Hydroxy Info

[sgort87]

Sup guys?

So I'm toying around with a hydroxy project, and I'm in need of some things I really have no idea where to begin looking for.

First, what peak pressure can burning hydroxy reach in an enclosed space at various starting pressures, say like 0-10ish?

Next, does anyone know of any decently-priced npt flame arrestors?

I may have more inquiries as the project continues, and handy reference links would be much appreciated. I wanna know as much about what to expect about this stuff before getting too far in. I've already taken out a 4' fluorescent. I'd rather my eye not be next.

[Zeus]

Well for starters, "hydroxy" is possibly the most unscientific term for a stoichimetric concentration of H₂/O₂. At least you didn't call it "Brown's gas"

Those mixes of gas are pretty nasty, so consider going for 5-10:1 Hydrogen to Oxygen. It'll increase the SOS in the exhaust gasses too.

And if you're thinking about putting this in a car, I'll fly to the US and bit­ch slap you with a buffalo tongue.

[PaperNinja]

why would you put it in a car? as fuel?

[Gippeto]

why would you put it in a car? as fuel?

Adds extra wattage to the sound system....might be explained if you google percolator fysics.

[sgort87]

My buddy says he's worked on it and had it running in a car. I'm not completely convinced of its efficiency, but it seems like a fun project.

I'm starting small for testing. I'll be trying a small engine first if we can get the electrolysis setup going well.

[jimmy101]

Next, does anyone know of any decently-priced npt flame arrestors?

Not exactly sure what you are up to but that request is pretty scary.

Why do you need a flame arrestor? Do you have your fuel and oxidizer in the same storage tank and want to keep flame from the combustion chamber from propagating back into the storage tank? If so we can expect that you wont be contributing to the forum for much longer.

If your fuel and oxidizers are in separate tanks you don't really need a flame arrestor since combustion can not happen in either of the two separate tanks.

If you are actually up to something that isn't stupidly dangerous you might consider just a long tube. Flame won't propagate through a small enough ID metal tube since there is too much heat loss to the tube walls and the flame front gets to cold. I'm not exactly sure how small the tube would have to be but I would suspect that anything less than 1mm ID would act as an efficient flame suppressor.

You do have to be careful not to be pumping a large amount of hot gases (burning or not) through the tube. Get it hot enough and it'll quite acting as a flame arrestor.

[sgort87]

I knew someone with at least a little faith would surface.

To clarify, the reason I'm asking for advice on this is because I respect how dangerous it is, and I want the right information and resources to do it safely.

In this setup, I don't have a storage tank, but the chamber housing the reaction needs to be protected. I made a backflash preventor using a water column, but since this 1/2L reaction chamber can produce 2-3 liters of expanded gas per minute, I'm not fully convinced that the flash won't find a way back through if the bubbles end up close enough.

I've thought about separating the gasses, as it's WAY safer, but the production efficiency goes way down. The chamber uses multiple spiral-wound SS420 electrode wires, each one about 2 feet long or so.

A flame arrestor would put me at ease. There are instructions on how to make your own online, but I'm unsure of their integrity. I'd much rather go with a professionally-made one.

A note on storage tanks: I don't plan on testing with any storage of mixed gas for now, but if this proves to work well enough, a small storage tank would allow for much quicker engine start-ups. I realize it's risky, so a large burst disc would be in order for that for sure.

[Technician1002]

I just found this;



It appears to have been tested in an actual EPA test. Link is pat 1 of 3.

In summary, it doesn't work in gas engines. It is hype to take investor money. There is a reward for anyone demonstrating an improvement on an EPA MPG test. It doesn't work for everyone seems to be it works for nobody doing standard testing and measurements.

[sgort87]

Again, I'm not convinced it actually will work, but I'm taking my buddy's word for now that he got an engine running on water only. It sounds like magic to me, but it's an interesting project.

Does anyone at least know more specifics on the possible pressures involved in its combustion?

[Insomniac]

No offence, but your buddy is either lying, or mistaken. We've been through the whole 'hydroxy as a fuel' a few times on the forum. And these are the facts:

1: Water is not an energy source. You can NOT create a device which splits water using electrolysis, runs an engine with the gasses produced, and uses the engine to produce the electricity to run the electrolysis rig. It flat-out does not work, and the math says it can not work, no matter how efficient you make it. Physics says no.

2: If your engine is continuing to run, then you are inputting energy from another source. Usually this is either gasoline, or potentially a battery or other source of electricity. In this case all your electrolysis is achieving is another source of loss to the system. It's reducing your potential fuel economy.

3: You can build an engine to run on hydrogen, or 'hydroxy'. Hydrogen and 'hydroxy' have stored chemical energy, which you can liberate via combustion. However you have to have used at least this amount of energy to generate the hydrogen in the first place. It's only acting as a storage medium for the energy, much as a rechargeable battery can store energy for later use.

4: Feeding hydrogen into a gasoline engine, in conjunction with gasoline, could potentially affect the combustion in a way which improves efficiency. However, supposing this (unlikely) situation arose, you'd be far better off modifying the engine to be more efficient while running purely on gasoline. You can't escape the fact that electrolysis is a highly inefficient process, with a great degree of energy lost through heat and undesired chemical processes. Adding electrolysis is always adding another source of inefficiency to the system, and thus lowers the maximum achievable efficiency of the system as a whole.

[CS]

I'm sure Gort is aware of conservation of energy. Insomniac maybe the fact hydroxy is a storage medium is its advantage. Longshot here but in the case of capturing energy derived from something like solar power, batteries aren't effective when it comes to x capacity over price.

FYI - http://www.netl.doe.gov/technologies/co ... rbines.pdf

As to the question on LH2/LOX:

f. Explosion Analysis: The method followed for the explosion analysis in Appendix B primarily came from references used in a seminar on the calculation and evaluation of fire and explosion hazards sponsored by the American Institute of Chemical Engineers. For confined gas explosions, the deflagration pressure wave is generally assumed to be 10 times the initial pressure. Calculations for a stoichiometric hydrogen-oxygen mixture show the deflagration pressure is approximately 143psia. When a pressure wave strikes a surface, a reflected pressure wave is developed. This reflected pressure is greater than the incident pressure and results from a momentum change, due to a change in direction when the moving air strikes a dense surface. The reflected pressure of a deflagration wave striking a surface normal to the incident pressure wave is approximately twice the deflagration pressure or, 285psia.[11,13]

[11] Tunkel, Steven J., "Methods for the Calculation of Fire and Explosion Hazards", AIChE Today Series. Course notes and excerpts, including:

[11a] Handbook of Compressed Gases, Third Edition, Compressed Gas Assn., Inc., Van Nostrand Reinhold, NY, 1990.

[11b] Kuchta, Joseph M., Investigation of Fire and Explosion Accidents in the Chemical, Mining, and Fuel-Related Industries - A Manual, U.S. Department of the Interior, Bureau of Mines, Bulletin 680, 1985.

[13] Grelecki, Dr. Chester, "Fundamentals of Fire and Explosion Analysis", AIChE Today Series. Course notes and excerpts, including:

[13a] Glasstone, Samuel (Editor), The Effects of Nuclear Weapons, Chapter III: "Air Blast Phenomena", United States Atomic Energy Commission, April, 1962.

[13b] Cook, Melvin A., The Science of High Explosives, Appendix II, American Chemical Society Monograph Series. Reinhold Publishing Corp., New York, 1958. Ref: http://www.dnfsb.gov/pub_docs/rfets/sir_19941201_rf.txt

With respect to the Shuttle Main Engines (SSME), please refer to:
http://www.pw.utc.com/vgn-ext-templatin ... CM10000046 01000aRCRD (Click on tab Characteristics)
Chamber Pressure: 2,994 psia

The 143 deflagration pressure is approximately 10 atm, but only 5% of the SSME chamber pressure.

Copy and pasted a article I found on another forum. I've underlined the part that seemed to give a layman terms. Probably way off the mark, but hey I threw in the towel. Googling this stuff was exponential growth of even more Googling.

[POLAND_SPUD]

what seems like magic for me are all those diesel cars that run on vegetable oil... that's awesome and not a scam

[Insomniac]

True CS, but in that case I imagine pure hydrogen would be better. Oxygen is readily available from the air, along with a convenient buffer gas. Carrying just the hydrogen increases your energy density, and is far safer.

The fact his buddy says it 'runs on water' is what led me to post my little thermodynamics rant. Perhaps Gort could clarify the specifics, because I can't see what exactly he's trying to achieve.

[Fnord]

For a 'fun project', might I suggest something like a go-kart instead of a car? To get it running you might only need to remove the fuel line and plumb a flow reg into the intake. Adjust till it doesn't sound ugly or 'knock'.

Breaking water down into Hydrogen/oxygen is going to take at least as much energy as burning it releases; much more in a non-perfect world. An on-board electrolysis setup might not even be possible. Probably not too safe either if there's pre-mixing involved.

For something more practical... a tank of hydrogen *only*, charged by a machine hooked up to a couple solar panels on the shed roof. Though if you're planning on storing it for long periods I'd have to recommend coating the inside of the tank or using one designed specifically for hydrogen (embrittlement is pretty well known around here).

[AlexYates]

For a 'fun project', might I suggest something like a go-kart instead of a car? To get it running you might only need to remove the fuel line and plumb a flow reg into the intake. Adjust till it doesn't sound ugly or 'knock'.

Breaking water down into Hydrogen/oxygen is going to take at least as much energy as burning it releases; much more in a non-perfect world. An on-board electrolysis setup might not even be possible. Probably not too safe either if there's pre-mixing involved.

For something more practical... a tank of hydrogen *only*, charged by a machine hooked up to a couple solar panels on the shed roof. Though if you're planning on storing it for long periods I'd have to recommend coating the inside of the tank or using one designed specifically for hydrogen (embrittlement is pretty well known around here).

It seems like very exciting project. Even I would love to make use of solar technology to solve fuel issue.