Our Quest for Alternative Energy

This past Tuesday, Dr. Riccardo Basosi gave a lecture on the principles of sustainable energy development. One of the sources of alternative energy he mentioned was natural gas. I wanted to find out how it was that natural gas was used as energy, so I did a bit of research.

Besides simply burning it, the process of using natural gas can be indirect – it can be converted into another medium of energy first. Natural gas is primarily made up of methane, and this methane can undergo process called steam reforming. It is a process that produces hydrogen gas. Hydrogen gas can be used as fuel in a fuel cell to produce electricity. Steam reforming is currently the process by which most hydrogen in the United States is made.

Steam-Reforming Reaction
Methane:
CH₄ + H₂O (+heat) → CO + 3H₂

In these reactions, carbon monoxide and hydrogen are produced. Carbon monoxide is a toxic greenhouse gas, but thankfully there exists another step in the process called the water-gas shift reaction (WGSR) which gets rid of the carbon monoxide:

Water-Gas Shift Reaction
CO + H₂O → CO₂ + H₂ (+small amount of heat)

Both the steam-reforming and water-gas shift reactions require a catalyst in order to be efficient. Although the end process of steam reforming and WGSR produces carbon dioxide, the overall amount produced through using the hydrogen in a fuel cell is 60% less than burning gasoline through a conventional internal combustion engine. There are, of course, “cleaner” sources of alternative energy out there, but the infrastructure for transporting natural gas throughout the United States already exists and natural gas is plentiful. Using natural gas as a major source of energy could serve as a transition step for the developed world into one that is more dependent on cleaner-produced hydrogen fuel.

Although natural gas is not renewable, methane gas potentially is. Methane gas is a byproduct of the decomposition of organic wastes, including the waste that is put into landfills. We could use the methane produced from our own trash to make hydrogen fuel! Talk about turning nothing into something…

Anyways, there it is. That is how natural gas is used. Apparently it is not the perfect energy solution, but it’s a step towards the right one.   

Sources:
http://www1.eere.energy.gov/hydrogenandfuelcells/production/natural_gas.html
http://en.wikipedia.org/wiki/Natural_gas