How do they use Hydrogen as an alternate energy source? How does it work?

Question

How do they make it? Or get it?

Answer 1

Hydrogen as simply a fuel.  Think of it like natural gas or LP gas.  Though there are differences, it can be used similarly.  But when hydrogen burns, it turns into water - no carbon dioxide at all.

To make hydrogen, you simply take the output of a large power plant (nuclear, coal, or whatever) and run the electricity (DC) through water to break it into hydrogen and oxygen and collect them separately.  Most environmentalists usually choke on the "big power plant" part of the discussion.  

How much power does it take to get hydrogen from the water?  More power than you get from burning the hydrogen.

Hydrogen power is not inherently cleaner (though you may get some advantage by restricting your dirty power to one big power plant rather than many small engines).  It simply moves the source of pollution back to the power plant.

Answer 2

It burns easily as a fuel source, it is just very difficult to store in usable quantities. Even under great pressure, their isn't much gas in a tank, because of it's low molecular weight.

Answer 3

Electrolysis of water to produce Hydrogen and Oxygen.

Hydrogen uses more energy than you get out of it.

Hydrogen is the lowest energy dense fuel on earth . At room temperature and pressure, hydrogen takes up three thousand more times space than gasoline containing an equivalent amount of energy . To put energy into hydrogen, it must be compressed or liquefied. To compress hydrogen to 10,000 psi is a multi-stage process that will lose an additional 15% of the energy contained in the hydrogen.

If you liquefy hydrogen, you will be able to get more hydrogen energy into a smaller container, but you will lose 30-40% of the energy in the process. Handling hydrogen requires extreme precautions because hydrogen is so cold – minus 423 F. Fueling is typically done mechanically with a robot arm

Answer 4

In a chemical reaction, hydrogen combines with oxygen and produces water, which is ecofriendly and some heat is liberated. Fuel cells and hydrogen powered vehicles belong to this category of hydrogen use.

The other use is to combine hydrogen nuclei to form helium in a thermonuclear reactor, like what happens in the Sun and other stars. This technology is not as yet fully mastered but may be in another fifty or hundred years, it may become a reality.

Answer 5

Most of the universe is composed of hydrogen. It condences under the influence of gravity and forms stars whos energy source is generated when hydrogen is fused into helium. The helium is fused into carbon and finally into iron. At this point the star runs out of usable fuel. Some very large stars then explode and this generates enough energy to fuse iron into heaver elements like gold and uranium. These elements mix with other matter in the universe and sometimes condence again into stars with planets.

On earth most hydrogen is combined with oxygen to form water. The oxygen was made by a star which exploded. The hydrogen probably was never part of any star. Once hydrogen is fused, it cannot be un-fused. "Un-fusing" (Nucleur fission) only ocurrs naturally in very heavy elements like uranium. These substances are called radioactive.

Water however can be easily "un-fused". Chemical reactions are thousands of times less energetic than nucleur fission or fusion. The natural way this happens is when green plants use the energy in sunlight to split water into hydrogen and oxygen. The hydrogen is combined with carbon dioxide to form a simple sugar. The oxygen gas is released as a waste product. Animals then eat the carbohydrates and combine them with oxygen. This forms carbon dioxide and water. Plants then take this animal waste and start the cycle over again.

Hydrogen combines directly with oxygen in the lab to form water and a great deal of heat:

2H2 + O2 -> 2H2O

This heat is then useful for doing some sort of mechanical work. Carbon will combine with oxygen as well, forming carbon dioxide:

C + O2 -> CO2

More heat is generated by combining carbon with oxygen, but there are two drawbacks. The first is that carbon is not used as a pure element. It is usually combined with hydrogen, oxygen, nitrogen, sulfur and even things like lead and arsenic. These other elements can form toxic by products and pollute the atmosphere. The other drawback appears to be that carbon dioxide itself is causing the atmosphere to become warmer than it naturally would be. Even a small change in global temperature can have dramatic effects.

Unlike carbon, hydrogen is only useful as a pure element, so there are absolutly no harmful by products formed. The steam generated by its combustion has no affect on the atmosphere.

The only problem with using hydrogen (other than the fact it is very explosive) is that it is not easy to generate. All hydrogen used as a gas must be artificially made, since there is no hydrogen in earth's atmosphere. The process involves electricity. When direct current is passed through water it splits the liquid into hydrogen and oxygen gas. This of course can be used to generate energy - however the laws of thermodynamics state more energy has to be used generating the hydrogen then the hydrogen generates as a fuel source. This makes hydrogen an incredibly efficient source of energy which is incredibly inefficient to produce.

What is needed are hydrogen generators which operate in the manner that green plants do. If special solar cells could be developed, there might be an economic way to produce hydrogen, since electricity would not be needed. These cells would probably produce more energy than ordinary silicon solar cells, which are only about 10% efficient at present.

Answer 6

Katrina is the only one that got this right.  The only economical process to produce hydrogen is by steam reforming of hydrocarbons, primarily methane.  Electrolysis simply cannot compete.

Answer 7

It is the most explosive of anything . If u use it in a car motor it will melt the pistons and if u have a leak it will blow up the hold building. If u have a wreck and break some lines or tank ,it could blow a huge hole and they couldn't find enough to bury .

Answer 8

Hydrogen comes from a number of places, but most is produced by one of two methods - 1) electrolysis, or 2) steam reforming of natural gas.  In the US, about 95% of the hydrogen we currently use comes from steam reforming - we use natural gas (largely methane) because it has the best hydrogen to carbon ratio of the common petro-fuels.  The benefits of a hydrogen economy really only show up if you get the hydrogen by doing electrolysis using renewable, clean energy.  It still won't be "free" since you have to buy the solar cells or wind turbine or whatever, but it can be clean if done this way.  Unfortunately, right now it isn't economical to do it that way.

Once you have the hydrogen, it is usually used as a compressed gas (anywhere from just above ambient up to 700bar (10000psi)).  It can be fed into a hydrogen combustion engine or a fuel cell engine.  Hydrogen combustion is an improvement over gasoline combustion for emissions, but still produces some - NOx.  The fuel cell engine produces water.