 Our next session is fossil-based energy systems. We're a little bit behind on time, so we're going to go straight into the talks. We've got three really interesting talks, one about ionic liquids, which is really important in terms of making materials that can do very good separations, very efficient separations in terms of CO2. We have a talk that will fold economics as well as technology into it, which is a critical piece because if it's not economic, it's never going to happen. And then we have a talk which is kind of special in terms of the combination of coal to electricity and generating hydrogen in a separated fashion altogether, which is sort of a special thing since coal is this vast resource that's very hard to use. And hydrogen is something which is carbon-free, but it's pretty hard to make without having carbon choke in some other place. So we have some neat opportunities in terms of the programs, but other than that, I'm not going to say more. So if Edward could head up, we'll get going on this. Our first speaker is Edward Magan from Chemical and Biomolecular Engineering at University of Notre Dame. He joined the faculty in Notre Dame in 1995 and currently holds the Doreenie Family Chair of Energy Studies. He's also the Chair of the Department of Chemical and Biomolecular Engineering, Edward. Thanks very much. It's really a great pleasure for me to be here to tell you about some of the work that our group has been doing on looking at ionic liquids for CO2 capture and separations. And so I'm here to report the results of our team. I show you a picture here of some of the faculty and students involved in this effort. And I think we don't need to explain why CO2 capture is important. I think yesterday's sessions really made this abundantly clear that we have to think about carbon capture if we're going to be able to meet some of the sustainability and CO2 targets that we all need. And the typical way that people think about this is in terms of thinking about coal. And certainly CO2 capture is important for coal. Coal is a huge available resource. There's a lot of coal reserves and installed base of coal-fired power plants. And we know that fossil fuels contribute or make up about 85% of our base energy load. But I'd like you to think about CO2 capture in other aspects as well. We know about shale gas is also now becoming a very important element for our energy mix. And although natural gas has a lot less carbon intensity than coal does, we still have carbon emissions. So we replace gas-fired power generation for the dirty old coal-fired power generation, but we still produce CO2. And so you can think about needing to do capture of CO2 from these situations. The flue gas at Neflin is a little bit different from coal-fired power plants. And then I really like Thomas' talk yesterday. I borrowed his image of this about the reduction of CO2 to make fuels or to make chemicals. And the obvious question here is where's this CO2 going to come from? You're going to have to do a separation if you want to be able to do CO2 reduction as well. And the other thing to think about is if you want to do CO2 reduction catalytically, how are you going to get the CO2 into solution? And I want to show you some work on ionic liquids that may be a very good liquid solvent that can generate very high concentrations of CO2 to be used in catalysis. And then lastly we heard yesterday about negative CO2 emissions, this notion of being able to use biomass, and then in the production of energy from biomass to still capture the CO2 in order to have a negative CO2 emission. So in all of these cases we're talking about having to separate CO2 from some effluent stream. And they have very different conditions, very different temperatures and pressures. So what we need is a very versatile platform in which to be able to think about doing CO2 separations. Now we just heard in the previous talk Professor Vowell talking about that the typical way of doing this is with amines and you can think about really post and precombustion as two examples, a different ends of the spectrum of our CO2 capture problem. In the top slide there you can see that what we have is kind of a typical postcombustion scenario where you take some carbon source and combust this in air. That generates a flue gas that's comprised of carbon dioxide, nitrogen, water, and some other things. And we need to do the separation to remove the CO2 from that. It's important to recognize that the flue gas there is at relatively low temperatures and pressures. Maybe 40 to 50 degrees C, maybe about one bar, and the partial pressure of CO2 is actually about a tenth of a bar. This becomes a pretty challenging separation to conduct. However if you want to do sequestration you have to raise that pressure of CO2 up to about 150 bar in order to sequester this. So that's part of the energy cost of this whole carbon capture process. On the other hand if you think about something like a gasification or a precombustion application, here we gasify the carbon. It could be from biomass, it can be from coal. We can then do a water gas shift reaction and then the primary system that we have to do a separation on is a high temperature and high pressure mixture of mostly CO2 and hydrogen. So now we're up to maybe 200 degrees C, 60 bar. It's a very different type of separation than we have to do from the postcombustion aspect. So there's really a range of different separations we could think about. If you do combustion of natural gas, very different conditions there. So what we'd like to have is a platform that can allow us to think about doing these type of CO2 separations for a range of things. We favor using solvent-based methods. This is a simple little movie kind of showing how this works. If you have a flue gas containing CO2 and say nitrogen or maybe hydrogen, you'd like to bring it into contact with a solvent shown here as these yellow molecules that preferentially will associate with the CO2. The other gas is left to either process or you can vent to the atmosphere. And then the complex solvent which carries the CO2 with it is then regenerated with some trigger. It could be heat, it could be other things like a photo effect or something. Then you can recycle the solvent and you've done the separation. So this is the basic idea behind a liquid-based separation of a gas. And this is a very well-established technology. This is one of the reasons why we like liquids. Gas processing with liquid contactors is well known in chemical engineering. The trick here is we need a solvent that can operate under these different conditions that we require. So some of those properties that we need are a high selectivity and affinity for the carbon dioxide. We'd like for these things to be what I would call tunable. That means they need to be amenable for use in either the pre- or post-combustion. Very different temperature pressure conditions can separate CO2 from either hydrogen or from nitrogen. And so we want to have the ability to kind of adjust the properties of the solvent to meet these different needs. Obviously you want this to be a thermally stable solvent because we want to be able to regenerate this and have a long lifetime. It can't be a one-shot type of a solvent. And especially in a pre-combustion application where the temperatures are high, we need to have very low volatility. If you're losing this continuously to evaporation or if you have to add extra processing to recover your solvent because it's volatile, this is really a very expensive proposition. So in the end what our goal here is is to try to optimize solvent properties in order to minimize the regeneration costs. We don't want to have to pay a huge energy penalty in order to recycle the solvent. But we also want to minimize the liquid flow rate so that the size of the equipment is smaller to reduce capital costs. And that's a kind of often intention between the regeneration energy and the capital costs. So as has been mentioned, the conventional technology for doing CO2 capture right now is aqueous amines. Just giving you an example of one type of an amine, a monoethanol amine or MEA. The idea here is that at low temperature you contact MEA, which is dissolved in water. It's about 70% water. And it takes two MEA molecules to react with each CO2 molecule, forming a carbamate and ammonium species. Further you can react with water to form bicarbonate. This reaction can be reversed by heating this up and you can recover the CO2 again. So this is proven technology. It's been around for a very long time and it works, but it has several drawbacks that really limit its application in the type of systems that we would like to apply it to. For one, the amines are volatile. They smell very bad. If you think about putting these in a power plant, you're going to have to have extra processing to capture the amines because you don't want to admit these to the atmosphere. I mean, you're also thinking about air pollution problems of taking CO2 out of the air and releasing amines into the atmosphere. That's not a very good trade-off. They tend to be very corrosive, so materials of construction are important. Probably the biggest problem with amines is that because you have all this water you're carrying around and having to vaporize during the regeneration process, they have a very large energy penalty. Upwards of 25, sometimes estimates are even 30% of the output power of the power plant is going to be used just to run the gas separation process. So the parasitic energy load of this is much higher than thermodynamics says should be possible. Our goal is really can we develop liquid solvents that can overcome some of these problems with conventional amines. We've been for some years now working on a class of liquids called ionic liquids, which have been around for about 20 years now. They're just simply salts that are liquid under ambient temperatures. If you look at this picture up in the upper right, this is one of our graduate students holding a little vial of an ionic liquid, and it's not 800 degrees Celsius, you can hold it in your hand, but that's a pure salt. It's not dissolved in water, it's not dissolved in a solvent. It's 100% salt, but it happens to be liquid at room temperature. There's a huge chemical diversity of compounds that can be made into ionic liquids, which really makes them intriguing platforms for thinking about gas separations. Because they're salts, they have a very high cohesive energy density. They're essentially non-volatile liquids. You can put this under an ultra high vacuum and it'll just sit there and won't do anything. You can see here, this picture here, this is an image of an ionic liquid with CO2 dissolved in it where we're pulling a vacuum. The CO2 just bubbles out of the liquid and the liquid stays behind. So the removal of CO2 from the ionic liquid is trivial, and that makes them very attractive. They tend to be non-corrosive. We don't have to use water. We can use these in an anhydrous manner, so we don't have to carry around the excess water baggage. And this plot here shows that they actually have an intrinsically high physical selectivity and solubility for CO2. This is a plot from my colleague Joan Brennike's experimental work showing you the mole fraction of the gas versus pressure at one temperature. The red symbols are CO2 and you can see oxygen and nitrogen are down here with very, very low solubilities. So already you have a solvent that this is sort of a stock, a pyridinium based, this trifleimid, which has a very high selectivity for CO2. The other thing that's important, and I'll come to this in a bit, is we can design these to even chemically react with CO2 to get even higher selectivities. So our approach in the GSEP project has been to follow this, what we call model guided discovery. And Ed Rubin, I think the next speaker is going to talk a little bit about how you do process modeling to try to understand the economics of CO2 capture. We think it's very important to start with process modeling, understand the nature of the process, and what are the properties of your solvent that are most important that are driving the costs? Mark Stothair at Notre Dame is doing some of that work for us, and then he tells the computational group here, here's some of the properties that we need out of our own liquid. Things like capacities, things, binding energies, heat capacities, those kind of things. And my group and Bill Schneider's group then try to predict with atomistic simulations what particular molecules should have those favorable properties. Brandon Ashfield in chemistry will then make those molecules and Joan Brenneke has the capability to measure the thermodynamic properties, gas separations and all the different properties as well. And then through an iterative process we try to optimize these things so that we're not just kind of randomly synthesizing molecules and throwing them into the lab, but we have some intelligent design involved in, I guess, intelligent design, that's not the word I was looking for. We have a good idea of what we're trying to make here. So let me tell you a little bit about some of the computational methods that we use. We like to be able to predict isotherms of CO2 and other gases in the ionic liquid from first principles. And to do that we use atomistic Monte Carlo simulations. The basic idea here is we have a liquid phase shown here in the upper left coupled thermodynamically, although not physically, to a gas phase. And we use a series of stochastic Monte Carlo moves to satisfy the phase equilibrium condition. And we can do that for a given set of temperatures and pressures and then we get a single point on an isotherm. Typically that means we have to simulate hundreds of these ionic liquid molecules in four to five nanometer periodic systems. These are now fairly standard kind of calculations that you can do a matter of days to get a full isotherm. So we can start from drawing a molecule on the computer to getting an isotherm in really less time than it takes to synthesize and measure it experimentally. And we can do this in parallel fashion on lots and lots of these at one time. So we now have a capability of doing rapid screening of ionic liquids for their uptake properties. And this just gives you an example of some of the things we can do. I'm showing you here two different ionic liquids on the left is something called butyl methyl imidazoleum bistrifilimid. The cation here is a butyl methyl imidazoleum. On the right is a very similar ionic liquid just that there's a hexal chain instead of a butyl chain. These two were chosen because there's an awful lot of experimental data on CO2 uptake in these ionic liquids and we wanted to benchmark our calculations against that. So here we're plotting pressure as a function of mole fraction of CO2 at different temperatures. And there's a lot of information on here. Bottom line here is that the simulations are quantitatively capturing the experimental isotherms and we're not fitting to the experiments. These are purely predictive calculations. One of the most important quantities for us to get right is the enthalpy of absorption. And for physically dissolving CO2 that ends up being between 12 and 16 kilojoules per mole experimentally and the simulations are able to capture that quantitatively. We can also do hydrogen. So if you're thinking about precombustion applications we'd like to understand hydrogen solubility as well. Hydrogen is much less soluble in the ionic liquid than CO2. Here there's also less experimental data. It's a very hard measurement to make but there is some. And so again for the same two ionic liquids I showed on the previous slide you can see different isotherms and the simulations here are now at different temperatures. Interestingly enough these lines correspond to different experimental sets of data. There are four, three of which agree with one another and one which doesn't. One which predicts hydrogen is much more soluble. Our simulations agree with the other three sets of experimental data. So in some sense the simulations are helping us provide a check on the consistency of literature data that maybe doesn't always agree with each other. The other thing that's interesting to me anyway is that the calculated and experimental enthalpy of absorption is actually positive for hydrogen in an ionic liquid. If you think about a free energy argument that means that entropy is what's really responsible for the solubility of hydrogen in the ionic liquid. And this is typical of very low solubility gases. What that means is that unlike CO2 if you heat the liquid up the solubility actually increases. And we're able to capture that positive enthalpy in our simulations and it's been observed also in the experiments. So what you'd really like to do now is be able to do the selectivity calculation. We don't want to just think about pure CO2 or pure hydrogen. So we've done that and this table has a lot of numbers I don't expect for you to look at these and see that I just would like to point out one thing about this is for these two different ionic liquids the selectivities that we compute are on the order of say 45 to 50 for CO2 over nitrogen. And this is based on just physical dissolution of the CO2 and nitrogen into the ionic liquid. We can calculate an ideal selectivity by just fitting the pure isotherms to a simple model and assuming that these things don't interact with each other and that actually gives us very good agreement with our computed selectivities. An important thing to point out however is that if I just made the approximation which is often done in the literature the experimental literature that the ratio of the Henry's law constants gives me the selectivity I would greatly overestimate the selectivity. You would estimate that it's on the order of 70 when in fact the selectivity is more like 50. And this is really I think one of the benefits of these models is that you can test these type of predictions because mixture experiments are much more difficult to conduct than the pure gas experiments. And so we didn't really have good information about this. So let me move on and talk a little bit about increasing the capacity of the ionic liquid for CO2. These physical solvents I've been talking about previously are very good if you have high pressures and low temperatures but in cases where that's not the situation the capacity of these liquids is going to be too low. So you'd like to add reactive groups in order to increase the capacity. And I just show you here an experimental plot again of mole fraction of CO2 versus pressure for a physically dissolving ionic liquid this is the one I was showing you on the previous slides. And what you can see here is that you have to go up to very high pressures 10 bar to get a mole fraction of about 0.3 for CO2 but that's occurring at 10 degrees C as the temperature increases that capacity drops dramatically and if you're operating around a tenth of a bar like you might in a post combustion capture application you really aren't dissolving any CO2 at all. So you need to add chemical reactivity to increase the capacity and the obvious question is how strong should you bind? If you bind very strongly you're going to have to pay a larger energy price to remove the CO2 and regenerate the solvent. So we'd like to try to maximize the capacity. Calculations done by Bill Schneider has helped us figure out how to do this. What he did is he looked at the relative free energies or reaction energies for CO2 binding on a conventional monoethanol amine and he based this as a zero energy reference state. So what he did is he added CO2 to MEA and the first CO2 bound and he called that a zero reference energy and then he went ahead and did the deprotonation reaction to form the carbamate and ammonium species and calculated that energy and set that as a reference. So what we call this first step when you can halt the binding of CO2 after the first case is a one-to-one binding. One amine for one CO2. The two-to-one binding though involves deprotonation reaction and it takes two amines for one CO2 and we know that this is the mechanism that's operational for MEA. So then Bill did a calculation where he added an amine group onto a cation of an ionic liquid, a periodinium and he found that relative to MEA the first binding event is slightly uphill and the second binding event is very negative, minus 71 kilojoules per mole for the deprotonation. So the prediction is that if you put an amine group on a cation you'll see the same two-to-one binding that you see with conventional aqueous amines. Surprisingly however, if you put the reactive group on the anion, in this case an amino acetate anion it's downhill for the first binding event but then it's a big uphill 71 kilojoules per mole to do the deprotonation reaction. So you can arrest the reaction here at this first step if you put the reactive group on the anion and this basically doubles the capacity of CO2 in the ionic liquid if you put the reactive group on the anion and not the cation. And this is unique to ionic liquids and so that's what we've done. We've also built a little model that's a very simple single-site Langmuir type model that says all right we're going to bind a CO2, one CO2 to one anion. If you can compute basically the free energy, you can calculate the equilibrium constant, you can get the isotherm, basic thermodynamics. We estimate the free energy by just calculating the translational entropy of CO2 in the gas phase and saying that that's what delta S is for this reaction. Then we compute the bond strength delta H. So for different delta Hs you can get different characteristic isotherms. Here is what the model would predict for 50 kilojoules per mole binding. At low temperature you get almost one-to-one binding and then as you raise the temperature the binding decreases. So the idea here would be you could capture CO2 at low temperature and low pressure and desorb CO2 at high pressure and high temperature and that would be the delta there is the capacity of your solvent. So we've shown that this works. You can add reactive groups on to anions. Here's two different amino acid based anions and the experiments show that we do get this one-to-one binding and the uptake isotherms are really consistent with the first principle's predictions. We've confirmed the mechanism here with calorimetry and vibrational spectroscopy and we think we understand the chemistry of these systems really well. So this really led us to develop this kind of class of ionic liquids having aprodic heterocyclic anions. These are examples, pyrrolide, imidazolide, and pyrazolide that can do this one-to-one binding and we can tune the binding strength by changing the R group functionality along the ring. So here's an example if you take something like a pyrrolide there's a reactive group here at this nitrogen center and if you just have basic pyrrolide CO2 will react and bind quite strongly 110 kilojoules per mole. This is the prediction. You can add electron withdrawing groups around the ring so in this case a cyano group at the three position the binding goes down to minus 70. If you put a little bit closer to the nitrogen group you're down to about minus 50 kilojoules per mole. And so our process simulations tell us that minus 50 kilojoules per mole is a sweet spot for some of the applications so we went ahead and made this two cyano pyrrolide system and sure enough experimentally we see exactly what we would have predicted from the models. We see this kind of Langmuir type isotherm so this is now experimental data and then as you raise the temperature the capacity goes down. Experimentally we're about minus 43 kilojoules per mole so the calculation is predicted minus 49. This is a pretty reasonable agreement with the experiments and I didn't talk much about this but we can also show that the viscosity of these things doesn't change when you react with CO2 which is different from amines. The viscosity of amines goes up considerably when you dissolve them in CO2. So over the course of this project we've made a whole bunch of these different ionic liquids and here are all experimental isotherms for a bunch of different anions with one particular phosphonium cation and so you can see from indizolide which has the highest binding of minus 54 we get very rapid saturation at low pressures whereas if you go down to 124 triazolide or 123 triazolide these have lower binding energies of say minus 37 minus 40 and the isotherms are much flatter here so we can kind of dial in the binding energy depending on what we want based on these kind of calculations. Now I should tell you that maybe the simulations aren't perfect what we found was that we're not able to quantitatively predict all of the isotherms perfectly well. We're using a very simple model we have a gas phase anion and we're just calculating the delta H of reaction of a CO2 reacting in the gas phase. What we observed experimentally is some different isotherms here for four different ionic liquids and the observation is that the this is a perazolide anion should bind the strongest followed by this 2-synoperolide and then a 124 triazolide and 123 triazolide should not bind very strongly at all. Unfortunately the calculations didn't catch that trend we did see that the perazolide should be the strongest binder but we missed the fact that 123 triazolide doesn't bind as strongly as the other ones. So in this case our simple model was breaking down and what we realized we had to do was add more reality into the model. So what we did is we did first principle is ab initio molecular dynamic simulation of the cation anion pair in the gas phase so this is showing that the anion interacts very strongly with the cation as you might imagine and this has a profound effect on the reaction chemistry and I won't go into the details of this other than to kind of cut to the chase and show you the result here here's an example of one this would be one 3-4 triazolide with a CO2 bound to it interacting with a particular cation and what you can see here is that the bond length here between the CO2 and the anion depends upon the interactions that the anion is having with the cation and this in turn affects the binding energy the plots on the left show you different distributions during the course of the simulation the distance between the CO2 molecule and the anion and the anion and the cation and what you can see is it's very dynamic and the energetics change because of the interactions between the anion and the cation if we put that added realism into the model what we can find is that we do get the proper order of the absorption now by using this ion pair model so this gives us a better result just real quickly now we also have been able to try to simulate the reaction in the formal condensed phase not just an ion pair in the gas phase and Quitten Sheridan has a poster 30 last night where he showed how this works we can construct a thermodynamic cycle basically and calculate salvation free energies in coupling that with the gas phase free energies to get condensed phase free energies the last thing I'll mention is that we're working on coming up with cooperative binding models where we can get beyond the sort of Langmuir model the Langmuir model is nice except you have a sort of delta pressure or delta temperature that sets your given capacity what nature has done is use cooperative binding for example in hemoglobin where you can get sigmoidal type isotherms so you have multiple binding where the first binding event makes the second binding event more favorable that leads to this sigmoidal type isotherm and now you need much smaller either pressure differences or temperature differences to get a given capacity so we've made a whole bunch of different ionic liquids with two to one uptakes that we hope will have this type of cooperative binding event and very recently we measured some of the isotherms for these and for this particular system we do start to see upwards of two molecules of CO2 binding for each ionic liquid and evidence although not quite perfect of some sigmoidal shape in this isotherm so we're pretty excited about that so just to quickly summarize we've designed ionic liquids that have both high CO2 capacity and can be tuned over a wide range of energies to make them suitable for different types of CO2 separations and what we're working on are improving the computational methods that can help us choose other ionic liquids and looking at cooperative binding events so finally I just want to acknowledge very grateful for the support of GSET that's allowed our team to come together and here's some pictures of my co-PI's Brandon Ashefeld did all the synthesis Joan Brenneke did the thermodynamic property measurement Bill Schneider the quantum chemical calculations and Mark sat here at the process modeling and thanks very much for this opportunity to present our work okay we have about three minutes for questions so what's the stability of the ionic liquids in the presence of water and especially water at high temperatures and then also socks and knocks great question so for water some of the ionic liquids we find will reprotonate the anions will reprotonate the presence of water the ones that I was showing you here don't do that the sinoprolite in particular the one where we've done most of our work we've done very extensive tests with water in fact all of them are stable in the presence of water the problem is the presence of water and CO2 because the acidic environment can deactivate them so the answer is some are stable some are not stable and we're trying to understand that socks and knocks will react with the reactive amines and very hard to get them back back off once they react so in any kind of an application if you have a lot of sulfur you'd have to have a desulfurization step before you would want to do the CO2 capture that's kind of our current thinking on that what kind of pressures are necessary to get the CO2 to disorb so typical if you look at the isotherms that we have there we want to we want to desorb them at as high a pressure as possible because then we have to take this up to pipeline pressures we can desorb these things at around 140 degrees C the ionic liquids are still stable and the pressures then are a few bar at that point and you can get good capacity we don't want to go to vacuum at all the economics of vacuum for these systems is not good so we want to absorb them at always above atmospheric pressure and desorb them at higher pressures and just use temperature as the driver but in principle you could use vacuum for this at lower temperatures it just turns out that for this particular system it looks like the economics are better if you use higher temperatures and higher pressures that's assuming of course that you have to compress the CO2 back up to pipeline pressures one last quick one I've heard that ionic liquids are very difficult to manufacture and worth more than their weight in gold so do you envision that these may have some of those same cost challenges and this is an issue with these are new molecules many of them have never been made before so they are worth their weight in gold when Brandon is making milligram quantities of them with this very talented graduate students the idea though is that these are not particularly exotic materials they're carbon, hydrogen, nitrogen and so if you were to make these on scale the cost will go down I'll tell you that Petronas the Malaysian oil company is making mercury removal with ionic liquids and they're using ton quantities of ionic liquids in that process the ionic liquids have been stable for a couple of years so there are examples of large scale industrial uses of ionic liquids and really what you need is you need those kind of applications where you can make these on scale to get the cost of the liquid down but we're very cognizant of that when we're designing these things we're trying to avoid any kind of exotic materials and that makes again Edward okay we're going to move on to our second person named Edward you do realize this is an all Edward session my last name is Edwards we have Edward, we have Ed Rubin we're just going to keep going and Turgut is Turkish for Edward so when we get to Turgut over there so our next speaker is Ed is with Engineering and Public Policy at Carnegie Mellon and he was the founding director of Energy and Environmental Studies and the Environmental Institute in addition to his very active research agenda his activities include roles as the coordinating lead author for the IPCC special report on carbon dioxide capture and storage advisor to the state of California and province of Alberta on policies for CCS board member of the UK research center and author of the recent national academy studies sorry cut that out and add it to my time add it to his time okay thanks thanks very much Chris it's a pleasure to be here I am really representing these folks, these are the colleagues back at Carnegie Mellon who've done all the heavy lifting on this project and the work I'll be presenting is due mostly to them very briefly it looks like all of us are starting talks with why the interest in carbon capture the professor and me can't help that assuming that some of you have come here without too much background in this I'll talk a little bit about the objectives and scope of our GSEP project some progress to date and some of the work to hit so why the interest in carbon capture in addition to Ed's comments and others is climate change and the fact that we need not small reductions but large reductions in CO2 emissions in order to achieve those goals if we were talking about 5 or 10% reductions to solve the climate problem we would probably not be talking about CCS 70, 50, 80% is a different story fundamentally CCS is the only technology available that we know of that can address carbon emissions from the existing use of fossil fuels which are likely to be around for some time so my view is more of a bridging technology something that will be necessary if we want to get large carbon reductions fairly quickly while we're working on a long-term sustainable future CCS also turns out to be a major component in all the modeling studies that are done globally when one looks at cost-effective strategies to meet climate change every modeling group who's looked at this shows that without CCS on the table the costs of achieving climate goals will be substantially higher than without trillions of dollars are typically estimates that come out of that so while the focus of this talk is on CO2 capture we shouldn't forget that it's really part of a capture and storage or sequestration system that has three major components first the ability to capture CO2 from power plants and other industrial sources that produce it again the CO2 might arise from coal combustion but it might also arise from natural gas combustion or the use of biomass so-called negative emissions in order to sequester or store it in a geologic formation which looks like the most likely option now one has to compress and transport it and so the compression is typically needed to turn it into a supercritical fluid, essentially a liquid that can be moved by a pipeline to appropriate storage sites we're going to be talking about two major approaches what we can do today we've talked about and Ed set this up beautifully postcombustion and precombustion here's a little more detailed schematic of what a postcombustion system would look like at a coal-fired power plant today this is what most of the utilities look like without the CO2 capture piece so the yellow box in the middle are a variety of technologies to address so-called criteria or conventional air pollutants, socks, knocks particulates, mercury and if one were to capture CO2 in a postcombustion environment we would add another piece of technology after that upstream of the stack as Ed indicated the current technology that would do that job is in a mean-based system we have CO2 at low concentrations and low pressure so this is a chemical solvent and its energy requirements are substantial the precombustion system looks a little more complex the CO2 capture piece here actually has two components there's a CO2 capture unit toward the back here which today would use a physical solvent so here we have high pressures and relatively high concentrations of CO2 so rather than a chemical solvent one can use a physical sorbent to do that job at a much lower energy cost but in order for that to work one first needs to add upstream a water gas shift reactor that basically is a chemical process that converts CO in the gas to CO2 and H2 so the CO2 capture unit is basically trying to work on a CO2 hydrogen mixture as opposed to the postcombustion which is largely a CO2 nitrogen mixture at much lower pressures again the chemical that would be used today favorably is commercial called Selexol it's a glycol like substance that has been used widely in industrial applications here's what some of this actually looks like in terms of hardware these technologies for both postcombustion and precombustion have been used at power plants both gas and coal fired power plants the two on the left at scales roughly an order of magnitude smaller than a commercial plant today these units are in the order of a couple of tens of megawatt electricity equivalent hydrogen production plants or this particular one uses a Selexol system to essentially do the same separation except the hydrogen is used to make chemicals instead of instead of electricity here are photos of two newer developments the one on the top is I would be fair to say a big deal this is the first large scale demonstration of postcombustion capture at a coal fired power plant it's what the community has been waiting at least a decade for in this calendar one won the lottery on this one the Sashpower boundary dam facility at 110 megawatts there was official inauguration on this just two weeks ago the plant started up a month ago the CO2 capture unit is in the this unit in the foreground so this is now operating at 90% capture and for the first month or so so far so good the picture on the bottom is a unit still under construction that is now scheduled to start next year it's a large gasification plant that the Southern Company is building and it will capture CO2 using Soexol as a solvent at a scale of 600 megawatts with about 65% capture so we're starting to see in these two examples and others that are planned in Europe the first large scale implementations of that if that's the good news this is the bad news they're expensive technologies through one significant digit in a new post combustion plant adding an immune system would increase the cost of generating electricity at that plant by roughly 70% the incremental costs are lower for gasification combined cycle and natural gas plants but still quite significant and in terms of an absolute cost of electricity we're different baselines we're talking about CO2 capture in this meeting because most of that cost is associated with the capture part of that system transport and storage well those costs can vary depending on site specifically roughly on the order of 20% so if you want to make a big dent in CCS cost you've got to go after the capture lots of ideas for how to do that this is a slide from the Department of Energy showing a variety of options that are being pursued in different scales and some notion of their time frames for success I was happy and delighted to see GSEP join that process a couple of years ago a request for proposals sought advanced carbon capture processes and consistent with philosophy looking for step out game changing improvements big improvements that could have big impacts in the next several decades and as a result of that solicitation three projects were selected Ed's project at Nautra Dame involving Ionic liquids Randy's project at Northwestern involving metal organic frameworks and Wilcox's project here at Stanford involving some novel activated carbon solvents so what am I doing up here a year later there was another RFP asking for development of a systems analysis framework to be able to evaluate novel processes these three in particular but others in general in the context of some rather rigorous criteria that GSEP had put in the original proposal for what they'd like to see in these advanced processes so we were selected along with Chris Edwards group here at Stanford to work on a systems analysis framework that could be used to get some quantitative metrics for just how these advanced systems would fare relative to baseline systems in the context of full power systems the approach we had proposed and have been following is to build on some prior work we've been doing with a lot of support from the Department of Energy with that support we've built a modeling framework called IUCM is the acronym if you google it integrated environmental control model essentially an easy to use model of a single power plant could be coal fired biomass and it basically includes all of the environmental control systems not only for air but also for water because water use is another issue here in solid way so it's basically a full blown mass and energy balance with engineering economic models and the ability to handle uncertainty we've proposed to build on this framework as a tool that we and others could use to ask and quickly answer a whole variety of what if questions what if I could create a material that had these characteristics and so on so the overall approach is basically to couple engineering process performance models with models of cost engineering economic models in a systems framework that has a probabilistic capability so one can look at uncertainties in a fairly rigorous way to identify both risks and opportunities and hopefully in a package that again is easy to use and portable so others can play with that so the software package if you were down to download it today is one that has a graphical user interface behind which is a lot of stuff you bring to the model information on the design of the power plant that you're interested in fuel properties some cost factors and the model delivers information on process performance emissions and costs so when this project started we had in it already a whole suite of technologies a number of CO2 baseline CO2 capture systems that we had worked on some other things we're doing for DOE and a whole suite of power plant and environmental control technologies and what we've been doing in this project is to work specifically with the three groups that GSEP has been funding to develop new process performance and cost models that could be implemented in this framework and used to assess some of the specific criteria that GSEP put in their original proposal and these guys have I think the biggest challenge ahead of them GSEP enumerated eight criteria I've reorganized them into four that basically deal with cost metrics and four more or less with cost metrics I've highlighted three of them the ability to capture and separate more than or equal to 90% of the CO2 to substantially reduce the energy penalties relative to what they are now but also to keep the cost low so it's a perfect GSEP challenge along with a number of other things so our job is to try to figure out how things are going in these directions and probably more importantly to try to use a larger modeling framework to suggest ways that one can move more effectively toward meeting these goals so let me tell you first about some of the work we're doing the three projects all have about a year left as does our project so we're about halfway through the project so this is really I intended this to be an informal progress report to GSEP and others let me tell you first about what we've been doing in the area of post combustion capture I should say I think one of the slides got lost a slide here I should back up and say first that all three groups that I mentioned are still working actively on their materials so they have not given us the formula the magic recipes yet for the materials they think will do the best job of that maybe it'll show up later a slide seems to have been dropped so what we've been doing is working with what I've called surrogate materials materials that are similar in nature to the materials that the groups are doing but they're not the last word one of those in Jen Wilcox's project here at Stanford is looking at we heard a little bit about this this morning as well some novel activated carbon sorbents these are basically solid sorbents that might do the job so on the on the left these data points are some data that Jen was kind enough to provide to us and the solid lines are fits to that data using a conventional Langmuir equilibrium model that does a nicer job down and lower in the temperature ranges that are likely to be relevant so what we have basically is a model representation of that on the MOF side we have with advice from the folks at Northwestern we've looked at a number of metal organic frameworks that they believe would be most useful to start playing with the data I'll be showing you so we've looked at a several MOFs we've also looked at some other solid sorbents not on either of those types so I'll show you some preliminary results in a minute based on this is a zeolite just call it ZIF 78 isotherms are the sort that Ed just showed so here is basically CO2 uptake as a function of temperature and pressure we'll look at a case study at 50 degrees Celsius which is a typical flue gas temperature coming in using isotherms both for CO2 and nitrogen where you'll notice the scale is quite different we wanted to start as simple as we could and so the first model that we've put together is a three-step process which involves adsorption and regeneration it's a pressure swing system where flue gas containing in this case idealized as as CO2 and nitrogen is fed into an adsorber and then when breakthrough occurs the system's reversed and there's a vacuum that pulls out the CO2 to give a CO2 rich product one of the things you can see in this system well I think I have another slide here I'm going to skip over the details it's in there here's a better representation let's look first at the one on the right on the left rather these two lines the blue line is showing CO2 recovery which is basically the CO2 capture efficiency and the red line showing the purity of the CO2 that's captured the GSEP target is 90% capture and for this sorbent at this temperature the only way to do that is at very low pressures probably unrealistically low but those are the numbers that would come out for a single stage vacuum separation so 90% purity low pressure and I'm sorry 90% recovery the purity levels are also don't exceed about 70% these two slides show specific work this is energy per unit mass of CO2 absorbed and the sorbent required to do that again we need to operate at low pressures is what comes out of the information here so we've run a preliminary case study using our IECM framework where we assume 90% capture in a single stage VSA system we pressurize the adsorber to a little over atmospheric pressure 1.2 and desorb at this very low pressure we press the CO2 to 135 bar which is basically pipeline pipeline pressures and here are some preliminary results let me just focus on this next to the last line which is the net power plant efficiency basically there's a lot of energy needed not only to do the capture but most importantly to do the compression if one actually had to go to these very low vacuum pressures to do that so the result in this case is a power plant which would be 39% efficient without CO2 capture takes a significant hit comparable to what it would take with a conventional amine system but also with lower purity and that would probably not be pure enough to put into a pipeline so the take home message here is we need to go back and build a more complex model of probably a two stage process and play with some additional parameters to achieve higher efficiencies and higher product purity with this system this was the best of the several sorbents that we looked at and so other materials would have similar challenges I think is the preliminary finding that we come out of here we also modeled a pre combustion system using ionic liquids again we used a particular liquid that was recommended to us by the group at Notre Dame here basically we're comparing we're substituting ionic liquid for a conventional select solvent the technology the process for doing that is the same using either either sorbent so there's an absorber this is syngas from the water gas shift reactor so it's essentially modeled as a CO2 hydrogen mixture in this case in both cases we've taken impurities out of the system and the adsorption is followed by a series of depressurization steps in flash drums and recompression to basically desorb the CO2 again we used data for that particular ionic liquid which Ed can probably pronounce and I can't and used it in a preliminary case study where again we're looking for 90% CO2 capture and taking an entire system compressed to a 135 bar with an idealized gas mixture of CO2 and hydrogen again there are details of the process model that I'll put in the presentation but here's the bottom line in terms of the simulation of the overall power plant this is the power just for the unit I just showed you and in this case the ionic liquid it turns out to be about 10% better in terms of energy requirements than Selexol not a huge breakthrough but a step in the right direction and we can step we can look forward to other properties High Bow Zao did this work also did some sensitivity analyses we're starting to play around with this to look at effects of various design parameters and what we really need to do CO2 removal efficiency if one backed off the 90% target moved down to say 85% actually some things actually started looking better so there's a lot of playing around that remains to be done I think in terms of preliminary messages that come out of this very early work we're just underscoring what Ed and others have said that work on novel materials really has to focus on high selectivity to ensure high capture efficiency as well as high purity these have all been idealized simple systems so we haven't mucked it up by putting any water vapor into either of these all of these materials are none of these materials like water vapor and so either you have to design one that is impervious to it or make the system more complex by taking a dehydration step which is really what you want to do so in order to improve the realism of this we'll need additional data on sort of behavior in the presence of water and other impurities and isotherms not for single component gases but for mixed gases in order to get more realistic performance estimates so none of those imperfections were in those results I showed you earlier let me just say a brief word about process cost models I'm not going to show you any cost results today we're working on that still a work in progress but just in terms of what our approach is and some preliminary conclusions from some other work we finished recently on some other processes what we try to do in our cost models are first estimate on the capital cost side what are often called direct equipment costs what would it cost to buy and install the equipment that one needs to do the capture what's often forgotten and often handled rather I was going to say sloppily that's not right with not as much care as is perhaps needed are a lot of the indirect costs so in a traditional cost estimate after you do an equipment costing there are a series of other measures things particularly called contingency costs they're all typically estimated as a percentage of your direct equipment costs there are some guidelines for how that can be done in some recent work I've stuck my head out and pointed out that major organizations who put out these guidelines like DOE EPRI and others in many of their own studies don't follow their own guidelines and tend to give numbers that are probably more optimistic than they should be for this stage of development we want to be careful in going forward the reason is that there's a lot of history that suggests that we tend to be optimistic technologically at the earliest stages of technology development but as technologies mature toward FOAK is called first of a kind a real commercial reality while ideally we all want to get to that low cost nth of a kind plant you have to start somewhere else and you can't get to the nth of a kind plant without building n plants if you never get past the first one you'll never get to the nth of a kind plant what we have found and I suspect we'll find in this case is that high capital cost is another major barrier and hindrance to the entry of new technologies historically there's a lot of data to show that we've done a poor job of predicting commercial costs at early stages of development so we're going to try to do a more careful and realistic job on that but the message that comes from the work we've done so far is that while as engineers we're always after the Holy Grail of improved efficiency there are tradeoffs and so there are challenges not only to the technical community in finding and tailoring more appropriate materials but also to the engineering community at large in finding ways of minimizing the capital cost of these systems and challenges in terms of how we can make things simpler, how we can reduce the size of vessels, how we can use materials that are cheap and not expensive those two sets of challenges I think are the ones I will want to emphasize here and the fact that they're inevitably going to be tradeoffs between cost and performance in terms of getting to that next best system so a lot of the work ahead we have a number of tasks that we had initially proposed that involve refining models characterizing uncertainties I haven't talked about life cycle analysis new materials come from and whether there are secondary impacts that need to be of concern what we'd like to try to do is try to reverse engineer our models and come back with advice to the process developers for what kinds of parameters they ought to be seeking and that will be a major focus of the work that's ahead so with that I will thank you with apologies for running over and take a question or two if there is one so we have a couple of minutes for questions Sally thanks so you said high selectivity is important but what's high do you have a sense of what's high what would be a target that somebody should be shooting for we didn't come with numbers if we go back to some of the some of the data that we showed it would depend on the particular material that we're talking about but the basic message is we need to do a better job of getting higher pureties on these separations so when we see 70% as a maximum for that particular those are basically substances that are reported in the literature it's not what people are currently working on what you really want is 90 and 90 so what that backs into in terms of the particular parameter we'll figure that out but that's what we're looking for over to Paul the effect of water vapor I think is a very problematic one for a lot of these materials and oh so on your task list one thing I didn't see on there but you did kind of mention it during the talk is sensitivity analysis and I encourage you to keep on on sensitivity analysis that might help with maybe you don't build the best plant to begin with but helps you later on when you get to the end you can start to do the 90% I don't like that but the solutions are to use the probabilistic ability that this model has and do a more rigorous job with which will involve some expert elicitation so I'm expecting that we're going to try to visit folks in the three groups to try to elicit their best estimates as to what kinds of properties might be achievable we can put some of those judgments into the models and get probabilistic results the likelihood of achieving different targets which is a more rigorous way and would account for a lot of interactions with that ideally we want to do that both on the performance and on the cost side because at the end of the day as you said you want to get the best system to do a job and we're going to try to figure out what those parameters are great thanks very much thank you okay the last of our speakers is Turgut Edward Gerr Turgut is a consulting professor of material science and engineering here at Stanford an executive director of Stanford's DOE EFRC center on nanostructuring for energy efficient conversion he served as the technical director of the NSF MRSEC center for materials research as the founding technical director for the Gabal laboratory for advanced materials at Stanford Turgut thank you Chris I will go for Edward why not just to keep the continuity well good morning everyone thanks for coming it's a pleasure to be here I'd like to thank Sally Benson and Richard Sassoon to give us the opportunity to share with you our research work let me recognize my coworkers the people on the first row actually are the ones that did the work Michael Stewart is a post-doc the audience here carrying the microphone he joined us about earlier this year David Jonson is a graduate student in mechanical engineering he's also in the audience and I was pleased to say that his poster got the honorable admission award last night so you can see him as well as his poster out in the lobby if you're interested he's mostly involved in the modeling aspect of the work that we are doing so I'm pleased to hear that we got mentioned and Brandon Long is also in the audience sitting there in the back row he's a graduate student in chemical engineering who just joined us about five six months ago and I'd also like to recognize of course my long-time colleague and collaborator Professor Roger Mitchell of mechanical engineering who's actually the official PI on the project and is sitting right there without further ado let me say that our primary focus is utilization and conversion of solid fuels in fuel cells in a more efficient and environmentally friendly matter and of course this presents its own challenges and I'll walk you through some fuel cell concepts how we will deal and handle solid fuels in fuel cell environments simply because a lot of the conventional fuel cells only handle gaseous fuels mostly hydrogen and maybe a few based on methane and other things but solids, handling solids or utilization of solids in a fuel cell environment poses its own challenges and so I will walk you through some of these concepts and of course conversion into electricity directly in a single reactor without actually burning them provides major advantages the ultimate goal of course is to go one step further in this into complexity and deal with and convert coal which presents its own set of challenges above and beyond simple carbon or carbon issues fuels like biomass does so the objective is to convert a dirty fuel like coal into something clean like electricity and hydrogen and that's where the GSEP project comes in and makes it possible for us to explore this particular exciting avenue so why do we care about coal coal is is oops, I'm sorry I'm on the wrong slide coal is is widely used it provides a lot of the energy globally and about 40% of all the electricity production around the world partly because it's still a lot cheaper than even natural gas after the shale gas discoveries and also it's widely available at abundant in the earth US has the largest coal reserves more than a quarter of the world reserves and most populous countries like China in India a large reserves of coal and they are using this resource for their technological and economic development in China about 80% of the electricity is produced from coal and in India it's still slightly lower but still very very high in the United States we're using less of coal especially after conversion of a lot of the coal fire plants to natural gas but still we're averaging a little lower than 40% of our electricity coming from coal in 2012 that's the latest that I could find from EIA reports which came down from about 45% from two years before that but it's not expected to go much further than that it's about 37% 38% over the long in the next few decades and we should and this trend is common to around the world as well as the world is going to use less in coal in sort of percentage of the share in electricity production but that's not a very good criteria or the parameter to work on I think we should look at the amount of coal that is actually being used and the amount of coal is going to increase by 50% between now and 2040 or 2050 time frame so the amount of coal is what's going to be of concern to us and you see in this graph although a lot of the renewables and natural gas derived power generation has increased it will be increasing or expected to increase over the years but still coal will reign as the dominant force in electricity production and thinking that considering that most of the coal and natural gas around the world now operate at around at the low 30% conversion efficiency only the new ones that are coming online are about a little over 35% closer to 50% depending upon the technology that they adapt that's still a very low conversion efficiency in terms of how we utilize it but more importantly as we've seen in the previous talks as well as in some talks yesterday that most of that CO2 that is produced is emitted as a small fraction of the flue stack gas composition it's only about 10-15% of the flue stack is the CO2 rest of it or major portion of it is nitrogen and we have all seen from the previous talks how difficult it is to separate CO2 on energy intensive and costy that is in terms of separation there is a real incentive to think differently about coal conversion and of course the fuel cells carbon fuel cells provide a major opportunity in that direction efficiency is of course the key if we can say increase the efficiency optimistically if we double it then you can do the numbers and it provides a huge incentive to look into that direction a carbon fuel cell this is an idealistic depiction of a carbon fuel cell what it is is a we have a bed of carbon or coal in the anode compartment so this is a fuel cell element on the cathode side we have air we extract the oxygen from the air oxidize it to make oxide ions we transport these oxides ions through an electrolyte and these oxide ions at the anode react with the carbon to form carbon dioxide releasing their electrons and those electrons travel through the external circuit to produce electricity and the only reaction product as you see is CO2 so this electrolyte could be a ceramic electrolyte it can be a molten carbonate or molten hydroxide or even aqueous electrolyte nevertheless the net reaction is different from burning it carbon plus oxygen going to CO2 but we do this by extracting electrical work out of that system while during this conversion and the driving force for this reaction is about a volt so we get about a volt of open circuit voltage in the fuel cell which is pretty good thermodynamic efficiency theoretical thermodynamic efficiency defined by delta G over delta H where during this reaction the entropy loss is so small that the theoretical efficiency of this conversion is 100 percent so what we are gaining is a very very high ceiling for efficiency of course we will have cell losses the risk of losses activation losses and what have you but the ceiling that we are starting up from is very very high so proportionately we produce less amount of CO2 but not only that we produce CO2 as a primary component of our fuel cell so we don't have to separate it you don't have to go through a post separation process you just seen the big real estate and a process plant for capturing CO2 from a coal fire plant also Sally showed that same picture from Saskatchewan plant it's a huge investment and a huge cost to do to separate CO2 and also bear in mind that you don't see any water involved in this process so waters also is a very precious commodity and a resource just to give you a benchmark about 40 percent of fresh water with drobbles in this country is for thermoelectric power generation so thermoelectric electricity generation uses a lot of water so there's a large incentive not to get water of course there's no moving parts here it's operates at constant temperature it's fuel flexible lots of solid fuels that we can use here and modularity of course gives us an opportunity to do this in a distributed manner but of course there's a caveat there are constraints major constraints that's why this is so difficult one of the major constraints is that we all know electrochemical reactions or charge transfer reaction occurs on discreet sites at the interface and that interface is usually between the electrode and the electrolyte and these are atomic stick or atomic scale sites that these reactions will occur because it has to collect all the participating species that reside in different phases at that interface onto that reaction site and that's where the problem is because you got a boulder of a carbon particle which has sizes anywhere from 50 to 50 microns to millimeters in size to be able to make a contact at atomic scale contact at an electrode site to make this electrochemical reaction happen so one of the techniques is to overcome part of this problem is to gasify solid fuel either using steam for steam gasification where we react with steam to form hydrogen and CO which is zinc gas and then oxidize this hydrogen and CO which is through the gas diffusion gets into the electrochemical reaction site at that interface and oxidize but we are chose to use CO2 as a dry gasification method. CO2 is our annual reaction product so what we do is in a way recycle that reaction product back to our mechanism and the CO is oxidized at the electrochemical interface. So that's what happens the CO that is formed here is oxidized by the oxygen that's coming through we have a ceramic electrolyte it restabilizes the cone which is commonly used in solid oxide fuel cells and it transports oxide ions through the vacancy mechanism. The vacancies are formed by extrinsic doping to maintain charge neutrality in the oxide so oxygen transports through the ceramic material only in the form of an ion not in the form of an atom or a molecule then this CO2 can react with a nearby carbon in the bed and forming more CO that feeds into the end of the reaction so this shuttle mechanism if you like is self feeding and provides higher kinetics than would normally do the end of the day again is this carbon plus oxygen going to CO2 we generate four electrons through the external circuit for every carbon atom that is consumed in the coal bed or in the carbon bed and we tried many different we tried this concept is a fundamentally sound concept with many different solid fuels this is for carbon we got about close to 220 or 30 milliwatts per square centimeter we did this with various kinds of biomass this is these are rice and corn stover and almond shells and wood and so on and so forth we also tried it with coal char which gives us a lot better performance than all the others at about 450 milliwatts per square centimeter I think this is still the highest performance based on coal usage in a carbon fuel cell now let me build upon this concept using the same platform if we just replace the air side on the cathode with steam so we have carbon on the side we have steam on the cathode side the oxygen activity difference between the steam and the carbon is a downhill gradient so it's higher over here than it's over here so this provides a thermodynamic driving force of about half a volt or slightly higher than that depending upon the temperature and the steam hydrogen ratios this provides a driving force downhill for the oxygens to be transferred from the steam transported through the electrolyte and be oxidized at the at the anode side and so we're turning a electrolyzer steam electrolysis requires anywhere from 0.9 volts to 1.3 volts 1.23 volts at room temperature depending upon the temperature regime it's a very high barrier splitting process we turn an electrolyzer which requires electricity to do a chemistry we turn that into a fuel cell which produces electricity as well as a fuel so what we're essentially doing is steam reforming in a fuel cell but with the carbon stream and the hydrogen stream completely separated from each other so there is no mixing and you can use this hydrogen for fampio cells in in applications so we have a steam carbon cell that produces hydrogen electricity but requires heat because of the endothermic reaction we have an air carbon system that produces electricity as well as heat so the obvious thing is to merge these two together and form a what we call an estates cell a steam carbon air fuel cell and that's where again the GISA project comes in to make this happen and allow us the opportunity to explore this exciting direction so what we accomplish here is nothing more than what is being going on in a coal gasifier you supply oxygen to burn part of the coal to derive the energy or the heat to derive the gasification process and we do this in the fuel cell but achieving electrical work at the same time so the project program objectives and tasks we have multiple items on this of course we are doing cell modeling for predictive studies and David's poster yesterday and also still outside is focused on this modeling work and you can talk to him we're of course characterizing our solid fuels in terms of their reactivity for the Woodward reaction needless to say about the experimental studies but the two most important parts of the program are the sulfur abatement and development in the sulfur abatement we have a two prong approach we try to develop solid sorbents to bring down reactivity to acceptable levels where the anode is going to operate without too much degradation and of course at the same time we like to develop tolerant anodes that would take that level of sulfur and be able to do the job without degradation so the electrode development is going to be an important portion of this project normally nickel, cermet and other metal anodes are used to develop solid fuel cells but they are not of course acceptable in the presence of sulfur so what we're looking at these materials are very versatile and gives us an opportunity to tune ionic and electronic transport properties as well as catalytic activity and they provide us also with the doping strategies on the A side and the B side where you can have multiple solpents if you like as long as you maintain or satisfy the Skoldschmidt criteria to maintain the perovskite structure but it provides a lot of flexibility in terms of tuning properties and because of the versatility of this, this whole list of very interesting electronic ionic and dielectric and catalytic properties that these family of perovskites exhibit and I won't go into but many of them are actually of industrial interest and being used in the technology so the two family of perovskites that we have identified so far are the titanate base and the vanadate base perovskites they have not been really explored too much in the catalytic area and there is some indication that these perovskites would have some stability against sulfur contamination they have good electronic conductivity they have reasonably matching thermal expansion coefficient so we are hopeful that these will be a step forward in that direction we already started making and synthesizing these things and doping on the A side as well as on the B side and characterizing them with XRD and XPS I won't go over all the details and we started putting them into cells and making what we call MEAs the membrane electrode assemblies here is the yttriadopt strontium titanate porous layer here is the zirconia electrolyte membrane here is the lanthanum strontium manganite cathode layer that we have been able to produce but we are still a few days away in terms of actual putting in a cell and actually testing it in the presence of coal so in the sense of the solid sorbent utilization we have identified some of the sorbents that make sense from a cost point of view as well as from their efficacy point of view going through some thermodynamic screening both in the literature as well as ourselves what we found is that most of the alkali oxides are effective solid sorbents but their utilization is always limited to a very thin skin around the particle because of the diffusion limitations so the obvious things that people have tried is to disperse them on inert supports what we like to explore is something slightly different we like to try to disperse them on reactive or consumable supports like carbon for instance in the same manner as the fuel in our fuel cell we like to load them onto carbon and gather the sulfur to levels roughly below 10 ppm or so that we think our oxide based anode materials will be stable too so this is the SEM picture of a carbon fiber because these fibers so that we could identify and see where we are in terms of their loading it's easier to work with them rather than with powdered carbon or coal here is after impregnation of these fibers with the calcium oxide calcium hydroxide using an ammonia as a dispersion and you can see both on the surface these red marks or red coloring is due to the calcium from the electron image both on the surface as well as within the bulk we have a fair amount of penetration and impregnation of these into the materials so lastly just to summarize the modeling results we have been able to show that this is a very viable approach to both electricity and hydrogen generation and you can tune your hydrogen and electricity production demand based on the requirements and demand of the market and you can do this in a very efficient way the primary efficiency that we have calculated or predicted based on experimental values or experimental data is roughly about 78% the primary efficiency of both conversion into hydrogen as well as into electricity the electrolyzers the alkaline electrolyzers for making hydrogen they operate around 65 to 75% so they are still efficient and comparably efficient but if you consider the round-trip efficiency the primary efficiency where they get their electricity from if it's cold derived it's about low 30% which make the primary efficiency of that electrolyzer around 20% rather than 78% so we are pretty excited about this project we haven't made a lot of progress because it's a young one but we feel that this is going to be a pathway to efficient conversion of coal into clean energy of electricity and hydrogen we get a we obtain a concentrated stream of CO2 no post separation is needed fuel flexibility and modularity especially from distributed generation from local fuels in Africa or any other parts of the world where power distributed power is badly needed this could be a sort of a model system to develop along those directions provided that of course we have overcome and solved a lot of the challenges and there are many, this is very very long but they can be addressed by basic research and some of the things that we are addressing in this program will provide insights into a few of these challenges mechanistic understanding of the conversion reactions effect of coal contaminants on the performance as well as other things that we will try to address during the project and I'll leave you with this message that the carbon fuel cells are a viable way of going into a transition to a low carbon power generation and we would like to thank the opportunity to be able to do this under GSEP support so with that I will conclude and take questions thanks Target we have about four minutes for questions thanks for that presentation Target has very very nice and really interesting thermodynamics of carbon conversion electrochemically have always been attractive so it's very neat to see this concept really being worked on a couple thoughts occur certainly electro oxidation of CO always has higher polarization hydrogen, same is true I guess in one view from combustion reactions CO always seems to be the last already hopefully that piece of it can be overcome somewhat the one question I guess to think about is that I'm not quite sure how you feed the fuel it seems like it could be batch process I'm not quite sure there and the other piece would be related to the fact that sulfur is clearly important it seems like there probably be some pre-fuel processing needed roughly a quarter of the periodic table seems to be in a lump of coal so maybe there might be some pre-fuel processing as well your thoughts on that well let me first start with the CO CO is not a very widely used fuel for soloxide fuel cells or for any of the fuel cells and based on the very small single cell studies CO has a high activation barrier versus compared to hydrogen but in big cells that we have measured in sort of prototype cells the hydrogen and the CO performances in the same cell came about 5 to 10 percent CO is slightly lower than hydrogen because when you get into the large systems you get the resistive losses that dominate more the kinetics of it in the we're hoping that in a steam rich environment hydrogen is a very very powerful gasifier it reacts with many of the elements that you mentioned in the periodic table forming arsine and phosphine chlorides and so on and so forth they're all volatile so they diffuse and land on the anode in a hydrogen poor environment with a carbon rich environment we're hoping that the volatility and the gasification of some of these arsine and phosphine for instance will be mitigated or diminished to a certain extent and that we will be able to capture some of that with a solid sorbent in the reactor now this is a tall order of course and we don't know until we try it whether how much or how much progress we will make in that direction but that's the that's the thought we have time for one more essentially you sort of covered the question a little bit mentioning these other elements arsine etc but I'm not sure the lack of hydrogen will solve the problem because in combustion of coal there are lots of these elements that appear in the normal combustion process in the exhaust I'm familiar with catalytic sensors that are used in some of these processes for CO measurement and they actually have shown silane poisoning deep in the pores so you'll have some issues with these kinds of elements you know half the periodic table is in coal and I'm sure you're going to end up with lots of volatile silane hydrides that might end up in your in your you're absolutely right and that's very likely that will happen there's a slight caveat that the environment in our anode is a reducing environment whereas in the combustor of course it's more oxidizing so I don't know whether that will make any difference in terms of the gasification rates of these impurities into the gas phase to land on the anode and elsewhere we will have to see but since the problem is so complex and so wide in terms of dealing with all the impurities in coal we expect that the major one the sulfur is being a primary sort of attack point if you like and if we can solve the sulfur problem then hopefully we will have some headway into dealing with the other impurities in time great, thanks very much Turgut