Isometric today released a protocol for durable carbon removal (CDR) through Electrolytic Seawater Mineralization (ESM) into public consultation. The protocol details how to monitor, report and verify (MRV) ESM carbon removal so that buyers can purchase carbon credits with confidence.
ESM splits water molecules into hydrogen and oxygen by passing an electric current through seawater (or, seawater electrolysis). This generates an alkaline stream and an acidic stream. Atmospheric carbon dioxide is added to the alkaline stream which increases dissolved inorganic carbon in seawater and produces carbonate minerals, both of which sequester atmospheric carbon dioxide. The acid stream is neutralized through the addition of alkaline rock and minerals. The two streams are then recombined and processed to an environmentally safe quality before returning to the ocean. ESM also has a co-benefit of producing green hydrogen.
Approximately 90% of the carbon dioxide removal happens through the dissolution of inorganic carbon in seawater, while the remaining 10% is through the production of carbonate minerals. The removed atmospheric carbon dioxide can be stored in seawater as dissolved inorganic carbon or carbonate minerals—where it has a durability of over 10,000 years—or stored on land as carbonate minerals, which have a durability of over 1,000 years.
Carbon removal through ESM occurs within a closed system, which allows for the quantification of carbon dioxide removal to be directly measured within the facility. This is a foundational piece enabling robust MRV that buyers can have confidence in. The protocol requires suppliers to comply with three key points when quantifying carbon removal via ESM.
- Direct measurement of the inputs and outputs of the ESM system
- Direct measurements throughout the ESM system to validate each step of the process
- Reconciliation calculations to establish confidence in these measurements
Carbon removal supplier Equatic provided critical feedback during the development of this protocol. Equatic has developed an electrolytic process for CDR that stabilizes carbon dioxide in seawater and creates an alkaline slurry that removes carbon dioxide from the atmosphere using a cooling tower. Equatic is currently planning ESM projects in Singapore and Quebec.
Erika La Plante, co-founder and Head of MRV and Environmental Impact Assessment at Equatic said:
“The ocean is the world’s largest natural carbon remover and seawater electrolysis is an invaluable tool that can accelerate and amplify its inherent carbon removal processes. This protocol will help ensure that seawater electrolysis is employed effectively, safely and reliably. With guidance from Isometric’s world class team of scientists and researchers, we will continue enhancing and refining our own closed-loop, electrolysis-based CDR solution to offer the highest integrity carbon removals possible.”
All Isometric protocols are developed in line with the Isometric Standard, which is the world’s most rigorous set of rules for carbon removal. This Protocol was created in collaboration between Isometric’s in-house Science Team and reviewers from Isometric’s independent Science Network of over 200 scientists and climate experts. Comments on this protocol are welcome from interested buyers, suppliers and scientists as it enters public consultation and will be considered before finalizing the protocol.
The release of this protocol brings the total number of Isometric protocols to nine.
