Convert CO2 into Fuel?

[LongTomH]

New Scientist has two interesting articles about systems that may allow conversion of CO2 into organic compounds like methane, which could replace fossil fuels.

The first is a system using nanotubes and sunlight:

The team found it could enhance the catalytic abilities of titanium dioxide by forming it into nanotubes each around 135 nanometres wide and 40 microns long to increase surface area. Coating the nanotubes with catalytic copper and platinum particles also boosted their activity.

<snip>

"If you tried to build a commercial system using what we have accomplished to date, you'd go broke," admits Grimes. But he is confident that commercially viable results are possible.

"We are now working on uniformly sensitising the entire nanotube array surface with copper nanoparticles, which should dramatically increase conversion rates," says Grimes, by at least two orders of magnitude for a given area of tubes.

One possibility mentioned is a cycle which would produce a mix of carbon monoxide and hydrogen, which could be a feedstock for biodiesel.

The other possibility is a system based on microbes, which can take up carbon dioxide and (ahem)fart biogas, with the whole process powered by electricity. The article mentions this as a possible storage mechanism for wind or solar electricity.

If either system is successful in converting CO2 into usable fuels, it would be essentially carbon neutral, since the carbon in the fuels would come from the air and be returned to the air.

Just as an aside, does anyone remember the days when 'fart' was not used in polite company? If I'd told my high school science teacher: "Hey, this hydrogen sulfide stuff smells like a fart!" I'd have been sent direct to the principal's office.

I remember the double take I did when I heard an NPR science report, featuring a researcher studying human flatulence.
(Yeah, I can think of a lot of things I'd rather research, too!) This guy was talking about the 'flatometer' he'd developed to measure the amount of gas a person farted in one day. Both the interviewer and the scientist were using the 'fart' word - on the air - right out in front of God and everybody. The only other time I'd heard it was in George Carlin's HBO specials - and George was likely to say damn near anything!

[Xipe Totec]

1. It's called photosynthesis

been around for a billion years or so...

[NNadir]

2. 40% of which now is devoted to human use.

[pscot]

3. If we pumped the CO2 into the Ogallala aquifer

farmers from Nebraska to the Texas panhandle could irrigate their fields with club soda. And the water would't even have to be pumped. It would just fizz up out of the ground.

[Dead_Parrot]

4. Or the "green freedom" approach from Los Alamos...

http://www.lanl.gov/news/newsbulletin/pdf/Green_Freedom_Overview.pdf

I quite like this one, since it
(a) seems to be based entirely on current technology, albeit in a new configuration
(b) produces synthetic gasoline - so we don't need to change our existing engine designs or infrastructure, and
(c) could give us a leg-up into sequesting CO₂ in a more stable form than compressed gas. In other words, we take the oil & coal out of the air, un-burn it and stick it back in the ground. Might be our best bet for undoing the damage...

[kristopher]

5. Why wouldn't we want to change our existing engine designs?

They are extremely wasteful; they deliver an average on-the-road performance of less than 20% efficiency.

The attraction is that it is carbon-neutral, however that relies on energy input from renewable energy sources that must be constructed. Using this platform for transportation would require building 5X the primary energy capacity as that of a battery electric light vehicle fleet.

It does hold promise for last ditch sequestration. Thanks.

[Dead_Parrot]

6. Oh, I'd agree we want to be IC as soon as possible.

But not every application lends itself to an all electric drive-train: some of them - the dump trucks down at the lithium mine, the cargo ships full of solar panels, the helicopters buzzing the off-shore turbines, and anybody who wants to rack up a few hundred miles every morning (think cops and taxis) - will still be hunting around for a source of power. PHEVs can cover most of that last bunch, or those tow-along power plants from the other thread, but they still need something to run off.

Plus, the mouth-breathers in thier Chevvy Trailblazers won't shit themselves to death at the prospect of being forced into a girly car. They can carry on for as long as they like, and pay for sequestration while they're doing it.

It's not ideal for a one-size-fits-all solution, no. But it would be fairly quick and painless to implement for the awkward cases: Should make a good wedge for transport, I reckon.

[kristopher]

7. I don't think so.

There are better (as in less energy intensive) ways to produce fuels by harnessing concentrated streams of (non-fossil) carbon that already exist within our infrastructure.