AI Assistant
Transcript
00:00:60Anna Stoppato: Okay, so…
00:06:380Anna Stoppato: Very, very shortly, we can, start.
00:13:190Anna Stoppato: With this…
00:21:770Anna Stoppato: Okay, so it is valid.
00:31:160Anna Stoppato: Okay, today… It is buddy, buddy.
00:43:350Anna Stoppato: Okay.
00:45:00Anna Stoppato: Okay, it is tired and also the computer.
00:49:110Anna Stoppato: Okay, so, okay, if you are two, okay, we will be also…
00:57:260Anna Stoppato: speedy, this lesson, but these are the two… the two meetings, the two lessons that we will have with external experts.
01:08:360Anna Stoppato: I already anticipate, but the first one… in the first lesson, I gave a different date, because the…
01:16:180Anna Stoppato: Later, they asked me to change the data, so we will have two lessons.
01:21:200Anna Stoppato: One mainly focused on the use of hydrogen in the boilers, so as fuel in the boilers. The second one, which is more focused, not on a specific technology, but
01:34:850Anna Stoppato: In the use for maritime transport.
01:37:530Anna Stoppato: Even if mainly it is related to the use of fuel cells in the…
01:46:370Anna Stoppato: the… Maybe bait. Yeah.
01:53:990Anna Stoppato: So, no, the people are coming here.
01:59:310Anna Stoppato: Okay, yes, I think so. The only thing on the 14, immediately after the lesson.
02:08:419Anna Stoppato: There will be some people from FinCantieri.
02:12:170Anna Stoppato: that, will come here
02:17:50Anna Stoppato: to present their company, so this was what I was going to say to you, to present the company, to present their recruitment,
02:25:770Anna Stoppato: strategy, because they are looking for energy engineers for their company. So, of course, the lesson will be recorded, but this part,
02:35:230Anna Stoppato: with, with the company will be… Here, of course.
02:41:530Anna Stoppato: And sorry, the same for the other lesson.
02:44:530Anna Stoppato: Core surgery.
02:46:470Anna Stoppato: it will be… so, the lesson with Pulidoro will be, again, will be recorded. In that case, it will be only a lesson on the usual.
02:56:440Anna Stoppato: hydrogen boilers, but again, they are here, so I don't know where do you live, but for people living near them, it can be also the opportunity to understand if there is some
03:08:970Anna Stoppato: Job.
03:10:250Anna Stoppato: opportunity, not only in this field, but of course, because they are,
03:15:850Anna Stoppato: They are also moving to different, different activities. They were real focusing on the… on the… not on the boilers, on the burners for the boilers. Now they are searching for new possible activities.
03:31:680Anna Stoppato: Which are… It can be interesting, for, for us.
03:36:600Anna Stoppato: And… so this is… I will, send you a…
03:41:550Anna Stoppato: official reminder, but this is… I hope that there is no any general problem related to the 14th of May.
03:51:290Anna Stoppato: For sure, I really appreciate it. Okay.
03:55:00Anna Stoppato: It will be recorded. For the lesson part, so the part for the exam, it will be recorded.
04:01:420Anna Stoppato: And, again, as anticipated, we will have this visit, but I don't have the… the gate until now.
04:09:960Anna Stoppato: They are looking to…
04:12:420Anna Stoppato: open the fuel cells in order that we can go and see the open… not only the box, because sometimes the box is interesting, but of course.
04:23:60Anna Stoppato: We cannot see the things. Okay, so now I hope that the… writes, works, work, because… I… last lesson.
04:33:540Anna Stoppato: I don't know what happened, and all the creatures disappeared.
04:37:230Anna Stoppato: So we start with this. Of course, I remind you that this is not a course of chem…
04:44:130Anna Stoppato: chemical engineering, so we will not go inside the chemical aspects, on the material aspects, but very generally on the aspects more related to the energy field, and then we leave to our colleagues, the…
04:58:930Anna Stoppato: optimization of the other part of the fuel cells. I start with this slide, which was one of the last slides of the last… of the previous lesson.
05:11:890Anna Stoppato: These are, summarized the main,
05:18:290Anna Stoppato: the main data related to the fuel cells. Note that the first column, which refers to the proton exchange membrane fuel cells, and this one, which is related to the solid oxide fuel cells.
05:36:530Anna Stoppato: refers to the two groups of cells which are more spread. Of course, also the others, some of them, some of the others, for example, the one related to the phosphoric acid.
05:51:180Anna Stoppato: And also, older.
05:54:110Anna Stoppato: as a… than the previous… than the other two, but now our focus will be mainly on these two.
06:01:210Anna Stoppato: kind of QSS. In any way, again, I underlined which are… so there are also other aspects that can be in…
06:10:900Anna Stoppato: Interesting, but what is important for us is to understand the operating temperature.
06:16:870Anna Stoppato: We have already seen how the high temperature, on theoretical point of view, penalize.
06:23:560Anna Stoppato: The deficiency, but on the other side, gives a, benefits, in the… Losses related to them.
06:34:500Anna Stoppato: passage of yours. The efficiency, note that this efficiency is the electrical efficiency.
06:42:150Anna Stoppato: And, what we also… also, as you can see, but again, there are… these are numbers.
06:50:390Anna Stoppato: Over 40%, and we can arrive with some cells also to 60 or 70%.
06:56:750Anna Stoppato: And again, I want to underline that we are speaking about small sizes, okay?
07:03:980Anna Stoppato: So… Huh.
07:07:340Anna Stoppato: no other technology is able to reach this efficiency. What we will say something today is related to the combining heat and power efficiency, and you can see that we can also obtain values very close to 90%.
07:25:360Anna Stoppato: And so, now we will see how we can,
07:28:880Anna Stoppato: produce also heat. And then something also related to the stock power, and you can see that we have
07:37:270Anna Stoppato: forget this one, but we can have fuel cells which sizes which are lower than 1 kilowatt, and again, we can reach these very high performances, and then we can arrive for some cells also to
07:51:790Anna Stoppato: Powers which are
07:55:180Anna Stoppato: Of several megawatts. Even if the most used, at present size is in the order of some tens to some hundred kilowatts.
08:06:890Anna Stoppato: The energy density, again,
08:10:380Anna Stoppato: it is a problem related to this kind of machines, as well as the power density. The lifespan, and we will say something about this, because, as you can see, these numbers are not… are not
08:23:490Anna Stoppato: Very, very high, even if, of course, they refer to the operating life, not to the
08:29:120Anna Stoppato: life, when they do not operate, then, okay, these other aspects are more related to the electrical part, we are less interested in this. The electrolyte, which is the… gives the name, generally speaking, to the
08:44:870Anna Stoppato: to the machine, the fuel type, and again, we will say something, but I remind you that this course is focused on hydrogen, because
08:54:50Anna Stoppato: We want to find something that is able to use the hydrogen. The startup time, and you can see that for some cells, for example, the PM, which is the one that we will analyze today, is less than 1 minute, and this is, again, a very important number.
09:10:440Anna Stoppato: And then here we can find… we will say certain, the advantages, the disadvantages, and also the possible application. Note that for the application, we are mainly…
09:23:320Anna Stoppato: see into the future, these are what we are expect… where we expect that they can be used. You can see that some of them are mainly focused on the transportation, and some of them, which is more for our… for us to the power plant.
09:42:70Anna Stoppato: Now, as I told you, I don't go to the details. In the material that is in the syllabus, you can find
09:52:750Anna Stoppato: some… many… some books where you can find some information about this. I will, I forgot, sorry, but I will put you,
10:02:250Anna Stoppato: exactly the pages that you can study in order to prepare to do the exam. Of course, you…
10:09:50Anna Stoppato: Books related to hydrogen fuel cell are very, very…
10:13:800Anna Stoppato: tall, but of course, it is not… we don't, you don't need… Okay, so the first, only to have an idea, these are, at present, the most spread. The PEM, which means proton exchange membrane Fuel Cell, or
10:30:670Anna Stoppato: And the acronym is the same, polymer electrolyte membrane fuel cells.
10:36:250Anna Stoppato: So…
10:38:110Anna Stoppato: from the name, the electrolyte, as I told you, is the electrolyte which gives the name to the cell, is a membrane, which is a solid membrane.
10:50:530Anna Stoppato: It is…
10:51:890Anna Stoppato: Usually, so I also put it here. The most used is this, it is called Napion, which is, okay, a patented name, which is tetrafluoroethylene.
11:07:370Anna Stoppato: membrane with some groups of sulfonates, which helps the passage of the… sorry, go back, to the… of the urine H+.
11:23:990Anna Stoppato: This is solid. This is a membrane, as I… as you can see here, there is a…
11:29:730Anna Stoppato: Seems rate of a membrane, which is…
11:33:70Anna Stoppato: Which needs to be wet, so there is water, okay?
11:38:680Anna Stoppato: What is this? Now, we can start from the anode. You can see that this is the… Mmm…
11:48:650Anna Stoppato: Here, enter the fuel, and you can see
11:52:350Anna Stoppato: Here we have the passage of fuel, which is hydrogen.
11:56:770Anna Stoppato: Okay, hydrogen?
11:58:880Anna Stoppato: Which is consumed, but… okay, then enter, and then exit. No, we cannot see the exit.
12:04:980Anna Stoppato: Dan.
12:06:940Anna Stoppato: The hydrogen passes through this, which is the anode.
12:12:820Anna Stoppato: Or better here, okay?
12:14:700Anna Stoppato: And here, It becomes, and this is the reaction.
12:22:560Anna Stoppato: This is the gas, diffusion layer.
12:25:770Anna Stoppato: Here, we have the action, so the hydrogen produce also electron.
12:31:500Anna Stoppato: Okay?
12:33:240Anna Stoppato: And dead.
12:34:770Anna Stoppato: This is the passage.
12:36:910Anna Stoppato: Okay.
12:38:380Anna Stoppato: the positive high, arriving here. On the other side, we have oxygen. As I told you, we can have pure oxygen, but more often we have air, so we have also,
12:51:640Anna Stoppato: We have also mainly nitrogen.
12:55:390Anna Stoppato: Okay, in that case, it is clear that the, percentage of
13:02:140Anna Stoppato: oxide and the composition of this fuel, of this, oxygen.
13:09:610Anna Stoppato: Changes from the beginning to the exit.
13:12:770Anna Stoppato: Okay the oxygen.
13:17:880Anna Stoppato: Combined with that.
13:20:180Anna Stoppato: Electrums.
13:21:940Anna Stoppato: Which arise from the load, from the external circuit, produce water.
13:28:340Anna Stoppato: Okay, so, at the exit, we will have also water.
13:34:10Anna Stoppato: The two electrons are made of, are mainly based on, carbonates, which are, porous.
13:44:630Anna Stoppato: So, they permit the flow of the gas, because note that here, until here we have the flow of gas, here we have the flow of yungs, but…
13:54:490Anna Stoppato: Until this point, we need that the electrode permits the passage of gas.
14:01:630Anna Stoppato: Okay, so the gas arrived here.
14:04:100Anna Stoppato: And then, of course, syrup.
14:06:120Anna Stoppato: It comes… the water has to pass here, and to exit on this phase, so the, electrodes are porous to permit the passage of…
14:18:20Anna Stoppato: of the gases. There is here a membrane, which is made usually on Teflon or other elements, which permits, to the water
14:30:600Anna Stoppato: this water, not to exit, and not to… and now I say something, so here we have this membrane, in order to
14:40:810Anna Stoppato: avoid that too much water comes into two electrodes. This is very important.
14:48:290Anna Stoppato: And, okay. And of course, I didn't say, but there are also… there is also the necessity of the use of catalysts. The catalysts, which are mainly based on platinum.
15:01:890Anna Stoppato: are needed in order to have the reaction, which takes place at this range of temperature between 60 and 80 degrees.
15:13:660Anna Stoppato: Of course, we don't have time to go inside the detail about this, but I only say something related to this specific fuel cell, which is related to the water. As I told you.
15:29:10Anna Stoppato: we need… sorry, we need water, we need that the membrane is completely wet, but we need that the two electrodes are not very wet, because if they are full of water, they don't permit also the passage of gas. So, one of the
15:47:210Anna Stoppato: activity. One of the main points on which the technology has to focus is the management of the water. We have water which is produced by the reaction.
15:57:520Anna Stoppato: Of course.
15:59:80Anna Stoppato: And, sometimes, but sometimes we need to add the water, so sometimes we add in the inlet with the hydrogen also water.
16:09:230Anna Stoppato: In order to… maintain weight this. On the other side, with the use of a membrane and with the
16:16:480Anna Stoppato: a good management also of the flaws of the fluids. We can…
16:22:650Anna Stoppato: we need to take out the water. An additional point, but it is clear, it is clear that we need to work at these temperatures in order to have liquid water, because we need that here is liquid water.
16:36:880Anna Stoppato: Of course, a small part of water will be also steam.
16:41:550Anna Stoppato: the maximum amount of water, steam… of steam is related to the temperature and to the pressure, the saturation pressure at this temperature, but… so… so we will have… have the exit. Liquid water.
16:55:970Anna Stoppato: And we have to manage this liquid water.
16:59:220Anna Stoppato: And then we have also to manage the steam, the small amount of steam, inside the product of the reaction, so we exit in this position.
17:10:240Anna Stoppato: So this is… okay, a second thing, last time, probably I gave an information, one colleague asked me, something which was at the end of the lesson, so probably I made an error.
17:25:79Anna Stoppato: the reaction produce thermal energy, in this case, and in order to maintain this temperature, we need also to cool the cell. Sometimes this management of water is sufficient, so sending inside with the fuel
17:43:240Anna Stoppato: water at low temperature, we can manage. Very often, we need to add a cooling system, where we take, where we have a heat exchanger with water, which comes from ambient temperature, and exits usually at
18:01:120Anna Stoppato: 10 degrees, a temperature which is 10 degrees higher than them.
18:05:990Anna Stoppato: The previous one, then they have been temporarily.
18:08:690Anna Stoppato: Of course, on the electrical point, this…
18:12:180Anna Stoppato: This necessity to take… to cool means that a part of the energy, which is released, is released as thermal energy, so if we are looking to the,
18:25:640Anna Stoppato: Electric efficiency. This means that the real electric efficiency will be lower, because a part of the
18:32:300Anna Stoppato: Chemical content of the fuel at the inlet.
18:35:760Anna Stoppato: has been transformed into thermal energy instead of electricity. But…
18:41:380Anna Stoppato: This is not very important, because we are not working at very high temperature, and this is a value, so you can see that efficiency can be very high.
18:50:390Anna Stoppato: So these are two pictures.
18:52:420Anna Stoppato: And, no, I say if I forget something before going on, yes, well, I say later. Okay, this is, real, machines, which is the Nuvera series, from General Electric, and you can see, and I think that it is important, these are
19:12:750Anna Stoppato: what I say? These are real values of two real fuel cells. You can see which is the power, so around 50, 60 kilowatts efficiency, peak efficiency.
19:26:430Anna Stoppato: Peak, and we will see what they say it meant. If you,
19:30:580Anna Stoppato: 58%, percent, and then you can see the fuel pressure, and we will say something about these pressures later. The input power, the power assistant.
19:45:540Anna Stoppato: Demands, de… The coolant, and so you can see fuel cell glucol mix.
19:52:670Anna Stoppato: What I want to say with you is this, which is the fuel quality.
19:57:770Anna Stoppato: You can see that here there are some,
20:02:230Anna Stoppato: acronyms, which are related to two different regulations, and I took, Only
20:09:630Anna Stoppato: let you know. So you can see this is… these are the limits of the Society for, Aerospace and Aeronautic,
20:19:80Anna Stoppato: Use, and these are… These are the limits.
20:28:110Anna Stoppato: So these are,
20:30:410Anna Stoppato: the content of hydrogen and of other fuels that is admitted in this kind of cell. And you can see that we want a grade 99.4097,
20:41:380Anna Stoppato: But 99.99, if we don't consider
20:46:490Anna Stoppato: They not tell you, so we can either LU,
20:49:770Anna Stoppato: Of course, not a lot, but we cannot have other. You can see that, which are the limit for the different elements.
20:58:40Anna Stoppato: What is important? Carbon dioxide, generally speaking, is not a big problem, especially if it comes with the air.
21:07:280Anna Stoppato: While there is a problem for the carbon monoxide, at this very low temperature, the carbon monoxide poisons the catalyst, so the life is very, very
21:19:250Anna Stoppato: short if we have carbon diox… carbon monoxide. While the carbon dioxide is mainly a diluent, we don't want it, but it is less dangerous than the carbon monoxide. Again, I already told you the past less, so sulfur must be avoided.
21:38:360Anna Stoppato: Again, sulfur, and every comp… Compost, or every…
21:42:940Anna Stoppato: Volecules that contain any, sulfur is really very dangerous for the…
21:49:630Anna Stoppato: For the catalyst. And this is, of course, and this is, okay, this is, for the aeronautic, this is another way to, to show, this is the so-called grade 4, and again, we need, in this kind of element, grade 4.
22:05:660Anna Stoppato: So you can see that we need very, very pure,
22:11:270Anna Stoppato: hydrogen, I come back, so these are the characteristics, so it…
22:15:930Anna Stoppato: of this fuel cell, which works only on hydrogen. If we don't have hydrogen, but we have metron, but
22:22:520Anna Stoppato: We need to reform before the fuel cell, so we cannot put the metal inside the fuel cells. Okay, and again, these are the efficiencies, so again, you can see this 58% is in that point, and as I remind you, it is for low
22:42:40Anna Stoppato: Lower than the design conditions.
22:46:550Anna Stoppato: and again, this is… this is characteristic of all the fuel cells. Of course, the competitor, of course, this… I took this picture from their…
22:57:690Anna Stoppato: Advertisement, so it is clear that the…
23:01:90Anna Stoppato: operative lists. Okay, before going to the second point, because,
23:08:580Anna Stoppato: See, now we are energy engineers. One important thing, which is one of the other problems of this kind of.
23:16:330Anna Stoppato: cell working at this low temperature, as I told you, is related to the positioning of the electrodes. This means that this efficiency, which is, of course, very, very high, is not constant in the time, so…
23:31:230Anna Stoppato: During the operation, it decreases, and usually speaking, the life is not very long, so after a period of
23:41:140Anna Stoppato: Now, I don't remember exactly. Here, it is written 2,000 or 3 thousand… ours.
23:48:370Anna Stoppato: We can also write to 400 hours, but this number is… not…
23:56:740Anna Stoppato: is too low, or generally speaking, is too low for,
24:02:970Anna Stoppato: sessionary applications, okay? So when we use… but there are some solutions, but if… one of the points, if we want to increase the use of this kind of cells for stationary application, one of the points on which is important to work is to increase this number of hours.
24:22:470Anna Stoppato: And you can see that this is mainly a problem of
24:27:510Anna Stoppato: Metals engineers, more than energy engineers.
24:31:110Anna Stoppato: But this number is acceptable for the,
24:35:790Anna Stoppato: for example, for the aerospace, or for also for the cars, because, of course, again, this number of hours is related only to operation hours, and generally speaking, it is acceptable. And this is why, very often, the…
24:52:170Anna Stoppato: First, the first, possible use of these machines, of these fuel cells, is thought to be in the,
25:01:290Anna Stoppato: in the…
25:03:70Anna Stoppato: For the transportation. But, but, I would like to add something, which is, this one.
25:15:480Anna Stoppato: Because, there is another aspect that I…
25:19:810Anna Stoppato: I want to say with you, and this, it's this one,
25:24:70Anna Stoppato: We have seen that we have the production of the…
25:29:600Anna Stoppato: electricity with an efficiency of 50%, 60%. It is very high, but it means that we have, in addition, we have a part of the
25:39:560Anna Stoppato: energy of the fuel that is released as heat. And, now I put the second, the size of these elements seems very.
25:52:870Anna Stoppato: suitable for domestic applications, okay? We said about, powers of some kilowatts.
26:01:390Anna Stoppato: As can be, for example, for…
26:04:850Anna Stoppato: a building, sometimes a building with only one apartment, but we can also think to buildings, the traditional, also in Italy, buildings with 6, 8 apartments. On the electrical point of view.
26:19:980Anna Stoppato: This size is perfect.
26:23:490Anna Stoppato: And so the idea is… Again, also to, okay, increase the…
26:31:520Anna Stoppato: the use of this machine. Can we use, then, for cogeneration?
26:36:960Anna Stoppato: And so, this is a…
26:39:750Anna Stoppato: possible solution. As you have seen, here, for this machine, there is not any indication, related to progeneration, but there are some studies, for example, like this one.
26:54:930Anna Stoppato: Okay, sorry, it is written in Italian, but this is the… P.E.M.
27:01:610Anna Stoppato: This is the connection with the electrical. So, in this case, it is fed by natural gas, but because now they are mainly fed of natural gas, but of course, they need the reformer before the fuel cell, what it is possible to do is to take
27:18:100Anna Stoppato: This is the… to recover thermal energy from two sources. The first is the cooling system.
27:26:770Anna Stoppato: And the second, are there…
27:28:920Anna Stoppato: the flue gases, okay? Which is the problem. The problem is that… or… which is the problem? We have two different problems. The first is specific of this, is related to the temperature. We have seen that we operate between
27:45:570Anna Stoppato: 50 and 80 degrees, so it is clear that the temperature at which we can recover the gas is, as in this picture, around 65 degrees, which
27:58:700Anna Stoppato: sometimes, for domestic application, it's not very high. So, many times, of course, it depends on the heating system in the buildings, but we need higher temperature. So, a possible application is like this one within the integration with the boiler. So, we have a preheating.
28:17:540Anna Stoppato: Of the water, and then the last heating can be done with this with this boiler.
28:25:630Anna Stoppato: Mmm…
28:27:970Anna Stoppato: The second problem, and this is common also to others, is related to, and again, we need to integrate the boiler, is, as you can see here.
28:39:520Anna Stoppato: This is for a small boiler. What we can see that we can produce 30% of electricity.
28:45:120Anna Stoppato: And then we recover 50% of heat. For larger, 40% of electricity, 40% of heat recovery. What is the problem? That, generally speaking, in domestic application.
29:00:630Anna Stoppato: The user needs more thermal energy, then electrical energy. So,
29:09:890Anna Stoppato: The size is correct for the electrical size.
29:14:30Anna Stoppato: It is smaller for thermal.
29:17:70Anna Stoppato: applications, okay? So, these are the problems, but it is clear that the size.
29:26:510Anna Stoppato: seems to be perfect for domestic application. Again, they use a boiler as an integrative boiler, can compensate this low,
29:37:140Anna Stoppato: thermal production. And there was another thing, I've…
29:42:970Anna Stoppato: Okay, see, an other proposal, again, is to use instead of the, the, instead of the…
29:51:120Anna Stoppato: Of the boiler, the use of a heat pump.
29:54:550Anna Stoppato: So, to have a preheat of water, and then use this water as a hot source for a heat pump. Again, all the solutions in the past were studied, which you can find, if you go on the web, you can find many solutions.
30:12:220Anna Stoppato: But… really… At present, the other main problem is related to the cost, but it is also clear that
30:19:950Anna Stoppato: Antila… Some years ago, the main goal for us
30:25:180Anna Stoppato: to increase the efficiency in the use of natural gas. Now, we have another goal, is how can we use hydrogen? So you can understand that with this different goal, also this solution can become
30:38:290Anna Stoppato: more interesting.
30:40:380Anna Stoppato: And then I go on the second…
30:44:190Anna Stoppato: used. And this is also the same cell that I hope we can see in the other department, which is,
30:57:360Anna Stoppato: The, solid oxide fuel cell.
31:00:360Anna Stoppato: Of course, again, the name is given by them.
31:05:470Anna Stoppato: by the electrolyzer, which is solid. It is mainly, based on, zero volume peptides.
31:14:650Anna Stoppato: It is solid, and it is not porous, so it is really solid, which permits, in this case, the passage of
31:23:950Anna Stoppato: Your oxygen's… oxygen, sorry.
31:27:860Anna Stoppato: Okay, so again, this picture is simplified, but again, we have on one side hydrogen.
31:36:690Anna Stoppato: on the, what, the other side? Oxygen. The oxygen… sorry, it is…
31:42:30Anna Stoppato: It's combined with the electrons coming from the external load.
31:48:430Anna Stoppato: to form.
31:49:710Anna Stoppato: yon oxygen. The oxygen use moves through these electrolytes. Now, in this picture, it seems very large, but it is very, very thin. It moves, arrives.
32:05:20Anna Stoppato: On the anode, where it…
32:09:240Anna Stoppato: It is combined with hydrogen to form water, and the two electrons, which goes Hmm, on the other side.
32:19:170Anna Stoppato: Okay.
32:24:570Anna Stoppato: Solid oxide, so the name comes from this element. I said to you that it is zirconium oxide, but there are many, many studies
32:37:140Anna Stoppato: to search for new material. Which is… One…
32:45:350Anna Stoppato: problem, but then we will see that there are also some advantages. This kind of electrolytes needs very high temperature in order to
32:57:30Anna Stoppato: guarantee the passage of the rules. If you remember, we said that
33:03:800Anna Stoppato: the resistance of the electrolyte to the temperature with this kind of the… for the ionic conductor, this resistance decreases with the temperature. So, we need high temperatures. What does… what is the meaning of high temperatures?
33:21:170Anna Stoppato: In the past, around 1000 Celsius degrees. Now, they are moving to 700 and 800 Celsius degrees.
33:31:580Anna Stoppato: And of course, on one side, this is a disadvantage, because it means that we need to operate at very high temperature, and you know that all the stresses become more important at high temperature. We are using different materials, and we need this.
33:50:210Anna Stoppato: Okay, on the other side, the high temperatures are very… give…
33:58:330Anna Stoppato: A first advantage, which is related to the reaction of the carbon monoxide.
34:07:100Anna Stoppato: Because the kinetic of the oxidation reaction of the monoxide of carbon at this very high temperature is very high, and so we don't have the problem of the poisoning of the,
34:24:710Anna Stoppato: The another, okay?
34:28:530Anna Stoppato: And so, what does it mean? It means that we can use as fuel, also.
34:35:120Anna Stoppato: Nitan in the past, for us, dirty hydrogen. So the grade of purity of hydrogen
34:44:330Anna Stoppato: Is lower than in the other fuel cells, and this is due to the very high temperature.
34:50:699Anna Stoppato: which is the advantage of using a solid. One is related to the fact that we don't need to… we don't have a liquid. And as I told you before, when we have, when we need in the electrolyte water.
35:09:270Anna Stoppato: there is… there are many problems in managing the water of the needs for the lateralizers, the water which is produced by the reaction, the necessity to avoid that some parts becomes full of water. In this case, we don't have this problem, so this is an advantage.
35:26:610Anna Stoppato: Another great advantage is that We can also… Change the shape…
35:34:810Anna Stoppato: A layer, a solid layer, completely solid layer, can have whatever shape.
35:41:290Anna Stoppato: When we have a liquid, it becomes a little more complex, so…
35:45:260Anna Stoppato: in the… for the solid oxygen cells, we have, and I think that I have also here a picture.
35:53:610Anna Stoppato: No, I don't know what It disappeared, I don't know why.
35:59:650Anna Stoppato: Okay, okay. And there are also some shapes which are, cylindrical, okay?
36:07:330Anna Stoppato: where the…
36:09:480Anna Stoppato: oxygen flows in the middle of a… you have to stick as a pipe. In the middle, we have the oxygen, the air. Then the…
36:21:890Anna Stoppato: Ugh.
36:22:830Anna Stoppato: There is a… the wall of the pipes are made by the electrolyte.
36:29:100Anna Stoppato: So, or better, the cathode, the electrolyte, they are not at the side of the pipe. We have the flow of,
36:38:670Anna Stoppato: Of the fuel. But, of course, also for this kind of solid fuel cells, we have a structure like this one, okay?
36:49:60Anna Stoppato: Which is the advantage, to avoid… which is the problem of… problem.
36:54:770Anna Stoppato: One of the problems of this kind of fuel cells is that,
37:00:330Anna Stoppato: At the bore… at the boundaries of the cell, we need to avoid the leakages.
37:07:340Anna Stoppato: Okay, because it is possible in the board here that the air and the fuel combine outside the fuel cell. When we use the shape as that of the pipes, we can avoid… we don't have the boundaries, and so this is easier to avoid the leakages.
37:25:580Anna Stoppato: Of course, which is the great advantage of this kind of seller, that it's very easy to build a stack
37:32:710Anna Stoppato: Because we put one over the other one. When we have F cylinders, the composition is a little more…
37:41:480Anna Stoppato: is a little more, complex. Okay, so… Now…
37:49:740Anna Stoppato: Before looking to this, and then to the other pictures.
37:55:990Anna Stoppato: Only one thing. As I told you, this kind of fuel cell is very sad now.
38:04:250Anna Stoppato: And one of the other… one of the main reasons is that, is what I said to you, that the possibility to use a hydrogen which is less pure. And one of the main,
38:18:80Anna Stoppato: Idea is that to try to reduce the value of the temperature.
38:23:290Anna Stoppato: In order to reduce the value of the temperature, the only way is to reduce the thickness of this rate, of this, of the electrolyte. As I told you in this picture.
38:36:560Anna Stoppato: Which you can find in the speech, and it was in very…
38:40:550Anna Stoppato: In specialistic books related to hydrogen, but you can think that the thickness is, 10 micrometers.
38:52:50Anna Stoppato: Okay, but they are starting to reduce. If we can reduce this thickness, we can reduce the resistance to the flow of yums, and we can also reduce the temperature. Good temperatures
39:05:260Anna Stoppato: Of course, we cannot think to arrive today.
39:08:50Anna Stoppato: To the ambient temperature, but for example, we can think to arrive to 500, 400 degrees, and it can be…
39:15:20Anna Stoppato: better. And so, again, this is the work mainly for metallurgic engineers. They are working on how to create this very thin,
39:28:510Anna Stoppato: layers.
39:29:770Anna Stoppato: And also how to create, The cell as a… There are…
39:38:300Anna Stoppato: now they are working with spray, so they spray the anode, then they sprite over the electrolyte, and then they sprite over the cathode, and so on. But, of course, this is not, at present.
39:51:130Anna Stoppato: It is, they are working on this, but it is clear that if in the future they will be able to do this.
39:58:620Anna Stoppato: We could have solid excite fuel cells, which works at lower temperature.
40:03:800Anna Stoppato: And this can be an advantage, but also now I will see how the energy engineer in the present situation, so taking into consideration the present temperatures, how they invented to operate in order to increase the efficiency. Again, it is clear that,
40:23:430Anna Stoppato: If we are working, I say, at 90 degrees, it means that the product of reaction exits at temperature, which can be around 500 degrees, and again.
40:35:210Anna Stoppato: If we have flow gases at 500 degrees, it is clear that the efficiency of the fuel cell will be lower, because it means that part of the energy which entered with the fuel has been transformed into thermal energy instead.
40:51:180Anna Stoppato: into electrical, energy. And here, before going here, I want to show you again, sorry,
40:59:340Anna Stoppato: I think that one,
41:02:840Anna Stoppato: one picture disappeared, because I had… Okay, there are also in Italy, and so I put some, experience in Italy, of,
41:14:140Anna Stoppato: or commercial USLs.
41:16:580Anna Stoppato: And this is one. It is, the… it was called Solid Power, now it is called Solid Air. And, these are the values. You can see that,
41:29:60Anna Stoppato: 1.7 kilowatts.
41:31:630Anna Stoppato: of, of power, and it is… Also small for the house.
41:39:550Anna Stoppato: Modulation between 30% and 100%. Degradation, so… Exhaust temperature, but…
41:49:140Anna Stoppato: It is… okay, this is a… sorry, I have this one, I prefer this one, sorry, this is Solidera, this one. Sorry.
41:57:380Anna Stoppato: This is the, this one…
42:01:260Anna Stoppato: stock that we… it is composed, this is what is commercial. 9.67 kilowatts, but what I would say, I hope that this is the… yes.
42:13:330Anna Stoppato: Okay.
42:15:440Anna Stoppato: The total efficiency, as you can see.
42:18:940Anna Stoppato: These machines, these fuel cells, are very, very useful, are very, very suitable for cogeneration.
42:26:260Anna Stoppato: Because, in this case, If the temperature…
42:30:800Anna Stoppato: In the cell is around 900 degrees.
42:34:950Anna Stoppato: We can recover, and you can see, of course, that…
42:40:880Anna Stoppato: We can produce… if we produce Thermal energy at 40 degrees.
42:48:20Anna Stoppato: Deficiency is higher than 100%. If it is 60%, it is higher than 90%. Of course, what is the meaning of an efficiency higher than 100%, which seems…
43:02:960Anna Stoppato: Impossible to be.
43:12:580Anna Stoppato: If you…
43:14:850Anna Stoppato: If you go back to the… it is related. If we can produce at very low temperature, we can have water inside the… liquid water inside the…
43:26:740Anna Stoppato: the exhaust gases.
43:29:880Anna Stoppato: And since, also in this case, the efficiency is based on the low heating value, it seems that we produce more than what we put inside, but this is the reason. It is clear that when we increase the temperature
43:44:580Anna Stoppato: at which we need heat, it is clear that also deficiency decreases, because we are not more able to condensate the water. In any case, note that this 40 and 60 degrees is not a very high temperature. Generally speaking.
44:01:600Anna Stoppato: we operate with a higher temperature, but also this efficiency… so this efficiency decreases. Anyway, this is very important, because it is clear that these fuel cells is on the market as congenerative unit.
44:16:220Anna Stoppato: Because if this is the technical data, it means that it is sold in order to be cogenerative. Here you can see some,
44:27:580Anna Stoppato: data, we don't need to go inside. Okay, and this is, sorry for this machine.
44:40:890Anna Stoppato: Okay, the lifetime. What I want to add, of course, they give us two different cores. One is when we operate with natural gas, the other with hydrogen.
44:52:430Anna Stoppato: I remind you that if you go back, the efficiency of the hydrogen, the theoretical efficiency of hydrogen is lower than the theoretical efficiency of natural gas, if you reminded the first lesson. So this is the reason why, and of course.
45:09:290Anna Stoppato: Real efficiency are lower, but the trend is exactly the same. And again, this is real machines. Again, you can see how the efficiency increases when the load decreases.
45:21:930Anna Stoppato: I was asked the last time, of course, the power is proportional to the current. This is another machine, this is from… it is called the Blue Gas circuit, I think, blue gas.
45:35:570Anna Stoppato: And you can see, again, which are the data related to this machine, again, with electrical efficiency of 57%, and the overall efficiency of 90%.
45:46:520Anna Stoppato: If I go back… okay, if you do the calculation, but I don't know why I don't find, because I was sure that I put…
45:56:30Anna Stoppato: Okay, no, okay, we can read it here. Again, what we can see is that
46:02:760Anna Stoppato: The ratio between the thermal power, or better, the electrical power and the thermal power is higher than 1.
46:10:680Anna Stoppato: And again, this is not very suitable for domestic application, because domestic users usually need more thermal energy than electrical energy. Anyway.
46:22:560Anna Stoppato: the values of temperature and the values of size are very, very suitable. And in the picture… so this is…
46:29:840Anna Stoppato: The same if you want to go, but these are the data related to the cell current density and cell voltage.
46:37:900Anna Stoppato: Which then give us the efficiency.
46:42:100Anna Stoppato: And this is, how, soft can become, congenerative.
46:49:280Anna Stoppato: This is for, this picture is for natural gas, but it is the same. Here we have a compressor.
46:56:780Anna Stoppato: And then, okay, they flew…
46:59:320Anna Stoppato: Here we have… don't look to the reformer, but here we have a preheater. We can send the fuel inside at temperature, which can be around 500 degrees.
47:10:520Anna Stoppato: So this is the path of the fuel, then…
47:13:770Anna Stoppato: The same… here we have a blog, and again, here.
47:17:790Anna Stoppato: We have a predator for the water, and then… so, sorry, for the air, then air enters.
47:24:320Anna Stoppato: Okay?
47:27:580Anna Stoppato: These are the outputs.
47:30:40Anna Stoppato: Okay, of course, the outer for the anode from the cathode, here.
47:34:440Anna Stoppato: And this is mainly water.
47:37:910Anna Stoppato: Water that is at high temperature, so this is not cogeneration ratio.
47:42:870Anna Stoppato: But we use the hot water, which exits at around 700 degrees. 800, of course, it depends on the temperature of the solid oxide fuel cells.
47:54:200Anna Stoppato: To increase the temperature of the fuel before it enters the cell, and later to increase the temperature of the air.
48:02:770Anna Stoppato: At this point, the temperature is high enough.
48:06:980Anna Stoppato: to have an additional heat exchanger, this is the cogenerative heat exchanger. So, these and these are regenerative, so we are only heating
48:18:900Anna Stoppato: Damn.
48:20:340Anna Stoppato: The two… the fuel and the, the…
48:25:200Anna Stoppato: and the oxygen and the air, and here we have the production of the hot water. Here, the temperature in this point is around 200 degrees, 300 degrees. Here, we have the production of
48:37:720Anna Stoppato: electricity. Not, one, okay, so here we have some, as you can see, some, recycle, especially on the
48:47:440Anna Stoppato: fuel side, the fuel side, why? I remind you that, and now I add also an additional aspect, which is this element,
48:58:720Anna Stoppato: If you remind, in the past lesson, I said to you that we cannot think to consume all the fuel inside the fuel cell.
49:09:230Anna Stoppato: Otherwise, at the last part of the fuel cell here, the partial pressure of hydrogen is so small that the efficiency becomes very, very small. So, we need to have…
49:24:770Anna Stoppato: at least 20% of hydrogen, which is not consumed. So, we can, in order not to
49:33:190Anna Stoppato: to lose this hydrogen. We can have here a recirculation, but it is clear that when we can recirculate
49:41:570Anna Stoppato: Also, some water can recirculate with the hydrogen. Or, very often, we have a burner.
49:47:840Anna Stoppato: What is this bar? We burned.
49:51:140Anna Stoppato: Hydrogen and air, because, of course, also on the side of the oxygen, we don't consume all the oxygen, and here we have a burner.
50:03:650Anna Stoppato: We use this burner in order to increase the temperature and to produce… to,
50:12:90Anna Stoppato: to increase the temperature of both the reactants before they enter inside the fuel cell. It is clear that this part… in this part, we…
50:23:200Anna Stoppato: Have not, com…
50:26:370Anna Stoppato: A conversion of the chemical energy of the fuel directly into the electrical energy, so we pass through the production of thermal energy, but this is the only way that we have in order to avoid that hydrogen is lost, or to avoid more complex, more complex,
50:45:980Anna Stoppato: processes in order to separate the hydrogen by the other… not… the only product of the
50:55:260Anna Stoppato: of the fuel cell is, of course, water, but we need to have, of course, we have, for example, nitrogen and so on. This is very used, okay?
51:08:900Anna Stoppato: And these help us, of course.
51:11:900Anna Stoppato: To increase the efficiency, because it promised to have a high temperature inlet, so…
51:21:270Anna Stoppato: We increase the efficiency of this part. Okay, I think that this is okay, and this is, if you want, the same balance that I showed you before,
51:34:460Anna Stoppato: for the PM, for the solid oxide fuel cell, again, the difference between… and I think that can be interesting, the…
51:43:600Anna Stoppato: Of course, these are data which are average data. This is made for a small volatile cell. This is made for a larger one.
51:54:880Anna Stoppato: again, the difference is that when the electrical efficiency is higher, of course, the thermal efficiency becomes slower, but again, you can see. Okay.
52:07:20Anna Stoppato: And so this is the same. You can find all this data that we said. But, okay.
52:14:620Anna Stoppato: Coming back, we said that, okay, we can use for cogeneration, and we have seen which are the possible applications
52:24:590Anna Stoppato: But the idea is… but if you want to increase the electrical efficiency, if we don't need thermal energy, or
52:34:700Anna Stoppato: If,
52:36:640Anna Stoppato: Yes, for example, in the solid oxide fuel cells, the temperature of the cell is very high. If we use them to produce heating for the buildings, it is clear that we decrease the energetic efficiency of the system. And so now, it's water.
52:55:150Anna Stoppato: I mentioned it in the first lesson, the previous lesson, which is related to the hybrid cycles.
53:05:710Anna Stoppato: The hybrid… there are some pilot
53:09:490Anna Stoppato: hybrid plants in the world, in Europe, in the EU, United States, of course. No real commercial one. But what is the idea? And this is one…
53:20:660Anna Stoppato: Probably the most, promising one.
53:26:130Anna Stoppato: This is a general one. This is a… Fuel sala.
53:30:720Anna Stoppato: Okay.
53:31:980Anna Stoppato: These fuel cells becomes, In… in this, in this, configuration, Not completely, but substitute.
53:43:660Anna Stoppato: The combustor of a… Gustarbin.
53:49:20Anna Stoppato: Okay.
53:49:980Anna Stoppato: So…
53:52:30Anna Stoppato: As you can see, this is… okay, this is ideal. This is the typical cycle of a gas turbine. Compressor.
54:00:790Anna Stoppato: Increase of temperature at constant pressure, expansion, and then decrease of temperature.
54:08:880Anna Stoppato: Soap.
54:10:650Anna Stoppato: the compressor.
54:15:120Anna Stoppato: Okay, this is a recuperative, regenerative, recuperative heat exchanger, and then the air enters inside the fuel cells inside with the fuel.
54:27:420Anna Stoppato: The fuel cells operate as fuel cells. For example, image to have a Solid oxide from your cell.
54:36:140Anna Stoppato: And done!
54:38:620Anna Stoppato: The product, the… Product.
54:42:480Anna Stoppato: Which is, of course, water, but we have also a lot of air.
54:49:310Anna Stoppato: enter inside the combustor, Insta, and again…
54:53:780Anna Stoppato: what is this? Instead, with the… sorry, it is on this side, sorry, I made an error. Okay, sorry, no, no, it's correct. So, as hot air.
55:04:770Anna Stoppato: On the other side.
55:06:830Anna Stoppato: the fuel, which is not being used, and as I told you, because we cannot use all the fuel if we want to have good efficiency.
55:16:30Anna Stoppato: is censored inside the code master as a QM.
55:20:620Anna Stoppato: And here we have the… Combustion, so… Done.
55:25:990Anna Stoppato: The product of the combustion in the turbine expands, there is a recuperator, and they go to the stack.
55:33:970Anna Stoppato: So, if you look, so… Compression?
55:38:420Anna Stoppato: Then, the first part of the…
55:41:980Anna Stoppato: It excha… or the heat increase is given in the recuperative.
55:48:360Anna Stoppato: It exchanger. A second part of until 3, from 3 to 4, is the…
55:57:200Anna Stoppato: On the point of view of the gas turbine, the fuel cell is a heat exchanger, increases the temperature of air, okay? Increases the temperature, then there is also the combustor, and then there is the expansion.
56:13:540Anna Stoppato: Two things,
56:15:680Anna Stoppato: It is clear that… If you have…
56:21:530Anna Stoppato: It, recuperative, it exchanges. What does it mean?
56:27:270Anna Stoppato: Look into the fuel… to the gas star bin.
56:32:830Anna Stoppato: What about the compressor ratio?
56:36:720Anna Stoppato: Of the, of this turbine, if it is convenient to have a cooperative heat exchanger.
56:48:700Anna Stoppato: You really know you hiding.
56:51:200Anna Stoppato: Perfect, it is not too high, and you can see that also in the picture, it is very small.
56:57:140Anna Stoppato: It is not wide, so it means that the temperature T6 at the exit of the turbine is very higher than the temperature T2,
57:07:410Anna Stoppato: At the exit of the compressor, so it is convenient.
57:11:710Anna Stoppato: Okay, so this is the first. And now, why it is not so high?
57:17:360Anna Stoppato: Because, of course, fuel cells.
57:20:990Anna Stoppato: Usually.
57:22:400Anna Stoppato: They don't work at high pressure.
57:24:990Anna Stoppato: Okay.
57:26:60Anna Stoppato: they don't…
57:27:830Anna Stoppato: they can use high pressure, but not the same high pressure that we have at the exit of the compressor. So.
57:36:640Anna Stoppato: It is clear that we cannot increase the…
57:40:940Anna Stoppato: Okay, we increase the pressure of the fuel cell with respect to the normal operation, but it is clear that we cannot think to go to 20 bars, okay? We can operate at 4, 5 bars.
57:55:860Anna Stoppato: Okay.
57:56:690Anna Stoppato: Because…
57:57:840Anna Stoppato: of course, the structure. You have to think… we are thinking about, we have the membrane, or we have the solid electrolyte, we have the…
58:07:570Anna Stoppato: Cato de, no, they are… very, didn't…
58:16:110Anna Stoppato: They are very stressed on the thermal and at the chemical point of view. We cannot add also the stress of higher pressure. And this is very important. So.
58:25:190Anna Stoppato: This is it?
58:27:260Anna Stoppato: This means that, of course, the efficiency of the gas star will be lower.
58:33:120Anna Stoppato: So this is the first point.
58:36:430Anna Stoppato: Second point, It is not clear from this picture, but…
58:44:240Anna Stoppato: If you do the calculation, you can understand that, more or less, the power of the fuel cell
58:51:920Anna Stoppato: Probably is something that 3 times.
58:56:310Anna Stoppato: 2 times something, 3 times the power of the gas turbine.
59:00:530Anna Stoppato: So, be careful. So, the… even if in this picture we drove only the cycle of the gas turbine, and it is the… it seems the largest part, the…
59:13:500Anna Stoppato: Production of power is mainly in the
59:18:280Anna Stoppato: in the fuel cell. The efficiency of the fuel cell is the efficiency of the fuel cells, so, for example, 50%, 40%. So, I think that… and so, the compressed efficiency, taking into consideration that
59:33:890Anna Stoppato: In this case, we have also an addition of,
59:38:970Anna Stoppato: We have also the combustion, but we have seen that we need the combustion, in any case, also in the SOFCA.
59:45:490Anna Stoppato: On the paper, the efficiency of this cycle can be close to 70%. Again, which is very, very high.
59:56:530Anna Stoppato: what I have to add,
59:59:610Anna Stoppato: Yes, only one thing, because I forgot. Yes, I was starting to say, but I forgot.
00:07:450Anna Stoppato: On the stress point of view, to increase the pressure in the fuel cell can be a problem. On the efficiency point of view, an increase of pressure is positive also for the fuel cell. If you go back, if you remind that efficiency is also related to the partial pressures.
00:25:630Anna Stoppato: Of the elements, increasing the pressure, increase also the
00:29:600Anna Stoppato: Deficiency, not a lot, but it is… it is convenient.
00:35:300Anna Stoppato: And now… Open and close the brackets.
00:39:970Anna Stoppato: This is a generic, a generic picture, but taking into consideration the size of the fuel cells,
00:50:640Anna Stoppato: One of the main applications can be not with the generic gas turbine, but with a micro-gas turbine, okay, whose size is suitable? As I told you, the size of the gas turbine is one-third than the size of the fuel cell.
01:06:650Anna Stoppato: And this is also an advantage, because we know that traditionally the fuel cells
01:12:770Anna Stoppato: don't have a very high compression ratio. So, the compression ratio, which is suitable with the fuel cells, is also suitable if we use, instead of a larger gas turbine, if we use a microturbine. So, again, we are speak… this can be convenient when we are speaking about sizes of
01:32:680Anna Stoppato: Less than 1 megawatt in total, okay?
01:37:210Anna Stoppato: Under good.
01:39:280Anna Stoppato: On the paper, we can reach efficiency of 70% with this very small plant.
01:46:340Anna Stoppato: And this is the same, these are the gate numbers. What is the difference between the first one and this one? In this case, you can see the power of the first cell in this case is 4 times the power of the gas turbine. We can also void the combustor.
02:04:830Anna Stoppato: We have the small combustor inside the softka as a part of the SOFCA, but we don't have an additional combustor. If you look.
02:13:110Anna Stoppato: You can see also in this picture, you have all the pressure, the temperatures, and the flow rate.
02:19:320Anna Stoppato: Of course, this, again, it is on the picture, with efficiency, which can be higher than 60%, but I think that on the chart, on the paper, also in this case, we can reach 70%.
02:33:360Anna Stoppato: The last… okay, so these are very examples, if you want to see. These are examples I skipped.
02:41:560Anna Stoppato: And, disease…
02:44:110Anna Stoppato: The last… no, not the last, but an additional example of efficiency of 75%, if we put together
02:53:450Anna Stoppato: the fuel cell, with a combined, cycle, gasoline, okay.
03:01:550Anna Stoppato: It is clear that now we are a little bit going to
03:08:170Anna Stoppato: very complex.
03:09:760Anna Stoppato: Plants, and ideally, probably.
03:13:600Anna Stoppato: It is not convenient, but as you can see, we can… the idea is that with this kind of plant, we can reach 75% of efficiency. Not… sorry, I forgot it was written, but I forgot in the two, President.
03:29:170Anna Stoppato: That this… both in this configuration and in this configuration, the temperature, in this case, for example, at 0.7, is high enough for congenerative
03:40:500Anna Stoppato: applications, okay? The temperature is more or less the same temperature that we have with the microturbine, so with temperature in the 0.7, which is… can be around 250 degrees, high enough to
03:54:730Anna Stoppato: For the production of hot water.
03:57:910Anna Stoppato: Of course, which is the difference with the gas turbine, is that in this case.
04:05:130Anna Stoppato: the… with respect to the total power, electrical power, the thermal power is maybe smaller. In the traditional gas… micro gas term, the,
04:17:740Anna Stoppato: Thermal power can be two times,
04:21:860Anna Stoppato: more so more, 2.5 times the electrical power. Again.
04:28:180Anna Stoppato: less convenient for domestic application. In any case, the electrical efficiency of this configuration is so good that we don't need to
04:38:620Anna Stoppato: Add also decogeneration.
04:41:520Anna Stoppato: But it is important to know. Yes, please.
04:45:440Anna Stoppato: indexing… Index? Yes.
04:53:720Anna Stoppato: Yes,
04:59:910Anna Stoppato: No.
05:03:980Anna Stoppato: Yes, sir?
05:06:150Anna Stoppato: Okay, yes, this is simplified, but you have to think that this is… sorry, go back… is, this.
05:17:110Anna Stoppato: With all the parts, yes.
05:24:50Anna Stoppato: It is… Deep.
05:31:800Anna Stoppato: We have a… Yes?
05:39:370Anna Stoppato: Yes, but it is not a problem, because it is… we are working at temperature which is high enough that also steam can be considered a gas.
05:49:750Anna Stoppato: Not a vapor, but a gas.
05:52:630Anna Stoppato: In any case, the objection.
06:00:810Anna Stoppato: In some way, but at the end here.
06:04:530Anna Stoppato: More or less, we have the same amount of water that we had with the in,
06:11:760Anna Stoppato: With a traditional combustor, because it is clear that in this combustor, we don't… we burn a smaller amount of fuel.
06:20:960Anna Stoppato: than in traditional… so if I had to do all the increase with the combustor, more or less, I need to wear the same, okay?
06:31:60Anna Stoppato: So…
06:31:970Anna Stoppato: The only difference is that now we have the water also at the inlet, not only at the outlet. Yes, but we can,
06:41:970Anna Stoppato: Okay.
06:42:980Anna Stoppato: Again, if we are speaking about micro-gas carbon, also temperature 25 is not so high, so generally speaking, we don't have problem of nitron oxide.
06:57:410Anna Stoppato: Or sites in the…
06:59:650Anna Stoppato: as a… in the fuel gas. But in any case, yes, of course, we can also think that this water can help to reduce the production of nitrogen oxides, but not if you are working with,
07:15:350Anna Stoppato: micro verstad.
07:17:480Anna Stoppato: Because the temperatures are lower, because But, you know, my… But yes.
07:27:930Anna Stoppato: We will see it, but not in the next lesson, when we will speak about the use of hydrogen as fuel.
07:38:40Anna Stoppato: That, when the temperatures are high, the water is a gas. You can use gas turbine without any problem.
07:51:190Anna Stoppato: Okay, okay, this is only to show you, only…
07:57:940Anna Stoppato: And I took only a few features.
08:00:650Anna Stoppato: This is, the fuel cell with only the steam turbine. This is, again, the same, which is… this is the fuel cell with the STIG. This is the fuel cell, gas turbine, organic ranking cycle, and I think, that it is. And, yes.
08:21:189Anna Stoppato: why I show you all it is, because I want to say, probably now, energy engineers are waiting, as I told you, for the work, for the optimization…
08:34:750Anna Stoppato: the optimization of the fuel cells, but the main problem is related to the cost. Now, what they are looking to can use elements which are less expensive.
08:48:240Anna Stoppato: Element which are less impactful on the environment, because we talk about
08:56:69Anna Stoppato: The use of catalysts, the use… they are very often critical materials.
09:03:840Anna Stoppato: And for the energy engineer, the work now is this one, how we can improve the efficiency, probably the
09:10:830Anna Stoppato: Efficiency of the fuel cell itself
09:13:970Anna Stoppato: is already very, very high, how we can improve, and these are very many different, configurations, but it is clear that
09:24:450Anna Stoppato: And… Yes, since the last goal, Very often is the cost.
09:32:880Anna Stoppato: The addition of a steamed carbon, organic agriculture usually is not so convenient, so we can write a lot of papers, we can do a lot of pilot plans, but probably
09:43:279Anna Stoppato: This is not the future of the use of the fuel cells.
09:48:229Anna Stoppato: Sorry, the last thing I forgot, but it can be interesting, again, for the generalist, for the energy system. I didn't say, but the solid oxide fuel cells can operate as reversible cells, so the same cell
10:07:730Anna Stoppato: Can operate also as electrolyzers.
10:11:250Anna Stoppato: So…
10:13:130Anna Stoppato: In the fuel cell, there is a flow… the flow of hydrogen and the flow of air, and we produce electricity. If we create a difference of voltage between the two electrodes, we can produce, and we have a flow of water and the flow
10:30:480Anna Stoppato: we can produce hydrogen. And this can be, again, and this is, again, one of the reasons why now we are looking and we are working a lot of these kind of cells, because this can be convenient,
10:47:500Anna Stoppato: in the present electrical market, energy market, where, as I told you, we are using the hydrogen as a way to store the electricity.
11:00:360Anna Stoppato: So… Instead of having an electrolyzer and a fuel cell, Since, usually, all we use
11:09:730Anna Stoppato: Electricity to produce hydrogen, or because we have,
11:14:410Anna Stoppato: In excess of electricity, or we use
11:18:10Anna Stoppato: the hydrogen to produce electricity, because we have a deficit of electricity. Instead of having two different devices, we can have only one.
11:27:340Anna Stoppato: Of course, the efficiency is lower, but the cost, again, is lower, so this is another reason to use and to study this kind of, of machine, and probably, this
11:39:900Anna Stoppato: will be.
11:40:960Anna Stoppato: The future, especially for the applications which are interesting… interesting for… for us, which is… which are the stationary applications, related to them.
11:51:650Anna Stoppato: Production of electricity, and…
11:54:270Anna Stoppato: of cogeneration. The fossils that we have seen, the PM, are more interesting, as I told you, for the transportation. So, problem. These are the two different paths. Of course, also the transportation, when we think about the consume of fuel, is a topic for the energy engineers, but…
12:14:170Anna Stoppato: We are more focused on the other part.
12:17:420Anna Stoppato: Okay, so…
12:19:30Anna Stoppato: If you have some question, I finished, but when there are only two students, the lesson is always shorter.
12:27:730Anna Stoppato: If you have questions about this, about the future.
12:31:500Anna Stoppato: Is the efficiency of the utilizability?
12:37:780Anna Stoppato: One of the Spain, lower.
12:40:990Anna Stoppato: And, US celebrity.
12:45:990Anna Stoppato: Sorry, if the, if the efficiency of the electrolyzer, the only electrolyzer, or in the fuel cell operating as electrolyzer? In the fuel cell… Yes, sir.
12:59:620Anna Stoppato: If you stay… of the… Global.
13:07:390Anna Stoppato: S, oh, no, it is, yes, comparable, yes.
13:14:860Anna Stoppato: But it's true, you know… the fertilizer?
13:26:350Anna Stoppato: Okay, the fuel cells are more ready, but mainly with the use with natural gas.
13:35:60Anna Stoppato: Because they don't… Okay, again, the, you know that sometimes the, the, the history, the…
13:45:770Anna Stoppato: The part of the development are strange, so… many years ago.
13:53:400Anna Stoppato: people started to speak about hydrogen, so they started to work on fuel cells. Then, the problem of hydrogen becomes… became less important, but the… so the electrolyzers
14:05:810Anna Stoppato: We're not the… I don't say not more started, but they were not, updated. Now, while
14:14:480Anna Stoppato: A work on the fuel cells was continued with the use of natural gas, because in any case.
14:21:780Anna Stoppato: The emissions of the fuel cells are lower, than a traditional,
14:29:310Anna Stoppato: engines, especially related to the emissions of, nitrogen oxides. And, because of… they are less, noisy.
14:40:940Anna Stoppato: So, for some niche applications, as in the buildings.
14:48:160Anna Stoppato: The use of fuel cells with natural gas was continued.
14:53:370Anna Stoppato: And so now, we need… okay, there is…
14:56:310Anna Stoppato: Of course, it is clear that it is… on one side, it is easier to use them with hydrogen.
15:03:340Anna Stoppato: And so this is… but, of course.
15:06:730Anna Stoppato: They have been optimized to work with natural gas.
15:10:390Anna Stoppato: But it is easier now to skip Here, we can… Beautiful.
15:20:260Anna Stoppato: I just said…
15:23:540Anna Stoppato: Yes, of course. Of course not, yes, in any case, if we are using solid oxygen, we have also the reaction of carbon with oxygen.
15:37:710Anna Stoppato: in the fuel cell itself. If we are using, for example, the proton exchange membrane fuel cell, the production is before the fuel cell, because we need to do the same reforming of metal.
15:52:480Anna Stoppato: And then the fuel cell itself is fueled only with hydrogen, but again, of course, but this is another part. The idea is also
16:03:280Anna Stoppato: But with the small fewer cells, it becomes difficult.
16:07:550Anna Stoppato: Then, to capture this year, too.
16:13:490Anna Stoppato: But, as you know.
16:15:610Anna Stoppato: At present, the capture is possible, but it is convenient when we have large emissions. We cannot think that every small fuel cell can have the capture. It can be convenient for only when we have large emitters, emissions, so…
16:34:160Anna Stoppato: And very concentrated. And this is not the case, not for the dimensions, nor for the concentration.
16:42:800Anna Stoppato: But, of course, Again, you know that there are many studies also to capture the CO2 by the atmosphere.
16:49:990Anna Stoppato: Of course, the stack of material cell is more convenient than the atmosphere, so…
16:56:810Anna Stoppato: If a technology will be developed, then…
16:59:840Anna Stoppato: It will be convenient for the atmosphere.
17:03:440Anna Stoppato: could…
17:04:570Anna Stoppato: can be applied also here, but it is not the present. At present, this is not the first way to be implemented to decarbonize the system.
17:16:820Anna Stoppato: As you're knowing… Sometimes, some discover in one field.
17:23:500Anna Stoppato: Become useful for a completely different ones, so it is possible, but at present not, but In any case…
17:31:450Anna Stoppato: The efficiency is very good, so the production of carbon dioxide is lower.
17:37:390Anna Stoppato: for each unit of electricity than the production from other carbon combustion engines and so on, and we don't have the production of NWIX.
17:48:910Anna Stoppato: In any case, of course, We cannot say that we are decarbonizing, but… The problem is the cost.
17:57:410Anna Stoppato: Because, of course, it is… And especially in the houses, the… Fuel cell, substitute the boiler.
18:07:790Anna Stoppato: Because usually we don't produce electricity in our houses.
18:12:910Anna Stoppato: But again, many money are put on this kind of,
18:20:400Anna Stoppato: But I think that to… mmm…
18:24:20Anna Stoppato: people from Polidoro, they speak about boilers, and so they really told you what it's about also there are too many mayonnaise on something.
18:33:680Anna Stoppato: That… sometimes doesn't.
18:36:500Anna Stoppato: Have the results, the expected results.
18:40:70Anna Stoppato: They are ready, but they wait on you.
18:43:640Anna Stoppato: Okay, so next lesson, we will go in the use of hydrogen.
18:48:340Anna Stoppato: In the gas turbine, or in the internal combustion engines.
18:51:950Anna Stoppato: As if you will, but… So, with the combustion.
18:56:880Anna Stoppato: Okay, I hope that today everything was recorded.