Ethanol Boosts Gas Engines
Holzman, David C., Environmental Health Perspectives
The gasoline internal combustion engine has more than 100 years of intense development behind it. But now three researchers from the Massachusetts Institute of Technology (MIT) have modified it in a way that elevates efficiency by a remarkable 25%, an advance that could greatly mitigate greenhouse gas emissions and offers compelling advantages over hybrids and diesels. "This has real potential," says David Cole, chairman of the Center for Automotive Research, a nonprofit organization of the University of Michigan.
The design logic is simple. One can alter an engine to create greater compression of the fuel/air mixture within each cylinder, raising thermodynamic efficiency. One can also add a turbocharger, which force-feeds more fuel/air mixture into the cylinders. This makes it possible to get more power out of an engine, or to downsize an engine without losing power, making it still more efficient.
The problem: boosting compression also boosts temperature, and too much heat can ignite the fuel/air mixture prematurely, causing potentially damaging engine "knock." But Daniel Cohn and Leslie Bromberg of MIT's Plasma Science and Fusion Center, and John Heywood of MIT's Sloan Automotive Lab figured out that a little squirt of ethanol into the cylinder from a separate tank could cool it in the same way that rubbing alcohol cools the skin--by vaporizing, then absorbing excess heat. The researchers have formed a company, Ethanol Boosting Systems (EBS), and have drawn several prominent figures on board, including Neil Ressler, former chief technology officer of Ford Motor Company.
How Alternative Engines Stack Up (compared with conventional gasoline engines, except as noted) Clean Diesel Electric Ethanol Hybrid Cost $3,000-3,500 $3,500-5,000 + $1,000-1,500 (a) possible (a) battery replacement cost (a) Efficiency 20-30% more 30-40% more 20-30% more Gain efficient (a) efficient (a) efficient (a) Emissions 25% lower Up to 50% lower [NO.sub.x] [CO.sub.2] [CO.sub.2] and PM emissions (b) emissions (c) reduction, compared with clean diesel (a) Technological Better engine Better engine Reduced Advantages performance (d) performance (e) engine weight, more space in engine compartment, compared with electric hybrid (a) Less complex Larger battery Higher torque and easier to means more and install than EH safety and horsepower, engine (b) luxury compared with electronic clean systems can be diesel (a) added on (e) (a) http://www.ethanolboost.com/Technology.htm (b) http://www.signonsandiego.com/uniontrib/20060207/ news_1n7diesel.html (c) http://www.ama.ab.ca/cps/rde/xchg/ama/web/advocacy _safety_envt_hybrid. …