Most Efficient Engines: Beyond ICEs

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In summary, nuclear reactions are much more efficient than chemical reactions, but the amount of mass change is negligible. Motor proteins can convert free energy from the hydrolysis of ATP to motion.
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wolram
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I am not talking about just ICE, but any thing that converts matter to energy.
 
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Black hole. Matter goes in, energy (Hawking) comes out :biggrin:
 
  • #3
wolram said:
I am not talking about just ICE, but any thing that converts matter to energy.
By "matter" you mean "fuel", right?
 
  • #4
I think that a matter/antimatter collider would be it.
 
  • #5
wolram said:
I am not talking about just ICE, but any thing that converts matter to energy.

There's only one "engine" that converts matter to energy, which is nuclear. Nuclear is currently very inefficient, capturing all of the various forms of energy released from a nuclear reaction (netruons, gamma, x-ray, etc.) isn't worth the effort.

I would guess that the most efficient engines currently made for converting stored energy in any form (chemical, electrical, etc.) to mechanical work would be either a high-end brushless electric motor (~90% IIRC) or maybe a purpose-built constant-speed turbine.
 
  • #6
Jimmy Snyder said:
I think that a matter/antimatter collider would be it.

Matter/antimatter has a high specific energy density, but you still have to capture the energy and utilize it somehow for it to be classified as an engine... I would guess that a matter/antimatter reactor would look very similar to a current nuclear plant (water or other working fluid heated into steam and run through a turbine).
 
  • #7
Mech_Engineer said:
There's only one "engine" that converts matter to energy, which is nuclear.
I thought that all engines did that. If e=mc^2 does not hold for chemical reactions, then what is the appropriate equation?
 
  • #8
zoobyshoe said:
By "matter" you mean "fuel", right?

Yes i mean fuel, so the energy could be plant based or any other thing you could think of.
 
  • #9
ryan_m_b said:
Black hole. Matter goes in, energy (Hawking) comes out :biggrin:

About 40% maximum efficiency?
 
  • #10
Loren Booda said:
About 40% maximum efficiency?

Really? Huh, why's that?
 
  • #11
Jimmy Snyder said:
I thought that all engines did that. If e=mc^2 does not hold for chemical reactions, then what is the appropriate equation?

Chemical reactions do not create or destroy mass; nuclear reactions are a different story.
 
  • #12
Mech_Engineer said:
Chemical reactions do not create or destroy mass; nuclear reactions are a different story.
Thanks for that explanation Mech_Engineer. However, I believe it is incorrect. I think that the making and breaking of chemical bonds involves the energy-mass equation e=mc^2 just as the making and breaking of nuclear bonds. the difference between the nuclear case and the chemical case is the amount of mass and energy involved.
 
  • #13
Jimmy Snyder said:
Thanks for that explanation Mech_Engineer. However, I believe it is incorrect. I think that the making and breaking of chemical bonds involves the energy-mass equation e=mc^2 just as the making and breaking of nuclear bonds. the difference between the nuclear case and the chemical case is the amount of mass and energy involved.

Maybe that's true, but I think for all practical applications the mass change is considered to be negligible in a chemical reaction.

http://www.chem.ox.ac.uk/vrchemistry/Conservation/page07.htm
 
  • #14
Mech_Engineer said:
Maybe that's true, but I think for all practical applications the mass change is considered to be negligible in a chemical reaction.

http://www.chem.ox.ac.uk/vrchemistry/Conservation/page07.htm
Yes, perhaps it is. In spite of what the article says, the amount of energy conversion for chemical bonds is exactly the same as for nuclear bonds, e=mc^2. In other words for 1 joule of energy, there will be the same amount of mass loss for either case. What differentiates the nuclear reaction from the chemical reaction is the mass and energy density.
 
  • #15
There are some motor proteins in biology that convert the free energy from the hydrolysis of a fuel molecule (ATP) into motion. Many of these are very efficient, and one in particular called ATP synthase is thought to work at ~90% efficiency (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1692765/).

NB: In the body, ATP synthase actually catalyzes the reverse of the reaction described in the paper. It converts the energy from rotary motion into the formation of a chemical bond, creating ATP. In the laboratory, however, it is easier to study the motor moving in the opposite direction, hydrolyzing ATP to create rotary motion.
 
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  • #16
Ygggdrasil said:
There are some motor proteins in biology that convert the free energy from the hydrolysis of a fuel molecule (ATP) into motion. Many of these are very efficient, and one in particular called ATP synthase is thought to work at ~90% efficiency (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1692765/).

NB: In the body, ATP synthase actually catalyzes the reverse of the reaction described in the paper. It converts the energy from rotary motion into the formation of a chemical bond, creating ATP. In the laboratory, however, it is easier to study the motor moving in the opposite direction, hydrolyzing ATP to create rotary motion.

Cool, Yegs!:cool:
 

Related to Most Efficient Engines: Beyond ICEs

1. What are "ICEs" and why are they considered inefficient?

"ICEs" stands for Internal Combustion Engines, which are the most commonly used engines in vehicles today. These engines use a combination of fuel and air to create small explosions that power the vehicle. However, this process is not very efficient as a lot of energy is lost in the form of heat and sound. This results in low fuel efficiency and high emissions.

2. What are some alternative engine technologies that are more efficient than ICEs?

Some alternative engine technologies that are more efficient than ICEs include electric motors, hydrogen fuel cells, and hybrid engines. These engines use different methods to convert energy into motion, resulting in higher fuel efficiency and lower emissions.

3. How are electric motors more efficient than ICEs?

Electric motors are more efficient than ICEs because they use electricity to power the vehicle, rather than burning fuel. This means that there is no combustion process and therefore no energy is lost in the form of heat or sound. Additionally, electric motors can be up to 90% efficient, while ICEs are typically only 30% efficient.

4. Are there any downsides to using alternative engine technologies?

While alternative engine technologies offer many benefits, there are some downsides to consider. For example, electric vehicles may have limited range and require longer charging times. Hydrogen fuel cells require a reliable source of hydrogen, which is currently not widely available. And hybrid engines still rely on some form of fossil fuel, although they are more efficient than traditional ICEs.

5. How can we transition to using more efficient engines?

Transitioning to more efficient engines will require a combination of initiatives. This includes investing in and developing new technologies, incentivizing consumers to switch to alternative vehicles, and implementing policies to reduce the use of traditional ICEs. Additionally, increasing public awareness and education about the benefits of efficient engines can also encourage the transition to these technologies.

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