Terrestrial Storage of Biomass (Biomass Burial): A Natural, Carbon-Efficient, and Low-Cost Method for Removing CO2 from Air

Terrestrial Storage of Biomass (TSB) is a Negative Emission Technology for removing CO2 already in the atmosphere. TSB is compared to other NETs and is shown to be a natural, carbon-efficient, and low-cost option. Nature performs the work of removal by growing biomass via photosynthesis. The key to permanent sequestration is to bury the biomass in pits designed to minimize the decomposition. The chemistry of biomass formation and decomposition is reviewed to provide best practices for the TSB burial pit design. Methane formation from even a small amount of decomposition has been raised as a concern. This concern is shown to be unfounded due to a great difference in time constants for methane formation and its removal from the air by ozone oxidation. Methane has a short lifetime in air of only about 12 years. Woody biomass decomposition undergoes exponential decay spread over hundreds to thousands of years. It is inherently slow due to the cross-linking and dense packing of cellulose, which means that the attack can only occur at the surface. A model that couples the slow and exponential decay of the rate of methane formation with the fast removal by oxidation shows that methane will peak at a very small fraction of the buried biomass carbon within about 10 years and then rapidly decline towards zero. The implication is that no additional equipment needs to be added to TSB to collect and burn the methane. Certified carbon credits are listed on various exchanges. The US DOE has recently issued grants for TSB development.