant for a grand bombard planned by the sanguine king.
The size and composition of the bombard is saved for a later question, but it and the cannon ball itself would be so huge gunpowder isn't potent enough or would need insane amounts of gunpowder to even fire the thing.
The Sanguine king has tasked his finest alchemists to find or create a more potent propellant for his Grand Bombard. While the world itself is fantasy I'd prefer this be a real substance. This propellant has to be able to be made, contained, and transported with 16th-17th century technology.