New DNA-like crystals capture carbon 400% more effectively
Breakthrough 'crystal' captures CO2 and could one day turn it into a fuel or turn water into hydrogen.
Wed, Feb 17, 2010 at 06:38 PM
Photo: UCLA-Department of Energy Institute of Genomics and Proteomics
UCLA chemists have created a synthetic "gene" that traps carbon dioxide emissions, according to research in the Feb 12. issue of the journal Science.
The research was federally funded by the U.S. Department of Energy's Office of Basic Energy Sciences. The discovery could have many applications in the fight against global warming. For one, factories could use the technology to capture carbon dioxide before it reaches the atmosphere. Burning coal could be made "cleaner" until renewable sources such as wind or solar take root. Tailpipe emissions could also be curbed with technology.
How the technology works is these DNA-like crystals code information based on the sequence of pores in the actual material. Carbon capture is highly efficient because the sponge-like material has a high degree of selectivity. According to the UCLA chemists, they achieved a 400 percent improvement compared to other carbon-capture systems.
"We created three-dimensional, synthetic DNA-like crystals," said UCLA chemistry and biochemistry professor Omar M. Yaghi, a member of the California NanoSystems Institute (CNSI) at UCLA and the UCLA Department of Energy Institute of Genomics and Proteomics. "We have taken organic and inorganic units and combined them into a synthetic crystal which codes information in a DNA-like manner. It is by no means as sophisticated as DNA, but it is certainly new in chemistry and materials science."
Concentrated carbon dioxide from the combustion of coal in oxygen is relatively pure. It lends itself to be processed and scrubbed. Broadly speaking, there are three different types of technologies for this: post-combustion, pre-combustion and oxyfuel combustion. In post-combustion the carbon dioxide is removed after combustion of the fossil fuel — this is the scheme that would be applied to fossil-fuel burning power plants. With pre-combustion, fossil fuels are partially oxidized in a gasifier prior to combustion. The latter burns the fuel in oxygen instead of air.
As CleanTechnica mentions, this technology is usually associated with "clean coal" technology. But not with these DNA-like crystals. That material could then turn the captured CO2 into fuel, or turn water into hydrogen. The success of this technology will depend on developing a material that separates carbon dioxide with greater efficiency. The chemists hope to eventually create a carbon dioxide-capture material with an ultra-high selectivity.
"DNA is a beautiful molecule that has a way to code for information," Yaghi said. "One member of a series of materials he has made has 400 percent better performance in carbon dioxide capture than one that does not have the same code."
In the early 1990s, Yaghi invented "crystal sponges" that can store gases that are usually difficult to store and transport. Molecules could go in and out of the pores unobstructed.
"We hope the materials we are creating will introduce a new class of structures that have controlled complexity," Yaghi said. "Chemists and materials scientists are now able to ask new questions we have never asked before. Also, new tools for characterizing the sequences and deciphering the codes within the crystals will have to be developed."
This kind of technology is the perfect stop gap measure while renewable energy sources such as wind and solar continue to mature.