As it is a blank round with a light wooden bullet, it probably used a fast powder, maybe something similar to Bullseye. It could be black powder. As the ball ammunition became very difficult to find, the appearance of the wooden bullet blank ammunition was welcomed by shooters. They simply pulled the wood bullet and reloaded the cases with 8mm Mauser bullets and a suitable propellant. The cases used Berdan primers of an odd size. I have reloaded fired Kropatschek cases with shotgun primers. Just chuck the case in a lathe and drill a suitably sized hole through the base. I remember that I had to grind a larger drill bit to the correct diameter for a shotshell primer. I still have that modified bit somewhere. I loaded with Pyrodex, using regular 8mm Mauser bullets. I always loaded them singly, I never put a round in the tubular magazine.
Cases can be formed from .348 Win brass, but you would need to buy some very expensive forming dies to do it. I just improvised a neck sizing die.
Hard to say what the Portuguese used blank ammunition for. Maybe training or firing salutes at military funerals. Wooden bullet military ammunition was in common military use by most countries at one time. The Swedes had a device that screwed onto a rifle muzzle to break up the wooden bullet.