Carbon Dioxide Removal: Mineralization | Climate Now Ep. 2.7

10 billion tons a year that is how much carbon dioxide we will need to remove from the atmosphere every year by 2050 to avoid catastrophic changes to our climate by 2100 we will need to remove 20 billion tons per year and we have some choice in terms of how we remove the co2 as we describe in our introductory video on carbon dioxide removal but the techniques we choose will invariably require a trade-off we can choose the most cost efficient options or we can choose those methods that will come with the strongest guarantee of long-term co2 storage in this video we focus on the most secure of cdr options mineralization [Music] mineralization is like the holy grail of cdr technologies because it traps co2 into the crystal structure of minerals thereby permanently sequestering it from the atmosphere every other proposed reservoir of co2 storage comes with some risk of impermanence forests can burn or be destroyed by pests soils that are cultivated to hold more co2 may lose it again if land users revert to earlier more destructive practices even storage of co2 in the pore spaces of underground geologic formations could escape through abandoned wells or along fractures and rocks but with mineralization co2 becomes a part of the rock there is nearly zero risk of it being re-released into the atmosphere so let's dig a little bit deeper into the technology how does it work and how feasible is it to develop this method as a major pillar of carbon dioxide removal removing co2 from the atmosphere through mineralization is not a novel technique in fact it is as old as the earth itself mineralization is the primary mechanism by which the planet regulates atmospheric carbon dioxide over time scales of millions of years whenever it rains co2 in the atmosphere reacts with water in raindrops forming a compound called carbonic acid as the rain lands on the earth's surface the carbonic acid reacts with exposed rocks slowly dissolving the minerals by breaking them down into their metal components those dissolved components then get carried by runoff and river water and are ultimately released into the ocean and because seawater has a slightly basic ph when these dissolved metals enter the ocean they react with the carbon dioxide in the ocean to form a carbonate mineral trapping the co2 into the mineral structure this process can happen inorganically but in oceans today most carbonate precipitation is facilitated by organisms that use the calcium carbonate to create their shells or skeletons every clam coral and microscopic foraminifera on earth is doing its part to sequester co2 into its mineralized hard parts and when these organisms die and their shells and skeletons settle on the seafloor and get buried they are taken out of contact with the earth's atmosphere and it will take tens or hundreds of millions of years of plate tectonic processes like mountain building for those carbonate minerals to reach the surface again when they could be exposed to rain and dissolve in fact the formation and burial of carbonate minerals is so effective that there is more than 10 000 times as much carbon stored as minerals in sedimentary rock as there is carbon in the form of co2 in the atmosphere unfortunately mineralization within the earth's natural carbon cycle occurs on very slow time scales that cannot keep pace with the rates of man-made emissions at most natural mineralization removes about 0.7 billion tons of carbon dioxide from the atmosphere every year humans emit nearly 40 billion tons of carbon dioxide each year but what if we could find a way to simulate this natural process and speed it up polka knops is a leader in the effort to engineer a climate change solution that mirrors the natural carbonate mineralization process coming from a background in physics renewable energy and waste systems he realized that you could build a high pressure high temperature reactor that mimics the natural mineralization process by reacting co2 and water with powdered rock in mr canop's reactor he is able to recreate the natural processes of rock dissolution and carbonate mineral precipitation that happen in natural co2 cycles at higher pressures and temperatures the reaction proceeds more rapidly and by powdering the rock he is able to maximize the reactive surface area of the starting material which also accelerates the reaction another advantage of engineering carbonate mineral reactions is that we can choose our starting material rocks that are rich in the minerals olivine hyroxine and plagioclase like volcanic basalts found in hawaii and iceland are far more reactive than average continental rocks this is because these minerals are rich in calcium magnesium and iron the metals that react with co2 to form carbonate minerals and luckily we have an abundance of basaltic rock on our planet the upper few kilometers of ocean crust which covers 70 percent of earth's surface is made almost entirely out of basalt so anywhere that the ocean crust hasn't been appreciably buried by sediment is a potentially viable mineralization site but even considering only on land rock reservoirs the potential capacity for carbonate mineralization is orders of magnitude more than we need to remain below 1.5 degrees celsius of warming we will need to remove a total of about 125 billion tons of co2 by the end of the century for comparison there are about 12 000 billion tons of co2 mineralization potential using rocks in the united states and europe alone enough to store a century's worth of anthropogenic emissions globally the rock reservoir capacity for mineralization is 60 billion billion tons of co2 so the material is there we just have to figure out the most energy efficient and cost effective way to use it generally proposed mineralization techniques fall into two categories which we will explore separately x-situ mineralization involves extracting rock from the ground to react with co2 whereas in-situ mineralization involves pumping co2 underground to react with subsurface rocks let's take a look at how x-situ mineralization works this technique can be one of the most expensive carbon dioxide removal strategies costing as much as six hundred dollars per ton co2 this is because to remove a high volume of co2 at a fast rate requires lots of fresh rock and lots of energy to power the mineralization reaction there are a few ways to reduce these costs but each approach decreases the realistic capacity of this type of sequestration let's consider the reactive material first for every ton of co2 we capture we need at least 1.6 tons of fresh magnesium and calcium-rich rock we could mine this rock from the ground and mechanically crush it which is the most expensive and energy-intensive option or we could use existing rock waste either from industrial processes or from the tailings of old mining operations this could bring the price of mineralization down to 50 dollars per ton but there is only so much waste material available the most optimistic estimates would provide about 1.3 billion tons of co2 storage annually which is only about 10 percent of what is needed another approach is to develop a source of revenue to offset the cost of energy and primary materials this is what mr knopf's company green minerals does by selling the carbonate and silica byproducts of the mineralization reaction if you make paper in europe there's about 6 million tons of lime used in paper manufacturing they add lime to that for a few reasons first of all for the color make it more white but more importantly to make it cheaper and to have better properties and then here is the idea just to yeah use instead of use the traditional line use this material finding a market like paper which values mineralization by-products at prices over one hundred dollars per ton could make mineralization a financially viable industry but how big could this industry be the european paper market for lyme can sequester about 2 million tons of co2 annually if replaced entirely with mineralization byproduct that market would need to scale up 5 000 times to reach the 10 billion gigatons of annual co2 storage we need by 2050 even if mineralization completely replaced the global market for lyme it would sequester less than 2 percent of the co2 needing to be removed annually there's simply not a large enough market to finance co2 reduction at the required scale one final approach to reducing the cost of x-situ mineralization is to forego using an energy-intensive reactor instead finely ground powders of reactive rock could be spread on beaches croplands or surface repositories this approach called enhanced weathering increases the surface area of reactive rock in contact with rain which speeds up the natural co2 weathering cycle enhanced weathering can cost less than 10 us dollars per ton of co2 if mining waste is used or 50 to 200 per ton if freshly mined rock is used and this technique could be employed at a large scale for example if we were to cover all 166 million hectares of agricultural land in the united states with crushed reactive rock enhanced weathering of that material could sequester up to 0.74 gigatons of co2 in a year and other nations with large agricultural output like china and india have the capacity to sequester similar amounts of co2 however a lot of uncertainty remains regarding how this technique would work in reality first it is not clear how quickly the powdered material would actually break down and other possibly hazardous metals could leach from the powdered rock into the soil during weathering so let's consider our other option the potential for in-situ mineralization the good news about this technique is that the subsurface rocks don't need to be mined and are already under temperature and pressure conditions that are ideal for mineralization that means that cost can be much lower than x-situ techniques ranging from about 10 to 30 us dollars for online storage sites and the potential storage capacity is orders of magnitude more than we need that said testing how well in-situ mineralization actually works is still in its nascent stages carb fix a collaborative research and industry project in iceland built the world's first carbon capture plant using mineralization in 2014 the plant works in tandem with an existing hydrothermal power plant atop iceland's basalt rich crust it can scrub co2 from gases released from the geothermal energy plant or the ambient air the co2 is mixed with hot water being pumped for electricity production at the power plant and the mixture is then pumped into the hot basalt subsurface there the co2 water mix travels through pore spaces and fractures in the rock reacting to form carbonate minerals at the carb fix site over 95 percent of the injected co2 mineralized in less than two years the six-year pilot program which is now sequestering carbon at a rate of about 10 000 metric tons per year has optimized the process such that the costs are around 25 us dollars per ton of co2 this low cost is due in part to the ideal location of the carb fix project and costs may be higher in regions less rich in water and geothermal energy resources but carb fix provided the proof of concept that in-situ mineralization can be affordably achieved in sum the possibilities of co2 mineralization are as promising as the approaches are diverse however like other methods of carbon capture and storage mineralization will require significant upfront investment and government support it must also be noted that the range in price that we examined for mineralization from 10 to 600 us dollars per ton only represents the storage costs of the co2 most of these techniques require that carbon dioxide is first captured from an emissions source or from the ambient air and then transported to the mineralization site those capture and transport costs can range from 25 to thousands of dollars per ton as we detail in our related videos on carbon capture and sequestration to learn more you can find our other carbon capture and sequestration videos on our website climatenow.com and you can listen to the complete story of how green minerals is helping to build the mineralization industry in our full podcast interview with poll knobs thanks and see you next time you

Channel: Climate Now

Views: 15,789

Keywords: climate change, climate now, climate tech, climate crisis, climate videos, climate science, carbon mineralization, carbon storage, carbon sequestration technology, carbon sequestration explained, carbon sequestration methods, carbon sequestration, carbon dioxide removal, CDR, carbon, CO2, carbon capture, carbon removal, pol knops, mineralization, climate change solution, how to solve climate change, how to save the earth from climate change, climate change documentary

Id: LK_bCFftGaw

Length: 14min 19sec (859 seconds)

Published: Tue Dec 21 2021