Regular Article

Geologic perspective for carbon sequestration by woody biomass burial

Geoclime, LLC, P.O. Box 13, Seabrook, TX 77586, USA

^* Corresponding author: jimgooding@geoclime.com

Received: 1 December 2022
Accepted: 26 June 2023

Abstract

Carbon sequestration by Woody Biomass Burial (WBB) leverages carbon capture through natural photosynthesis, followed by the isolation of dead or fallen wood in a relatively shallow Underground Wood Vault (UWV). Long-term geologic containment, including any greenhouse gas decomposition products, depends on the careful selection of UWV location and depth. To achieve carbon sequestration durability of 100 y, an initially low-moisture UWV should be built as follows: (a) low-permeability, high-plasticity clays with a hydraulic conductivity of ≤10⁻⁹ m/s, and with vertical/lateral separation distance of ≥1 m from the nearest aquifer; (b) residual compaction voids at least partially filled, with loose, smectite-rich clay; (c) capped with ≥2 m of clay compacted to achieve hydraulic conductivity <5 × 10⁻⁹ m/s; (d) restricted to locations where the 50-y seismic Peak Ground Acceleration (PGA) is ≤9% g (8.8 × 10⁻¹ m/s²). A UWV built in a low-PGA location, with larger cap and confinement thicknesses and/or lower hydraulic conductivity, should be capable of sequestration durability approaching 500–1000 y or more.