Stability Assessment of Calcium Carbonate Dissolution in Seawater as a Marine Carbon Dioxide Removal Mechanism

Climate change presents an urgent global challenge, necessitating innovative solutions for carbon dioxide removal. Ocean Alkalinity Enhancement (OAE) has emerged as a promising strategy for mitigating legacy CO₂ emissions and advancing net-zero targets. The primary advantages of OAE lie in its potential for long-term and stable carbon dioxide sequestration in the ocean. Bioenergy with Carbon Capture and Storage (BECCS) represents a novel approach to atmospheric CO₂ removal; however, identifying suitable geological storage sites remains a significant challenge. The dissolution of calcium carbonate in seawater through the injection of point-source CO₂ from biomass power plants offers a viable solution to this storage dilemma. This project aims to investigate the stability of OAE via calcium carbonate dissolution by testing three distinct alkalinity levels (+2000, +4000, +8000 µmol/kg) re-equilibrated to baseline pH and atmospheric partial pressure of CO₂ (pCO₂) conditions. The alkalinity treatments were incubated at various temperatures to evaluate their stability under differing environmental conditions. Key objectives include assessing the stability of alkalinity across varying salinities, identifying precipitation thresholds, and examining the influence of temperature on OAE performance.

Presentation Preference: Oral

Primary Presenter: Amanda Melendez, Georgia Southern University (amandabmelendez312@gmail.com)

Authors:

Amanda Melendez, Georgia Southern University  (amelendezperez@georgiasouthern.edu)

Kimberly Gilbert, pHathom Technologies  (kim@phathom.tech)

Tyler Cyronak, Georgia Southern University  (tcyronak@georgiasouthern.edu)