Transforming the carbon dioxide dissolved in the sea into an aqueous solution of calcium bicarbonates even with potential beneficial effects on the marine ecosystemThis is the mission of the start-up Limenet, which presented its technology at the Oceano amiCO2 conference. CO2 sequestration in marine waters: motivation, opportunities and methods.
The popular event dedicated to strategies for the removal of atmospheric CO₂ from the ocean took place in collaboration with the Politecnico di Milano and the University of Milano-Bicocca with a double event on May 8 and 9. The Participation was possible both in person and remotely through registration on the site.
Limenet has more than five years of research, several patent applications already filed and a pilot plant built in La Spezia, in the Ligurian city, the start-up has industrialized its technology. and removed its first 150 kg of carbon dioxide using a modular giga-tonne scale facility.
Meet Limenet.
As the start-up's website explains, Limenet is inspired by the geological carbon cycle, a natural process by which carbon is exchanged between the three "spheres" that make up planet Earth and which constitute gigantic carbon sinks. natural carbon: geosphere (the land), hydrosphere (seas and oceans), biosphere (fresh water) and finally the Earth's atmosphere. As one can easily guess, CO₂ passes through them as well.
Limenet so "limits" to reproduce this natural cycle, but at a super-natural speed: the technology was indeed designed to reproduce this natural cycle, but at a super-natural speed: the technology was in fact designed to reproduce this natural cycle. to exponentially accelerate the dissolution of limestone, up to daily scales.
This process not only reduces CO₂ in the atmosphere, but also dissolves carbonate compounds in seawater, increases its alkalinity, counterbalancing its increasing acidity.
Help for the seas and oceans.
The phenomenon of acidification of the seas and oceans is constantly increasing, with devastating consequencesabout a quarter of the carbon dioxide present in the atmosphere ends up in the oceans, and this is where the acidification of the seas and oceans occurs. is transformed into carbonic acid which dangerously modifies the phles acidifying and endangering the marine biota, that is to say the thousands of species that live there, first and foremost the corals.
For decades corals have been subjected to the terrible process of "white death" or coral bleaching, which results in loss of color (as is the case with hair after bleaching, to which the name refers). and often death, but not only.
The acidification of the water also causes the dissolution of the calcareous shells of clams, mussels, sea snails and calcareous plankton, on which the diet of many other animals depends more or less directly.
For more information, please read the study “pH and buffering capacity of surface oceans: past, present and future”. published in 2019 in Nature.
The stages of the process.
Limenet works in three distinct phases:
1. Crushing – Calcination – Hydration
2. CO₂ – Calcination and production of calcium bicarbonate
3. CO₂ storage.
First, the limestone raw material (CaCO₃) is crushed, calcined and then decomposed into CaO (quicklime) and CO₂ by thermal decomposition in an electric furnace powered by renewable electricity.
The quicklime is then hydrated, becoming slaked lime (Ca(OH)₂). Half of the product obtained is immediately used to eliminate the carbon dioxide produced by the calcination. The process takes place in the Limenet reactor by mixing CO₂ and Ca(OH)₂ in seawater: Ca(OH)₂ + 2CO₂ → Ca(HCO₃)₂
The other half of the slaked lime is available for downstream carbon sequestration in phase 3, i.e. storage. Decarbonized slaked lime is actually used to store CO₂ from external sources in the form of calcium bicarbonates. The calcium bicarbonate (Ca(HCO₃)₂) produced enriches seawater with its alkaline properties.
This last phase is extremely important for the reasons explained in the previous paragraphs and has been the subject of research by the European Union Institute for Security Studies (IESA). Desarc-Maresanus, a project created to study and counter the acidification of the seas and oceans.
Blockchain storage stability and security.
For three months, the chemical stability at different concentrations of the calcium bicarbonate solution produced by the Limenet industrial plant was measured in 7,000 liter tanks, in order to ensure chemical stability at different concentrations. permanent storage of CO₂..
A repository is defined as permanent when the stored component remains in a stable – i.e. unchanged – state for more than 10,000 years.
The results of these experiments will soon be published by the Politecnico di Milano, which is supporting Limenet in this particular phase.
The process of converting carbon dioxide into calcium bicarbonates – i.e. producing negative CO₂ emissions. is monitored by Limenet via the blockchain. Each stage of the processing in the factory is recorded in decentralized databases: in doing so, a trace remains of each operation in the process – the equivalent of an imprint of the sole of a shoe – on Polygon, the second layer of Ethereum.
Limenet's negative emission certificates are realized by the minting of purchasable NFTs. (Not Fungible Tokens, i.e. something unique and irreplaceable).
To give maximum transparency to its action, Limenet has finally provided for the certification of its process and its NFTs by a third party through an MRV monitoring system. (Monitoring, Reporting & Verification).
One technology, many use cases.
Limenet, among the various use cases, is investigating the combination of proprietary technology with amine filters to capture CO₂ from ship exhaust with downstream production of calcium bicarbonates.
Here you enter the pilot project underway at the Italian Navy Naval Test and Support Center in La Spezia, in which the Politecnico di Milano and its departments of chemistry (Cmic), environment (Dica) and of Aerospace (Daer), as well as the University of Genoa.
The plant was designed and built, with the support of Hyrogas, to eliminate waste from the plant. 10 kg/h of carbon dioxide in the form of calcium bicarbonates. During the work, which began in the spring of 2022 and was completed in February 2023, the start-up produced decarbonated calcium hydroxide which, by reacting with CO₂ of external origin, led to the production of calcium bicarbonate.
These 150 kg represent for all intents and purposes the first negative CO₂ emissions obtained thanks to Limenet's technology.
إرسال تعليق