Pellets are typically stored in a large silo and then gravity fed. They may then grind them like coal and blow it into a furnace/boiler. This produces steam, turns a turbine and creates electricity. Also, the boiler can just heat water or create steam to service existing hydronic heating systems.
The major benefit to torrefication is the long term storage. When wood fiber rots it also gasses off carbon monoxide. This makes storage in large amounts dangerous to humans that enter these storage facilities. Torrefication eliminates this rot that occurs when moisture contacts regular pellets.
I looked up the term ‘torrification’ in wikipedia yesterday. From the description offered of the process, I find it hard to believe that it can be cost effective with alternatives such as oil or natural gas. I’d like to see a per-BTU comparison of the 3. Most of the sources I found during a (admittedly brief) search all seemed like cheerleaders rather than even moderately unbiased sources.