Converting plant material into biochar–a type of charcoal–could reduce carbon dioxide emissions by 12 percent a year, according to a new analysis published in Nature Communications. The study concludes that in most cases, this is a better use of biomass than burning it in power plants.
The process of making biochar involves exposing biomass to high temperatures in the absence of oxygen. This produces oil, hydrogen, and carbon monoxide–all of which can be made into biofuels–as well as biochar, which can be applied to cropland as a fertilizer. And because biochar traps carbon, the process is a way to sequester carbon dioxide, offsetting carbon dioxide emissions.
The article is publicly available here. Researchers have been making the case for biochar for years, although some argue that other approaches to reducing carbon dioxide levels in the atmosphere could have a bigger effect.