Limenet is a groundbreaking Italian startup that is leading the way in the European CDR landscape.
Founded in 2023 by three engineers and entrepreneurs, it took 18 months after its start for it to build and operate one of the largest facilities worldwide for CO2 ocean storage in the form of bicarbonates.
Limenet’s pioneering accomplishment reinforces its status as one of the leaders in the ocean carbon removal industry, marking a significant milestone with the technology’s advancement.
Limenet’s Industrial Storage Plant
Located in Augusta, Italy, the Limenet industrial facility has a maximum storing capacity of 800 tons of CO2 per year.
Limenet has successfully demonstrated the removal of the first batch of biogenic CO2 sourced from a biogas upgrading facility operated by Nippon Gases. The CO2 utilized is derived from the production of biogas through the fermentation of organic material.
The process begins with seawater drawn from the ocean, which is then combined with biogenic CO2 and lime coming from the local quarry of the partner Leone La Ferla.
Within minutes, the CO2 is turned into calcium bicarbonates and it’s safely stored into the oceans. The final product is a clear pH-equilibrated bicarbonate solution mixed with seawater, making it chemically stable for millennia. Among ocean-enhanced alkalinity techniques, Limenet’s technology is maintaining the same pH level in the output water as in the input, preventing pH fluctuations that could harm marine ecosystems. This feature is also underlined in the BCG report Harnessing The Ocean.
Equipped with advanced industrial sensors, Limenet precisely measures the amount of CO2 processed in real time, offering a high-quality carbon removal solution that relies on direct measurement rather than predictive models.
The local community and Limenet’s facility
Limenet facility has received strong support from the Local Authorities of Augusta (Italy). Key partnerships have been established with the Local Municipality and the Port Authority, which have actively supported Limenet through every phase of the project.
Limenet gained positive feedback from the local community also thanks to public engagement activities. They encompassed scientific dissemination events for adults and educational events in schools covering topics related to climate change and the role that CDR solution can play to address this challenge. As part of the school event, students also enjoyed a tour of the plant, where they had the opportunity to learn more about Limenet technology and on industrial facilities.
Limenet’s Technology will be an Integrated Solution of Capture and Storage
In 2024 the facility covered only the final stage of Limenet’s process, focusing on ocean storage but in the near future, the process will be integrated with a Direct Air Capture technology to passive mineralize of lime.
To produce the lime, the company will build a proprietary vertical electric kiln able to produce the green lime powered exclusively by renewable energy. 50% of the lime will be used to neutralize 100% of the CO2 coming from the calcination of limestone, storing that carbon into the ocean as calcium bicarbonate. The other 50% of lime will be used to capture CO2 from the atmosphere with a passive DAC system. The lime that turns into limestone will be used to feed the kiln again.
This new approach couples the high quality measurability of DAC with the flexibility of Ocean Storage, having also a co-benefit for the ocean to counteract locally.
The science that backs the Limenet technology
Limenet’s method is an emerging approach to DAC + ocean alkalinity enhancement (OAE) designed to address the traditional uncertainties associated with marine CO2 removal processes, such as abiotic and biotic precipitation, and the exact amount of CO2 stored.
According to the article Sanchez et al. (2024) Plankton Food Web Structure and Productivity Under Ocean Alkalinity Enhancement, the pH-balanced storage method stands out as one of the most promising techniques for improving ocean monitoring, reporting, and verification (MRV):
“…releasing a CO₂-equilibrated solution (9). This makes monitoring, reporting, and verification of carbon dioxide removal (CDR) relatively simple, as the alkalized water has absorbed the intended CO2 before its dispersion.”
MRV is essential in CDR to ensure transparency, reliability, and measurability of CO2 removals. It verifies that the adopted technologies deliver real impact while adhering to environmental standards.
Indeed, among the techniques of marine CDR (mCDR), Limenet’s technology belongs to the category of closed systems mCDR, that differ from open systems as the carbon removal process is isolated and happens in a controlled environment. According to the aforementioned BCG report Harnessing the Ocean, closed systems “compared to open mCDR systems, MRV can be applied with greater certainty and the data is more reliable, which gives a clearer pathway to advancement. This also means results of closed systems are easier to monitor.”
Environmental co-benefits of the Limenet Solution
Beyond rising temperatures, ocean acidification is one of the biggest threats of climate change. Along with removing carbon dioxide from the atmosphere, Limenet’s process offers the key environmental co-benefit of counteracting ocean acidification. By introducing bicarbonates into seawater, the technology enhances its alkalinity, boosting the ocean’s natural ability to resist pH fluctuations.
Scientific research led by the Italian university Milano-Bicocca is currently evaluating the impact of Limenet’s technology on plankton and benthic organisms, with promising results.
Limenet’s foundation and future steps
Limenet was founded from the will of Stefano Cappello, Giovanni Cappello, and Enrico Noseda to actively address the climate crisis. As Stefano Cappello stated, “It is our generation that must drive the change. Because if we don’t do it, no one else will.”
This unwavering commitment fueled over six years of research, which laid the foundation for Limenet’s work and ultimately led to the company’s establishment in 2023.
Today, Limenet can count on a team of 15 engineers and researchers fully committed to the mission of defending our climate.
In 2025 Limenet plans to develop the capability of hosting the entire process at one single location. The facility will be located in Sicily, where the storage module is already operational. This location was chosen also in light of the positive feedback and support that Limenet has already received from the local community.
Read more: Podcast: “Ocean alkalinity enhancement improves marine life,” Stefano Cappello, Limenet CEO
