Isometric recently certified the world’s first Electrolytic Seawater Mineralization (ESM) Protocol. The protocol details requirements and procedures for carbon removal through ESM so that buyers can purchase carbon credits with confidence.
Certification follows a comprehensive public consultation that included feedback from buyers, suppliers and leading academics with expertise in seawater mineralization and marine carbonate chemistry. Full details on the evolution of the protocol and how Isometric handled feedback are available in the changelog and the public consultation summary.
The first step in ESM passes an electric current through seawater to split the water molecules into hydrogen and oxygen. This generates an alkaline stream and an acidic stream. Atmospheric carbon dioxide is added to the alkaline stream, which increases the amount of carbon dissolved in the seawater and produces carbonate minerals—both of which sequester atmospheric carbon dioxide. The acidic stream is neutralized through the addition of alkaline rock and minerals. The two streams are then recombined and processed to an environmentally safe quality.
Approximately 90% of the carbon dioxide removal in ESM happens through the dissolution of carbon dioxide in seawater, while the remaining 10% is through the production of carbonate minerals. The removed atmospheric carbon dioxide can be stored in the ocean as dissolved inorganic carbon or carbonate minerals—where it has a durability of over 10,000 years. On land, carbonate minerals can be stored in sites like landfills—with a durability of over 1,000 years.
ESM also has a co-benefit of producing green hydrogen—a carbon-free fuel which can be used to decarbonize hard-to-abate sectors.
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. The Isometric protocol requires suppliers to comply with three key requirements 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.
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.”
This protocol was developed in line with the Isometric Standard and was created in collaboration between Isometric’s in-house Science Team and reviewers from Isometric’s independent Science Network of over 300 academic experts. This level of scientific rigor means that buyers can be confident in the high quality of all ESM credits issued against this protocol.
