Shipping is one of the dirtiest industries. Now it's trying to clean up its act

In the port of Antwerp in Belgium, a small boat whizzes around, shuttling 16 passengers back and forth. The "Hydroville" is fast, silent and, most strikingly, it produces zero pollution.

Built by Compagnie Maritime Belge (CMB), it's the world's first sea-faring vessel to burn hydrogen in a diesel engine. No carbon dioxide or sulfur oxides are released during the process. The ship produces some nitrogen oxide, but that's converted into harmless nitrogen and water by a catalyst. In one of the dirtiest industries in the world, it's a tantalizing glimpse of a cleaner future.