Turning CO2 into fuel ?

[marchesarosa]

I have just come across some articles about using CO2 plus other stuff as a components of synthetic fuel. CO2 sequestered from fossil fuel burning power stations could be used as the source of CO2 which is otherwise difficult to accumulate in quantity being such a dilute gas in nature.

www.carbonsciences.com/

They are reportedly combining methane and CO2 to produce gasoline. Maybe:

14CH4 + 2CO2 + 3O2 ===> 2C8H18 + 10H2O

Can it work?

www.biopetroleo.com/english/

www.tagtele.com/videos/voir/65750/1/ this video takes a while to load.

www.stuff.co.nz/dominion-post/business/4774809/Lanzatech-looks-to-go-global-without-leaving-home

The University of Minnesota is also involved in research to make "renewable" petroleum using bacteria, sunlight and CO2.

www1.umn.edu/news/news-releases/2011/UR_CONTENT_314387.html

Presumably this synthetic fuel production would be carbon neutral since EXTRA fuel can be produced whilst not increasing the amount of CO2 already produced from other sources i.e. fossil fuel combustion.

Have I understood this process correctly? Is it like getting a double shot of energy from the same fossil fuel, for the same CO2 emissions? First shot when the fossil fuel is burned, second shot when the waste CO2 is recycled with bacteria, sunlight etc to make a synthetic hydrocarbon? There would presumably be energy costs involved in these processes but would it be worthwhile overall? Would it take up a huge surface area of algae-filled ponds?

Intriguing. Or is it an April Fool joke?

Abstract in the Journal of Biological Chemistry here
www.jbc.org/content/286/13/10930

[principled]

Marchesa, thanks for the links.
I'm no expert, but my understanding of the current position is as follows:
1) Producing Synthetic fuel: This has been done since the 1920s and was used by both Germany (during WW11) and latterly by S. Africa to get around fuel embargoes. The process requires the production of CO from CO2 and then the synthetic fuel can be produced via the Fischer-Tropsch process (http://www.greencar.com/articles/5-things-need-fischer-tropsch-process.php).
The problem with CO2 is that it is a very stable molecule and so requires a large energy input (around 12.5MJ/gram CO2) to split of one oxygen atom. That's why there is a lot of focus on solar to do this (but I assume it could also be nuclear or wind(!)). The other problem- as you say- is collecting the CO2.
But, scaling these things up could prove difficult. This is from a Guardian article:
"And scale is certainly needed. According to Sandia, if all of America's 100 million-strong vehicle fleet were to run on fuel derived from CO2 under its 'Sunlight to Petrol' programme, then the solar power plants alone would cover 2,250 square miles. And this doesn't include the vast number of air-scrubbing towers required to capture the CO2 in the first place."

2) As for methane and bacteria, speed seems to be against it at the moment. From the same Guardian article:
"Over in Asia, Fumio Inagaki is hoping to let nature take its course. Based at the Japan Agency for Marine-Earth Science and Technology, he has been exploring the talent of seabed bacteria to turn CO2 into methane, or natural gas. Although this process is generally pretty slow, taking billions of years, Inagaki is now exploring ways to accelerate it to a mere century."

But, technology is fast moving and with the current price of fuel, I'd say that we should keep a watching brief on this. After all, it only takes one breakthrough to change the outlook completely.
P