Switchgrass and biodiesel
Biodiesel can be made from a variety of oils, fats, and greases, but switchgrass (or any other grass) is not a suitable feedstock for biodiesel. There are thermochemical processes, notably pyrolysis, that can be used to produce liquid fuel from switchgrass and other forms of biomass.
We have a great deal of information about biodiesel production here: http://www.extension.org/pages/28783/biodiesel-table-of-contents#.VCQ-1RYZnCY
and about switchgrass here: http://www.extension.org/pages/30730/feedstocks-for-biofuel-production-table-of-contents#.VCQ_GBYZnC...