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Increasing Fuel Mileage With Hydrogen?
cr0sh asks: "I was recently looking into the costs and availabilty associated with small, hydrogen fuel cells (results: they are still expensive), when I came across this site about the Hydrogen-Boost [Warning: Pop-ups]. Looking at this site, it seemed like just another in the long line of scamming 'get more mileage/power' engine products out there, but it intrigued me enough to continue looking into it. I eventually came upon another site on
hydrogen experiments. A little more searching revealed this one about constructing your own Hydro-Boost device, which goes into detail about how you would build such a system. None of these sites answered the big questions, however: 'does it work?', and 'if so, how well?'. I also wanted something a little more authoritative. So, back to digging...which came up with this paper from OSTI [PDF]. The very first line of the abstract of this paper reads 'It is well known that hydrogen addition to spark-ignited (SI) engines can reduce exhaust emissions and increase efficiency.' This paper seems to advance the notion that such a system like the 'Hydrogen Boost' system may actually work. Does Slashdot think such a system would work? If so, how it could be improved, especially given today's rapidly rising gasoline prices, here in America?"
"On the experiments site, via the link to 'Hydrogen Experiments Part 2', the author references the first site. He ultimately decides to 'home-brew' his own system instead, and gives enough detail for anybody to do so. I was hoping the author had more details on the effects caused by dumping hydrogen into his engine, but that doesn't appear to be.
A notable observation on the Hydro Boost Device is that instead of using a stainless steel mesh as the other guy uses (which would seem to be a superior material to use, though difficult to find), this design uses galvanized steel bolts for the electrodes, making it something that can be built from materials found at a local building materials warehouse."
I did some research and ended up chosing a Honda hybrid. There just wasn't enough of an availability to the consumer to drive something based on hydrogen. At least not yet.
My civic hybrid gets 45-47 MPG, is quiet as hell, and was fairly cheap. GM and Ford both have alternative fuel vehicle programs, but until I can go down to the local dealer and drive home with a hydrogen F-150, I'll be in a hybrid.
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Free your mind.
Most fuel cells that will be used in cars will be PEM (proton exchange membrane) fuel cells. The problem with PEM fuel cells is that it requires a platinum catalyst to remove the electron from the hydrogen aton. As we know platinum is one of the most expensive elements on earth. The key is to find a catalyst that is cheaper and just as noble as platinum. There are other hydrogen fuel cells out there, but they usually operate at high temperatures (the main advantage of PEM). It is not like you want to wait 5 minutes for your car to warm up before you leave.
The energy required to break the water up into hydrogen and oxygen will be at least equal to, and in a practical electrolytic cell it will be greater than, the energy you get back by burning the hydrogen later on. Typical electrolytic processes are around 60% efficient, from memory. This energy comes from the battery, which is about 92% efficient, which comes from the alternator, which is about 60% efficient, which is driven by the engine. So I get a loop efficiency of about 30%.
However, there may be some subtle advantages in adding gaseous hydrogen and oxygen to the fuel mixture. I doubt they would compensate for the efficiencies in the first paragraph.
You should ignore this post, the oil companies are paying me $$$ to suppress these crazy inventions.
I think you are talking about water injection. It's been done since at least WWII. They use to use it on I believe Mustangs for added horse power. It isn't the hydrogen burning it's the fact water steam expands at a higher rate than gas vapors. There have been a few systems for cars. The downside is it tends to over heat the engine. I WWII they just used it briefly as an emergency measure. I don't believe there was any improvement in mileage or polution, just horsepower.
As a private pilot I can tell you that, for your typical piston engine aircraft, engine performance is reduced on humid days.
More moisture = less air available in the same volume.
However, I can also tell you that the difference, at least low altitudes is negligible.
You can get a minor boost in power from water injection. This happens in 2 ways. 1 the water cools the intake air, and cooler air is more dense giving you more power. The other way I've heard is the high heat splits the water and then the two parts burn. What water injection is really good for is it helps prevent detonation in high boost engines, and your pistons get a nice steam cleaning every cycle. Power gains are usually not worth mentioning 1-2% at best.
The person to go looking for on this one is Roger Billings; he's currently with the International Academy of Science (I drive by there every morning on my way to work). He was driving hydrogen-powered ICE vehicles back in the '70's.
He ran into two problems with running an engine on Hydrogen.
He got hydrogen engines down to such an artform that he modified a Volkswagen Beetle ('72, IIRC) to run on the stuff for a college competition (he was an undergrad at the time), and the emissions coming out of the tailpipe were actually CLEANER than the air going into the intake. Basically, any Carbon Monoxide or unburned Hydrocarbons (common vehicle pollutants) which made it into the intake were finished off in the process, and the hydrogen fuel didn't produce any such emissions (water vapor).
I'd be wary about adding hydrogen to a gasoline engine to help the economy. You'd need a significant amount of hydrogen to make any real difference, and hydrogen storage these days is either:
Sorry guys, but this sounds like B.S.
... by the Dew of Mountains the thoughts acquire speed, the hands acquire shakes, the shakes become a warning
"# high-pressure gas (expensive, heavy tanks and very little capacity)"
They aren't really heavy any more. They are made out of composite materials, with pressures up to 700bar (10000psi).
That's not how it works. Water injection by itself doesn't add any power at all, but rather acts to prevent detonation (you know, pinging). Most fighter engines in World War II had variable-speed superchargers, but they couldn't use max boost below the critical altitude because it would cause detonation. The Americans used a water injection system that could be used in emergencies to prevent that and allow a higher boost setting to be used, increasing power. The Germans used MW-50, a 50/50 mix of water and methanol which served the same purpose and may have been more effective at it; I don't remember.
Disclaimer: IANAL. This post is, however, legal advice, and creates an attorney-client relationship.
This "hydrogen boosting" is just adding a different fuel to the mix. Of course the "mileage" will increase because you are getting more power from the other fuel. The other fuel is probably more expensive than gasoline, so why bother? Not only that, but you are "misfueling" your vehicle, so unless you really know what you're doing it could impact the performance and/or lifetime of the engine and it certainly voids your warranty.
For all intensive purposes, "whom" is no longer a word. That begs the question, "who cares"?
First, an acid filled generator will produce acid spray in the hydrogen. Which gets into the engine...which is made of aluminum and iron. Instant damaging corrosion time.
If you use the alternative electrolyte, sodium hydroxide, that just dissolves the piston.
Second, it is possible that (assuming the article isn't a complete troll) the engine used was fouled up and the acid mist actually cleaned up the plugs a bit. Cleaning plugs on old dirty engines usually increases gas mileage for a short while till the thing starts poorly and fouls up again.
I don't know why chemistry teachers bother, honestly. Conservation of energy, thermal changes in reactions, then their little charges grow up and forget the lot, and start believing in fairy dust.
Panurge has posted for the last time. Thanks for the positive moderations.
The vast majority of the postings here are by people who obviously didn't bother to read the SAE paper cited in the original posting.
:)
The paper shows a dramatic improvement in pollution and no improvement in efficiency.
You can build your own hydrogen reformer but to use it practically, you have to be able to recalibrate your car's computer. ie. it's one of those projects that can consume months and years of your time. Some of us enjoy that
I live nearby, the address of the company is a residential subdivision in a small town nearby. The site also fails several of the test from the recent Seven Rules for Spotting Bogus Science article.
There's a lot wrong with this. The first tip off is the fuel line magnet they have for sale, which is widely known to be a hoax. Besides, other posters on here are right: Electrolysis cannot make enough hydrogen to make a difference without draining too much mechanical energy from the engine. Placing more load on the alternator would increase the resistance of it to the engine, cancelling out the effect.
Also, modern fuel injected vehicles would not correctly cope with that sort of air/fuel ratio enrichment. Even equiped with an o2 sensor and ecu, the vehicle would probably go into a "limp home" mode if it detected a fuel-rich senario.
Hydrogen does not carry the same energy as gasoline. It would require far larger amounts of hydrogen to run an engine than gasoline. Auto makers have made purely hydrogen vehicles before, and they work, but require very complex and expensive
Nothing says that you have to inject the water after the fuel, nor do you have to inject the water in the same manner the fuel is injected.
Note that some of the older fuel injection designs, instead of having multiport injection (one injector/cylinder), they used throttle body injection. (One injector at the throttle body). You could just add a water injector at the throttle body. One guy did it on his Dodge Shadow (http://www.karlsnet.com/mopar/) - There's a lot of info not on that page, he was an active poster on the Allpar (http://www.allpar.com/) forums until he changed jobs and no longer had much time to experiment or post on the forums. Too bad, the guy had some great ideas and was very good at documenting his results, and open to suggestions/constructive criticism. (He had a few errors in some formulas and said, "oops, you're right" and subsequently made corrections on his page.)
retrorocket.o not found, launch anyway?
Here are a few reasons Biodiesel is a better immediate solution.
- Biodiesel requires no diesel engine modifications to run
- The fuel infrastructure exists now. No modifications needed.
- Mass production is very feasible
- No net carbon dioxide emissions (if made with ethanol)
- Renewable
- For every 1 unit of energy used to make biodiesel 2.3 units are gained
- In a modern diesel engine (VW TDI for example) there are fewer toxic emissions than in a gas/electric hybrid (Toyota Prius for example).
For more info check out the fact sheets at biodiesel.org.I've ridden in many an Ambassador taxi. I doubt all three figures. In my experience we typically went down the highway at 80-90 Km / H. They do get pretty good fuel mileage, typically 16-18 Km / l, thats about 10.5 miles per liter. There are about 3.6 liters / American gallon which puts us in the 37-38 miles per gallon range. Good for old technology but not that amazing today.
When working out your "mpg" remember:
gallon (US) = 3.7854 litre
gallon (UK) = 4.5460 litre
So please state your units. Gallons is ambiguous. Better still... use metric.
Water injection is used to cool the intake air in supercharged aircraft engines. Kind of like an intercooler but cheaper and lighter.
It makes use of water's heat of vaporization to reduce the fuel/air mixture temperature before it goes into the cylinder, and it reduces the chances of detonation (knocking)under high intake pressures. Also cleans the plugs and valves rather nicely. One problem, water is not compressible like air is, so you can blow your engine big time with too much water injection. BOOM.
Incidentally, adding hydrogen to the intake won't accomplish squat, except possibly jack up the chamber temperature. Not what you want in a long distance engine.
What you do want is more oxygen, so adding a supercharger or turbocharger to compress the intake charge is good, or possibly nitrous (NOS for you rice heads out there) for a bit of extra kick.
Trying to inject pure oxygen just drives the temperature up to acetalene torch temperatures. That's rocket territory, reciprocating engines can't survive that kind of heat. Plus the violence of the combustion makes detonation knock look like a pat on the head from Grandma. BOOM!