Presentation on theme: "Artificial photosynthesis: If plants can do it, why can’t we? Mercer University School of Engineering Professional Practices, Dr. Davis D. Hodges Courtesy."— Presentation transcript:
Artificial photosynthesis: If plants can do it, why can’t we? Mercer University School of Engineering Professional Practices, Dr. Davis D. Hodges Courtesy of Cesar Paes Barreto
The Natural Process: What is Actually Happening? In nature, plants use photosynthesis to convert sunlight and carbon dioxide into oxygen and a carbohydrate food source. Chlorophyll is a vital piece of this process. It captures the energy of sunlight and allow it to be used to power the complex chemical reactions inside the plant. Plants then use this energy to make a compound called NADPH repeatedly cycle NADPH between its two forms in order to bind oxygen to the carbonof carbon dioxide in order to create various forms of carbohydrates. These carbohydrates are a very efficient source of chemical energy. Courtesy of Chris Higgins
Reproducing a Natural Process: Easy, Right? The true challenge: Splitting the water –This reaction consists of two parts: First, the water molecule is split into an oxygen molecule and a loose proton and electron. This reaction is driven, artificially, at least, by a hydride catalyst. Scientists are trying to determine the material that will best serve its purpose as the catalyst for this reaction. Second, the loose protons and electrons form a hydrogen molecule. The molecule that performs this in nature has been isolated, but it does not perform the same in laboratories as it does in plants.
Making fuel from carbon dioxide In order to maximize the efficiency of this process, carbon dioxide must behave similar to a liquid. This is being accomplished by heating the gas to a high temperature under high pressure. This makes reactions involving the carbon dioxide much faster, cleaner, and more efficient. Courtesy of Sean, PublicRoutes.com
The Uses of Reproducing the Process Food Resources –Plants use photosynthesis for food, so if we are able to reproduce the process, we could use it to create a food supply limited only by the amount of sunlight, even in the most barren of tundra and driest of deserts. Fuel Resources –Since the food produced is a hydrocarbon, we could manipulate the process to make various fuels with this process. These can range from simple fuels such as natural gas to more complex molecules such as gasoline and even jet fuel. Courtesy of PistonHeads.com
Once the process is perfected, even 3 rd world countries could become self-sufficient – for both food and fuel. The only requirement will be sunlight, a resource that is universally abundant, and whatever catalysts and chemicals are developed for use in the process. The possibilities for its use are endless Courtesy of LML How useful will this actually be?
But will it ever actually get there? Right now, the research being conducted uses extremely expensive materials and is not very efficient. Any true benefit from this research appears to be several years, possibly even decades away, but new advances are constantly pouring in, and progress is accelerating towards a promising future. Courtesy of Allison, Blavish.com
References Photosynthesis. (n.d.). Retrieved March 24, 2008, from http://en.wikipedia.org/wiki/Photosynthesis http://en.wikipedia.org/wiki/Photosynthesis Snyder, Kendra. (2007). New Developments in “Artificial Photosynthesis.” Retreived March 23, 2008, from Brookhaven National Laboratories Web site, http://www.bnl.gov/bnlweb/pubaf/pr/PR_display.asp?prID=07-31 http://www.bnl.gov/bnlweb/pubaf/pr/PR_display.asp?prID=07-31 Beardsley, Tim. (1998). Catching the Rays. Scientific American, 278(3) 25 Rodriguez, Jose A. and Hbrek, Jan. (2007, December 17). Water- Gas Shift Mechanism Revealed. Chemical & Engineering News, 85(51) 23 Jacoby, Mitch. (2007, October 8). Turning Water Into Fuel. Chemical & Engineering News, 85(41) 9 Gust, Devens and Moore, Thomas A. (1989, April 7). Mimicking Photosynthesis. Science, 244, 35-41 Penner-Hahn, James E. and Yocum, Charles F. (2005, November 11). BIOCHEMISTRY: The Photosynthesis “Oxygen Clock” Gets a New Number. Science, 310, 982-983