The prototype and a new design of modular biochar torrefaction system were devised here, as a spin-off from "2010 Project on the Promotion of Green Community in Chiayi County" in Taiwan. Results from the batch tests using the prototype confirmed that the ratio of biochar to fuel in terms of CO 2 eq is greater than 1.0 for densely-packed materials such as camper wood (Cinnamomum camphora (L.) Presl) and bamboo (Dendrocalamus latiflorus Munro), and less than 1.0 for looselypacked rice straw (Oryza sativa). Note that the dried weight densities are 157.6, 150.4 and 37.4 kg/m 3 , respectively. Therefore, a new design was proposed based on the 200 kg straw bale of density of 147.1 kg/m 3 . However, the feasibilty will not be assessed until its completion in the near future.