Hemp is much less damaging to the land where it is grown because it leaves these minerals behind. The pulp of the hemp plant can also be burned and processed into charcoal, methanol, methane, or gasoline. The process for doing this is called destructive distillation. Fuels made out of plants like this are called biomass fuels. This charcoal may be burned in today's coal-powered electric generators.
Methanol makes a good automobile fuel.
In fact it is used in professional automobile races. The United States government has developed a way to make this automobile fuel additive from cellulosic biomass. Hemp is an excellent source of high quality cellulosic biomass. One other way to use hemp as fuel is to use the oil from the hemp seed. Some diesel engines can run on pure pressed hemp seed oil.