@davemb: "Gasoline infrastructure costs ... Things wear out, rust out, etc. Of course this is also true of a hydrogen infrastructure as well, ... . In the instance of the gas station, from my observation I expect that the above-ground hydrogen tank would last significantly longer than the buried gas tank, and would be cheaper to replace."
How large are these above-ground hydrogen tanks likely to be? One can pave over buried tanks and use the space to park the tanker truck that refills the tanks. Modern gasoline tanks are fiberglass, and don't rust. I assume environmental regulations also prohibit having connections on the bottom of a buried tank (as does the USCG in boats) so the water which collects in the bottom of the tank can't corrode the connection and cause a leak into the groundwater (or the bilge in the case of a boat).
A buried hydrogen tank would have the advantage of a more consistent thermal environment, what with all that earth insulating it. If a fence post is required to be below the frost line, I'm sure that a buried gas tank must be, too.
Back in the early 1970s, Chemical & Engineering News (published by the American Chemical Society) had an article on hydrogen power for motor vehicles, using internal combustion engines, not fuel cells. The article also described a novel way to store hydrogen at low pressures.
The idea back then was that engine technology was not the problem, fuel sources and pollution was, and that hydrogen had several advantages over gasoline, diesel, and propane, but several obstacles to its implementation as well. From what I see the obstacles are still here, and will in some way affect the use of hydrogen fuel cells.
First, every chemistry major knows there are much better things to make from petroleum than simple non-renewable fuels. (Among other things, "Plastics." as Benjamin was told.)
Second, the only by-product of hydrogen combustion is water, which is not usually considered a polllutant in the same sense as CO, CO2, and NOx emissions.
Third, the colder it gets, the harder it is to vaporize gasoline and diesel fuel. Hydrogen, which boils at -252.9C / -423.2F, will still be a vapor in arctic / antarctic climates, whereas even propane gas turns to a liquid around around -42C / -44F (the record low temperatures in Alaska during the winter (October - April) run from -46C / -50F to -62C / -80F; Antarctica is even colder. reaching −80 °C / −112 °F to −90 °C / −130 °F in the interior in winter).
In a car crash, gasoline vapors hang near the ground waiting for a spark to ignite them, whereas hydrogen readily rises and dissipates, greatly reducing the risk of fire or explosion.
Four major disadvantages to hydrogen as a fuel source are production, distribution, storage, and panic.
Production: as pointed out in other posts, electrolysis requires electricity produced by some other (expensive) fuel source. The article proposed that thermal cracking of water in nuclear plants would be more efficient for large-scale production of hydrogen.
Distribution: gasoline stations are served by tanker trucks. Hydrogen stations could be served by trucks or by gas lines, similar to natural gas.
Storage: storage is done in heavy tanks, as for all gases. Gaseous hydrogen, being a small molecule like helium, tends to leak through joints or other small openings (which is why your helium-filled balloons eventually shrink and stop floating, even in mylar).
The article reported on some research into using rare-earth hydrides to store hydrogen. These "tanks" are lighter because the hydrogen is bound to the rare-earth substrate, not stored under high pressure in a heavy tank. An advantage of this system is that the the evolution of hydrogen from the substrate is an endothermic reaction, meaning it absorbs heat, so you need to apply a little heat to get the hydrogen out. If the tank is punctured in an accident, the release of hydrogen ends up cooling the tank, self-limiting the release. See also Wikipedia article on Lanthanum (Hydrogen sponge bullet).
Alas, like many ideas, this one died on the vine since gasoline was still cheaper than any other alternatives. Still, in my youth I thought this was neat. Still do!
Panic: The author termed this the "Hindenburg Syndrome." Mention "hydrogen" and everyone thinks of the ill-fated Nazi Zeppelin's last trip to Lakehurst, NJ, and assumes hydrogen is too dangerous. This isn't so. According to the Wikipedia article on the Hindenburg Disaster:
"Hydrogen fires are notable for being less destructive to immediate surroundings than gasoline explosions because of the buoyancy of H2, which causes heat of combustion to be released upwards more than circumferentially as the leaked mass ascends in the atmosphere; hydrogen fires are more survivable than fires of gasoline and of wood. The hydrogen in the Hindenburg burned out within about 90 seconds."
Thanks for reminding me of the earlier generation Honda FCX.
I'm pleased that Toyota is expanding into this market - the more players, the more infrastructure can be supported, and the more credibility the solution builds.
At the same time, I believe that when press releases are reprinted or reported in a publication that the "rst of the story" and the context be explained. Is this innovation, something new, or another company doing the same old thing. With mpodern graphics tools, an artist's conception of a car may even appear as real as a production vehicle on the street. Readers may not know all the background information (which is why they're reading to learn more).
Note also that the Clarity is Honda's second-generation fuel cell vehicle; the original FCX was introduced in December 2002. In addition, Hyundai has been selling the fuel-cell version of its Tucson in Europe since February 2013.
In my view a "public relations piece" is not so bad if it is reasonably honest and captures the public interest. In another newsletter it was mentioned that Toyota is also to get involved with refueling infrastructure, so it seems to me that they are serious about this. If they want to "join the party" by all means let's let them in; the more support, the better.
Bert, I'm fully aware of your support for the FEV concept, and I appreciate that. However, my concern is that adding a mobile reformer to the vehicle both eliminates many of the advantages of the concept, and is a disincentive for transitioning away from gasoline, which is in my view necessary for the sake of the environment-increasingly so as we resort to unconventional oil and gas reserves for production. And, as a user of hydrogen myself, my view is that you are a little too afraid of the handling and use of hydrogen.
The fuel nozzles in the hydrogen refueling systems are designed to completely seal the pump-to-vehicle connection before allowing any fuel to pass into the tank, yet are as easy to use as a gasoline refueling nozzle; when you refuel a gasoline vehicle, the evaporative emissions system is ineffective, and vapors will be emitted during the process, and they linger in search of a source of ignition, as many people foolish enough to smoke while refueling can tell you, if they manage to survive the incident.
During the refueling process is the only time that 10,000psi pressures exist outside of the vehicle's storage tank. Pressure reducing valves located in the tank outlet reduce the pressure to typically under 50psi (less in smaller cells; the cells I use run at 5-6psi).
High pressures do exist in ICE vehicles; upto 25,000 to 34,000psi in the fuel rails of a common-rail diesel engine, and around 5,000psi in the accumulators in antilock braking systems. If the system is properly designed, it is not a problem. The pressure tanks in the FCV undergo a series of very severe tests to insure their safety and ability to survive accidents and fire exposure. Hyundai's brochure on their Tucson FCV (which I picked up at the WHEC event in Toronto) devotes two entire pages to discussing safety measures incorporated in their vehicle, including photos of the results of crash tests and fire exposure tests.
When I mention costs, I'm referring to whole systems costs, which would include not only distribution and storage, but extraction and processing costs as well. Remember there are no gasoline mines; gasoline is a highly refined product, made from oil at considerable additional costs, including both oil distribution and hydrogen distribution to very sophisticated and very costly refineries (so costly that the industry often prefers shipping oil a thousand miles to an existing refinery to building a local refinery). Purifying hydrogen for use in a fuel cell is child's play by comparison to that.
Gasoline infrastructure costs (including burying of gas station tanks) are not one-time costs. Things wear out, rust out, etc. Of course this is also true of a hydrogen infrastructure as well, but the cost of maintaining fossil fuel infrastructure in the US alone runs in the neighborhood of 100 million dollars per year. In the instance of the gas station, from my observation I expect that the above-ground hydrogen tank would last significantly longer than the buried gas tank, and would be cheaper to replace.
So, if I haven't convinced you, I guess we'll just have to agree to disagree. In any case, the fact that this thread has been active for so long indicates a lot of interest in the subject. I thank you and everyone for that.
Thanks for the detailed post, Dave. Glad to see that any fuel cell longevity issues seem to have been addressed. However I'm a bit skeptical about the high pressure requirements for hydrogen storage, and your claim that the distribution system is cheaper than that of gasoline or diesel.
I can fill the tank of my car, and leisurely reattach the gas cap, without all of the gasoline evaporating in an instant. And when I do put the gas cap on, it only needs to retain a pressure of, I'm not exactly sure, but something on the order of 50 psi. That's for evaporative emissions, with the engine off, in cars after 1995 or so.
Compare this to 7500 psi or even 10,000 psi needed for hydrogen storage. There's nothing close to that high pressure in cars today. I find it very difficult to accept that distributing and storing hydrogen is cheaper than gasoline, even if the one-time cost of burying the fuel tanks in gas stations is steep. Sounds to me like a maintenance nighmare in the making, not just for cars, but also for delivery trucks or delivery pipelines. No?
To remind you, I'm the guy who loves the FEV concept, but wants it married to an on-board reformer. Rather than messing about with 10,000 psi tanks, on board.
This article strikes me as a public relations piece ("vaporware") intended to buy good will and time. Honda's Clarity was unveiled in November 2007 and production started in November 2008. They have been driving around on hydrogen for more than 4 years. I don't see much significance in Toyota's announcement except that they'd like to join the party.
A lot of people have strong comments on the web, both for and against hydrogen. To answer Don's points as recorded by you:
1. Terrestrial hydrogen is an energy carrier or transfer medium; of course that's true. That's also true of electricity, and in reality, fossil fuels as well. Neither of these alternatives, in fact, "contribute net new BTU's to the economy". Why should that be a goal? If we are ever to get out of the mess we're in, we need to create and consume less energy, not more. As economist Ken Boulding once said "Anyone who believes that growth can continue indefinitely within a finite system is either a madman or an economist."
2. We don't "create" hydrogen; and we don't "create" fossil fuels either. In all cases, we are using what is there. On a whole systems basis it is a lot simpler and more efficient to use hydrogen as a fuel than gasoline, and a whole lot cleaner too. Remember, "there is no away"; transforming water into hydrogen doesn't throw anything away. When we use it in a fuel cell, we get clean water back. When we burn gasoline in an engine, we get polluted water back, together with all the other constituents of the fuel, in modified and recombined form. Eventually, in a few thousand years, the earth may transform them back, if we're lucky, or if we are still around.
3. We have many times more water than it would take to close the loop. Remember that a fuel cell is 2 to 3 times as efficient as a gasoline or diesel engine. It takes as much water to make a kWh of gasoline as a kWh of hydrogen. And how can a hydrogen source so benign that we can drink it (in fact, must drink it) be a worse feedstock than the toxic soup that feeds our gasoline refineries?
4. I can only assume that you are combining the weight of the hydrogen tank and the hydrogen fuel in your calculations. But we don't consume the tank, we only consume the hydrogen. The gravimetric density of hydrogen is higher than gasoline. A kg of hydrogen contains 33.3 kWh of energy, roughly that of a US gallon of gasoline (usually gaven as between 34 and 35kWh). A gallon of gasoline weighs roughly 2.7kg. Of course the volumetric density is "ludicrously low". That makes it useful for providing lift in airships: it's also why it is ludicrous to call the Hindenburg fire a hydrogen fire. The loaded Hindenburg contained substantially more energy in the form of petrol (both diesel and gasoline) than was contained by all the hydrogen lift bags in its hull. That's also why we do not use atmospheric-pressure hydrogen as a fuel; we compress it.
5. Of course this source of hydrogen is fossil-fuel-dependent; but not as "extremely" so as the gasoline in an ICE vehicle's tank. So what are we trying to say here? At least we have the option of getting our hydrogen from other sources. Here in Canada, at least, we produce a very significant portion of our hydrogen from non-fossil-fuel-dependent sources.
If the hydrogen comes from natural gas, traditional steam reformation (still in use by the fossil fuel industry) runs at between 70% and 75% efficiency, according to industry figures I have seen. When boosted to 10,000psi for use in an automobile, the overall efficiency would be about 62% with conventional compression techniques, according to a GM study a few years ago. This is better than any fossil fuel to electricity conversion (more than twice that of a coal-fired plant). Better methods are now coming on stream; for example, Membrane Reactor Technology's membrane reactor has a claimed efficiency of better than 82%. Linde has developed an ionic compressor that is much more efficient than standard compression, so we could see overall natural gas to 10,000 psi conversion efficiencies in the range of 75%. It's important to remember that this process is a part of the process of making gasoline and diesel transportation fuels as well; increasingly so as we turn to unconventional sources such as tar sands, shale oil and oil shale.
If the hydrogen comes from hydrolysis, conversion efficiencies range from 65% to 85% depending on the size and type of electrolyzer used. High differential pressure electrolyzers greatly reduce the compression requirements. If you use electricity from fossil fuels (especially coal) hydrolysis makes little sense. It makes sense when your electricity comes from renewables, and using hydrogen as a storage medium on the grid can help integrate renewables into the grid.
Here in Canada we make a lot of hydrogen by electrolysis from hydroelectric power, where it has the side benefit of helping to balance electric power production with power demand, an in some cases, flood control requirements. We also collect large amounts of byproduct hydrogen from sewage and water treatment and certain industrial processes such as chlorine production, paper production, flue gases from steel refineries, etc.
Ontario has a lot of hydro power and renewables in its electrical mix, and closed our last coal-fired power plant a few weeks ago. Air Liquide, one of our largest hydrogen producers, produces hydrogen from electrolysis from hydroelectric power.
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