hydrogen powered FD3S
11-21-07, 08:49 PM
#102
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12-03-07, 10:59 AM
#103
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Hydrogen isnt suited for ICE engines. Why? Although its the most energy dense element on earth, its also the lightest. Diesel have less energy then gasoline but its also heavier which makes up for the lower energy content. Point is that hydrogen sure got the energy but the energy turns into heat and not to gas pressure.
To be able to use hydrogen in ICE engines you need a medium which convert heat to gas pressure, maybe water? Hydrogen ignites in the combustion chamber along with water. The water will suck up the heat like if there was no tomorrow and then you have steam pressure.
Like this: http://www.eskimo.com/~ghawk/rotary.html
That was awhile ago and i havnt heard anything about a success. Maybe it didnt work so well.
To be able to use hydrogen in ICE engines you need a medium which convert heat to gas pressure, maybe water? Hydrogen ignites in the combustion chamber along with water. The water will suck up the heat like if there was no tomorrow and then you have steam pressure.
Like this: http://www.eskimo.com/~ghawk/rotary.html
That was awhile ago and i havnt heard anything about a success. Maybe it didnt work so well.
Last edited by Eson; 12-03-07 at 11:07 AM.
04-27-12, 09:03 AM
#104
I think that was a cone..
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yes, but to electrolyze water, you must use a lot of electricity, and that isn't cheap especially when many many more electricity generation plants will need to be built to support a large supply of hydrogen. does anyone know if we have any other real alternatives to mass hydrogen production than electrolysis?
09-12-12, 12:42 AM
#105
RE EVOLUTION
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Originally Posted by Element85
Different catalysts can be used to do hydrolysis without electricity. You just need a metal that wants the extra electron more than water ... chemistry anyone?
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09-18-12, 03:30 PM
#106
Hydrogen as a motor fuel is a completely absurd and ridiculous idea.
Hydrogen, even when compressed to state of the art pressures (around 750bar) still only has about 30% of the energy density of gasoline. This means your 300mi range of a current automobile turns into 100mi, or less than an electric car.
Hydrogen is impossible to safely or efficiently store. Because molecular hydrogen is so small, it leaks through any vessel in which it is store, especially when stored at high pressures. The state of the art vessels currently leak at about 1% per day.
Hydrogen is EXTREMELY flammable. Gasoline easily ignites at air fuel ratios of around 10:1 to around 20:1. Hydrogen ignites from 1:4 to 180:1. Now consider the above point, would you want to walk into a well sealed garage that has had a hydrogen fueled car in it with any type of ignition source present?
Storing gasses at high pressures creates a significant safety hazard. A 50L hydrogen tank at 750bar contains enough force that if ruptured it could produce an explosion similar to 5lbs of TNT from the compressive force alone even if the fuel does not ignite.
Even if you figure out how to remedy ALL of this, hydrogen is still EXTREMELY less efficient than gasoline/diesel because:
ALL hydrogen sources except electrolysis produce similar or worse emissions and byproducts than fossil fuels, or are low yield and extremely inefficient. Electrolysis is 66% efficient. This means that if you burn diesel in an engine in your vehicle, you get ~40% efficiency. If you burn it in a generator, you get about 45%, but then you waste 34% of that in the electrolysis, then you burn the hydrogen in your vehicle at 40% efficiency, so effectively, you go about 1/3 the distance for the same amount of raw fuel.
Aside from all this, there are 2 more points:
1) battery electric vehicles are improving rapidly, and offer a real and current alternative to IC engine vehicles. The overall efficiency is much higher than hydrogen, and all the safety and storage concerns are less.
2) IF, by some scientific breakthrough, someone finds a way to produce abundant hydrogen, it will STILL make more sense to use it in large scale fuel cells to efficiently produce electricity, then drive an electric car.
Hydrogen, even when compressed to state of the art pressures (around 750bar) still only has about 30% of the energy density of gasoline. This means your 300mi range of a current automobile turns into 100mi, or less than an electric car.
Hydrogen is impossible to safely or efficiently store. Because molecular hydrogen is so small, it leaks through any vessel in which it is store, especially when stored at high pressures. The state of the art vessels currently leak at about 1% per day.
Hydrogen is EXTREMELY flammable. Gasoline easily ignites at air fuel ratios of around 10:1 to around 20:1. Hydrogen ignites from 1:4 to 180:1. Now consider the above point, would you want to walk into a well sealed garage that has had a hydrogen fueled car in it with any type of ignition source present?
Storing gasses at high pressures creates a significant safety hazard. A 50L hydrogen tank at 750bar contains enough force that if ruptured it could produce an explosion similar to 5lbs of TNT from the compressive force alone even if the fuel does not ignite.
Even if you figure out how to remedy ALL of this, hydrogen is still EXTREMELY less efficient than gasoline/diesel because:
ALL hydrogen sources except electrolysis produce similar or worse emissions and byproducts than fossil fuels, or are low yield and extremely inefficient. Electrolysis is 66% efficient. This means that if you burn diesel in an engine in your vehicle, you get ~40% efficiency. If you burn it in a generator, you get about 45%, but then you waste 34% of that in the electrolysis, then you burn the hydrogen in your vehicle at 40% efficiency, so effectively, you go about 1/3 the distance for the same amount of raw fuel.
Aside from all this, there are 2 more points:
1) battery electric vehicles are improving rapidly, and offer a real and current alternative to IC engine vehicles. The overall efficiency is much higher than hydrogen, and all the safety and storage concerns are less.
2) IF, by some scientific breakthrough, someone finds a way to produce abundant hydrogen, it will STILL make more sense to use it in large scale fuel cells to efficiently produce electricity, then drive an electric car.
09-18-12, 03:33 PM
#107
There actually have been engine systems built using aluminum oxidation as a hydrogen production mechanism, but the cost of aluminum compared to the efficiency improvement, plus the mechanics of keeping a constant reaction and getting rid of the AlO2 make it an impractical system. Anyway, as stated above, if you could figure this out, it would still make more sense to send the hydrogen to a fuel cell than an engine.
09-18-12, 03:43 PM
#108
This is NOT true. There are several types of fuel cells that can operate directly from methane. The problem is that most natural gas sources are not pure enough to be used in a fuel cell, as they contain enough of corrosive substances like sulfur to coat and corrode the catalyst sites on the fuel cell substrate, causing the cell to fail in short order.
The primary focus of fuel cell research is reducing their vulnerability to contaminated fuel. Hydrogen fuel cells are currently available and cost-effective, we just don't have a source of hydrogen to run them from.
The primary focus of fuel cell research is reducing their vulnerability to contaminated fuel. Hydrogen fuel cells are currently available and cost-effective, we just don't have a source of hydrogen to run them from.
