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'Diamonds from the Sky' Approach Turns CO₂ Into Valuable Products

posted by martyb on Friday August 21 2015, @05:17AM   
from the lucy-in-the-sky dept.

Phoenix666 writes:

Finding a technology to shift carbon dioxide (CO₂), the most abundant anthropogenic greenhouse gas, from a climate change problem to a valuable commodity has long been a dream of many scientists and government officials. Now, a team of chemists says they have developed a technology to economically convert atmospheric CO₂ directly into highly valued carbon nanofibers for industrial and consumer products.
...
Because of its efficiency, this low-energy process can be run using only a few volts of electricity, sunlight and a whole lot of carbon dioxide. At its root, the system uses electrolytic syntheses to make the nanofibers. CO₂ is broken down in a high-temperature electrolytic bath of molten carbonates at 1,380 degrees F (750 degrees C). Atmospheric air is added to an electrolytic cell. Once there, the CO₂ dissolves when subjected to the heat and direct current through electrodes of nickel and steel. The carbon nanofibers build up on the steel electrode, where they can be removed, Licht says.

To power the syntheses, heat and electricity are produced through a hybrid and extremely efficient concentrating solar-energy system. The system focuses the sun's rays on a photovoltaic solar cell to generate electricity and on a second system to generate heat and thermal energy, which raises the temperature of the electrolytic cell.

If it bears out, this is an incredibly important result, as it solves a number of challenges like atmospheric carbon and the demand for carbon nanotubes at once.

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Original Submission

• 10% of the Sahara desert? 10% of the Sahara desert? (Score: 2) by bd on Friday August 21 2015, @07:30AM

  by bd (2773) on Friday August 21 2015, @07:30AM (#225744)

  So, they say that it would take "just" 10% of the Sahara desert to impact atmospheric CO2 levels within 10 years?
  Somehow that just seems too good to be true. But I guess there is a catch.

  So, let's run the numbers...

  Volume of the atmosphere at ground level pressure: 5.13e18kg/(1.2 kg/(m^3)) = 4.3*10^18 m^3
  10% of the area of the Sahara desert: 0.1*9.4 million km^2 (source: wikipedia)
  (Volume of Air)/(10% of Sahara desert)/(10 years) = 0.014 m/s

  seems like a legitimate processing speed. It neglects, of course, that the ration between the area this device uses
  for atmospheric conversion and the area it uses for collecting solar energy is neglected. But it still is within the
  right orders of magnitude, I guess.

  But then, the incredible scale we are talking about there... on the one hand the athmosphere is BIG.
  On the other hand it shows just how big the Sahara desert is.

  In Europe, one of the more heavily developed parts of the world, over an area of 3 million km^2,
  4.7% are used for buildings (source: destatis). So, this would mean we have to build a _lot_ of stuff,
  ten times the area of all buildings in Europe.
  Covering such a massive amount of land with any kind of construction is going to be prohibitively expensive.
  Is there even enough construction material available to cover such a large land mass?

  I guess a nice and relatively inexpensive source of carbon nanotubes is just not enough as a future
  outlook for some people these days...

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• Re:10% of the Sahara desert? (Score: 1) by WillAdams on Friday August 21 2015, @06:22PM

  by WillAdams (1424) on Friday August 21 2015, @06:22PM (#225966)

  Space elevator?

  Parent