There’s loads of buzz round high-quality carbon seize applied sciences, but it surely looks like they’re all the time 10-20 years away from industrial scale. So, for now, we’ve had no alternative however to depend on lower-quality and nature-based carbon capturing options. Whereas these options are nice choices, they often have some type of impermanence related to them. For instance, planting a tree is an efficient answer, however when that tree dies or is burned, its saved carbon is launched again into the atmosphere.
The highest rising improvements to sequester carbon completely embrace biochar, enhanced rock weathering, and carbon mineralization—the latter is the main focus of this weblog.
Carbon Mineralization
Carbon mineralization is a course of that mimics the Earth’s main carbon dioxide (CO2) regulation technique. Earth naturally converts CO2 within the environment into rocks or minerals over hundreds of thousands of years. In our oceans, even dwelling beings sequester CO2 of their exoskeletons (e.g., shells, coral reefs, and many others.) that’s buried below the seafloor once they die, and that may take a whole lot of hundreds of thousands of years to be recycled into the environment.
The pure mineralization cycle is comparatively easy; nevertheless, pure mineralization can not sustain with the surplus CO2 that people have generated. At the moment, pure mineralization can solely sequester 0.7 GT of CO2 per yr. Sadly, people emit almost 36 GT of extra CO2 emissions per yr (IEA 2022).
Whereas the method is comparatively easy, it took researchers till about 20 years in the past to know the kinetics behind the response in order that they may mimic it in a lab. Carbon mineralization traps CO2 into the crystal construction of carbonate minerals leading to its everlasting sequestration. That is carried out each in-situ and ex-situ manners.
For in-situ operations, CO2 and water are injected underground to create a calcium carbonate by-product that shops the CO2 when reacted with calcium-/magnesium-bearing minerals. In-situ operations are topic to environmental situations, and gases and water can leak out of cracks in underground reservoirs.
Enter Greenore
Greenore, not too long ago named an APAC Cleantech 25 firm, is spun-out of Columbia College and based by Xiaozhou (Sean) Zhou who was researching sustainable ironmaking, and carbon sequestration and utilization processes. Greenore converts iron and metal making by-product, slag, into chemical merchandise (calcium/magnesium carbonate, iron oxide, silica, alumina, and uncommon earth focus), whereas consuming CO2 as a reactant. Greenore has developed a catalyst that mimics the Earth’s pure mineralization course of with out its time constraint.
Greenore achieves this by way of ex-situ mineralization, a course of that mimics in-situ mineralization above floor. On account of its excessive availability, alkaline industrial stable wastes may be utilized for ex-situ mineralization corresponding to metal slag, iron slag, mine tailings, cement waste, and extra. These supplies are usually wealthy in calcium-/magnesium-based minerals which might sequester CO2 faster than different pure weathering processes.
Precept of Greenore’s Carbon Mineralization Pathway
Based on Greenore, decarbonizing metal manufacturing and lowering its waste from manufacturing is a world problem because it accounts for 7% of the anthropogenic carbon emissions. China has an estimated 660M tons of CO2 sequestration potential capability from legacy slag waste, the place the UK has an estimated 190M tons of CO2 sequestration capability. This waste is mostly discarded in landfills the place it poses environmental hazards. Slag-based carbon mineralization not solely reduces CO2 emissions, but additionally employs waste utilization making it a profitable alternative for engagement.
Greenore reduces its overhead prices by using industrial waste as its feedstock, and its carbon seize and utilization (CCU) options are versatile with the vary and scope of the CO2 sources. The carbon may be sourced from ambient air, flue gasoline, and many others., and may be sequestered by way of any CCU know-how like level supply or direct air seize (DAC).
Greenore’s course of converts as much as 0.2-0.25 tons of CO2 per ton of waste slag or 1,248 kg of CO2 per 1,000 kg of metal slag processed with minimal reagents and chemical substances utilized and recycled. As soon as processed, the sequestered CO2 can be utilized as feedstock for cement, papermaking, paints, 3D printing, plastics, and many others.
Greenore’s ex-situ course of is modularized however can course of comparatively massive volumes of slag waste. A typical module can course of 50k tons of slag per yr or 10k tons of CO2. A module may be arrange on a “Construct, Personal, Function” mannequin in centralized markets, however licensing can also be adopted for areas the place markets are nonetheless rising. This has attracted partnerships with large gamers like POSCO, SD Metal, Harsco, and extra.
In partnership with Baotou Metal, a metal producer, Greenore entered its first industrial scale of a carbon mineralization plant primarily based on slag. The plant efficiently produced its first batch of calcium carbonate in July 2023. In January, Greenore partnered with TBM, a developer of a recyclable various to plastic and paper, LIMEX. Greenore’s CCU calcium carbonate will likely be built-in into TBM’s LIMEX materials.
Ahead trying, Greenore isn’t stopping at slag. In February, Greenore accomplished a Sequence A spherical led by Amperex Expertise Restricted (ATL) to discover battery recycling. “Essentially, the chemistry of using carbonic acid may be utilized to lithium battery recycling,” stated Zhou.
As governments, industries, and analysis establishments collaborate to additional develop and deploy carbon mineralization applied sciences, innovators like Greenore are paving the way in which for carbon mineralization to be commercially accessible. And whereas this know-how might not be as value aggressive as different CDR strategies, it’s a everlasting carbon sequestration pathway that’s not solely a waste administration answer however may even be utilized in invaluable merchandise. Nevertheless, realizing this potential would require continued embrace of innovation, vital funding in its infrastructure, and collaboration throughout sectors past iron and metal slag waste.
