OT of an OT: Ethanol

[Jack Simth]

Why burn sugar ethanol when we can Manufacture Crude Oil?

Which, incedentally, also gets us such useful things as plastic, in addition to fuel, takes no conversion of the existing distribution setup (just conversion in production - instead of pulling it out of the ground, farm and alter), and even allows for recycling. Assuming, of course, that the company's claims are accurate.

[Thermodyne]

Well from my poorly educated point of view, it is foolish to waste time and money on carbon based fuel sources. At some point in the future, we will reach the atmospheric tipping point for atmospheric carbon load. I would like to see a government backed push into hydrogen. Right now, the major challenges are basically just engineering, and money will usually push to technology past these kinds of barriers.

[Jack Simth]

Funny thing about that.... plants, and things that eat plants, have a net 0 atmospheric carbon impact when you burn the resulting fuel - plants took the carbon out of the air, animals ate the plants to get their carbon, carbon is bound up in the fuel, carbon goes back into the air when burned. Some of the carbon gets pulled out for things like excrement and plastics, so in general it will actually reduce the amount of carbon in the air, not increase it.

Might have a little problem if global warming is the only thing holding off an ice age, but hey, everything has risks.....

Biggest problem with hydrogen is that it only stores the energy used to split it; it doesn't capture it from the sun (like a plant does) in order to make hydrogen burning (to water, rather than helium....) a viable option, you first need more power than you plan to generate from burning the hydrogen. And even then, we still need plastics.

[Captain Kwok]

Yay! A good old biomass discussion!

Ethanol could work for the US in a limited capacity, such as replacing 15% or so of gasoline if developed well. Which is good! Like Jack Smith said, ethanol does not add any net CO2 emissions - like fossil fuels or even synthetic fossil fuels would. Bio-desiel is also gaining popularity, although it's a mixture of various fatty acids.

Corn is the most commonly used crop for ethanol in the US, but there are other alternatives (like Will mentioned, switchgrass etc) that have less environment impact.

Brazil's fuel industry was almost entirely ethanol-based from the mid-70s to the early 90s - until they had too many cars - so they've now got to import some gasoline. The main reason why Brazil was able to do this was sugarcane, which is one of the most efficient plants for making ethanol.

The holy grail of biomass is the ability to degrade cellulose effectively. A number of cellulose-degrading enzymes have been isolated from fungi and have been cloned into E. coli etc. for fermentation of organic materials.

Ethanol is probably best suited to displacing gasoline use, rather than as a power source. It'd be better to develop the other greener alternatives (hydro, wind, etc) for now.

Bio-plastics tend to be made out of cellulose or starch-based polymers and are really just starting to gain popularity. Right now a significant percentage of landfill is petro-plastics that will take forever to degrade, so they'll keep making up a higher and higher percentage of our refuse. You'll probably notice a few of the more green stores using starch-based bags.

Lastly, the hydrogen dream is nice but it's a little ways off. I think it will take the invention of something like fusion power to provide the amounts of extra electricity we'd need to split water into hydrogen. If that happens, then we might get lucky and see a new H2 economy.