Torrefaction is a developing thermal process that has mainly been used to convert lignocellulosic feedstocks, both cultured and wasted, into a "charred" product that can be used as a fuel for power plants, combustion units, and gasifiers. Beneficial characteristics of torrefied products are increased energy density, removal of free water from the feedstock so that water is not being transported to the use facility, grindability indices similar to coal, and a more bio-stable product better suited for outdoor piled storage over the raw input material. A thorough review of the literature involving the torrefaction of fibrous agricultural wastes, food wastes, and non-lignocellulosic wastes (bacteria, algae, yeast, etc.) is presented in this paper. In general, average torrefaction operating conditions yielded greatly improved biofuels over the raw input feedstocks. (C) 2019 Published by Elsevier Ltd.