top of page
  • Writer's pictureKlimaDAO

Harness the ocean's power: Limenet’s CDR technology and a new type of carbon for KlimaDAO

KlimaDAO has just been announced as the first offtaker for Limenet’s novel ocean alkalinity enhancement credits. In the fall of 2023, over 99% of voters in the KlimaDAO community came out in favor of deploying USD 600,000 from the DAO Treasury to secure the delivery of these Carbon Capture, Utilization, and Storage credits. In now making these credits available via the Carbonmark marketplace, the DAO is directly supporting the development of a highly measurable and permanent carbon dioxide storage solution in seawater through calcium bicarbonate. Here, we explore this technology and its potential, and how KlimaDAO and Limenet are teaming up to harness its power and expand the Voluntary Carbon Market (VCM).

Carbon dioxide removal (CDR): An overview

Until recently, the VCM has focused almost exclusively on carbon reduction or avoidance credits that fund projects reducing or mitigating ongoing emissions. This is understandable: as explored in our blog post on the different roles of carbon mitigation and removal credits, this approach has a crucial role to play in the ongoing effort to stabilize our climate. However, recent technological advances give humanity other options in terms of removing carbon from the earth’s atmosphere. Indeed, according to the SBTi standard, a credible net-zero strategy must combine both emissions reductions, avoidance and the active removal of unavoidable carbon dioxide emissions.

The term ‘CDR’ refers to a range of methods and technologies aimed at pulling CO2 out of the atmosphere and storing it permanently. It is a wide-ranging concept that embraces both natural approaches like reforestation and technological methods like direct air capture (DAC). Once it is deployed at scale, CDR could complement emissions reductions by helping restore balance to the carbon cycle and buying time for economies to transition toward carbon neutrality. Furthermore, CDR offers potential new opportunities in carbon removal credits, which incentivize organizations to directly take CO2 out of the atmosphere. If CDR projects can reliably quantify, verify, and account for CO2 removal, they can generate extremely high-quality credits by permanently eliminating or storing emissions.

Some CDR techniques are already viable, while others require more research and development. The most promising types of CDR technologies and approaches include:

  • DAC: Engineered systems such as that deployed by Climeworks, which use chemical processes to directly capture CO2 from ambient air.

  • Bioenergy with carbon capture and storage (BECCS): Growing biomass for energy production and capturing the resulting CO2 emissions before release.

  • Afforestation/reforestation: Planting trees and restoring forests to absorb and store more carbon dioxide.

  • Enhanced weathering: Accelerating natural chemical reactions that bind CO2 by spreading crushed minerals.

  • Carbon mineralization: Converting CO2 into stable inorganic carbonates, locking away the carbon.

  • Biochar production: Converting biomass into long-lasting charcoal that can be added to soils to store carbon.

  • Ocean alkalinity enhancement (OAE): Adding alkaline compounds to seawater to increase its buffering capability to absorb more CO2.

Limenet are focused on the last of these. Through a new cutting-edge OAE approach, they aim to not only capture CO2 but also help restore in a controlled way marine ecosystems affected by ocean acidification — a devastating side effect of excess atmospheric CO2. 


OAE is one of the less widely known but still immensely promising types of CDR. Simply put, it is a human-engineered intervention that speeds up nature’s processes, amplifying the ocean's natural carbon absorption power using alkaline mineral additions. Adding ground rock minerals such as limestone to seawater converts dissolved CO2 into stable bicarbonate ions, sequestering it for millennia. The resulting CO2 deficit prompts atmospheric CO2 to move into surface waters to restore equilibrium. The oceans are already the planet’s largest carbon sink; if scaled appropriately, this approach could significantly improve the ocean's vast capacity to absorb and store carbon.

Moreover, being based in nature and using minimal geoengineering-style interventions, OAE has relatively predictable effects and also multiple environmental co-benefits beyond slowing climate change. These include:

  • restoring damaged marine ecosystems by creating favorable conditions for coral reefs and calcifying organisms;

  • boosting biodiversity and fisheries through improved water quality;

  • enhancing coastal protection and erosion control by reversing acidification;

  • improving coral reef resilience and regeneration;

  • stimulating the growth of pH-sensitive marine vegetation like seagrasses;

  • protecting pH-sensitive marine species including plankton and mollusks; and

  • safeguarding marine food webs by preventing acidification-induced collapse.

By comprehensively promoting ocean health, OAE represents a climate solution with immense potential to revitalize our seas.

Limenet’s approach

There are different ways to add alkalinity to the ocean, including spreading finely ground alkaline substances over the open ocean, depositing alkaline sand or gravel on beaches and coastal flats, and reacting seawater with alkaline minerals in reactors before returning it to the ocean.

Limenet have pioneered a method they term ‘Buffered Ocean Alkalinity Enhancement’ (BOAE) or “pH equilibrated OAE”, which aims to accelerate and optimize the natural carbon cycle between rocks, ocean, and air. BOAE involves producing calcium bicarbonate by reacting carbon dioxide, slaked lime, and seawater in a controlled reactor. The slaked lime is produced by an indirect calcinating limestone using heat from syngas combustion in a gasifier. The syngas also provides biogenic CO2, previously captured and temporarily stored by biomass. The calcium bicarbonate is then dissolved in the ocean, which mimics and amplifies the natural geological weathering process of carbonatic rocks. Dissolving the calcium bicarbonate increases the alkalinity of the ocean, which enhances its ability to absorb and store atmospheric CO2. In a nutshell, Limenet have industrialized the geological carbon cycle via electrical and thermal energy.

The founders of Limenet—Giovanni Cappello, Stefano Cappello, Enrico Noseda, and Valdis Bisters—incorporated Limenet as a startup after five years of research done together with Stefano Caserini, Mario Grosso, and Simona Masina, renowned experts in biogeochemistry who established the Desarc Maresanus research group, where they published more than 10 scientific articles related to Limenet's technology (the Limenet papers are available here). They also developed the first prototypes of the BOAE technology, which have already been proven to remove kilograms of carbon dioxide through the formation of calcium bicarbonates. These achievements demonstrate the academic rigor, innovation, and real-world application of Limenet's technology, providing a solid and proven basis for its implementation and expected performance.

Limenet have also made significant strides in transparency and digital monitoring, reporting, and verification (dMRV). They are partnered with RINA, a renowned verification body with extensive experience in naval and marine auditing, to verify the methodology and the Project Design Document of the Limenet productive industrial plant. As the oldest verification body worldwide and the most widely accredited verifier of carbon standards and methodologies globally, RINA brings an exceptionally high level of credibility to the verification process, including compliance to ISO 14064-2. 

To achieve maximum transparency and traceability, Limenet have developed a groundbreaking method of tracking negative emissions using blockchain technology. By leveraging the power of the blockchain, Limenet have created a virtual mirror of their technology, enabling seamless communication between the plant's computers and decentralized databases on Polygon. This innovative approach guarantees transparency, high traceability for reporting activities, and eliminates the risk of double counting. Only data that have already been collected and verified by RINA are securely recorded on the blockchain.

Limenet's issuance of these credits natively on a public blockchain positions them as pioneers in integrating CDR and web3 technologies.

Limenet X KlimaDAO

Our partnership with Limenet comes at a crucial time, as humanity wakes up to the fact that expanded strategies are becoming increasingly necessary in the fight against climate change. OAE represents a new frontier in efforts to stabilize our climate and our ocean. By funding Limenet's proprietary technology, KlimaDAO has not only secured high-quality CDR credits but is also directly contributing to the restoration of our planet’s atmosphere and oceans.

Limenet's achievements in scientific research, patent filings, successful prototypes, and strategic partnerships with reputable organizations like RINA exemplify their unwavering commitment to transparency and rigorous verification in their carbon removal process. With a solid foundation established through their small-scale work, the aspiration is to scale this groundbreaking process to make a substantial impact on humanity's emissions throughout the twenty-first century.

Further, this is more than just a simple offtake agreement. Limenet clearly recognize that the future of the VCM is on chain. By bringing their high-impact carbon onto public blockchains from inception, they are cultivating a competitive advantage in the CDR space. Of course, KlimaDAO is also strengthened. Through KlimaDAO’s purchase of the first carbon credits generated through Limenet's carbon removal process, Carbonmark is the only place where there is a liquid market for these assets. This accelerates the evolution of KlimaDAO's ecosystem, stimulating increased economic activity on chain and fostering growth and innovation within the wider climate solutions space. Given the power of web3 technology, these credits can also be used in hugely innovative ways. For example, Carbonmark’s API allows programmatic (i.e. automated) offsetting of credits to be embedded into other applications, such as supply chain emissions calculators and even platforms like SAP, enabling organizations to retire fractions of these credits representing permanent removals at source at the very moment the emissions are recognized.

In conclusion, the partnership between KlimaDAO and Limenet is a landmark moment. With our shared commitment to transparency, rigorous scientific research, and digital innovation, we are poised to make significant contributions to a sustainable and climate-resilient future. This shared vision of a greener tomorrow is backed by an unwavering dedication to implementing the technological advancements necessary to achieve it. Together, KlimaDAO and Limenet are not only redefining the fight against climate change but also shaping the future of carbon markets and sustainability. As the world becomes increasingly digital, web3 technologies and blockchain-based carbon markets will play a vital role in the climate solutions landscape. This partnership serves as a compelling testament to the power and potential of these technologies when harnessed for the benefit of people and planet.


bottom of page