 Good afternoon and welcome to this webinar on advances in the chemistry of carbon dioxide capture. My name is Ellen Mantis and I am the director of the chemical sciences roundtable of the National Academies of Sciences, Engineering and Medicine. For those not familiar with the roundtable it provides a neutral forum to advance the understanding of issues of importance to the chemical sciences and engineering and promotes the exchange of information among government industry and academic sectors. This year we are continuing our series of webinars on emerging topics. We launched our series of webinars last year and all presentations and recordings from 2020 are available on the CSR website. Today we will be reviewing some available technologies for CO2 capture exploring chemical and engineering challenges and finding improved carbon capture agents and describing some new technology under development. The format will consist of three presentations. There will be time for one or two clarifying questions after each presentation, but all other questions will be addressed in our discussion time after the presentations conclude. Dr. David Myers will be our moderator for this webinar. He is a member of the chemical sciences roundtable and vice president of specialty businesses and strategic accounts of the specialty construction chemicals business of GCP applied technologies. He will be asking the questions on behalf of the audience. Questions can be submitted via the Q&A button on zoom located in the bottom control panel. The chat feature has been disabled for audience members. For those tuning in via live stream on the CSR website, please submit questions via email. With that I would like to introduce our first speaker, Raghavir Gupta. Dr. Gupta is co founder and president of Sustion, which is a technology startup with admission of development and deployment of low carbon energy technologies to achieve net zero emissions. Dr. Gupta, please go on. Thank you, Elaine, and thank you for everyone pretending it and I want to thank the chemical sciences roundtable of National Academy of Sciences for this opportunity to participate in this panel discussion. So before so next slide. Can you go to the next slide? Yeah, so I got it. Okay, just, just before I get started in the on the subject I just want to give a very brief introduction of Sustion. I've been working in this field for the last 30 plus years and three years back, you know, I co founded Sustion with a couple of my colleagues, and with the sole purpose of developing and deploying technologies that can significantly reduce greenhouse gases by through disruptive innovations. So this form is perfect for us to, to talk about it what those disruptive disruptive innovations could be in CO2 capture and CO2 utilization, and we are also looking at hydrogen production. So in here in our company we basically work very closely with the academic and national labs, Department of Energy, industry and private sector to really see how we can take these innovations and convert them into to deployable technologies. And I think the commercialization and scale up is an important part of our mission. And I'll give you some examples in my presentation. So before I get started on the subject matter I think most of you are aware of the recent book, which was released last month by Will Gates, and I had an opportunity to read this book. And in the last few last couple of weeks and I think it's pretty, you know, this book presents, this book basically presents a pretty good assessment of the state of affairs today and what we need to do to reach to the net zero because climate change is an existential threat for all of us for the humanity. In this book, the way Bill Gates organizes the technologies into five sectors, how we plug in means how do we produce electricity. I think which is important for chemical industry because a lot of talk about, you know, electrifying the chemical processes rather than using natural gas or other heating media, which generates CO2. So we make things that's bread and butter for chemical industry whether we making ethylene or we making propylene or making ammonia, or we making concrete or cement. How do we grow things where ammonia and fertilizer industry becomes very important. How do we get around the fuels is still most of our transportation sector is dependent on fossil fuels. Big emitters of CO2 and how do we stay cool and keep cool and stay warm. So I think this pretty much hits a lot of touch points where chemical industry really plays into it. So, so with that background, so basically what is our really the challenge. I think in worldwide, we emit about 40 gigaton per year of CO2 worldwide and US is roughly six gigaton. And if you take the total greenhouse gas emissions, which are about 51 gigatons, so we, we have 80% of the greenhouse gases coming from CO2. So to basically deal with this problem, we'll have to look at all sources of CO2 and consider all methods of capture utilization storage there are no silver bullets that one technology can basically solve the problem. And I think the technology has been around for a while. I think one of the region, we have not seen a lot more industrial adaptation of this technology is a lack of regulatory framework. Some of the economic incentives, which exists, I think there are 45 Q type incentives, but we need more of them. And also the poor understanding of the CC us value chain. So this flow shot flow chart shows a very simplistic picture where, you know, we emit CO2 in process industry electricity generation with everybody knows, you know, steel cement, and these are what we call point sources. And then I also included air direct air capture which is, which is now getting more and more attention. So we capture the CO2 and I'll talk about some of the technology which we can use. And once we capture the CO2 we can store it in a geological sequestration or the and has all recovery and then load of emphasis on CO2 conversion. And for the CO2 conversion. We need, you know, basically carbon free energy, either hydrogen electricity or methane to make products, and I'll briefly touch upon this you know. So the next. So if you look at the CCS value chain, the capture cost capture is 73% of the problem so if you look at the CO2 cost CO2 is $100 certain so $73 roughly goes in the capture, about 11% is compression, 3% in the transportation, 8% storage and 5% monitoring monitoring. If you store the CO2 underground. So, so the capture is the largest component where most of the work has been done from the R&D and technology side you know so I'll talk about that. So, so if you look at the capture pathways, this is a little bit simplistic chart but it pretty much in a depicts what we need to do to deal with the CO2 so what I've done is I've divided various pathways where we basically either produce energy or produce chemicals. So if you take the any industrial process where we basically, you know, make ammonia, methanol, cement, steel, so either we need heat for the reaction or carbon is basically an input. And in the end, we need to adjust the hydrogen to CO ratio so we need to get CO2 out so so the number of industrial processes which basically generates CO2 either in the process or just by heating it. So the thing we do with the combustion of fossil fuels whether it's a coal gas or coal natural gas heavy oil, biotomine, we burn it to generate power and heat and we generate CO2. And depending on how we generate how we burn it, the fuel gas can contain five to 15% CO2 I'll come back to that in a minute. So if we make hydrogen or any other products from natural gas, we basically also capture CO2 what we call it pre combustion capture because that CO2 is removed before we utilize the the final fuel for final product. And then the technology where we can burn the fossil fuel with pure oxygen, we call oxy combustion and then we essentially make a concentrated stream of CO2. The last line I added here in the in the slide is the direct air where we could we could remove CO2 direct air is extreme the air is the very dilute in CO2. So, so there are separation challenges which are touch upon it. So if we look at these pathways they probably represent about 50 to 60% of the CO2 emitted globally and and all fossil based the power power systems require post combustion capture because there is, you know if you're going to accept the oxy combustion also is a post combustion but you've got concentrated CO2. And the CO2 capture technology selection depends on the in the CO2 concentration temperature pressure and other characteristics of the gas which we are handling. So just to get to the next level. So what are the various capture pathways so there are a number of capture pathways which are being developed so so I basically put you know the the five main pathways one is the absorption and absorption can be a physical absorption. The CO2 is physically absorbed like in methanol or glycol based materials or in ionic liquids, or it could be chemical absorption which is most prevalent in the industry where we use amines alkaline solutions. Hydrate you know hybrid amines ammonia modified ionic liquids. So into the adsorption where we physically absorbs where we absorb CO2 on a solid surface. It could be physical absorption like geo lights or activated carbons or metal organic frameworks which you will hear in the next presentation and or chemical adsorption and chemical absorption. Either you use amine and amine and rich sorbent or metal oxide like sodium oxide or potassium oxide or the carbonates. You can use membranes with membranes are challenging for the flue gas, but there are opportunities and I briefly touch upon that. Then there are biological pathways for station oceanic fertilization mark micro algae which I will not discuss, but they are being researched. And then there are options for you know condensing CO2 using cryogenic pathways and there's some technology being developed so. You know professor long my next presenter will talk about most of the adsorption by solids and I'll basically spend some time on the chemical adsorption which is probably the most advanced technology for CO2 capture. So just to show you give you a flavor of what type of flue gas we get with various CO2 concentrations so I basically put the major sources of the CO2 here. This is a coal powered power plant where most of the work has been done CO2 is 11 to 14% with very low partial pressure. Natural gas power plant even it is even lower than coal power plant is less between four and 6% so that as the CO2 concentration goes down the difficulty of separating it becomes more harder in the air as we all know the CO2 is only 400 ppm. So this is really a very difficult separation, but if you take some of the chemical side if you take a natural gas processing plant where you remove CO2 from natural gas. The CO2 could be 99% right from the from the processing plant without any additional capture similar same is the case for ammonia or ethanol plants. So a very interesting case is cement plant where CO2 could be 20% and and I think more of cement plants are really taking advantage of this high CO2 concentration. So you know so one of the things which you know it is not very well appreciated that you cannot just take one process and adapt that process for all CO2 streams. So the capture is basically a you know combination of materials which go into the into the process and the specific process designs because you just cannot have one material which will work on all processes or all one specific process will work with all the other applications. So and I'll give you some specific examples of various you know some of these some of these things which are in the slides because if you're going to use a solvent for a natural gas combined cycle plant flue gas. That solvent probably needs to be done very differently for a coal fired plant versus a cement flue gas. So I just wanted to make sure that you appreciate this distinction you know. So one of the major industrial workhorse for CO2 capture is the solvent based post combustion CO2 capture technology where we use the aiming you know most of the work is based on mono ethylene amine which has been around in chemical industry for last 50, 60 years. And the process is quite established so basically you take the flue gas go through a direct contact cooler where you cool the gas flue gas down, then basically you have a tall column filled up with backings where you you basically contact the pump the amine and amine solution and flue gas they basically move up concurrent wise. In some designs you have a cooling water because the reaction is exothermic so you need to control the temperature and then the clean gas is vented. And then the the the sorbet which is laden by CO2 is sent to a regenerator where you regenerate it and then regenerated solvent is sent back to the absorber and cycle completes the regeneration is typically done with with steam. So so this is a basically a basic process which has been around very you know for long time in the industry. So typical solvents could be primary secondary tertiary or hindered amine. You know they they can produce CO2 at very high purity, you know, the design of the systems are very well understood in terms of CO2 recovery gas flow rate etc. But the there are some challenges with flue gas which typically don't see we don't see them with the other other gas streams like natural gas processing plants. There's been a lot of work in last 10-15 years funded by Department of Energy, and also by industry where you know we're looking at advanced solvents which have a lower regeneration energy requirement I'll touch upon that. And, and combined with high CO2 absorption capacity and tolerance to the gas impurity so these could be water lean solvents, phase change solvents or high performance functional solvents. So if you look at the commercialization challenges for these materials is one is the low overall absorption rate if we can increase the absorption rate we can reduce the column height and the capital cost. High regeneration energy is one of the most important challenge because this is basically directly relates to the total capital cost. Then loss of solvent due to degradation, solvent loss due to emissions, corrosion and wastewater treatment. And some of the technology provider which supply the commercial technology for this application are Mitsubishi, Shell, BSF, Acre Solutions, Floor and you know and there are other new technologies which are coming up in the market. So, so just to talk about a couple of problems, you know the low overall absorption rate for a mean based solvents is a is an important part because the volume of flue gas is so high, for example for a 500 megawatt coal plant. The volume of flue gas is 1.2 million actual cubic feet per minute. So you could see the amount of gas we are handling. So, we basically looking at the packing designs for better contacting absorption column height and some of the process intensification. One of the things we are doing in our team is developing some catalytic additives to enhance the absorption rate. You know you can see an example of a packing process intensification by using a rotating pack bed. So you can even intensify by a factor of 10. In this case, the one second example is we basically are developing a catalytic additive which can be added. And by adding 2000 ppm of the catalytic additive will be increased absorption rate by 43%. Initially this couldn't really reduce the overall column height and maybe column diameter and reduce the overall capex. So I think these are these innovations are being pursued. You know, and then the second part which is a high regeneration energy for a mean based solvents, this varies between 2.1 to 3.8 giga Joules per ton of CO2. This is the largest contributor of the CO2 removal cost. So there are a number of innovations which are being happening. You know, people are redesigning the flow sheet where using advanced flash strippers, more heat recovery ultrasound assisted regeneration to reduce this heat duty. So basically looking at, you know, the catalytic additive I just talked about it. We could speed up the regeneration rate and reduce the temperature and you can see some of the initial data we got. We could reduce the overall heat duty by up to 30% in this case, you know. So, and then other than that, I'm not going to read through that, but these are real challenges when we scale up the lab technology to commercial technologies. We need to worry about oxygen, which is there in the flue gas, what radical scavengers for my solvent and treatment volatility of the solvent aerosols which are generated. So all these things have to be really taken care of it for a commercial process to work and I think a lot of work is ongoing in the industry and and academic community. Just briefly touch upon the sorbent base you took after technologies, you'll hear that in the next presentation but just to give you various options, you know, physical adsorption of the work which is being done in alumina, geolites, activated carbons, mobs, porous polymer networks. Then, you know, chemical absorption like mostly alky alky oxide materials, and also the aiming and concentrated sorbents. There are the hybrid materials where you combine the best properties of amines and metal organic frameworks. But there are commercialization challenges you know obviously you know one of the things is CO2 concentration in flue gas you know the system for direct air capture will be very different than that will be for old flue gas water in the flue gas. Then degradation with oxygen flue gas contaminants and long term stability. I think the one of the most important thing for the sorbent based technology is the reactor and process design because you are we are handling large amount of flue gas and we need to figure out whether it's going to be fixed bed reactor or a fluidized bed reactor. You know, I think a lot of industrial players are moving to the structure bed material reactor which I'll show you an example in a minute, then the gas solid contacting becomes important. The gas transfer because absorption reaction is exothermic and end up and regeneration is endothermic but and we need to figure out how do we supply the heat to the regeneration and how do we remove heat from the absorption. And then pressure because flue gas is at very low pressure. And the issues are like attrition corrosion disposal and loss I mean leaching these are typical losses so one of the example I want to give you commercial example is the technology which was developed by swante. I'm running this at 30 ton per day scale this is a rotating absorption machine. You know using a basically a you know heat exchanger design where it rotates slowly between absorption regeneration and purging. And they got a 30 ton and now they're scaling it up to 2000 tons per day system. The membrane based technologies are being developed for flue gas but again we need to realize the flue gas partial pressure is very low. And, and sometimes CO2 concentration could be very low so I think there are projects which are being pursued for cold flue gas cold based flue gas as well as cement flue gas. There are a number of membranes from polymer membranes to to to facilitate a transport membranes and non facilitated where you, you facilitate the permeation of CO2. But again, you know you, these are good for CO2 concentration of greater than 10% volume typically the CO2 purity is low and will require significant downstream purification and the CO2 nitrogen selectivity of membrane over 50 doesn't really buy much, that flux could be very useful in terms of reducing the overall cost. So there are a few few things I wanted to just to give an example so Department of Energy has funded some large demo projects from the CCUS one is the air products facility in Port Arthur, which began in 2013 it is connected with a steam methane reformer CO2 capture. This is the Arthur Daniel Midland in in back to Illinois, which is an ethanol facility, which started in 2017. Then the Petronova plant in Texas, unfortunately this plant is now closed, but this heat this plant ran quite well. And then the the shell console proper technology at boundary damage socks power in Canada so there are examples of CO2 capture from from from from industrial streams and flue gases. Briefly turns upon the direct air capture, you know just I'm just going to get one or two slides direct air capture I just said there are challenges, because CO2 is only 400 ppm in the in air so we have nitrogen and oxygen is 2,500 times as of CO2 and water is 100 times. And the second is to one ton of CO2 removes require requires us to handle 3200 tons of air at 50% removal so this is not a trivial amount of flow which we need to handle so somebody has to design a million tons of CO2 plant from direct air capture. One can imagine how big that system will be and what type of energy and and hardware we will need to deal with that so this is something. Think about it, then the, then the minimum energy for removal is 22 kilojoules per mole and then you need some multiples of that to put that energy to separate that out. The genetics has to be fast. The sorbent needs a fairly high capacity, it has to be dirt cheap, and it needs to survive for a long time we can't afford to change this material. So I think the key thing to this one is the is the you know it's not only the sorbent you know we need to understand process engineering and economics. They all need to go hand in hand to really really develop this technology and load of work is being done and on in this area. So current technology state there are three companies which are really too well up to wrap this up pretty quickly if you don't want one minute, one, one, one, one, one minute. So, thank you, carbon engineering, client works and global thermostat, these are the three pioneers in the direct air capture area that other companies we are also do started some work at early stage we are at early stage, we are doing that, but I think this this solution is definitely needed to get to the net zero and and the you know and the last thing is the CO2 utilization if you want to do something with CO2 we will need some energy which is carbon free, because CO2 is the most oxidized form of the form of the carbon. So I was in a national academies committee a couple of years back where we looked at the, how do we valorize the CO2 and there's an NS report and this is a reference in the presentation if you're interested so we looked at various pathways and what are the challenges from removing the CO, utilizing the CO2 because it's a very stable molecule, you know, so this basically identify all the research needs for CO2 removal, the CO2 utilization. So, so in summary, I think we have, you know, 51 gigaton per year global greenhouse emissions CO2 is about 40, and we need to do something about it to get to the net zero target. I think the chemical energy industry sectors account for more than 50% of the CO2 emissions so they get all. They all know about it, I think the solvent based capture technologies are most advanced, and they can be effectively used for point sources, no skill there are scale up and degradation challenges which are being addressed. Regeneration energy is the largest component of CO2 and I think there's a lot of R&D which is being done there to reduce this number, the direct air capture or deck has to be part of portfolio solutions to achieve net zero emissions. I think utilization offers some interesting options to make products, but the scale to match CO2 emissions with the utilization options is going to be a challenge. So, so I don't want I want to leave you that we can take on this challenge, this is a plant which Dave and I we work together. When I was at RTI, we designed, built and operated this 50 megawatt CO2 capture plant at Tempi Electric, we captured 1000, 1000 tons of CO2 in this plant. So this is all doable. The problem is solvable, but we need, we only need, we need interdisciplinary approach and best minds engaged, and I think we can achieve this goal. So thank you very much for your attention, sorry I took few minutes longer than I expected. Dr. Gupta, thank you very much for that talk you certainly covered a lot of ground. I think we'll move on to our next speaker, who is Dr. Jeffrey Long, who will speak about absorbent technologies. Dr. Long is a professor of chemistry and professor of chemical and bimolecular engineering at the University of California at Berkeley. He is the director of Berkeley Center for gas separations in his research group focuses on the designing controlled synthesis of novel inorganic materials and molecules towards the fundamental understanding of new physical phenomena. With that, Professor Long. Thanks. Hi everyone. So I'm going to switch a little bit and talk about some fundamental science geared towards discovery of new CO2 capture materials. And my focus will be on really a material that behaves in a completely different way from other porous solid CO2 absorbance. And it involves a cooperative mechanism for CO2 adsorption. And this allows for a switch like behavior to the material where you can go from fully loading CO2 to fully unloading the CO2 with a small temperature or pressure change. And the materials that we work on are, here we go, our metal organic frameworks, and these are to us sort of designer zeolites, where you can use the power of synthetic chemistry to adjust the poor size, the poor geometry the poor shape, or the poor dimensions, the surface functionality of the material. And it's that chemical tune ability combined with record high surface areas that make moths powerful for separation such as CO2 capture. And for using a porous solid material like this. I think that you would implement this in a CO2 capture process. The simplest way would be, you could just fill a column with the material, and bring the flue gas in one side. And if you've done your job as a chemist, right, then only CO2 will stick to this very high internal surface area of the material. And the other gas molecules will come out in in purified form. And as you run the gas through the bed eventually you'll, you'll fill up the moth, and you'll then need to desorb CO2 in a pure form. And to do that, you'll either raise the temperature, or drop the pressure of the bed. And once you release CO2, then you'll start again and capture more. Most all of the materials that you would put into this kind of device show a Langmuir type adsorption behavior. And this means that if we look at equilibrium uptake of carbon dioxide, then we have a very steep rise at low pressures, and eventually you saturate the surface of the material. What it means is that once you've loaded CO2 onto the material, you either have to go to a very deep vacuum to pull all the CO2 off, or to go to very high temperatures to desorb much of the CO2. And so this leads to a lot of costs and energy use in doing an adsorption desorption capture process. And if you think about how these, the shape of these adsorption isotherms, they're really not ideal for having an efficient separation. What you'd really like to be able to do is something akin to how hemoglobin works. So you're all probably familiar with hemoglobin, it's this amazing biomolecule, which has four different iron heme units. Those iron hemes can selectively bind an oxygen molecule. And when you bind oxygen at one of the hemes, there's a rearrangement in the protein backbone that opens up access to the other three hemes. And so hemoglobin actually binds and releases for oxygen molecules simultaneously. And that cooperative adsorption process leads to a step shaped adsorption isotherm instead of that Langmuir shape that we saw before. And so this allows hemoglobin to bind and release these oxygen molecules with quite a narrow change in the concentration or pressure of oxygen. And that's exactly the kind of thing we'd like to do for having an efficient separation. And nobody realized that this was possible in a dense way in a porous solid material, until we accidentally discovered that it's possible for carbon dioxide in a mean functionalized moth. And just to introduce the moth. This is a starting point for this story. It's based on moth 74, which has a honeycomb like structure. And here you're looking at a view going down one of the channels within the honeycomb. And in moth 74 these channels are about 12 angstroms across. And what we're going out are running along the at the corners of each hexagonal channel, you have these rows of green atoms. And these are coordinatively unsaturated metal centers. And they're spaced about six and a half angstroms apart, as you go along the channel direction. And so there are six such chains, one of each corner of hexagonal channel. And what we're going to do is we're going to attach a diamine to each of those metal sites. And so you're going to have rows of metals with diamonds attached. And it turns out that that creates a material that shows cooperative CO2 adsorption. And the way it works is CO2 is actually inserting into the metal mean bonds. And when you do that insertion, you transfer a proton from the backside of this nitrogen on the bond amine to a dangling amine to form an ammonium cation that's attracted to the carbamate. And you can think of that as activating this next metal amine bond for CO2 insertion. And so CO2 is being zipped up into ammonium carbamate chains. And there's one of those chains running along each corner of a hexagonal channel within the material. So what you're seeing here is a cross cut of one of those channels. There's ample room for diffusion of CO2 in and out. And like hemoglobin, this material, it simultaneously binds and then releases carbon dioxide at a very specific temperature and pressure. And so that kind of behavior is reflected in these step-like adsorption isotherms. And so what you see here is that at a specific pressure and temperature, you can all of a sudden have this vertical rise and CO2 is taken up in a cooperative process. And this works because we've got just the right diamine chain length to form these ammonium carbamate chains. And the point of this is that with those steps, you can then have a very large separation capacity with a small temperature or pressure change. And so if we compare sort of classical amine solutions like an MEA solution in water or amine adsorbents, then these Langmuir isotherms mean that when you load the materials with CO2 and then go to regenerate and desorb CO2, you actually leave most of the carbon dioxide in the solution or in the solid. Even if you're doing, say, 100 degree increase in temperature, a lot of CO2 is going to remain undesorbed. In contrast for these step-shaped isotherm materials, if we position the step in the right place, then a very small temperature or pressure change can give us the entire capacity of the material, say 15 weight percent CO2, as opposed to two or three weight percent CO2. So this small delta T can be a big advantage in terms of the energy associated with the CO2 capture process. So knowing the mechanism of how this material adsorbs carbon dioxide allows us to adjust the adsorption step position and try to optimize the material for a specific CO2 capture application. And the sort of handles we have are, since we're inserting to this metal amine bond, if we change the nature of the amine bound to the metal, we change the thermodynamics of the reaction with CO2 and that will move the adsorption step position. If we change this spacer between nitrogens, that changes the structure of the ammonium carbamate chains being formed. And again, changes the thermodynamics and then finally changing the substituents on the ammonium forming nitrogen will change the energy of this chain forming ammonium carbamate interaction. So these are all handles or knobs that we can do tune in adjusting CO2 uptake properties of the material. And so this is just an example showing if we attach these four different diamonds to this inexpensive magnesium based moth. Then as we build up steric encumbrance at the ammonium forming nitrogen, we can push that step out in pressure at a given temperature. So we've tested many, many different diamonds within this material. More than 80 now, and by changing that diming we can adjust the adsorption step at 40 degrees anywhere from two parts per million, where you're very effectively capturing CO2 from air to out past two bar, which may have uses for high pressure CO2 removal. So with this kind of tune ability, you can target a specific application and essentially what we're doing here is we're changing the thermodynamics for the material binding CO2. And you can see the delta H for CO2 adsorption here we can adjust anywhere from minus 40 kilojoules per mole to out past minus 100 kilojoules per mole. So as you go to these stronger and stronger, anthropically, anthropic contributions to the driving force, you're generally making more and more tightly wrapped chains. And so you can see you pay a larger and larger and traffic penalty. To change the diamine within this moth we move along this line, but the ability to move along this line allows us to target a specific CO2 capture application and make it as efficient as possible. So previous speaker already mentioned a lot of the different capture needs. Some of those are listed here. And the point is, the CO2 concentration in those various streams can be widely varying from very low pressure such as in air to significantly high pressure such as in natural gas sweetening or in hydrogen producing hydrogen for fertilizer. So a lot of research focus has really been on coal, flue gas capture, but optimizing materials for all of these other places we need to decarbonize is an extremely important research direction. So these materials are being developed commercially by a company called mosaic materials this company was started by Tom McDonald in the center here who was the PhD student that originally discovered the cooperative CO2 absorbance. And the kind of thing they do is produce these materials at low cost in large quantities, and also in structured forms that mechanically robust and won't show attrition during a separation process. And so I'm going to finish just by giving you a small additional story about the tune ability here and how we can adjust chemistry within these materials to try and address process issues that come up when you really start to integrate an absorbance in a separation. And so perhaps eight years ago we were approached by ExxonMobil. They were interested in the stepped absorbance for natural gas, flue gas capture and they wanted their process to operate at very high temperatures, capturing and releasing at very high temperatures, and that can minimize water co-absorption. And so, if you if you need to go to very high temperatures for these materials, one issue that can come up is above 130, 140 degrees C you start to possibly volatilize the diamonds. And the solution that we came up with was from studying crystal structures. We realized in this crystal structure that the Ethel groups are leaning over towards each other on neighboring sites around the periphery of the channel. And we thought, perhaps we can just make a covalent connection there and still maintain that cooperative chain forming mechanism for CO2 absorption. And so we started testing tetramines. So one of those is shown here and amazingly these tetramines in fact organize within the material. You can see now we've got two attachment points, as well as hydrogen bonds between neighboring tetramines. And these become now very robust to extreme conditions for CO2 capture and release. And so this is just showing a thousand adsorption desorption cycles for a low concentration. This would be a natural gas type of flue gas. And we're capturing at 100 degrees C. And then releasing you can heat up to 180 and you see there's no loss of capacity as we cycle these materials. And seeing that we thought perhaps we could even do steam stripping for regeneration. For capture in a place where you have access to steam, particularly low grade steam that's not being efficiently used for electricity generation. This can be a very low cost option for regenerating your material. And I won't have time to go into details, but these are IR spectra just showing that we can actually do isothermal cycling where we're switching from 120 degree C stream containing CO2. We have CO2 adsorption to form those ammonium carbamate chains, and then we can switch to this the pure steam stream at the same temperature and remove the CO2. And that can be cycled. And so, just to give you an idea of what's going on here, here's a GIF that one of my students made. So here we're going to focus on one of the channels in the moth. You can see how the tetra means our binding will rotate 90 degrees here's a top view. With CO2 adsorbs, there are actually two different types of chains that form one at each end and slightly different energetics. So these materials actually show a double step, instead of a single step. Once you're loaded with CO2, you can bring in steam, desorb the CO2 and start again. Finally, I just want to mention that there are a lot of needs for developing new approaches to CO2 capture the amount of energy that's going to be needed for regenerating a lot of materials used in these processes is tremendous. And as the previous speaker pointed out, it's particularly costly for separating CO2 from air. And so this is a necessary research challenge, but we don't actually have good solutions yet for materials that can effectively do this with low energy penalty. So I think I'd like to encourage people to take up that research challenge. And fundamentally it is a materials synthesis challenge. So I'll just wrap up there and thank some really brilliant students, postdocs and collaborators, some sources of funding and thanks for your attention. Thank you, Professor Long. One question that came from the participants was around the robustness of these materials and you mentioned that these were quite robust in kind of at least simulating industrial processes. How well do these stand up relative to absorbance solid absorbance that are commonly used in carbon capture. Yeah, so the degradation mechanisms for mean solutions and solids. That's always an issue that you need to address. And the current materials being used do degrade fairly quickly. So the way we're tying down the amines and these solids can actually lead to longer lifetimes where the decomposition pathways accessible and solution or not necessarily accessible in these materials. Also, if you operate at lower temperature conditions, you have less degradation. And so one of the advantages for these materials can be less degradation as you cycle. Thank you very much. So we'll move on to our our final speaker, Dr on Alba Rubio, who will talk about dual function materials. Dr Alba Rubio is a an assistant professor in the Department of Chemical Engineering at the University of Toledo for current research interests involved the rational design and synthesis of nano materials for catalysis and sensing with a special interest in producing fuels and materials sustainably and developing technologies to improve the human condition. With that, Professor Alba Rubio. I thank you very much for your kind introduction. So, as it was said, I'm going to be talking about dual function materials that can capture and convert CO2. So, um, the toward good time Dr long has been talking about CO2 capture, and I would be talking about some materials that in addition to capture can also convert CO2. So let me see if I had the control here. So a brief introduction of my group has been already mentioned, but what we do is the synthesizing materials, well defined materials for catalysis and sensing applications. And we especially focusing in multifunctional catalysts that are catalysts that can do different things during the course of the reaction. And one of the examples of the research that we do in our lab is the development of dual function materials for CO2 capture and conversion. So here we represented this in our recent review paper. This type of materials dual function materials DFM for sure, as materials that can capture CO2, and then converting to value added products. So the same material can do both things. And in this case, CO2 is being hydrogenated to methane and water. So this is one of the reactions that has been mostly used for dual function materials. And this methane is not expected to be released to the atmosphere if not being used as a fuel source for the, for the industry. And so we are developing materials to to in our case in our lab we are developing these type of materials to produce higher value added products such as methanol and high alcohols as part of the career award that I got from NSF two years ago. So it has been already mentioned the carbon capture and sequestration as a good way to take the CO2 from the environment or from flu gas to store in geological formations. But we are more excited about capturing CO2 and utilizing that to produce other value added products. And as part of that, we are developing these dual function materials that I just mentioned, which has some advantages. But both are serving conversion components are together in the same material. Also, they both can operate these are thermally so both the capture and the conversion can happen at the same temperature. So it's not needed those thermal swings regeneration that recording all their capture processes. Also, they can treat the alerted CO2 streams. And importantly, this could help to eliminate transportation and storage of CO2 because these materials can be used in situ to convert CO2 into value added products such as fuels that can be used back in the, in the plant, right for for energy. So here, I would like to show these dual function materials process flow diagram proposed by Professor Farrauto's group. Actually, my research is very inspired by by the research that he has this group has been doing. So I'm going to be showing many, many of his papers today. So here are these flow diagram what we have is a power plant in which we have the flue gas. Some of those pollutants are going to be removed before reaching the dual function material. So these dual function material is going to be saturated by CO2 by using hydrogen that ideally could come from renewable sources such as for example, the electrolysis of water with renewable energy. This hydrogen can be flow through the dual function material to hydrogen, do the hydrogenation of CO2 into methane and also regenerate the material for future capture. And that methane can be recycled and use as a fuel in the power plant. This production of methane from CO2 is for the use of dual function materials is especially interesting because it's an isothermic reaction. So the heat that is going to be released here can help the CO2 distortion and the spillover of CO2 from the sorbent to the catalytic sites. So here there is an example of a dual function material which we have the support gamma alumina. Then the sorbing in this case is calcium oxide and the catalyst that is ruthenium nanoparticles. In this case, the flue gas, the CO2 is going to be absorbed onto the calcium oxide. This is going to be a spillover to the ruthenium nanoparticle. And with hydrogen is going to be hydrogenated to form methane and water. And actually this isothermic reaction is going to promote the distortion of the CO2 to continue the reaction, the further capture and conversion. So as I said, these dual function materials has two components, the absorbent and the catalyst that is going to convert CO2. And the most used absorbance in these dual function materials are usually metal oxide and metal carbonates, which are good because they are inexpensive and highly reactive. However, both has the problem that after a while because you need to be regenerated at high temperature, they can sintered and lose the capacity to absorb CO2. So the way that this is studying the literature, how to improve this is by dispersing this metal oxide and metal carbonates on the surface as a support. So the particles, the material is very well dispersed so it cannot easily sintered. So they can be stable for longer. That would be the absorbent component of the dual function material. And now I'm going to be talking about the catalyst component. So once the CO2 is absorbed, the different metals that can be used to convert the CO2. So in this case, one of the metals mostly used for dual function materials is nickel. So nickel is a very inexpensive material that can be used for for these reactions. And also it's very versatile so we can do different reactions by using nickel. So in this case, there is a table with different dual function materials that use nickel. So nickel with calcium oxide or nickel with calcium and sodium as the promoter or nickel sodium carbonate. So most of them has been synthesized by typical synthesis method of catalysts. So these nickel dual function materials catalysts have been used for the dry reforming of methane, the reverse water gas shift, the dry reforming of methane, or methanation. But as I said before, methanation is especially interesting for the study of these materials, because this is so thermic I can contribute to the distortion of CO2. So here, one of the advantages is that both the absorption and the reaction can take at the same temperature. So first we have CO2, CO2 diluted is being absorbed on the material and saturated. And then there is the reaction by flowing hydrogen or another compound that is going to be reacting with the CO2. So both the absorption and the reaction can occur at the same temperature. However, these temperatures are kind of high. And this is due to the fact that nickel need high temperatures to be reduced. So on the, here in this paper, they show that when using flue gas, clean flue gas, using a nickel sodium oxide luminal catalyst, the activity and the production of methane was very high. But when flowing a flue gas that contains some air and steam, the activity dropped dramatically. And they found that this is because nickel is becomes oxidized and is not easily reduced because of the high temperature required to reduce nickel. So, what was proposed is doing alloys of nickel with other noble metals such as platinum palladium or ruthenium in this other paper. And by only adding 1% of the noble metal they were able to reduce the reduction temperature to around 320 degrees C, which is much, much more convenient and only by using 1% of the noble metal. Making the catalyst more stable and being able to use that at lower temperatures. But in addition to the alloys of nickel with noble metals, noble metals have also been used to for the development of dual function materials such as ruthenium and rhodium. So here there is a table that has different ruthenium and rhodium catalysts with the solvent component. Again, most of them synthesized by conventional method and for methanation. And as you can see here by using noble metals we can do this absorption and reaction and much lower temperature, which is very convenient from the power point of view. And this is also different dilutions of CO2 and then flowing hydrogen for the conversion. Continuing with the ruthenium and rhodium. So you might be wondering if we need a solvent and a catalytic component is it is better to add first the solvent and then the catalyst is the or the opposite. So in this study they found that this is better to put the solvent first, impregnate the support first with the with the solvent and then the catalyst because if that way ruthenium can be more dispersed on the surface without being encapsulated by by the solvent. Additionally, they found that even with physical mixtures of catalyst and solvent. There is an increased activity in the methanation and this is due to the fact that even when the solvent and the catalyst are separated. Still there is this spillover of CO2 from the solvent to the catalyst improving the the hydrogenation. This shows that this catalyst with ruthenium calcium oxide on gamma alumina was stable for for many cycles and this was with a clean flue gas, a simulated flue gas. But when working under more realistic conditions such in this case with the steam and oxygen. They found this like ruthenium, when we have CO2 and oxygen becomes oxidized ruthenium oxide. Even when we flow hydrogen to do the CO2 methanation, the rate at which the catalyst is reviewed is not as fast they should be so somebody decrease the the absorption capacity as well as the methanation rate. We also studied how to how the the absorptive capacity of the of the species in affect the effectiveness of the dual function materials showing here that if they capture component dissolving is able to capture more CO2. Also the methanation rates are going to be increasing. In this study, it was compared Rodion with ruthenium. And we can see here with 5% of ruthenium and only 0.1% of Rodion, the production of methane with these dual function materials is very similar. However, we need to take into account that the current price of Rodion is much much higher than ruthenium. So it seems like this Rodion materials, even when able to produce methane from CO2 is not the most convenient one. And in the literature, it's not. There has been also some examples of no noble metals. So all of them are not Rodion ruthenium metals like that. And also metals that even when they are no noble metals, they can work at lower temperatures, not as high as Nico. So in this example, these authors supported iron, copper and chromium on to hydrotal side, modified with potassium. So they found that by doing the CO2 capture, these CO2 forms carbonate on the potassium. And then when switched to hydrogen that is this changing here. So we're going to be reacting with the CO2 to form CO. So this is to producing gas and some CO2 that was not converted. And even when this material use no noble metals, they found that the material was stable under ideal flu flu gas and also under more realistic conditions involving oxygen and water. So the literature has used copper, which is something that we are very interested in our lab. So in this case they use copper alumina, and they promoted that with potassium and barium. And they found that when promoting with potassium. As we can see here, we can capture CO2. And then once that we switch to hydrogen for the hydrogenation we produce CO also some very small amount of methane. But interestingly, they found that by surface studies that copper remain reduced, not oxidized. And also they found formate species, which are especially interesting for us because formate species are found when obtaining CO or when producing methanol. And in our lab we are interested in producing these dual function materials to obtain methanol. So we believe that copper could be a good metal for for dual function materials. Finally, I would, I would like to talk really quick about this very recent study that they use dual function materials to convert CO2 directly from air. In this case, 415 ppm of CO2 in air were used with this material that I mentioned before containing ruthenium and sodium oxide, and they found very good CO2 capture methanol rates. Very interestingly, because of the dialogue system and the different flows that they use, they found that it was enough for them to maintain the ruthenium reduce during the reaction due to the hydrogenation of the CO2 that hydrogen in the environment was enough to maintain ruthenium reduce. So the catalyst was stable also for for many cycles. And additionally, they showed that by adding, when they have a moisture, some moisture in the flue gas, the activity drops. But this is irreversible. So it can be, sorry, it's reversible. So it can be returned to the previous activity just by removing that moisture. So we are a little on time already. So let me just summarize this with this my my vision of the future of dual function materials. So I believe most of the studies has been done to synthesize dual function materials by using conventional techniques to synthesize catalysts such as impregnation. I believe that trying to control the proximity between the solvent and the catalyst can help to produce dual function materials more efficient. Also, these copper nanoparticles, if we are able to control the oxidation during the reaction and everything that could help to produce all their value added products in addition to methane, such as methanol high alcohol. The idea is producing methanol so it can be using a direct fuel cell to to power the plant. So that could be also something very interesting and I also got very excited about seeing this study in which dual function materials can be used directly to take CO2 from air. So with that, I would like to thank you all for for coming to the organization for inviting me to to give this talk. And once I would like to thanks my my current group. Well, this is before pandemic so there are some new students and some of them has already graduated also former students and collaborating this project. Thank you. Thank you, Professor Alvaro Rubio. There's been a number of questions that have that have come in but I'd like to just focus on one for now if I could, and that is the utility of this sort of a catalyst system for producing other chemicals other than methane and how selective these catalysts are for the desired end product. Yes, so I think we can actually we have shown that we can produce methanol with these type of materials. So, I believe that there is, it's just a, this is in infancy right so there is still a way to modify the catalyst properly so what we are doing right now is doing this inverse catalyst in which we put as I show at the beginning this leg with structure right that we put one piece on top of another. So in a way that we can produce this interfacial size to promote the production of older other products other than the methane. So, but this is a little more challenging that the typical catalyst that we synthesize because we also have this foreign component that is also affecting the oxidation state and everything. So definitely there is, there is a way to produce these high higher value added products but yeah it needs more development. Thank you very much. Okay, we could now move into the, the panel discussion part of the of the webinar. Thanks to the speakers to all get on from on your video. Like to remind the audience that you can submit questions through the Q&A button on zoom which is located the bottom of your screen and if you actually don't see the icons just hover the mouse over there and they, and they should appear. You can also email questions to CSR at nas.edu and I'll have the pleasure of actually posing the questions to the this distinguished panel. One question and maybe I'll direct it since you spoke last, Professor Albarubio is the, your thoughts on the challenges of scaling up these these intricate technologies to solve this very pressing problem. And in particular the problems you think that will arise when you begin to confront these materials with real life flue gas versus kind of lab grade flue gas that that is, you know, the source of both experimentation. If you could start Dr. Albarubio and we can move through the panel with that question. Yes. Yeah, so that's, that's a nice question so as we know the flue gas is not just CO2 right is there are more components in there and the most problematic might be sulfur oxides and nitrogen oxide so especially there has been in the literature has been shown. Some people have been using this simulated flue gas with SO2 and show that these SO2 reacts with potassium carbonate to form potassium sulfide. And this is actually eliminating the capture capacity of the material. So definitely this more complex or real actually real flue gas is going to be something that need to be systematically studied with this type of materials, because they can affect the catalyst but also the manufacturing component. So yeah this is something that that in our studies we have in mind and it's something that makes things a little more complicated but can be, can be overcome. Professor Long I mean could you speak to the same question with respect to your materials. Yeah, so it does depend a lot on the source of CO2 and you know coal flue gas is one of the dirtier inlets that we would have and socks and knocks can be a problem. We have studied a couple of materials for socks and knocks degradation or, or, you know effects and what those studies show, you know we've we've particularly used SO2 combined with water in the incoming stream. And that SO2 is adorbed onto the amines in the moth. And, you know with the first couple of cycles you lose something like 30% capacity for CO2 uptake that you can't recover. But then cycling after that we seem to maintain about 70% of the capacity. And so we don't quite know exactly you know why we're retaining some of that capacity. But if you, if you have a large dose of SO2 of socks that gets over into your material, what you can do is you can actually recover by washing out the amines in the moth and replacing them. So you can fully recover. If you have an accident with your, your desox unit for example and get a large dose of of socks onto the absorbent. You don't have to throw away the the moth and rest and get a fresh batch of moth. Dr. Gupta, you've done some work with scale up of some of these technologies. What would you say are the major issues, any technologies likely to confront in scale up? I think the scale up here in the flue gas case is pretty daunting because of the sheer volumes which we are handling here in this case. You know this is not a typical, you know, like if we look at the socks knocks removal we were handling PPM levels of socks and knocks from the flue gas but here in the CO2 case. We are, you know, some cases 15-20% CO2 with large volumes of the flue gas. So that means we need fairly large contactors, you know, fairly large amount of steam and energy and process optimization. So I think it's all doable, you know, it's just matter of, you know, doing learning by doing things. And I think some of the projects which, which were installed and I gave the example in my presentation like for example the share scale technology at boundary dam, there were challenges with aiming and forming the sorts, you know, into the real flue gas and then they have to redesign parts of the system there. So obviously, we have much better understanding now than we had five years back in terms of all these technology issues. I'll say yes, we should not ignore them as we design this, try to get as much information about flue gas, what is the contaminants we have, what are the properties of the solvent will be and how do we design these systems to deal with those just because afterwards the changes in the system are very expensive and painful, you know. Right. So part of the original warranty in this sector was driven by the by the power sector and the needs of either coal combustion or coal gasification and natural gas as well. I guess what are your thoughts on how these technologies can be applied into the industrial sector whether it's steel production cement production or other industrial processes and are there unique kind of technical challenges associated with that. So let me start with that. So, so let's take the example of the cement industry, I think it's a perfect example. So, all the learnings which we had for doing CO2 capture from coal flue gas. Essentially, all those learnings can be applied to the cement industry. Fortunately, the cement flue gas contains about 20% CO2 which is higher than in a cold, cold flue gas which is about 1314% but it has some other contaminants like for example the socks and knocks are much more severe in the cement flue gas. In other words, we probably have to have a preconditioning unit going into the cement flue gas but essentially, all the technology components which were there for the cold flue gas can be directly used for the cement flue gas. You know, also there is a possibility of integrating waste heat in the cement plant which we don't have in the coal plant to reduce the steam duty on the regenerator a little bit. Similarly, steel industry is true. The natural gas is a completely different system because if you go into the combined cycle we have 4% CO2 and most of the technologies which are designed for 14% CO2 they typically don't work well for 4%. You need to rethink about the reactor design and the process design. And so I think there are some challenges but I think we are learning about it, how to do it. And I think we should be able to get there with some demonstration plans. Anyone else on that one? All three of you mentioned direct air capture, but somewhat in passing is it was not really the central theme of the research. What are your thoughts on the unique technical and scientific challenges related to making air capture a reality on a large scale? Do you have any questions? Sure, I can try. It's a very dilute stream so you're unmixing 400 ppm of CO2 from the one bar air and that means there's this big minimum energy requirement. So right away you're going to have to spend quite a bit of energy doing this separation. You know, we don't want to, we want to get as close to that of course as we can. A lot of the, probably the main energy requirement currently is in regenerating after capturing CO2 from air. So normally a company like Climeworks, you're doing resistive heating and thermally using temperature increase to release the CO2 as well as a vacuum. So it's both heat and vacuum for getting the CO2 off these materials. And the energy requirements there are very large and it's that regeneration energy we need to improve in lower. Also the time to heat up the materials and then cool the materials back down. That plays into how quickly you can do an adsorption desorption cycle. New ways of efficiently removing and adding heat into the adsorbent can be really important. And then another issue is capture rate. You know, if you're only taking, say, 20, 30% of the CO2 out of air when it moves through your device, then you need to blow a lot more air. So materials that can have good kinetics and extract a high fraction of CO2 in the air are important. And then also capacity, the higher your capacity for taking CO2 out of air, the less often you have to regenerate and put in that additional energy and time. So those are some of the factors that we should think about in developing new materials. I can, I can also add something. So I had a small chart in my deck slide. I didn't have time to go through it, but as Professor Long said, I think the sorbent is critical in terms of the energy and the reactivity and master's but I think the pressure design cannot be underestimated. First and foremost is the pressure drop, because you can't afford to have a lot of pressure drop because, you know, you have to compress that air to push the air through the reactor. And that number, even if you have 0.1 psi, it adds up very quickly into real kilowatt hours. So that is the, is the heat for the regeneration and the numbers right now which are being loaded in industry are somewhere around 2000 to 3000 kilowatt hour per ton of CO2. So if the electricity is five cents a kilowatt hour that number adds 200 to 150 dollars a ton, just for that regeneration energy and then you've got auxiliary loads on the vacuum and everything else and then you've got capital. This is, this is a real challenging engineering problem, but I am very optimistic. I think with the innovations as Professor Long said, how do we selectively heat the material, don't waste the heat, how do we push things, how do we design through computational fluid dynamics. I think all these things are being done and I'm very optimistic that we will be able to reach to a point where the cost could be quite reasonable for this system. Which applications do you all feel are closest to fruition and actually being implemented at scale. Okay, so I can go there. So, so I think in terms of the cement industry has been extremely aggressive for really implementing CO2 capital. There are a number of projects which are coming up and impact DOE is funding number of front end engineering design studies for large cement plants. So I think the cement industry was another thing where every ton of cement we produce we produce one ton of CO2. So it's a fairly large penalty on cement industry so they are very keen to see something going on. So that's number one which is happening. Number two is the hydrogen production industry using steam methane reformers. I think that industry with every kilogram of hydrogen you produce and an SMR, you produce 10 kilograms of CO2 roughly maybe 9.6. So that industry is getting very motivated to figure out put the CO2 capture units on that. I think then there's the projects on NGCC and natural gas combined cycle. I think there are projects in the steel industry, you know, Arsler and Mitchell just announced the study. So they want to capture CO2 from the steel plant. So, so I think the industry of decarbonization is moving much faster than the power sector carbonization right now. Anyone else on that one. I can, I can say a little bit about, you know, the types of materials that I was talking about. Those are much earlier stage than, you know, solvent based systems and things that are, you know, going into cement capture processes. And the place that those are nearest to being used would be in much smaller scale applications initially, such as scrubbing CO2 in the atmosphere of a submarine or in a space vessel, you know, and then next maybe direct air capture, you know, these can be replacements into a system like climate spills. But those, those are, those can be relatively small devices that are modular. And, you know, the number of cycles required at these low concentrations of, you know, streams that you're removing CO2 from significantly less. Those are advantages for some of these sort of newer materials, and also the way our materials operate I think they have the biggest advantage at these dilute conditions. So what are the big scientific challenges moving forward. You know, what are the scientific problems need to be addressed to be able to be able to move to the next level with with kind of engineering applications. Yeah, I solved them all. I don't, is that, who would you like to respond. Professor long. Okay. All right, sorry, I don't want to dominate things here. Yeah, I, I mean, so I think addressing a very difficult high work cost process like direct air capture. We have a lot of need for just how do we make a material that can, can give us the performance we, we want. But the next step for a lot of, at least, you know, for us after you discover these materials that can have this special switch like function. We're really working with developing processes and working with process engineers and different process designs to figure out how to how to best utilize these very unusual materials. And the good news is there's a lot of tune ability. We're working with a process that you encounter a problem. Sometimes we can solve that problem by, you know, a tweak to the material, or a change in how we make the material. And so, you know, getting materials chemists working with process engineer and modelers. I think there's a lot of opportunities there for, for having dramatic low dramatically lower costs associated with these separations. If I can add to that. So I think if you look at the research and the technology development in this particular domain. I think there's a lot of work which has been done between TRL one to TRL four and there are a lot of good ideas. But, but I think we don't have that much emphasis going from TRL four to TRL six and TRL seven. And I think a lot of technology really don't go that far because the universities don't have that kind of expertise. And industry was a little bit reluctant to invest a lot of money into those developments. And I think that that situation is now changing. So I think there is a critical need to really take some of these technologies to TRL four, five, six level and fail fast. And really, really, you know, try to push like what SpaceX is doing is, you know, figure out the disruptive ideas whether they work or not move on to the next one. There's a critical need for those types of engineering breakthrough. I will not say scientific breakthrough, but the engineering. How do we put these things together? Like, for example, these unique mob structure, but Professor Long is working. How do we put them in devices? How do you mass produce those devices? How do we really implement those devices? I think that is really missing in the, in the currently in the system, you know. And I would like to add that even when the direct air capture seems like very interesting right and it's exciting as well. I think we should put our effort right now in trying to avoid releasing CO2 right to the atmosphere more than taking whatever is in there right because it takes more energy right to do that. So if we can have an implementation and make sure that these carbon cycles are close right and we don't release that CO2 to the atmosphere. I think we should invest more energy in trying to keep this carbon cycle close right more than taking the CO2 from the air. Thank you for that and I guess we'll let that be the last word in this webinar. I'd like to thank all three of our speakers, Professor Albarubio, Professor Long and Dr. Gupta. All three presentations in the recording of the webinar will be posted to the CSR website by the end of the week. The URL I believe is on your screen. If anyone has additional questions, comments or concerns, please email those to to CSR at nas.edu. Our next webinar if you enjoyed this one will be held on September 9 2021 will discuss sustainable chemical manufacturing. Also note the CSR will host a one and a half day workshop on diversity, equity and inclusion in chemistry and chemical engineering on May 25 and 26 of this year. If you have any more information about these events and others and you can subscribe for updates on the CSR website. Thanks for all of you participating thanks of course particularly to our three speakers, and I look forward to seeing you on another one of these in the future. Thank you. Thank you. Thanks everyone. Thank you.