If the production of hydrogen gas from water is an energy-loss process, why is it ever done?
It is done when it makes economic sense and that is usually in instances where it is used on site for welding or is produced on site for use as an ingredient to manufacture something, such as ammonia, and is not being used as an energy source.
Are there any instances when the electrolysis of hydrogen from water, to be used as an energy source, make sense?
Yes, if the energy that you use to make the hydrogen is cheap enough, then it doesn't matter that you get less than you put in. What matters is that by producing hydrogen gas you are able to store energy which might otherwise have gone unused. For example, a future application might involve photovoltaic solar panels that provide the energy to produce hydrogen via electrolysis of water during the day, that can then be used anytime, day or night, as a fuel. In this instance you are using the hydrogen gas as a sort of battery to store energy from the sun. Although sunlight is free, this may or may not make sense depending on how long it takes to amortize the cost of the photovoltaic solar panels and the associated electronics, and how long they will last.
Another example is the proposal to use electrolysis as a means to store excess energy derived from hydroelectric power plants that is available, but unwanted, during off-peak hours, such as nighttime. Again, there are costs involved that must be amortized and, in this instance, if migratory fish could speak, they would argue that hydroelectric power is actually not free.
What about using free energy from my car battery to produce hydrogen gas from water and use it to improve gas mileage?
Well, if the energy supplied by the battery was actually free this might be a good idea, but it's not. Every watt of energy that comes out of your battery is produced by more than a watt of energy that came out of your engine. If you make some unrealistic assumptions and assume that internal combustion engines are 100% efficient at converting chemical energy to mechanical energy, alternators are 100% efficient at converting mechanical energy to electricity, and the electrolysis process is 100% efficient at converting electrical energy to chemical energy, then what do you get when you put one watt in? You get one watt out! One watt of energy from hydrogen gas looks the same as one watt of energy from gasoline. You have gained nothing. In actual practice you will lose, because the internal combustion engine and the alternator both lose energy as heat in the process, and there are losses associated with electrolysis as well.
That may be true, but isn't my engine always producing electricity anyway? I see the alternator belt spinning the same speed, irrespective of how much electricity I'm using. Isn't that electricity a free byproduct of my engine that's just going to waste when it's not being used?
No. You pay for every tiny bit of electricity your engine produces. Electricity is produced by the car's alternator only when the car's voltage regulator tells it to do so. It does so when it senses that the battery's voltage has dropped, which happens when something draws current from the battery. When the alternator begins producing electricity it puts a load on the engine. When that happens, it becomes proportionately harder for the crankshaft to turn the belt that connects the crankshaft pulley to the alternator pulley. When you draw any amount of electricity from your car, you are decreasing your gas mileage because the engine has to work harder to sustain the same speed and also produce electricity. When you drive with the lights on you are decreasing your gas mileage. Even listening to an iPod requires energy from the engine that would otherwise have been used to propel the car forward.
But the alternator pulley is always turning, even when the lights and radio are turned off.
Yes, but it is easier to turn it when the alternator is not producing electricity. If you could connect a hand crank to an alternator you would feel that it becomes harder to turn it when current is being drawn from the battery. After overcoming the friction of the belt and the pulley bearings, any additional resistance is directly proportional to the amount of electricity being drawn.
I understand that water is not a fuel, but can't it be used to boost the performance of my engine?
No. Once again, the process of electrolysis will take more energy from your engine than the hydrogen can give back. Some web site scams are trying to draw in more victims by stating that "water is not a fuel, but simply boosts the performance of your current fuel." Different words, still false.
If water does not contain energy, why do some race cars use water injection to get more power?
Water injection is sometimes used to lower cylinder temperature to avoid detonation (pinging). Many power-enhancing features, such as modifications to increase cylinder head pressure and advancing the ignition timing, also increase the cylinder temperature and cause the air-fuel mixture to burn improperly and detonate. By adding some measure of cooling, water injection enables the use of other modifications which enhance power.
Doesn't the Crower 6-cycle engine use water as a fuel?
No, this ingenious design by Bruce Crower is a hybrid engine, acting as an internal combustion engine for four cycles, and then a steam engine for two cycles. It uses water to convert the waste heat of the internal combustion process to mechanical energy. A small amount of water is injected after the internal combustion exhaust stroke. The water flashes to steam and the resultant expansion drives the piston down. Water is not the fuel for this cycle, just as water is not the fuel for a steam engine. The fuel is the hydrocarbon that created the heat that converts the water to steam.
If water does not contain energy, how does the fuel cell that is marketed for recharging laptops work? It runs on water only.
I have not had the opportunity to take one of these devices apart, so I can't say for certain how it works. However, I can state that it is in all likelihood simply a lead-acid battery, since a lead-acid battery does the same thing as the device they are marketing. I believe what the promoter calls the cartridge is simply a lead-acid battery. All batteries require an electrolyte to transfer ions and the electrolyte in a lead-acid battery is an acidic solution consisting of sulphuric acid and water. Until recently, all automotive batteries were stored on the store shelf without water and you had to add water to first activate the battery. In this instance you are buying a $20 cartridge (the battery) and adding water to it to activate the electrolyte. Once you have used the initial charge that the battery came with you cannot add more water to get more electricity any more than you can add water to you car battery to recharge it. In this instance, the company doesn't even provide a provision for recharging the battery. They require you to buy a new one! It is not a fuel cell.
What is a fuel cell?
A hydrogen fuel cell is a device that converts a fuel (hydrogen gas) and an oxidant (oxygen from the air) directly into electricity. While some energy is still lost as heat, the process is more efficient at converting hydrogen into energy than simple combustion. The byproduct of a hydrogen fuel cell is water, so water is the exhaust of a hydrogen fuel cell, so to speak, and not the fuel.
What is Brown's gas?
Today that depends on who you ask. Sarcasm aside, among the large collection of web sites that claim water is a fuel, the term Brown's gas is often defined differently.
Technically, Brown's gas is simply a 2:1 molar mixture of hydrogen and oxygen. This is the ratio of the gases as produced via electrolysis, but of course you can make this mixture indirectly by other means.
The name comes from Yull Brown, who invented a type of common-ducted electrolyzer used for the on-site production of hydrogen and oxygen for welding. Whereas, most electrolyzers keep the oxygen and hydrogen separate, a common-ducted design immediately combines them as a mixture which is then used directly for welding.
Does Brown's gas contain atomic hydrogen?
No, contrary to what some web sites claim, Brown's gas contains only diatomic hydrogen and oxygen molecules. The confusion perhaps arises from a welding technique known as atomic hydrogen welding, which utilizes atomic hydrogen.
What is atomic hydrogen welding?
Atomic hydrogen welding is a technique that uses only hydrogen, not Brown's gas, which is a mixture of hydrogen and oxygen. In this technique, hydrogen is not used as a fuel but as a transport mechanism for transporting a tremendous amount of energy from the plasma of an electric arc to a work surface. A jet of hydrogen gas is projected through an electric plasma arc and an endothermic chemical reaction takes place, with the arc providing the energy to disassociate the hydrogen atoms from one another as follows:
H2 + 422 kJ (from electric arc) —› H + H
Recall that hydrogen atoms do not like to exist alone so as soon as they leave this region of hot plasma they recombine on the work surface in an exothermic reaction, giving up as heat the energy they just gained:
H + H —› H2 + 422 kJ (released as heat)
The hydrogen gas then burns up in the atmosphere. No oxygen is used and the final combustion of the hydrogen with the oxygen in the air contributes little to the heat created when the atomic hydrogen converts to diatomic hydrogen. So in this case, the disassociation and association of hydrogen was used as a transport mechanism to transfer the energy from the electric arc to the work surface.
If you still believe that water is a fuel, I commend your passion, but encourage you to do some more research. Don't take my word for it. Ask a scientist, an engineer, a high school science teacher, or a college professor. Don't trust anything you read in an advertisement. Don't trust anyone asking for your money. Think for yourself and be smart about where you get your information.
Have more questions? Send me a question at paulatglasserdotcom and I'll respond as soon as I can and may add the information to this section if it's appropriate.