backtop


Print 50 comment(s) - last by Hare.. on Jun 11 at 5:04 PM

New technology promising to cut CO2 and save gas

Alternative energy comes from unusual sources -- huge rivers, massive arrays of silicon panels, nuclear reactions, and massive spinning metal blades.   But German researchers are getting power from a source that might strike scientists from decades past as particularly peculiar -- they're making power from automobile exhaust gases.

In an era of ultra-expensive fuel and concerns about emissions fueling global warming, the automobile has come under increasing scrutiny with users looking for ways to extend gas mileage and cut emissions.  Fraunhofer-Gesellschaft, a leading German research organization, is developing materials and designs for a thermoelectric generator which will help to solve both problems.

In automobiles, two-thirds of the fuel used is emitted as waste heat. In total, 30 percent of the energy is lost in heat from the engine block and a further 30 to 35 percent is lost to exhaust fumes.  Many teams of researchers have began to look at how to recapture some of this heat and heat from similar industrial engines and transform it into electricity.  Such devices are known as
thermoelectric generators or TEGs for short.

The TEG generator takes a temperature gradient, driven by the difference between the waste heat and the ambient temperature and uses that gradient to produce electricity.  Greater temperature differences yield great results.  The
Fraunhofer Institute for Physical Measurement Techniques IPM has a number of thermoelectric materials under development that will harvest this heat in automobiles. 

Dr. Harald Böttner, head of the Thermoelectric Systems department states, "The temperatures in the exhaust pipe can reach 700 degrees Celsius or more.  The temperature difference between the exhaust pipe and a pipe carrying engine cooling fluid can thus be several hundred degrees Celsius."

The
thermoelectric converter the team is developing takes the gradient created by the exhaust gas and uses it to drive charge carriers through a semiconductor.  This creates a looped current flow similar to a battery.  The technology is relatively straightforward, but the real challenge is finding optimal thermoelectrics with high carrier mobility.  The research team is hoping that the device will make the alternator obsolete, providing power to the car's consumer electronics, onboard computers, and charging the battery.  Böttner states, "This would make it possible to cut gas consumption by between five and seven percent,"

Researchers point out that with 50 million cars on the road in Germany with an average on-road time of 200 hours a year per car, if only one kilowatt each was produced by the TEGs, this would amount to
ten terawatt hours per year. 

The researchers are hoping to begin to construct prototypes of their designs very soon.



Comments     Threshold


This article is over a month old, voting and posting comments is disabled

RE: Even better
By Reflex on 6/6/2008 7:57:35 PM , Rating: 3
E85 has only 65-70% of the energy in a gallon that gasoline has. Its not a matter of 'designing an engine for E85' because that dosen't get around the basic problem, namely that the fuel simply does not have the same amount of energy as gasoline.

E85 is to gasoline as gasoline is to diesel, it has less energy per unit of measurement so regardless of how efficient you make the engine it will always have less mpg than an equivilent design running a higher energy content fuel.


RE: Even better
By sprockkets on 6/7/2008 1:43:52 PM , Rating: 2
Again, you are wrong. Ethanol has a higher octane rating, allowing for higher compression ratios for equivalent efficiency to a gasoline engine. The problem is, is that if you need an engine to run on either E85 OR gasoline, you cannot change the compression ratio on the fly to run either one best. SO, to offset the lower compression ratio with E85, you have to use more ethanol in the air/fuel mix.

If an E85 only engine ran gasoline, it would be destroyed due to premature detonation.


RE: Even better
By masher2 (blog) on 6/7/2008 1:46:56 PM , Rating: 2
While you are correct, the higher compression ratios achievable with E85 -- or even an all-ethanol fuel -- would still not come close to achieving the MPG from pure gasoline-only fuel. The difference in energy content is too large.


RE: Even better
By dschneider on 6/7/2008 4:42:55 PM , Rating: 5
I think I run on regular and my wife runs on E85.
Cause there is a lot of premature detonation.


RE: Even better
By nugundam93 on 6/9/2008 12:56:37 AM , Rating: 2
hahahahaha somebody give him a 6! that was one witty comment there.


"If a man really wants to make a million dollars, the best way would be to start his own religion." -- Scientology founder L. Ron. Hubbard














botimage
Copyright 2014 DailyTech LLC. - RSS Feed | Advertise | About Us | Ethics | FAQ | Terms, Conditions & Privacy Information | Kristopher Kubicki