Author: Somnay Yash
Date: February 2008
Chemists at UCLA have recently discovered a novel approach to contain carbon dioxide emissions and curb the detriments of global warming.
UCLA professor and investigator of this discovery Omar M Yaghi is confident that his method of sequestering carbon dioxide will be a reliable option for abating the effects of global climate change.
Global warming is currently the center of a storm of political debate. While some scientists believe that increased carbon dioxide levels are part of a natural course of climate change, a majority believe they are human made and dangerous to the planet's ecological balance. However scientists on both sides attest that climate trends in recent decades will inevitably lead to increased acidity of oceans and rising sea levels.
Manufacturing companies that rely on burning coal require emitting carbon dioxide wastes. Many such companies remain reluctant to curb these practices since they may compromise overall productivity. However, the possibility of trapping carbon dioxide before it reaches the atmosphere offers a novel solution to the problem and eliminates the necessity for a cap on industrial activity.
The structures that trap carbon dioxide emissions are a new class of materials designed by Yaghi and his team called zeolitic imidazolate frameworks, or ZIFs. These incredibly robust and resilient structures can withstand extreme temperatures without compromising their stability. This gives them a particular usefulness when placed in thermally unstable smokestacks of industrial plants. In doing so, these crystal ZIFs can effectively filter out unnecessary carbon emissions before they enter the atmosphere, and reduce the artificial heat that is being trapped in the Earth's atmosphere.
"[These] structures can be tailored precisely to capture carbon dioxide and store it like a reservoir...". Yaghi also added that, "nothing escapes- unless you want it to do so."
After synthesizing multiple ZIF structures, Yaghi and his team discovered three which had a particularly high ability to capture and confine carbon dioxide. The molecular specificity of these three crystal structures was demonstrated by Rahul Banerjee, a UCLA postdoctoral fellow, and Anh Phan, a UCLA graduate student. The crystal constructs are shaped complimentarily to the unique molecular structure of carbon dioxide; almost like two puzzle pieces. Thus, these structures can selectively capture carbon dioxide as it is released, while rejecting other gaseous compounds.
The unique molecular structure of carbon dioxide is what allowed Yaghi and his team to construct a selective crystal construct. According to Phan, "The beauty of the chemistry is that we have the freedom to choose what kind of door we want and to control what goes through the door."
Along with specificity of the ZIF's comes its incredible power and efficiency. According to Banerjee, "for each liter of ZIF, [one] can hold 83 liters of carbon dioxide". With enough ZIFs, it is possible to sequester massive amounts of carbon dioxide with minimal space.
Yaghi and his team's brilliant discovery is among a crowd of efforts to reduce industrial emissions and restore normal climate trends. Yaghi's novel approach to this problem is not only plausible, but also manages to please both environmentalists and industrialists by both reducing emissions and offering an alternative to industrial activity caps. By bypassing the politics and pleasing both sides progress can be made on this pressing issue.
Written by Yash Somnay
Reviewed by Nadia Ramlagan
Published by Pooja Ghatalia.