Shallow Geologic Storage of Carbon to Remove Atmospheric CO ₂ and Reduce Flood Risk

Abstract

Geologic carbon storage currently implies that CO ₂ is injected into reservoirs more than 1 km deep, but this concept of geologic storage can be expanded to include the injection of solid, carbon-bearing particles into geologic formations that are one to two orders of magnitude shallower than conventional storage reservoirs. Wood is half carbon, available in large quantities at a modest cost, and can be milled into particles and injected as a slurry. We demonstrate the feasibility of shallow geologic storage of carbon by a field experiment, and the injection process also raises the ground surface. The resulting CO ₂ storage and ground uplift rates upscale to a technique that could contribute to the mitigation of climate change by storing carbon as well as helping to adapt to flooding risks by elevating the ground surface above flood levels. A life-cycle assessment indicates that CO ₂ emissions caused by shallow geologic storage of carbon are a small fraction of the injected carbon.

Abstract

This project demonstrates that injecting solid particles of biomass can store carbon and raise the ground surface at rates that would reduce atmospheric CO ₂ and help adapt to flooding caused by climate change.