Yep, you're missing this part:

> However, through anaerobic digestion – where bacteria break down organic matter, producing biogas – the distillery can also use the liquid waste from the process to make fuel and eventually recycle all of its waste products this way.

Basically, they have solid waste which was and is going to be used for cattle feed, and they have liquid waste which they're now converting to bio-gas by feeding it to bacteria.