Carbon Sequestration

Biomass fuels such as wood, herbaceous materials and agricultural by-products are the world’s third largest primary energy resource, behind coal and oil. At best, conventional biomass to energy is considered to be carbon neutral. Harvesting biomass to produce energy may not be sustainable because it can result in reduced soil productivity by depletion of carbon and nutrients. Biomass pyrolysis addresses this dilemma, because it can utilize waste products and about half of the original carbon can be returned to the soil (Lehmann, 2007).

carbon sequestration
In a recent paper published by the Ecological Society of America, Johnannes Lehmann of Cornell University discussed the basics of biomass pyrolysis (excerpts from: Lehmann, 20007, Bioenergy in the Black, available as a PDFpdf).

“Pyrolysis is one of many technologies to produce energy from biomass (Bridgwater,2003). What distinguishes pyrolysis from alternative ways of converting biomass to energy is that pyrolysis produces a carbon-rich, solid byproduct, biochar (Figure 1). Under complete or partial exclusion of oxygen, biomass is heated to moderate temperatures, between about 400 and 500°C (giving the proces