just biomass.

That is not the understanding I have. I believe you need 'oil' of some sort.

That's correct. For the hydrocracking process, you require oil. For the more general BTL process in which biomass is first gasified to syngas, any form of biomass will do. Both hydrocracking and BTL have fallen under the "green diesel" moniker, but they are very different processes. The only similarity is that both result in a hydrocarbon diesel.

Thanks for the clarification.

I suppose my point still stands for the BTL gasification process.