In the paper they are actually producing both biochar and biocoal. The biochar is the solid fraction produced during pyrolysis. The bio-oil (volatile hydrocarbo

In the paper they are actually producing both biochar and biocoal. The biochar is the solid fraction produced during pyrolysis. The bio-oil (volatile hydrocarbons) are then further distilled to produce biocoal. By tweaking temperature and process parameters they can likely optimize for production of one or the other.