How is biochar produced?
Biochar can be made in many different ways, primarily using one of three dominant processes of thermal decomposition: pyrolysis, gasification and hydrothermal carbonization. Energy products in the form of gas or oil are produced along with the biochar. These energy products may be recoverable for another use, or may simply be burned and released as heat. In addition, biochar can be made from a wide variety of biomass feedstocks. As a result, very different biochar systems emerge on different scales. These systems may use production technologies that do or do not produce recoverable energy as well as biochar, and range from small household units to large bioenergy power plants. See Chapter 8: Biochar Production Technology and Chapter 9: Biochar Systems, in Biochar for Environmental Management: Science and Technology, edited by Johannes Lehmann and Stephen Joseph, Earthscan 2009.
