Banyu Carbon employs a simple, light-driven process to remove carbon dioxide from ocean surface waters, allowing for additional carbon to be reabsorbed from the air. Captured CO2 can then be stored in geologic formations or used in long-lived products.
Banyu Carbon’s design uses a novel photochemical process. Sunlight drives a chemical reaction that causes CO₂ to be released from seawater, enabling a similar amount to be reabsorbed from the atmosphere. Because only a small fraction of the sunlight is needed for the chemistry, the remainder can be used to generate solar electricity. The liberated CO2 can then be stored in geologic formations or used in products for long-term storage. The photoacid molecules at the heart of Banyu’s process are easy to make, contain no rare or toxic elements, and are kept separate from seawater.
Because Banyu Carbon’s process directly removes CO₂, it addresses the root cause of global warming and ocean acidification without major impacts on other earth systems. Compared to competing approaches like direct air capture, the technology is projected to be cost, energy, and land-use efficient. Additionally, because only a small amount of sunlight is needed to trigger the reaction, the process can be used to generate solar electricity.
Additional oceanographic and technical expertise is needed to help move from lab-based demonstration to a functioning real-world pilot. This includes optimizing the photochemical process and helping develop monitoring, reporting, and verification methodology. Similarly, additional technical support is needed to ensure integration with partners who pump large volumes of water (e.g. through cooled power plants), enabling the technology to be scaled up to levels that could meet global carbon removal demand and help avoid the worst effects of global warming.