Naked Science Forum
General Science => General Science => Topic started by: vdblnkr34 on 04/01/2022 14:11:27
-
Hi.
Can i pump O2 and H2 with performance fuel pump for sport cars?
-
Could you clarify your question? Do you want to run the car on only oxygen and hydrogen? Do you want to use liquid O2 and liquid H2 or gasses?
-
Can i pump O2 and H2
Yes, separately.
-
Could you clarify your question? Do you want to run the car on only oxygen and hydrogen? Do you want to use liquid O2 and liquid H2 or gasses?
Gases, yes. Separated. Need to move them into the storage silo under atmospheric pressure or something.
-
Can i pump O2 and H2
Yes, separately.
Nice to know it will work, thanks.
-
Car fuel pumps deliver small volumes of liquid at high pressure and low flow rates. Consider a high performance car running at 300 kph and consuming 0.25 l/km - the pump is delivering .020 liter per second, or around 18 gram/second of gasoline. assuming the energy densities are similar, the car would need 18 grams of hydrogen gas = 200 liters at atmospheric pressure per second. That's quite a different pump - more like a fan.
When you consider filling the storage vessel it's worth comparing filling rates with liquid fuels. 1000 liter/minute of gasoline or diesel is on the slow side, and the fuel density is 10,000 times that of hydrogen gas, so to shift the same amount of potential energy in a reasonable time you will need to pump 10,000,000 liters of hydrogen per minute - a serious turbine.
-
I was planning to pick it up from electrolysis of water. Dont need a big pump, than from a storage silo will need to convert it or compress it more or into liquid state.
I was thinking to find out.
How much mol of hydrogen in cubic meter? And how much mol of propane in cubic meter?
-
I was thinking to find out.
How much mol of hydrogen in cubic meter? And how much mol of propane in cubic meter?
A mole of gas is about 22.4 liters @ STP.
A car will run (not very well) on hydrogen gas and air, but I doubt it would be very good for the car in the long run.
-
A mole of gas is about 22.4 liters @ STP.*
Since there is 1,000 liters in a cubic meter, that is 45 moles per cubic meter, for both Hydrogen and Propane.
- But when you look at the energy content, a mole of Propane (C3H8) has far more hydrogen atoms than 1 mole of hydrogen (H2).
- Propane has heat of combustion of 2.2 MJ/mol
- Hydrogen has heat of combustion of 0.29 MJ/mol
- The reason Hydrogen might be preferred in some applications is that it doesn't release CO2 when burnt
https://en.wikipedia.org/wiki/Propane
https://en.wikipedia.org/wiki/Hydrogen
*This is at 1 atmosphere of pressure. In practice, both Hydrogen & Propane are stored under pressure.
- The difference is that Propane becomes a liquid, and that stores energy in a very compact way (eg in a taxi fuel tank)
- Hydrogen does not become a liquid at everyday temperatures, so it takes up a very large amount of space for the energy it contains (a taxi of equivalent range would have no room for passengers or luggage).
-
Will need 7.5 times more of hydrogen gas. Not so bad i guess.
Can hydrogen be compressed?
Does hydrogen react with water any how?
-
Can hydrogen be compressed?
Of course, it's a gas.
Does hydrogen react with water any how?
Not at normal temperatures and pressures.
-
What matters for a vehicle isn't heat of combustion per mole, but per kilogram - energy density. Hydrogen delivers 141.8 MJ/kg, all liquid fossil fuels around 40 - 50 MJ/kg.
Liquid hydrogen is the ideal fuel (which is why it is used for rockets) but has presented handling and storage problems in the past. I think the engineering problems have actually been tackled very effectively in MRI machines, where loss of liquid helium is dangerous and expensive, so I see hydrogen as the fuel of the future, with 100 times the energy density of batteries.
You can run an internal combustion engine on hydrogen with a bit of modification, and that would make an intermediate step towards all-fuel-cell electric propulsion. An alternative route would be to hydrogenate organic waste to produce a more conventional liquid fuel, simply using carbon /carbon dioxide as a recyclable "carrier" for the energy invested in electrolysis.
-
When considering effectiveness of a power source, you need to consider:
- MJ/litre: How much of the space is taken up by energy storage?
- MJ/kg: How much mass do you need to power it?
Stationary applications aren't really bothered by:
- MJ/litre: just use a huge storage tank, like the old Town Gas "gasometers"
- MJ/kg: You don't have to accelerate it anywhere, so mass is not so critical
Vehicle applications are more bothered by:
- MJ/litre: The vehicle needs to fit within 1 lane of the road, and still carry a useful load. Hydrogen gas at atmospheric pressure is really poor by this measure; pressurized hydrogen gas is better, but not enough to match liquid petroleum gas.
- MJ/kg: You have to accelerate and decelerate the fuel every time the vehicle starts and stops. Hydrogen is pretty good by this measure. But using regenerative braking in conjunction with a battery can double the fuel efficiency (at least for city driving).
-
Also should be good to burn oxygen with hydrogen together?
-
When considering effectiveness of a power source, you need to consider:
- MJ/litre: How much of the space is taken up by energy storage?
- MJ/kg: How much mass do you need to power it?
Stationary applications aren't really bothered by:
- MJ/litre: just use a huge storage tank, like the old Town Gas "gasometers"
- MJ/kg: You don't have to accelerate it anywhere, so mass is not so critical
Vehicle applications are more bothered by:
- MJ/litre: The vehicle needs to fit within 1 lane of the road, and still carry a useful load. Hydrogen gas at atmospheric pressure is really poor by this measure; pressurized hydrogen gas is better, but not enough to match liquid petroleum gas.
- MJ/kg: You have to accelerate and decelerate the fuel every time the vehicle starts and stops. Hydrogen is pretty good by this measure. But using regenerative braking in conjunction with a battery can double the fuel efficiency (at least for city driving).
The killer is MJ/£ or $
So far in this thread the OP has come up with lots of ways to get fewer MJ for more £.
-
Yes its true. Like $5 a litter. But, prices for gasoline are growing and soon price for fuel will be like cigarettes' today. And it will be profitable than. ;)
-
NASA pays less than $4 per kilogram for liquid hydrogen, with pretty much the same potential combustion energy as a gallon of diesel, in about twice the volume and a quarter of the weight. Totally feasible and competitive.
-
Also should be good to burn oxygen with hydrogen together?
No problem. Oxygen is indeed free of charge at present, though there are Government plans to privatise the atmosphere. The Opposition intends to nationalise and tax it instead.
-
NASA pays less than $4 per kilogram for liquid hydrogen, with pretty much the same potential combustion energy as a gallon of diesel, in about twice the volume and a quarter of the weight. Totally feasible and competitive.
Can i sell them some liquid hydrogen too?
-
Apparently, NASA's new Space Launch System requires so much liquid Hydrogen that they can't currently store enough on site.
When they get ready for a launch, they pump the liquid Hydrogen from their big storage tank into the rocket
- If they scrub the launch, they can pump the remaining liquid hydrogen back into the tank
- But while the rocket is sitting on the launch pad, they allow the Hydrogen to boil off as a very effective and low-mass method of keeping the liquid Hydrogen cool.
- Apparently, if they scrub the launch, there is not enough liquid hydrogen left onsite for another launch attempt the same day....
Maybe you could start by selling them another liquid Hydrogen tank (with built-in-refrigerator).
-
Can i sell them some liquid hydrogen too?
If you can make it at a competitive price, there is a growing market not only for rockets but also cars. Get ahead of the curve and make a fortune!
-
Not a bad Idea. Probably can be used liquid nitrogen solution as refrigeration system.
Can I build hydrogen compressor to liquid on my own?
-
Not a bad Idea. Probably can be used liquid nitrogen solution as refrigeration system.
No. Nitrogen boils at 77K, hydrogen at 20K.
Can I build hydrogen compressor to liquid on my own?
Other people have, so why not? Or just buy one and save the research and development cost. H2Prime, Linde and AirLiquide, for example, all manufacture the kit in various sizes and have years of experience.
-
I just looked at NASA website and found that they also buy CO2.
That's funny.
-
Hello, you can pump O2 and H2, I also pumped it and it was fine, so if you want, yes
-
What is better. To modify internal combustion engine to run on hydrogen/oxygen gas or power the steam engine using hydrogen/oxygen burners?
-
NASA pays less than $4 per kilogram for liquid hydrogen, with pretty much the same potential combustion energy as a gallon of diesel, in about twice the volume and a quarter of the weight. Totally feasible and competitive.
They get it from steam reforming methane though and it generates shitloads of CO2.
-
How difficult to convert propane gas engine to a hydrogen gas engine?
-
May be quite easy, provided it's not made of metals that are easily embrittled. Hydrogen is very easy to burn. You'd have to change the jets/carburettor/injectors whatever.
-
Can i power steam engine by burning hydrogen with oxygen or without?
Could be that better than internal combustion?
-
NASA pays less than $4 per kilogram for liquid hydrogen
They could buy about 140Kg of crude oil for about $90 ( the oil price is quite high at the moment).
So that's about $1.5 per Kg.
That 1Kg of oil provides about 42MJ of energy when burned.
So that's $.036 per MJ
A kilo of H2 provides about 140 MJ
And that's about $0.029 per MJ
Or they could use methane
It's about $5 per million BTU
1 BTU is about 1 KJ
1 million BTU is about 1GJ
So, it looks like gas is really cheap.
Or, in the UK £2.2 per therm
and 100 MJ =1 therm
So your $4 that you pay for a kilo of H2 would get you about 250MJ of energy as natural gas.
You can see why someone might want to run a rocket on natural gas.
But it's beside the point.
The fuel is a tiny fraction of the cost of a rocket.
Building a pump that will deliver the volume of LH2 needed is more difficult than building one for kerosene.
Not least because the density of H2 is low, so you need to shift large volumes of it and you have to pump that volume into the rocket against the back-pressure of the rocket engine. Pressure times volume = energy.
So the energy (or power) cost of pumping is directly related to the volume that you need to deliver.
A kerosene pump can have a much lower power requirement than a LH2 pump.
It's quite likely that NASA already thought of these things.
-
That's a very precise calculations. Burning hydrogen is more efficient?
-
A kerosene pump can have a much lower power requirement than a LH2 pump.
It's quite likely that NASA already thought of these things.
So why do they use hydrogen rather than kerosene?
-
That's a very precise calculations
Not really.
That's why I used the word "about" so much.
So why do they use hydrogen rather than kerosene?
Because it has a higher specific impulse- even though it's a nuisance to use.
-
Liquid hydrogen is good for upper stages, less good for lower stages (although it works). The low density increases the size of all the pipework and pumps and tanks so the thrust/weight ratio for a hydrogen rocket is a lot worse and this cancels out the effect of the higher exhaust ratio- the stage delta-v is about the same. Still, a hydrogen fueled upper stage is lighter, and this makes the lower stages smaller and cheaper.
That's mostly why the second and third stages of the Saturn V were hydrogen fueled, but the first stage was fueled by kerosene; and it's why the Space Shuttle took off on about 90% solid rocket booster thrust.
-
The statement is pretty intriguing; the use of the individual gases of O2 and H2¬ is in itself the most creative question. You can definitely, work on this but would need it in bulk to fuel your car and carry out any operation.
To make the gases work, you will need to get them in compressed silos, with hundreds of thousands of tons of this gas available. The better solution would be getting these gases in a liquid, which will likely provide more of the gases, yet making them available and storing them would be an issue, but this will probably make your car run long distances. If you work on that figures in liters and mole of the gas, it will be about 22.4 liters @STP, which means you will have 22.4 liters of the gas in liquid state (most fortunate case) to make it at one mole, which will keep your car running for long.
-
Also should be good to burn oxygen with hydrogen together?
-
https://www.cittimagazine.co.uk/news/electric-vehicles-charging/hydrogen-vehicles-arrive-at-teesside-international-airport
is worth a visit. Not that people who run commercial airports know anything about engineering or economics, of course.
-
You should move the element sensor down a tile and possibly add a Filter-gate after the AND-gate with a timer of about 3 seconds.
Another issue is that the element sensor is too far away from some pumps; an electrolyzer produces 112.0g/s of hydrogen, so two pumps should suffice. I recommend that you remove the outer pumps.
If you follow all of these steps, everything should be fine.