Harnessing Solar Energy to Split Carbon Dioxide

I am not a fan of the super-expensive, speculative, high tech “solutions” some people propose for dealing with global warming. I believe there are two obvious, relatively inexpensive and logical solutions we should be focusing on: alternative energy and trees (reforestation and preservation of forests). These two solutions use existing technology or near-future technology at relatively low prices and can help local economies.

But sometimes the more speculative solutions are worth considering at least as supplemental to the obvious solutions.

This comes from the September 2007 issue of the UCSD Alumni magazine. It appears that a UCSD chemistry professor, Clifford Kubiak, has an innovative solution to excess carbon dioxide in the atmosphere: harvest it for industrial use. This has also been covered in Technology Review. Kubiak is developing a technology that uses solar energy to split carbon dioxide molecules into carbon monoxide and oxygen. The carbon monoxide would then be used in industrial processes like the production of plastics. There is already a good demand for carbon monoxide in industry, so the market already exists. Today, carbon monoxide for industry is produced from natural gas. One use of carbon monoxide is making artificial fuels, including artificial gasoline. This is being billed as a way to store solar energy: capture solar energy, split carbon dioxide, use the carbon monoxide to synthesize fuel, use the fuel for energy. One problem with this is that then you release the carbon dioxide back into the atmosphere, but it is still better than making the fuel from oil and then releasing new carbon dioxide into the air.

Many people are pushing for splitting of water to make hydrogen. My understanding is that this is not as practical as it is being billed. Hydrogen is harder to store and transport than liquid fuels made from carbon monoxide.

My questions about this technology are these:

1.) is it worth devoting solar energy to splitting carbon dioxide rather than using it to feed our energy grid?

2.) is the money this would require better spent elsewhere (alternative energy and trees, again, being a pretty cheap way of dealing with global warming using existing technology and near-future technology)?

3.) would this process split enough carbon dioxide to make a real difference? (Kubiak himself admits probably not in itself, but every little bit helps and if it helps reduce release of more carbon dioxide into the air, then it may be worthwhile).

4.) is there a sufficient market for the carbon monoxide that is produced (if it is used to make artificial then probably the market is potentially huge) and would carbon monoxide produced this way be competitive with carbon monoxide produced conventionally (I have my doubts, but worth considering)?

With these questions as caveats, I do find this technology to be intriguing and a possible supplement to (not substitute for) the obvious solutions of alternative energy and trees. If we can cut carbon dioxide production with alternative energy, remove carbon dioxide by sequestering it in trees (the best sequestration technique), AND remove carbon dioxide for production of carbon monoxide for industrial use, we may really be on our way to solving the global warming problem. But we must always be careful of assuming speculative, high-priced, high-tech solutions are the way to go. More often than not they are the wrong way to go.