Green Tech

[[Syl]]

Thanks, Es. Bookmarked.

[[Syl]]

Hydrogen Generating Technology Closer Than Ever

Because the technology could be used to generate hydrogen on demand, the method makes it unnecessary to store or transport hydrogen - two major obstacles in creating a hydrogen economy, Woodall said.

The gallium component is inert, which means it can be recovered and reused.

"This is especially important because of the currently much higher cost of gallium compared with aluminum," Woodall said. "Because gallium can be recovered, this makes the process economically viable and more attractive for large-scale use. Also, since the gallium can be of low purity, the cost of impure gallium is ultimately expected to be many times lower than the high-purity gallium used in the electronics industry."

As the alloy reacts with water, the aluminum turns into aluminum oxide, also called alumina, which can be recycled back into aluminum. The recycled aluminum would be less expensive than mining the metal, making the technology more competitive with other forms of energy production, Woodall said.

"This technology is feasible for commercial use," Woodall said. "The waste alumina can be recycled back into aluminum, and low-cost gallium is available as a waste product from companies that produce aluminum from the raw mineral bauxite. Enough aluminum exists in the United States to produce 100 trillion kilowatt hours of energy. That's enough energy to meet all the U.S. electric needs for 35 years. If impure gallium can be made for less than $10 a pound and used in an onboard system, there are enough known gallium reserves to run 1 billion cars."

"Since standard industrial technology could be used to recycle our nearly pure alumina back to aluminum at 20 cents per pound, this technology would be competitive with gasoline," Woodall said. "Using aluminum, it would cost $70 at wholesale prices to take a 350-mile trip with a mid-size car equipped with a standard internal combustion engine. That compares with $66 for gasoline at $3.30 per gallon. If we used a 50 percent efficient fuel cell, taking the same trip using aluminum would cost $28."

[[Syl]]

Hydrogen brewing gets an electrical boost

A new microbe-powered device can extract up to 99% of the available hydrogen from biological compounds that have stumped previous attempts to ferment fuel from plant waste. The secret is to give the bugs a helping hand with a kick of electric charge.

[[Syl]]

Grass Makes Better Ethanol than Corn Does

Farmers in Nebraska and the Dakotas brought the U.S. closer to becoming a biofuel economy, planting huge tracts of land for the first time with switchgrass—a native North American perennial grass (Panicum virgatum) that often grows on the borders of cropland naturally—and proving that it can deliver more than five times more energy than it takes to grow it.

But yields from a grass that only needs to be planted once would deliver an average of 13.1 megajoules of energy as ethanol for every megajoule of petroleum consumed—in the form of nitrogen fertilizers or diesel for tractors—growing them. "It's a prediction because right now there are no biorefineries built that handle cellulosic material" like that which switchgrass provides, Vogel notes. "We're pretty confident the ethanol yield is pretty close." This means that switchgrass ethanol delivers 540 percent of the energy used to produce it, compared with just roughly 25 percent more energy returned by corn-based ethanol according to the most optimistic studies.

[Menolly]

Interesting.
Since it's grass, could the land be put to other use as well? Such as pasturage until the grass is harvested and resown?
Unlike a field of corn, which has to be devoted to only growing the corn.

[Prebe]

It's a prediction because right now there are no biorefineries built that handle cellulosic material

But there will be very soon:

Look at this (commercial)

BioGasols development of the optimized process of bioethanol production from lignocellulosic biomass can further be integrated into a conventional bioethanol production where fibres will be a residue of low value. Conversion of this fraction into ethanol can increase the production capacity of up to 20 percent along with an improvement of the protein fodder from the process. BioGasols technology can also be applied as bolt-on plants to power plants fired with wheat straw or other lignocellulosic biomass materials.

This is a commercial sight, and it is hosted at the Danish Technical University, and is probably just trying to harvest government grants from the eco-greenies. However, plenty of scientific articles back the efficiency of the second generation biofuels up. Thanks to cutting edge enzyme technology.

NOVO has taken out the patent rights of the gene constructs involved in the enzyme production.

[[Syl]]

Federal Lab Says It Can Harvest Fuel From Air (With a Catch)

Scientists there say they have developed a way to produce truly carbon-neutral fuel and useful organic chemicals at large scale using water and carbon dioxide removed from the air as raw materials.

[Prebe]

Interesting. I just skimmed it though. Is there an exergy calculation in there somewhere? And why does it have to be nuclear plants? Any kind of electricity should do.

[[Syl]]

Kind of like Will It Blind, I imagine the line of thinking at Los Alamos generally tends to end with the question "Can we use nuclear energy?"

[Prebe]

Kind of like Will It Blind, I imagine the line of thinking at Los Alamos generally tends to end with the question "Can we use nuclear energy?"

Nice link! And... D'OH!