Tech Talk - PEM Electrolyzer Systems - Hydrogen Production Technology Explained - Ellerich Hyfindr
Hello, my name is Steven. Welcome to Hyfindr Tech Talk. Today we are going to talk about Electrolyzers. PEM electrolyzers for that matter. There are different kinds, but PEM is one where there is considerable growth at the moment, and we are lucky to have somebody here today who has deployed several systems all around the world. He works for NEUMAN & ESSER and I'm very pleased to welcome Max Ellerich. Welcome, Max. Hi, thank you for having me. Perfect. So, Max, electrolyzers, big topic. Let's go quickly into this. What is a PEM
electrolyzer? A PEM electrolyzer actually is kind of a machine where you enter water and electricity and get out green hydrogen. The water is being split and it's feeding hydrogen, green hydrogen. Okay, it sounds like a magic shoe box. But please take us one level deeper. What is actually happening inside and what do you need to do to make it work. Maybe let's start with a very tiny cell in the system and then let's get bigger and bigger. Okay? Absolutely. Because I think that's the best way of understanding that.
Yeah. If I'm looking at a cell of a PEM electrolyzer. We have a cell of it here. Right here, exactly. This is like a cell with the plates and the membrane and so on. Just explaining it easily: you feed water to the cell, and there is a voltage applied to it, and this voltage in combination with some catalyst is splitting the water into oxygen and hydrogen. And what happens then is very interesting. The hydrogen is being sucked through a separator, which is a proton exchange membrane, which is why this is called PEM electrolyzer. Right there we come from, okay. Because I mean, the core of a hydrogen atom, the nucleus, is a proton. Yes. This proton goes through
the membrane and what you have left then and the water here on this side is oxygen. So, you have water with oxygen left because the oxygen cannot pass the membrane and, on the other side of the membrane, you have the hydrogen. Okay, so essentially you're pushing in water here and then, as I see, you coming up with water, which has well, obviously, water plus oxygen, because some hydrogen has left now and then the hydrogen on the other side also with water. Yes. So, there's an effect called water drag. When the hydrogen passes through the membrane, it drags water with it. Because of this,
we have water also on the other side. You have very, very tiny amounts of oxygen around the PPM level, so oxygen cannot pass this membrane. Okay, so this is one cell. And then how does this go in the bigger system? The point about this one cell is that it's only producing a little bit of hydrogen. So you need to have many cells to produce more hydrogen. The idea
of what you do is you add many cells on top of one another. So, it looks a little bit like this. It's always repeating adding cells here. Okay. You're basically putting the one on top of the other until you're stacking them. And that's where the famous word “stack” comes from, right? Perfect, exactly. Because this kind of stack cells, you stack like between maybe 100 and 200 cells to one stack and then push a lot of water in parallel through all the cells. Then on the other end, you get out water with oxygen and water with hydrogen. Alright,
okay. I read from time to time that, you know, all of this we're talking about, you know, megawatts system big, so there's probably lots of water going in and lots of hydrogen coming out. How does it look to make all this work? Yeah. The point is, as you say, I need to have a pump or a system that pushes the water through, that separates the hydrogen from the water, that releases the oxygen and so on. So maybe I can explain the system a little bit on how such a system can look like. Okay. What do you have here? I know that this may... this looks already very technical, but I know we have some pictures of the system later, so… Yeah, okay. So please take us through this quickly. Yes,
yes, it won't take too long. The stack which we saw before, it is exactly this one here. This is the module. Actually, what you need to have like a water tank where you have the water stored and you have to pump the water through the stack.
Yes. This is happening here, like there's a pump, a process pump, feeding it and then getting the oxygen out. Okay. This is called “oxygen separator”. Why? Because you have to get rid of the oxygen. Otherwise, the oxygen would always enrich and enrich in the process. Yeah. So, there's like a vent or something and you're usually venting the oxygen to the atmosphere. Doesn't the oxygen go up and the water stay down. Yes,
exactly. But then you must relieve it. Okay, yeah. But this is exactly the idea. On the bottom you have water and on top of that you have oxygen. Alright, okay. So, the oxygen is leaving here. You are mostly cooling it down to recover some residual water and oxygen. But this is the general idea of this one. However, the water is super critical for PEM electrolysis process, like the water must be in the right temperature, in the right amount, in the right quality, like there are no particles or ions or anything allowed in the water. I couldn't just take water out of the river. No, please don't. You only do it once. Please don't. For at least this process here,
for our system in general, it is okay. Yeah. Because the system that you usually built, you have like a water purification at the very beginning, at the very front. You get then some water like tap water or something. That's what we're going to see. Exactly. It's being cleaned and then it's being fed here. The point is, what you will also have to do is, you will have to cool down the water. Because when
the water is going through the stack, there are some electrochemical things happening. There is heat generated, because you don't have an efficiency of 100% due to the dissipation. But it doesn't boil, does it? No, no, no. It's around 60, 70, 80 degrees. Right, okay. So you want to then going in with a cooler temperature like around what kind of temperature? You have a delta T of five degrees maybe. In
this area over the stack. But the point is, you must get rid of the heat and the water. Yes. Right. Because otherwise, the water would heat up more and more and you would exceed these 60, 70, 80 degrees, which is why there's a second loop which you see here, cooling down some of the water. Yes. Here. And then you're polishing the
water. Polishing practically means when your water is passing by the pipes. Yes. It catches some ions from the stacks and from everything it touches, and it can catch ions. Ah, you’re deionizing. Exactly. And we have ion catchers here. Deionizing the water and feeding it back into the separator. Alright. So, that's in general. So purification, so water comes from here, purification in there in the tank, cooling and then loop through the system.
And this is the hydrogen side of it. Exactly, what you see here is the hydrogen side. Because on one side, you have the oxygen and water coming up and then you have the hydrogen popping up. Exactly. So, you have just two outlets here. Just one inlett, but two outlets here. And then for the hydrogen, we do exactly the same kind. We have a hydrogen separator and the water is on the floor and the hydrogen is on top. And then you relieve the hydrogen and this is your product of your process. So, what's quite interesting, this hydrogen is usually at around 30 bars, maybe even higher of pressure, because in this membrane, in this stack, it is building up pressure for the hydrogen side. So,
you get all your pressurized hydrogen coming up from such pump. The pressure comes from the actual electrolysis process? Exactly. In this one membrane, so per membrane, there’s a delta pressure of the membrane of around 25 bars or something to resist this pressure. And you can take that pressure. Yes. Because not only the membrane,
you also have some layers above it, on top of it and below it. That’s essentially your hydrogen side here and then what, I mean, just being curious, what do you have over here. This is the electrical aspect? Exactly, it’s the electrical section because you need like direct current on your stack. So there’s usually first, a transformer and then a rectifier on your system. Okay. Now we've understood the basic process that you have several loops. Can we see how this looks in a real system? Like one that you build? Yes, sure, of course. I brought here just an image from the two megawatt electrolyzer. We have both
like this. Two megawatts? So sorry to interrupt you, it's one megawatt per stack? Yes, exactly. I recognize these ones. These are the stacks. Exactly, this is the stack that we saw before. You actually see some screws here. Yeah. It's just to tighten everything together. Because as I said,
you have 30 bars in there, so things want to go apart from one another. This is really a crucial aspect here. And the stacks are usually, nowadays, in the 1, 1.25, 1.5 megawatt range. How many cells are we talking here? In between 100 and 200 usually in this range. Alright. So this is what you would find here. But, so you add - you grow bigger by numbering up your stacks. Yes, yes. You should find the stacks here. This is this water separation vessel that we saw before for the oxygen. You pump the water,
filter it again, because I said that the water quality is very important. Polishing? The polishing is here. This is the filter. This is just for catching very tiny parts that could be in the water, maybe from some components. What happens when the water
is not as pure? What happens? Your stacks will degrade over time, like the PEM Stack, the membrane, the catalysts and so on. If, for example, you have ions in your water, they will bind to the catalyst and then the degradation will increase. Okay. Degradation means basically, you know, it's being,
it's no longer as good or something. Like a battery, a battery degrades over time and actually it’s the same what's happening here. Okay, so essentially you're doing that to keep the stacks long and happy life. Yes, exactly. And this is, as I said, the system layout and how you build the system is very crucial to the longevity of these stacks. Okay, right, right. You have this one here, so filter, stack,
back again to this vessel. Yes. Venting the oxygen. Yes. And then here, we have a pump, heat exchanger, have these resins to water polishing and feed back the water to here. Yeah, that was the ion removal. Then you have another... this is a fresh dionized water tank, I see. Exactly. So, as we said, we are losing water. Yeah. Because of water splitting up. Oh yes, obviously. The more water that's being lost, the more hydrogen we get.
Exactly. So, yes, good news. Yes. So we have to feed in new water to the system. We have the water treatment. What we discussed before, and the water is just stored here in this tank. And then we're using this water from the tank to re-supply this O2 separation vessel with water. Tell me, a container. What kind of water can I put in there? Well, okay,
river water maybe on one extreme, but what kind of water am I putting in there? So it depends, of course. I mean, you can actually purify nearly every water at the end. Yes. The question is just how big is the water purification system that I have there? So most water we are using, like here in Europe, tap water or something, but still, you have to react to different water qualities so that you are happening to find it at the spot where you want to deploy the electrolyzer. Okay, cool. And then over here. Exactly. So over here is the hydrogen side of the system. So the water side,
as one could say, water tank, hydrogen side, stacks. Okay. Exactly. And this is the water treatment at the beginning. Okay. So it's like… okay, from water to hydrogen. Oh, yes. Yeah, perfect. Yes, exactly. But I mean, what you have to do, you have to separate water from hydrogen as well, as we discussed before. This is happening here, by the way, this is smaller than this because the pressure is higher. So you need less volume actually, for doing this. So you separate here and then you go to the H2 purification. So why do you need this? When I'm doing a PEM electrolyzer,
my quality of hydrogen after this one here is already at 99.9%. But if you want to use hydrogen, especially for mobility, for fuel cell or something, you need 99.999%. Exactly. So out of the stack, I'm getting three 9s or maybe even four? After this separation here, cool it down a little bit and then you have three 9s. Three 9s, okay. So here, how do you,
just very quickly, how do you get the other two 9s in there? It's a PSA, a pressure swing adsorption. You have like two vessels and, in each, there is like a granular. Okay. And then the hydrogen passes by, the water is being sucked in this granular and then the hydrogen goes out like dry. Like the silica gel. You know, the one you sometimes find in your clothes. Yes, yes. So like this is being in there.
So we have two columns usually because this one is being loaded with water, obviously, when hydrogen is flowing through there and there's more and more, more, more, more water. And then there comes a time when it's fully loaded. So what's happening then, your process is turning to the other column. Then the water, the hydrogen is being fed through this one and the second one is being regenerated in this time. So one is always in the regeneration phase meaning, sweating out the water. The water that was collected before and then you always go back and forth, right. Which is why this is called a pressure swing adsorption, it swings. Ah, alright, okay. So that's probably a lot of control going on there. You have to have some, let's say, programming
and computer systems to do the automation that control that, you know, and all the measure. I have two questions. So we said, at 30 bar? Or at what pressure are we getting hydrogen out here, out of this container? We are getting out of this container hydrogen at 30 bar. At the outlet of the container that means in the container you’re already at higher pressure. But 30 bar is the outlet pressure. And that 30 bar was mainly generated within the stack? Exactly. Within the cell. In the cell, you’re generating it. Another question I have to ask you and this
is because I've had an interesting conversation on another video about cell voltage monitoring. Do you guys have that in there as well? Okay. It's mostly so the stack suppliers. So we are integrators. The stack suppliers usually supply you cell voltage measurement and then you can measure the voltage of each cell and also track it over time. Because the degradation that we were talking about before will be reflected in a higher voltage per cell.
So the voltage will increase from time to time. Okay. So Max, I know you brought another model with you, it's like this system. I don't know whether we can get that on. Let me try. We had that over here and then we got,… oh,
yeah. So that.. Because I found that pretty impressive but maybe you could tell us.. Take us through how something like this would look if it's in my backyard now. Yes, so what I showed you before was a two megawatts system, alright? So this here is like now a five megawatt system that we're having. Like
you have these three containers. This one is for the power electronics. So we have what? We have three containers? One which is kind of shaded here. We have this one and this one. Exactly. The one we just saw before, which one would that be? It’s a mix
between these two. Because when you have only two stacks, you can merge like both containers into one. Okay, where you go from water to hydrogen. Exactly. But now this is happening in both containers. So you have all the stacks here and the balance of plant elements. Exactly. So what you will see there, for example, is the water treatment. That's the gas treatment and so on. Processwise, it's nothing different from what we saw before. Okay. But to be honest, I thought that you're making these
containers because you want standard, you know, like, kind of containers, basically standard systems. Yeah. And now isn't this like a deviation from the standard when you say this could be a little bit different, now I'm going to make two containers and then... Oh, okay. Very good question. So actually we have two standards for two different sizes. You standardize the five megawatt, which is like what you see here. This is five megawatt? This is five megawatt. Exactly. You can count here. Okay. You should see… one, two,
three, four, five stacks. Alright. So like we add five stacks to five megawatt here. This green one you see is the oxygen separator. It's really big right now, as you see. But for the 5 megawatt, this is a standard platform. And also,
if we would do a project with 10 or 20 megawatt, we would do multiples of this one. So it would be twice these container arrangements. Okay, but this is a standard for the five megawatt setup. And the other one is a two megawatt setup. Exactly and that's it. So these are the two standards we go with and all the sizes that we need to do, we do with these two platforms. They would be multiples of this. Exactly, yes. What you see here on top, what is new, what we didn't discuss before, is a dry cooler. For just getting off the heat from your water. Okay. So essentially the outside part of that, the
heat exchanger, which we saw on the PnID before. Exactly, exactly. So that's big. They get pretty big. And this is also for the cooling? This is like the pump and everything that you need there. And also there's a chiller. I don’t know where you can see this, but all the cooling components are usually, obviously, placed outside of the system. Okay, tell me one. So, this we talked about, you said this is a power... What's going on in there? It's a power box. What you need to do, you need a transformer to transform your voltage from your grid to a lower voltage.
Okay. Because the stack runs at maybe 300 or 400 volts, rather like 300 volts roughly. So adding five stacks would lead you to 1500 volts. So you need to transform power from the grid usually down, and then you need to rectify it because you need to get from AC to DC. Okay. So that's all what happens in there. Yes. Okay, so just for your part, the PEM electrolysis, which is your specialty, this is what you do,... this,
you know? When we do a project, we offer like everything as a turnkey solution. We supply with all of this. Yeah. I mean obviously we do not, we would not build this ourselves. Also me personally, I really don't understand what's happening in there and just understand you get DC. You have the requirement of what current you want, basically. Yes, exactly. Okay,
perfect. That's it. Max, we have little time left, but in the presentation, I think we had some photos still of some real system. If I'm not mistaken, so let me pull this up. Yes, sure. So this is how it looks in real. Exactly. So this is one, this is a megawatt system. This is how it would look in real from the outside. Yes. So, yeah, practically what you see here on top is a little bit. Yeah. This is a dry cooler, all the pipings and it's really a container stuffed with technology.
So yeah, lots of things happening in there. Isn’t it hard to keep this running? I mean, how long can this run? Can it run by itself? Yes. In general, it can run by itself and it's usually I mean, for such a system, it's best if it just keeps on running. I mean, like with everything, like also with your car or something, the best is just to keep it running and never turn it off again. Okay, so but then come the humans who only sometimes need it. You need to do service
from time to time. But in general, you want to keep the system warm, you want to keep everything running. Oh, okay. Okay. It's just a picture from the inside, so you get a little bit an idea. There are valves, piping, sensors,... This is essentially what you put together for an entire system and then your customer in the end is getting hydrogen or he’s getting that plant. Exactly. You get that plant. Exactly. So he can then operate it. Exactly. So he's not getting a stack only from us,
or only to take care of the plant or something. He's really getting everything and can start operating and producing hydrogen themselves. Okay. So I know I said this in a certain way, your customer, but essentially, I mean, it's about understanding how these PEM electrolyzer systems work and then we see that, you know, it's you can't just put a cell on the table so I can now start doing electrolysis, you need a whole system around it.
I quite like this picture that you've brought here. Can you just tell us about this very, very quickly? So this is our first operating system. It is in Brazil. It is close to Fortaleza, like in the north of Brazil. So which is what you're seeing here, and actually it's an electrolyzer, 1.3 megawatt in this case. Okay. Which is here. By the way, this is this power container that
we were discussing before. Yes. And it's being implemented in a hard coal plant, power plant. Oh, so this is a coal power plant in the background. They're having the electrolyzer now for producing green hydrogen because they need hydrogen for the process to cool down. But it wasn't a problem to put that beside a coal plant? I mean, with all the pollution and all that. I mean of course you have to comply with safety regularities and everything, but I mean these are all ATEX protected things that you're using in your system. Then you
also have a fence, I mean, here you see it, I think, around it. I was just thinking about it. Sometimes when the systems operate, they have certain air quality, but you don't have much air going in? It's more water. Yeah, exactly. We need the water quality is what is really important. Max, can you just, as an outlook, tell us where is this going? I mean, it's great that you guys have now, you know, the standardized model, two megawatt, five megawatt. So what's your vision of the future and how do you see things going at the moment? What I see is we need a numbering up and we will do a numbering up of these systems. Right? I mean, these systems will get slightly bigger, but especially they will get more in numbers.
It's very important to get these systems industrialized, so you will be able to produce one by one and not doing a project individual job always, but it has to be a standard system. And then, I mean, there are so many demands for hydrogen. I mean, you know, better than I. These systems can really help in order to fulfill that. What I would say is that, you know, we had a bit of conversation before this. I know you are a production guy, actually. Yeah. So it's
actually good for all the hydrogen people out there. But the production guys are coming in because I think you've got to help us serialize this more and get like many more out there. I think container, just like they did in the shipping industry, can do a lot to, to standardize things and get things going. Max, it has been an absolute pleasure having you on here! Thank you for explaining us, taking us through an entire system. And thank you for watching. And, if you've enjoyed this, please give us a like. If you want to know more about the hydrogen economy,
there's more videos here, on this channel. You can also go on Hyfindr.com where you find all the technology that you need to make the hydrogen economy work including such electrolyzers. Thank you for watching. Please follow us or give us a like or whatever and just enjoy your day building the hydrogen economy or what else you're doing. Thank you very much for watching. Thank you Max. Thank you very much. Goodbye.
2024-04-08 19:34
