Speaker 1: Get in touch with technology with tech Stuff from how
Speaker 1: stuff works dot com. Hey there, and welcome to tech Stuff.
Speaker 1: I'm your host, Jonathan Strickland. I'm an executive producer and
Speaker 1: a love of all things tech. And on November I
Speaker 1: ran across an article titled quote can we produce enough
Speaker 1: green hydrogen to save the world? End? Quote? And I thought,
Speaker 1: I haven't done an episode about hydrogen and the proposed
Speaker 1: hydrogen economy for quite some time. It might be a
Speaker 1: good sign to revisit this topic and remind everyone what
Speaker 1: it's all about, because when it comes to conversations about
Speaker 1: transitioning away from a dependence on fossil fuels, hydrogen is
Speaker 1: frequently part of that conversation. Today, we're gonna explore why
Speaker 1: that is, and whether we can in fact produce enough
Speaker 1: of it responsibly in a green way to create a
Speaker 1: true hydrogen economy. Spoiler alert, that's just one component of
Speaker 1: a hydrogen economy. I'll talk a lot about that in
Speaker 1: this episode. First, we gotta just lay some groundwork, right.
Speaker 1: Hydrogen is the most abundant element in the universe. It's
Speaker 1: what stars are made out of. According to the Los
Speaker 1: Alamos National Laboratory, if you were to gather all the
Speaker 1: atoms in the universe all the matters. So you've got
Speaker 1: all the atoms in the universe all in one room, Well,
Speaker 1: it would need to be a really big room, but
Speaker 1: more than nine percent of all those atoms in that
Speaker 1: room would be hydrogen. So at first you might think
Speaker 1: that means we're lousy with the stuff here on Earth,
Speaker 1: and we kind of are. But there's some other things
Speaker 1: about hydrogen that makes that whole plentiful thing a little
Speaker 1: more misleading when it comes to our day to day experience.
Speaker 1: So first, pure hydrogen has a boiling point of minus
Speaker 1: two hundred fifty two point nine degrees celsius. That's minus
Speaker 1: four hundred twenty three point two degrees fahrenheit. That means
Speaker 1: anything warmer than that extremely cold temperature will cause hydrogen
Speaker 1: to boil off into a gas. To make hydrogen a liquid,
Speaker 1: you would have to cool it down to thirty three kelvin.
Speaker 1: Zero kelvin represents absolute zero. That's when you essentially have
Speaker 1: no molecular movement at all. Absolute zero is colder than
Speaker 1: empty space, which is somewhere around two point seven kelvin,
Speaker 1: So thirty three kelvin is toasty in comparison, but it's
Speaker 1: still colder than anything you're gonna find occurring naturally on
Speaker 1: our planet. So on Earth, unpressurized pure hydrogen is going
Speaker 1: to be in gas form, and this is a problem
Speaker 1: because hydrogen is also the lightest element. The heavier elements
Speaker 1: in Earth's atmosphere will push down and hydrogen will move
Speaker 1: up higher and higher until it actually escapes Earth's gravity,
Speaker 1: so pure hydrogen will float off into space. Capturing hydrogen
Speaker 1: from the atmosphere isn't really a practical solution because of this.
Speaker 1: So hydrogen also has a strong tendency to bond with
Speaker 1: other elements, and that's really another very important thing. So
Speaker 1: we can get to hydrogen here on Earth, but it's
Speaker 1: bonded to other stuff Like two Hydrogen's can bond with
Speaker 1: an oxygen atom and form water H two O. So
Speaker 1: more on that in a bit as that's key to
Speaker 1: the challenge of making a working hydrogen economy is figuring
Speaker 1: out how to get hydrogen out of these compounds and
Speaker 1: elements and things, not elements, but you know, mixtures. So
Speaker 1: there are three common isotopes of hydrogen. The ordinary, boring
Speaker 1: pure hydrogen that we tend to talk about is called protium,
Speaker 1: and that consists of one proton that is orbited by
Speaker 1: one electron. So the nucleus of pure hydrogen protium isotopes
Speaker 1: is just a proton. Then you have deuterium that one
Speaker 1: adds a neutron to the nucleus, so now you've got
Speaker 1: one proton, one neutron in the nucleus orbited by one electron.
Speaker 1: Then you have tritium that's a radioactive isotope and it
Speaker 1: has a nucleus with one proton and two neutrons orbited
Speaker 1: by a single electron. This stuff does occasionally form in
Speaker 1: Earth's atmosphere when cosmic rays interact with the air, but
Speaker 1: it has a pretty darn short half life. It's just
Speaker 1: half life of twelve point three years. So when you
Speaker 1: pair that with the fact that it's super light, so
Speaker 1: little eventually flowed off into space. It's also very uncommon
Speaker 1: for cosmic ray interactions. They aren't super commonplace. There's very
Speaker 1: little chance for any significant amount of tritium to accumulate
Speaker 1: in the atmosphere before it decays. Back in sixteen seventy one,
Speaker 1: a philosopher and intellectual named Robert Boyle was doing some
Speaker 1: exploratory research. He was using iron and dipping it into
Speaker 1: different types of acid, and he saw that the reaction
Speaker 1: in one of these combinations produced some bubbles some gas.
Speaker 1: Many folks will call boil the the father of chemistry,
Speaker 1: but at this point his observation mostly just consistent of
Speaker 1: it's a gas man, you know anything more about it.
Speaker 1: Almost a century later, Henry Cavendish, another philosopher and scientists,
Speaker 1: identified hydrogen gas as a distinct element. The French chemist
Speaker 1: Antoine la Vasier gave hydrogen its name. Now, the earliest
Speaker 1: record I could find of a gas balloon that used
Speaker 1: hydrogen as the lifting agent dates to seventeen eighty three
Speaker 1: in Paris, but hydrogen was used for balloons and airships
Speaker 1: for decades until really the Hidden Hindenburg disaster in nineteen
Speaker 1: thirty seven that scared people quite a bit and stopped
Speaker 1: a lot of people from using hydrogen as a lifting agent.
Speaker 1: Hydrogen gas, by the way, is extremely flammable in the
Speaker 1: presence of oxygen. So the Hindenburg caught fire as it
Speaker 1: was docking with a mooring mast, and it was a
Speaker 1: massive fire. It killed thirty six people, including one person
Speaker 1: on the ground. There were a lot of people who
Speaker 1: were on the Hendenberg who survived with some with severe injuries.
Speaker 1: But still that's a pretty awful disaster. And it was
Speaker 1: caught on film and there was a radio uh presenter
Speaker 1: who was talking through the whole thing. If you've ever
Speaker 1: heard the phrase, oh the humanity that comes from the
Speaker 1: Hindenburg disaster, and it truly was a spectacular catastrophe that
Speaker 1: tragically killed many people. Now, there are several hypotheses as
Speaker 1: to what actually started this fire, but it was definitely
Speaker 1: the hydrogen that provided the fuel for it to spread
Speaker 1: so quickly and to cause such a disaster. So disasters
Speaker 1: like the Hindenburg definitely raised huge warning flags with anything
Speaker 1: associated with hydrogen and fuel in many people's minds, and
Speaker 1: it persists to this day. There are people who say, well,
Speaker 1: we don't want to invest in any sort of hydrogen
Speaker 1: approach to energy storage because of the possibility of another
Speaker 1: Hindenburg like disaster. Now, in the eighteen hundreds, a mixture
Speaker 1: with hydrogen was used as gas for street lamps, so
Speaker 1: it was actually being used as a form of fuel,
Speaker 1: And in eighteen thirty nine Sir William Robert Grove would
Speaker 1: conduct some experiments that led to the development of hydrogen
Speaker 1: based fuel cells. So we'll talk more about fuel cells
Speaker 1: in a little bit, But first, burning hydrogen gives off
Speaker 1: water vapor and some other trace by products depending on
Speaker 1: how you're burning. If you're burning it with pure oxygen,
Speaker 1: you get water vapor. If you burn it in atmospheric conditions,
Speaker 1: you'll get some small byproducts like various hydrogen oxides. It
Speaker 1: all depends upon the composition of the air at that point,
Speaker 1: but it does not produce carbon dioxide like burning fossil
Speaker 1: fuels does. So it seems like hydrogen would be a
Speaker 1: super awesome fuel source for us to go with if
Speaker 1: we could be reasonably certain that the method we're using
Speaker 1: would contain this reaction and not result in a in
Speaker 1: a Hindenburg like disaster. But that's something we can totally do.
Speaker 1: We can do that. I mean, cars are driving around
Speaker 1: using gasoline as fuel, and gasoline is flammable, So why
Speaker 1: don't we just switch to hydrogen. I mean, it's it's
Speaker 1: the most plentiful stuff in the universe and it burns lean. Now, granted,
Speaker 1: water vapor is a greenhouse gas, we have to accept this,
Speaker 1: but water vapor also can incorporate into the water cycle
Speaker 1: on Earth and out of all the greenhouse gases. We
Speaker 1: actually understand water vapors roll in greenhouse gases the least,
Speaker 1: But what's the hold up with hydrogen? While the big
Speaker 1: one is that most of hydrogen on Earth is bound
Speaker 1: together with other stuff like water that hydrogen and oxygen
Speaker 1: or hydrocarbons like the hydrocarbon is an organic compound made
Speaker 1: up of hydrogen and carbon. So if you have a
Speaker 1: carbon atom and four hydrogen atoms, you would have methane.
Speaker 1: To use pure hydrogen as fuel, you first have to
Speaker 1: find a way to shake those hydrogen atoms loose from
Speaker 1: those molecular bonds. So that means to produce hydrogen gas,
Speaker 1: we first have to pour some energy into compounds that
Speaker 1: have hydrogen in them to break those molecular bonds. You
Speaker 1: gotta come up with a good way to do that
Speaker 1: so that in the end of the day, the energy
Speaker 1: stored in the hydrogen gas that you have harvested is
Speaker 1: more than the amount of energy you used to get
Speaker 1: the gas in the first place. Otherwise you have a
Speaker 1: net loss and energy. If you pour more energy into
Speaker 1: making the hydrogen gas, then you would get out of
Speaker 1: consuming the hydrogen gas. You're losing energy. We call this
Speaker 1: a bad thing. This is true for all fuels, by
Speaker 1: the way. So if it cost us more energy to
Speaker 1: get petroleum and to refine that petroleum into fuel, then
Speaker 1: the petroleum fuel itself could store we would not be
Speaker 1: using fossil fuels to begin with, because we would be
Speaker 1: losing energy. We would instead say, why don't we use
Speaker 1: whatever it is we are relying upon to get the
Speaker 1: petroleum in the first place as our energy source. But
Speaker 1: that's not the case. Now. We can measure the energy
Speaker 1: content of various fuels by using an apparatus that allows
Speaker 1: the fuel to burn under what's called standard conditions. Sanery
Speaker 1: conditions means zero degrees celsius and one bar of atmospheric pressure.
Speaker 1: One bar is close to one atmosphere at sea level,
Speaker 1: it's actually a little less. A container of water with
Speaker 1: a known starting temperature and a known mass will absorb
Speaker 1: the heat that's released from this reaction, so you burn
Speaker 1: whatever the fuel is. The heat gets captured by a
Speaker 1: known quantity of water that's at a known starting temperature.
Speaker 1: You measure the change in temperature of the water, and
Speaker 1: that can give you the amount of energy that was
Speaker 1: released by this process. Dividing that by the mass of
Speaker 1: the fuel that you burned will give you the energy
Speaker 1: content of the fuel typically expressed in jewels program or
Speaker 1: or more typically mega jewels per kilogram. This is called
Speaker 1: the specific energy of the fuel. Natural gas, which is
Speaker 1: mostly composed of methane, has a specific energy of fifty
Speaker 1: five mega jewels per kilogram. Get selene has a specific
Speaker 1: energy of forty six mega jewels per kilogram, so it's
Speaker 1: not as energy dense in this respect as natural gases.
Speaker 1: Coal has a specific energy of twenty four mega jewels
Speaker 1: per kilogram. Wood is all the way down to sixteen
Speaker 1: mega jewels per kilograms. So what about hydrogen. Well, hydrogen
Speaker 1: packs a wallop at one hundred forty two mega jewels
Speaker 1: per kilogram. But hydrogen is a gas, so a kilogram
Speaker 1: of hydrogen, the lightest element, is going to be an
Speaker 1: enormous volume of gas. The mass is the same, a
Speaker 1: kilogram is a kilogram, but the volume the amount of
Speaker 1: space it takes up, is different. So this is deceptive.
Speaker 1: We can't just talk about hydrogen the least massive element,
Speaker 1: in terms of mass. It makes more sense from a
Speaker 1: practical perspective to talk about in terms of volume, because
Speaker 1: that's how we're going to handle it. How much energy
Speaker 1: is stored in hydrogen for a given unit of volume,
Speaker 1: I'll tell you in just a second, but first let's
Speaker 1: take a quick break to thank our sponsor. Okay, So
Speaker 1: for practical purposes of using energy storage, we should really
Speaker 1: look at how much energy hydrogen has per unit of volume,
Speaker 1: not unit of mass. This is truly what we mean
Speaker 1: by energy density. So gasoline has an energy density of
Speaker 1: thirty four point to mega jewels per leader. Natural gas
Speaker 1: has an energy density of twenty two point to mega
Speaker 1: jewels per leader. So we see the gasoline comes out
Speaker 1: ahead when we look at it by volume, not by mass.
Speaker 1: But what of hydrogen. Well, if you compress it so
Speaker 1: that you can put it in hydrogen tanks, you're looking
Speaker 1: at an energy density of about nine mega jules per leader.
Speaker 1: So you need more leaders of hydrogen than of gasoline
Speaker 1: in order to do the same amount of work when
Speaker 1: you're burning it as fuel. In other words, because gasoline
Speaker 1: has the energy density of thirty four point two mega
Speaker 1: jewels per leader, hydrogen at nine, so that's an issue. Still,
Speaker 1: hydrogen would burn clean compared to fossil fuels, so we
Speaker 1: would just need to have enough hydrogen to compensate for this.
Speaker 1: So how hard is it to get pure hydrogen from
Speaker 1: various sources and how do we typically produce hydrogen gas? Well,
Speaker 1: right now of hydrogen production comes from wood or fossil fuels,
Speaker 1: and the most common process is called natural gas reforming
Speaker 1: or steam methane reforming. This involves exposing methane gas, that
Speaker 1: carbon with four hydrogen atoms connected to it, two very
Speaker 1: high temperature steam this cause. This is a couple of
Speaker 1: successive chemical reactions, and the end result is you get
Speaker 1: hydrogen gas and carbon dioxide. This, as you might imagine,
Speaker 1: is a problem because carbon dioxide is a greenhouse gas,
Speaker 1: and so is methane actually, and this process creates one
Speaker 1: and makes use of the other. So while you could
Speaker 1: burn the hydrogen gas and not create any carbon dioxide,
Speaker 1: the actual process of producing the hydrogen gas using this
Speaker 1: method releases CEO two. So this is a good reminder
Speaker 1: that when we talk about alternatives to fossil fuels, we
Speaker 1: actually have to look at a very big picture, not
Speaker 1: just what happens when we burn the alternative, but how
Speaker 1: do we produce the alternative does that in turn create
Speaker 1: more greenhouse gases? We have to look at the whole
Speaker 1: chain to make sure we're minimizing the emission of greenhouse
Speaker 1: gases and the release of potentially hazardous materials. You can
Speaker 1: produce hydrogen safely this way, and even in an environmentally
Speaker 1: friendly way. If you can capture the carbon dioxide, if
Speaker 1: you have a method of carbon capture and you're able
Speaker 1: to capture the CEO two that's being given off by
Speaker 1: this reaction, then that might be a good way to
Speaker 1: produce hydrogen. However, adding those components, like the carbon capture components,
Speaker 1: increases the expense of producing the hydrogen. It's it's more
Speaker 1: expensive to do it that way, and as you add
Speaker 1: in the cost of producing the hydrogen, it means that
Speaker 1: you're going to have to sell the hydrogen for higher
Speaker 1: costs to recapture that and economics plays a very important
Speaker 1: part of this proposed hydrogen economy. If it is not
Speaker 1: cost efficient, it is a very hard sell. Money is
Speaker 1: another part of the puzzle that we have to manage.
Speaker 1: We have to be careful about that. So if it
Speaker 1: comes out that fossil fuels are significantly cheaper to produce
Speaker 1: and use than hydrogen, it's really hard to get momentum
Speaker 1: to switch from fossil fuels to hydrogen. If fossil fuels
Speaker 1: become scarce and therefore become more expensive, or the production
Speaker 1: of hydrogen becomes cheaper, then that could provide the economic
Speaker 1: incentive to make the switch. Or if the environmental impacts
Speaker 1: of using fossil fuels, we're creating expenses that were out
Speaker 1: of control. If it were a point where we said
Speaker 1: we have to switch from fossil fuels because dealing with
Speaker 1: the consequences of fossil fuel use is getting too expensive,
Speaker 1: then we might see a switch as well, but it
Speaker 1: would probably be a little late for that. There are
Speaker 1: methods of producing hydrogen that don't rely on this approach.
Speaker 1: So one of them is that you could take charcoal.
Speaker 1: Charcoal is when you really break it down, mostly carbon
Speaker 1: and water when you get down to it. So you
Speaker 1: can put charcoal in a very high temperature reactor and
Speaker 1: burn charcoal at a temperature between twelve hundred and fifteen
Speaker 1: hundred degrees celsius. Doing so well, it will release gas
Speaker 1: and that gas will separate out and then reform into
Speaker 1: hydrogen carbon monoxide. So yeah, hydrogen, but carbon monoxide is
Speaker 1: toxic to many animals, including us, and it also plays
Speaker 1: a part in the formation of smog. So that's not great.
Speaker 1: I guess the one positive thing I could say is
Speaker 1: carbon monoxide itself is not a greenhouse gas on its own.
Speaker 1: But the way that the article I first mentioned at
Speaker 1: the top of this episode is really focusing on is
Speaker 1: a third method to produce hydrogen. It is one that
Speaker 1: only produces oxygen and hydrogen. Those are the only two byproducts.
Speaker 1: It is the process of electrolysis of water, and electrolysis
Speaker 1: refers to the separation of bonded elements and compounds through
Speaker 1: the use of an electric current. So the idea is,
Speaker 1: if you pass an electric current of sufficient strength through
Speaker 1: certain materials, you can break the molecular bonds holding the
Speaker 1: atoms of that material together. Pure water, as it turns out,
Speaker 1: isn't great for this. You would need a very very
Speaker 1: strong current because pure water is a poor conductor of electricity.
Speaker 1: What you need are electrolytes in the water. And I'm
Speaker 1: not talking about the stuff that plants crave. I'm talking
Speaker 1: about the substance that when you put it in water,
Speaker 1: creates an electrically conducting solution. It introduces ions. In other words,
Speaker 1: but you need to make sure that whatever electrolyte you
Speaker 1: include in the mixture doesn't electrolyze more easily than water does,
Speaker 1: because otherwise, what will happen is you put the electric
Speaker 1: current into the solution and the electrolytes will electrolyze, whereas
Speaker 1: the water will not, and you won't release hydrogen until
Speaker 1: you just have pure water again, and you're back to
Speaker 1: where you started. So one of the ions that is
Speaker 1: frequently used for electrolysis would be sulfate ions, because sulfate
Speaker 1: doesn't electrolyze more easily than water does. So you've got
Speaker 1: your water and you've got your electrolytes in it, and
Speaker 1: then you put two electrodes, and one of them is
Speaker 1: connected to the negative terminal of the battery. One of
Speaker 1: them is connected to the positive terminal of a battery.
Speaker 1: I'm just using a battery for this particular example. It
Speaker 1: doesn't have to be a battery. So you've got your
Speaker 1: negatively charged electrode that's called the cathode, and you've got
Speaker 1: your positively charged electrode that's called the anode, and you
Speaker 1: insert them in the water. Now, what will happen, assuming
Speaker 1: you've done this correctly, is that hydrogen gas will bubble
Speaker 1: up around the cathode, and oxygen will bubble up around
Speaker 1: the anode. One of the traditional challenges associated with electrolysis
Speaker 1: of water on a large scale is that the electro
Speaker 1: catalysts catalysts are things that facilitate the reactions and chemical reactions.
Speaker 1: They make chemical reactions happen more easily or with less
Speaker 1: energy if you prefer. The electrode. Catalysts that we tend
Speaker 1: to use for electrolysis also tend to be pretty rare
Speaker 1: and expensive. Like one of the common ones is platinum,
Speaker 1: but platinum is not easy to get. It is rare,
Speaker 1: and so it's very costly, and that means the cost
Speaker 1: of building out the system to produce hydrogen will get
Speaker 1: driven up. And as I already mentioned, cost is one
Speaker 1: of those factors we can't just ignore when it comes
Speaker 1: to creating an alternative fossil fuels. So in some scientists
Speaker 1: at the University of Houston announced the development of a
Speaker 1: new electro catalyst made from a conductive nickel foam material
Speaker 1: and a ferris metaphosphate. The relevant point here is that
Speaker 1: this stuff costs less to make than if you were
Speaker 1: to go out and get platinum. So this is a
Speaker 1: push to make hydrogen production economically viable. And like I
Speaker 1: said before, you have to take this big picture into account.
Speaker 1: So that doesn't just include the materials you need to
Speaker 1: perform electrolysis on water. You also have to ask where
Speaker 1: is the electricity coming from? What is providing the electricity
Speaker 1: I'm using for electrolysis. If you trace back the source
Speaker 1: of your electricity and ultimately you're drawing electricity from a
Speaker 1: coal firing power plant, then you haven't really solved any problems.
Speaker 1: The pollution is still in the equation. It's just over
Speaker 1: in the electricity production side as opposed to the direct
Speaker 1: hydrogen production side. In fact, depending upon your approach, you
Speaker 1: may be consuming more fuel and using up more stored
Speaker 1: energy than you are producing by creating hydrogen if you
Speaker 1: have a very inefficient system, and you'd be using a
Speaker 1: process that releases greenhouse gases to boot, so that would
Speaker 1: be a really bad idea. The article talked about green hydrogen,
Speaker 1: and by that they meant using some sort of renewable
Speaker 1: energy source to create the electricity, such as wind power
Speaker 1: or solar power. That can be a step in the
Speaker 1: right direction. If you're using wind power, solar power hydro
Speaker 1: power or whatever, and you're generating more electricity then you
Speaker 1: need to supply given area at a given time. Then
Speaker 1: if you were to pair those facilities with an electric
Speaker 1: electrolyzer facility, electrolysis facility, if you if you will, that
Speaker 1: would make a of sense because electricity is a use it,
Speaker 1: store it, or lose it commodity. At some point, you
Speaker 1: might be producing more electricity than you need at that time,
Speaker 1: and rather than lose it, you can put it to work.
Speaker 1: You can take that excess electricity and put it to
Speaker 1: work to produce hydrogen. So that article I mentioned at
Speaker 1: the beginning of this episode goes into this concept in particular,
Speaker 1: and it talks about a project in Len's Austria. That
Speaker 1: project is called H two future H two, referring to
Speaker 1: hydrogen gas. The goal is not just to create hydrogen
Speaker 1: gas using electricity from renewable energy sources, but to use
Speaker 1: the hydrogen as a fuel source for steel production. It
Speaker 1: would be co located with a steel production plant, so
Speaker 1: this would create green steel and steel production usually requires
Speaker 1: burning a lot of coal and uh. It turns out
Speaker 1: that steel and cement production together are responsible for about
Speaker 1: twenty percent of all carbon diet side emissions in the world,
Speaker 1: So if you could bring that down by creating a
Speaker 1: hydrogen based steel production plant, you could drastically reduce the
Speaker 1: amount of carbon dioxide that's being emitted into the atmosphere.
Speaker 1: I'll talk more about these plans in just a second,
Speaker 1: but first let's take another quick break to thank our sponsor.
Speaker 1: The H two future project is a small scale test.
Speaker 1: So this electrolyzer is paired with that steel plant, and
Speaker 1: it's going to run at a capacity of six megawatts,
Speaker 1: which is not particularly powerful in the grand scheme of things.
Speaker 1: According to the article I was reading, which is over
Speaker 1: on fizz dot org p h y s dot org,
Speaker 1: this will result in the production of twelve cubic meters
Speaker 1: of hydrogen per hour, and if the test proves promising,
Speaker 1: the plant could invest in building a much larger electrolyzer
Speaker 1: that could offer rate at a capacity of one hundred megawatts,
Speaker 1: significantly more powerful than six megawatts. The article also mentions
Speaker 1: a similar project in Cologne, Germany called Refine, but it's
Speaker 1: r E f h y n E. It is a
Speaker 1: ten megawatt electroalizer that's co located with an existing hydrogen
Speaker 1: refinery that's been using the steam reforming method to produce
Speaker 1: hydrogen up to that point. Like the H two Future project,
Speaker 1: this is a test, it's a pilot program. It's not
Speaker 1: going to produce nearly as much hydrogen as the steam
Speaker 1: reforming process at this level of power. It comes down
Speaker 1: to about a hundred eighty thousand tons from the steam
Speaker 1: reform process versus hundred tons from electrolysis. But again, this technology,
Speaker 1: if it works, could be scaled up and then you
Speaker 1: would see more and more hydrogen being produced through electrolysis
Speaker 1: and less through the steam reforming process. Now I focused
Speaker 1: mainly on hydrogen production, but that's still just one piece
Speaker 1: of making a viable hydrogen economy. It's a super important one, obviously,
Speaker 1: because if you don't have hydrogen, then the rest of
Speaker 1: it doesn't make any sense at all. But even if
Speaker 1: we were able to make plenty of hydrogen, let's say
Speaker 1: that we've solved that problem. We've come up with an
Speaker 1: electrolysis approach that uses green energy, it's incredibly efficient, and
Speaker 1: now we're just churning out hydrogen like crazy. We still
Speaker 1: have some other challenges. For one thing, we've got designed
Speaker 1: stuff to store the hydrogen and we have hydrogen tanks,
Speaker 1: but we would need to build a lot of them
Speaker 1: and to UH to test the various designs out, we
Speaker 1: would have to design stuff to run on the hydrogen.
Speaker 1: So what are our options here, Well, first, you could
Speaker 1: burn hydrogen fuel like gasoline. There are hydrogen internal combustion engines,
Speaker 1: for example, and you would refuel them in a way
Speaker 1: very similar that the way you refuel a gasoline powered engine.
Speaker 1: So there are vehicles that use this UH in the
Speaker 1: exact same way it cars use gas or petrol. Or
Speaker 1: you could use fuel cells, which in a way is
Speaker 1: essentially that electrolysis process, but in reverse. So with a
Speaker 1: fuel cell, hydrogen based fuel cell. I should add there
Speaker 1: are different types of fuel cells, but we're specifically talking
Speaker 1: about the hydrogen based ones. You on a very basic level,
Speaker 1: you have hydrogen and a fuel cell on one side
Speaker 1: of the cell. You have oxygen on the other side
Speaker 1: of the cell, and between these two gases you have
Speaker 1: a special membrane with a catalyst on it, and the
Speaker 1: hydrogen passes through the membrane, but the membrane requires the
Speaker 1: hydrogen to ditch an electron. First. It says, all right,
Speaker 1: you can come through, but your friend can't. So the
Speaker 1: electrons like ah. But the electron really doesn't want to
Speaker 1: be with a bunch of other electrons. There are a
Speaker 1: bunch of negative dancings, and we all know that similar
Speaker 1: charges repel each other. So you have more and more
Speaker 1: electrons building up. They do not want to be with
Speaker 1: each other. You provide a pathway for those electrons to
Speaker 1: follow a circuit. In other words, you make them do
Speaker 1: work along this circuit, and eventually the electrons are allowed
Speaker 1: to rejoin the hydrogen nuclei, which again are just protons.
Speaker 1: Remember that are on the other side, and that also
Speaker 1: combines with the oxygen and you end up creating water
Speaker 1: as a result. So you get electricity, water and heat.
Speaker 1: That's the only thing the fuel cell gives off. Hydrogen.
Speaker 1: Internal combustion engines aren't really that much different from standard
Speaker 1: combustion engines. They require some modifications, like you wouldn't want
Speaker 1: to have spark plugs that have platinum tips, for example,
Speaker 1: because that would react with the hydrogen. You want special
Speaker 1: fuel injectors, special valves. You also would need a specialized
Speaker 1: hydrogen storage system otherwise known as a hydrogen tank. The
Speaker 1: combustion chamber would also need to be optimized to really
Speaker 1: harness the most energy out of combusting the hydrogen because
Speaker 1: remember hydrogen, uh, the energy density is lower than that
Speaker 1: of gasoline, so you need to really optimize the engine
Speaker 1: to take advantage of all that power as much as
Speaker 1: it can to make it as efficient as possible. Hydrogen
Speaker 1: burns way more readily than other fuels, so it also
Speaker 1: burns faster. The big advantage of this approach over fuel
Speaker 1: cells is that a lot of the work has already
Speaker 1: been done, which means making vehicles that run on hydrogen
Speaker 1: as a combustible fuel is relatively inexpensive. A lot of
Speaker 1: the work has already been done in that field. But
Speaker 1: burning hydrogen in a combustion chamber is not the same
Speaker 1: thing as burning it with pure oxygen. It means combining
Speaker 1: it with atmospheric air, and that also means that there's
Speaker 1: nitrogen in the air and you will eventually start producing
Speaker 1: nitrogen oxides as a byproduct. Now, it's a much smaller
Speaker 1: amount of nitrogen oxides than you would typically typically get
Speaker 1: with a gasoline or diesel powered engine, but it still
Speaker 1: means that the hydrogen combustion engine cars are not pollution free.
Speaker 1: And because we need to look at the volumetric energy
Speaker 1: density of hydrogen. Those engines produce less power than a
Speaker 1: comparable gasoline engine. Fuel cell vehicles get a bit more
Speaker 1: omph out of a similar amount of hydrogen than the
Speaker 1: hydrogen combustion engines do. Actually they get a lot more.
Speaker 1: Fuel cells can be pretty efficient, like around the seventy
Speaker 1: percentile range. They produce electricity, so you would pair these
Speaker 1: fuel cells with an electric motor, and in many ways,
Speaker 1: fuel cell vehicles and electric vehicles are very similar. It's
Speaker 1: just that electric vehicles run on batteries that have to
Speaker 1: be recharged. Fuel cells rely on fuel. It's in the name,
Speaker 1: so you have to refuel the fuel cell rather than
Speaker 1: recharge it. Obviously, vehicles would just be one potential use
Speaker 1: for hydrogen. It could be used as a fuel in
Speaker 1: tons of different applications. But there's still other problems that
Speaker 1: we would have to solve. A big one is infrastructure.
Speaker 1: It took decades to build out the infrastructure we've got
Speaker 1: for fossil fuels, and that infrastructure has grown over the
Speaker 1: course of more than a century. It's an estable, published
Speaker 1: and entrenched system. In many ways, it's an investment. In
Speaker 1: other words, so we would have to build out something
Speaker 1: similar for hydrogen if we were to depend upon that
Speaker 1: more heavily as an energy storage method, so that would
Speaker 1: be a really big price tag. Also, revisiting the production
Speaker 1: issue for just a moment, there's the question of where
Speaker 1: do you get the water. If you're relying on the
Speaker 1: electrolysis method, preferably you would be using freshwater. It provides
Speaker 1: fewer problems than salt water. But in some areas, fresh
Speaker 1: water is a very precious commodity that's in short supply,
Speaker 1: so it would make very little sense to switch to
Speaker 1: water and have it become even more scarce by dedicating
Speaker 1: a good portion of it towards energy. There are projects
Speaker 1: that are experimenting with using sea water as a source
Speaker 1: for hydrogen, but seawater has lots of other stuff in
Speaker 1: it that can cause problems from this process, and it
Speaker 1: may be small problems, like relatively small problems like corrosion
Speaker 1: of the electrodes, which is, you know, it means you'd
Speaker 1: have to replace the electrodes a much much more frequently
Speaker 1: in the electoralizer. But there are other problems as well,
Speaker 1: like the possibility that you would start producing chlorine gas,
Speaker 1: which is deadly stuff. We've been talking about switching to
Speaker 1: hydrogen as a primary energy storage solution for a really
Speaker 1: long time. The term hydrogen economy, which describes a holistic
Speaker 1: system of delivering energy through hydrogen, first popped on the
Speaker 1: scene way back in nineteen seventy and I talked at
Speaker 1: General Motors. A guy named Bernard Patrick John O'Meara Bachris,
Speaker 1: or just John Bachris, came up with this phrase. Dr
Speaker 1: Bachris was a chemistry professor and a proponent of hydrogen
Speaker 1: for quite some time. This concept would see support come
Speaker 1: and go over the years. Sometimes it would get a
Speaker 1: little more focus, sometimes fade into the background. In addition
Speaker 1: to the benefit that hydrogen would produce fewer pollutants than
Speaker 1: fossil fuels, hydrogen economy would turn a country with water
Speaker 1: access into a self sufficient nation from an energy standpoint,
Speaker 1: which in turn would bolster now sational security because it
Speaker 1: would mean the country wouldn't have to rely upon fossil
Speaker 1: fuel resources that are produced in other countries. So in
Speaker 1: the early two thousands, during the administration of George W. Bush,
Speaker 1: the hydrogen economy got a lot of support, largely for
Speaker 1: that reason it would remove our dependence upon foreign oil.
Speaker 1: There are people who oppose the development of the hydrogen economy,
Speaker 1: not saying it was a bad idea necessarily, but saying
Speaker 1: it's going to end up being too costly and not
Speaker 1: efficient enough to meet our needs, so it would at
Speaker 1: best be distracting and at worst be completely wasteful and
Speaker 1: and waste time and resources that could be spent on
Speaker 1: different alternatives. And they may well have a point. It's
Speaker 1: really hard to say right now, but hydrogen is likely
Speaker 1: to be at least a component of alternate fuel and
Speaker 1: energy solutions moving forward. It could end up being a
Speaker 1: huge component if we get fusion to work, because fusion
Speaker 1: would rely upon isotopes of hydrogen, and then you're talking
Speaker 1: enormous energy density ease that more than dwarf the combustible
Speaker 1: fuels we're talking about now. How big a part hydrogen
Speaker 1: is going to play as a fuel remains to be seen.
Speaker 1: It may require breakthroughs in both production and in how
Speaker 1: we put it to use, and until we have a
Speaker 1: storage and transportation infrastructure built out to support this, will
Speaker 1: not be able to really rely upon it as extensively
Speaker 1: as we do fossil fuels. So can we produce enough
Speaker 1: hydrogen to meet our needs. I think the right answer
Speaker 1: now is not yet, or maybe the answer is that's
Speaker 1: just one part of the challenge, and we have to
Speaker 1: solve a whole lot of problems to make hydrogen practical.
Speaker 1: So let's not worry about too much. Let's try and
Speaker 1: solve these problems first. Now, I do think it's worth pursuing.
Speaker 1: I think fuel cells are super cool. I know some
Speaker 1: people who love electric cars and that model, and they're
Speaker 1: totally dismissive of fuel cells, But personally, I think both
Speaker 1: models can work. And besides, even if we don't get
Speaker 1: fuel cell vehicles rolled out on a wide scale, we
Speaker 1: may put hydrogen to use in many other places. That
Speaker 1: wraps up this episode. If you guys have suggestions for
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Speaker 1: Stuff podcast dot com website. There you will find ways
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