The Methanol Economy. 2 CH3OH instead of H2
This is my third, and hopefully final thread on the potential ways to convert Hydrogen into usable fuels. In this installment, we examine how it can be used to create a fuel that will burn directly in an automobile engine: Methanol. There are two main components to the process. The first is more recent, and the second one dates back to World War II, when Germany used it effectively to produce fuel from its coal reserves when it was unable to obtain petroleum. You'll also be happy to know that this particular option is endorsed by some prominent scientists.
In the end, the only necessary raw materials are Carbon Dioxide, and Water. It involves some interesting catalysts, but those are not consumed, so there's no need to worry too much about them.
Methanol economy - Wikipedia, the free encyclopedia,
Methanol: The New Hydrogen - Technology Review
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Quote:
Originally Posted by Wiki Methanol Economy Article
Methanol has a high
octane rating (RON of 107 and MON of 92), which makes it a suitable gasoline substitute. It has a higher
flame speed than gasoline, leading to higher efficiency as well as a higher latent heat of vaporization (3.7 times higher than gasoline), meaning that the heat generated by the engine can be removed more effectively, making it possible to use air cooled engines. Besides this methanol burns cleaner than gasoline and is safer in the case of a fire. However, methanol has only half the volumetric energy content of gasoline (15.6 MJ/L vs. 32.4 MJ/L).
So you can see it basically takes 2 gallons of Methanol to equal 1 gallon of gasoline. However, from a safety standpoint, the fuel is actually safer than ordinary gasoline, so at least that's not an issue.
Process #1 : The Reverse Water Gas Shift Reaction
This takes CO2 + H and gives us CO + H20. The result is Carbon Monoxide, which is hazardous, but Carbon Monoxide and Hydrogen are the raw chemical components which are utilized in the next step. This product (CO and H) is also knows as "Syngas"
Reverse Water-Gas Shift Reaction - Marspedia
Process #2 : Fischer Tropsch Reaction
In the Fischer Tropsch Reaction, H and CO are reacted in a variety of ways to yield any number of hydrocarbons, but the most promising right now is Methanol.
Fischer,
The Fischer Tropsch Process | Renewable Petroleum Information,
Development of the Modern Fischer-Tropsch Process,
http://www.netl.doe.gov/publications.../rd/R&D089.pdf
That last link is a nice slide presentation. As you can see I am very excited about this, because it means the only aspect of the energy crisis that's important, is figuring out the power grid. Once that's solved, creating fuel for use in automobiles is a non-issue. Also, it might be possible for manufacturers to vary their production so as to schedule it around high winds, or bright sunny days.
Process #1 is endothermic, consuming 9kj per mol
Process #2 is exothermic, so it supplies its own energy..... kind of.
