Sunday Matinee: Back to the Future With Jack Nicholson’s Hydrogen Car–Now Explosion Resistant!

Would you like to know more about our friend Hydrogen?  

 

Hydrogen is often advocated as an energy medium. Here are some relevant facts.

 

  1. Hydrogen does not occur free in nature in useful quantities. It has to be made, usually by splitting water H2O to get the hydrogen. This requires all the energy you are going to get from burning the hydrogen and a bit more on account of inefficiencies. Therefore, hydrogen is an energy transfer medium rather than a primary source of energy. Hydrogen is obtained by splitting water (H2O) into hydrogen and oxygen. The energy to split the water should be nuclear or solar. Nuclear is cheaper.
  2. Hydrogen is the lightest of the elements with an atomic weight of 1.0. Liquid hydrogen has a density of 0.07 grams per cubic centimeter, whereas water has a density of 1.0 g/cc and gasoline about 0.75 g/cc. These facts give hydrogen both advantages and disadvantages. The advantage is that it stores approximately 2.6 times the energy per unit mass as gasoline, and the disadvantage is that it needs about 4 times the volume for a given amount of energy. A 15 gallon automobile gasoline tank contains 90 pounds of gasoline. The corresponding hydrogen tank would be 60 gallons, but the hydrogen would weigh only 34 pounds. 
  3. When hydrogen is burned in air the main product is water. Some nitrogen compounds may also be produced and may have to be controlled. Should greenhouse warming turn out to be an important problem, the key advantage of hydrogen is that carbon dioxide (CO2) is not produced when hydrogen is burned. 
  4. Since hydrogen is not available in significant quantities in nature in pure form, the main present way of getting hydrogen is steam methane reforming, and this will probably remain the most economical way as long as methane (natural gas) is available cheaply and in large quantities, and hydrogen is required only in small quantities. When the price of methane goes up to more than three times its present price because of scarcity, hydrogen will be obtained by splitting water H2O into hydrogen H2 and oxygen O2. The chemical reaction is written2H2O + energy => 2H2 + O2.The well developed way of splitting water is by electrolysis. If fossil fuels, e.g. coal, oil or natural gas, are used to generate the electricity, there is no advantage over using the fossil fuels directly. Indeed you still get all the CO2, and there is a considerable loss of energy. Therefore, the large scale use of hydrogen depends on using either nuclear or solar electricity. In both the nuclear and solar cases, there are possible but undeveloped technologies that don’t use electricity as an intermediate form of energy. [2003 September: There is a thermochemical process for splitting water that is claimed to be twice as efficient as elactrolysis. Here’s an article on the sulfur-iodine cycle by Ken Schultz of General Atomic given at a Stanford University Global Climate and Energy sponsored meeting in 2003 April. To get good efficiency it requires reactors operating at a higher termperature (950 C) than present power reactors. Schultz’s article also discusses solar thermal production of hydrogen. (There are also proposals to combine getting heat for houses and chemical processes and electrolysis with some saving of energy.) 
  5. In either case, the law of conservation of energy tells us that all the energy to be obtained by burning the hydrogen must be supplied by the primary source, e.g. nuclear or solar. Of course, since these processes aren’t 100 percent efficient, there is some loss of energy. Therefore, the use of hydrogen as an intermediate is justified only when there is some reason not to use the primary source directly. For vehicles the reason is that both nuclear nor solar power plants are too big to carry around, except that nuclear power is suitable for large ships.
Advertisements

2 responses to “Sunday Matinee: Back to the Future With Jack Nicholson’s Hydrogen Car–Now Explosion Resistant!

  1. Oh, you and all those confusing facts. What does all that matter? 😉

    You can’t argue facts with moonbats.

  2. Please keep spreading this information along with the truth about the inefficencies of ethanol production. People need to realize, if there was a cheaper way to create mass energy , it would be known and exploited immediatly.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s