Turning carbon dioxide into fuel

[wolram]

I am no chemist but i found this article interesting, is it viable and suited to mass production

https://www.sciencedaily.com/releases/2016/08/160825113217.htm

Date:
August 25, 2016
Source:
University of Toronto
Summary:
Every year, humans advance climate change and global warming by injecting about 30 billion tons of carbon dioxide into the atmosphere. Scientists believe they've found a way to convert all these emissions into energy-rich fuel in a carbon-neutral cycle that uses a very abundant natural resource: silicon. Readily available in sand, it's the seventh most-abundant element in the universe and the second most-abundant element in the Earth's crust
.

 

[Borek]

Their goal is a laboratory demonstration unit

Long way from happening.

 

[Ygggdrasil]

Figure 2 from the associated publication in Nature Communications is a bit concerning. On the first run the nanocrystals are capable of reducing 4500 nmol/g/h of CO2, but by the second run, this drops to ~1,200 nmol/g/h, and by the tenth run, this drops to below 500 nmol/g/h.

Dan Nocera and Pam Silver published a different approach in Science a few months back, which they termed a "bionic leaf"

Chemist Daniel Nocera of Harvard University and his team joined forces with synthetic biologist Pamela Silver of Harvard Medical School and her team to craft a kind of living battery, which they call a bionic leaf for its melding of biology and technology. The device uses solar electricity from a photovoltaic panel to power the chemistry that splits water into oxygen and hydrogen, then adds pre-starved microbes to feed on the hydrogen and convert CO2 in the air into alcohol fuels. The team’s first artificial photosynthesis device appeared in 2015—pumping out 216 milligrams of alcohol fuel per liter of water—but the nickel-molybdenum-zinc catalyst that made its water-splitting chemistry possible had the unfortunate side effect of poisoning the microbes.

So the team set out in search of a better catalyst, one that would play well with living organisms while effectively splitting water. As the team reports in Science on June 2, they found it in an alloy of cobalt and phosphorus, an amalgam already in use as an anticorrosion coating for plastic and metal parts found in everything from faucets to circuit boards.

http://www.scientificamerican.com/article/bionic-leaf-makes-fuel-from-sunlight-water-and-air1/

Here's a link to the publication:
Liu et al. 2016. Water splitting–biosynthetic system with CO2 reduction efficiencies exceeding photosynthesis. Science 352: 1210 doi:10.1126/science.aaf5039

 

[General Scientist]

Recently carbon dioxide has been turned into ethanol using some sort of spiked nanospheres tipped with copper and adding electricity

 

[CapnGranite]

Solar photothermochemical alkane reverse combustion
https://www.uta.edu/news/_downloads/pnas.201516945.pdf
"An efficient solar process for the one-step conversion of CO2 and H2O to C5+ liquid hydrocarbons and O2 would revolutionize how solar fuel replacements for gasoline, jet, and diesel solar fuels could be produced and could lead to a carbon-neutral fuel cycle. We demonstrate that this reaction is possible in a single-step process by operating the photocatalytic reaction at elevated temperatures and pressures. The process uses cheap and earth-abundant catalytic materials, and the unusual operating conditions expand the range of materials that can be developed as photocatalysts. Whereas the efficiency of the current system is not commercially viable, it is far from optimized and it opens a promising new path by which such solar processes may be realized."

This another process that's been developed and published this year. In the end, the processes probably won't be economical as far as creating cheap fuel so much as they would help reduce carbon dioxide levels.

 

[Alex163]

Including Ygggdrasil's point about the dubious long-term efficacy of the nanocrystals. The quoted "lack of toxicity" of silicon nanostructures is also questionable. I've worked with TEOS before and am almost certain that a painful, raspy cough I get whenever I breathe winter air, began due to my stupid failure to wear a respirator when boiling the stuff. No problems breathing in CNT's in the couple of years before this.
How will megatons of nanosilicate waste affect a population? Has any decent, long-term study been conducted on this problem that doesn't just just consist of "well, sand's existed for a long time"?