Dry Ice as a Power Source

No.

It may be able to 'become' the fuel to turn a motor, but it woudl take a coupkle extra steps and would probably not be a very efficient way to turn a motor.

CO2 doesn't 'burn'. That is it doesn't react readily with Oxygen. So there would likely need to be another couple precesses and perhaps another consumable for your engine to use CO2.

It won't be easy and the result probably won't be an advancement, but I wouldn't trust anyone who tells you too quicjkly or without sufficient explanation that something is imposible.

In this life, possibility isn't what you need worry about. It is probability.

1. The dry ice could be used as a source of coolth to drive a Stirling Engine, though.
2. Were the dry ice to be under pressure, the pressure difference could be used to turn some sort of turbine.

Neither of the above arrangements uses dry ice as a fuel.

You could, perhaps, use the sublimation product to inflate a balloon and then after it was inflated, you could use it to drive one of those little "air" powered cars across the floor.

The dry ice is under pressure and it is from it's generated gas (expanding pressure) that would turn the motor - make sense?

It does indeed, now. It's an energy carrier, like electricity or clockwork.

The above item 2 is applicable.

Interesting. If it can turn a turbine, is there anyway to measure the strength of the energy produced to understand how strong the melting dry ice (expanding gas) would be - getting a sense of how powerful the expansion is? Is there anything to read about this being a source of power?

Take some dry ice, put it in a plastic soda bottle, add water, screw on lid and wait.

You could even rig a pressure gauge up to the lid.

The problem is sublimation is a relatively slow process, occurring at the outer layer of material, so you'd need a relatively large surface area to feed your motor.

If you just have dry ice and put it in a soda bottle, but have no access to water - will the same thing happen, taking longer, and with the same level of force?

If you are going to put dry ice in a bottle and put the lid on, you had better stay well away from it.

I would often buy a pound or two of dry ice as a kid and use it for my own experiments and just for fun.. but who didn't?

anyhow.. I have done this, and it's quite dangerous. Much like a stick of dynamite. you are lucky if you can find a shred of the bottle that used to be.

I tried this many times over the years. It can take less than a minute or an hour, but it will go.

the more water, and the warmer, the faster the reaction.

A question: Why does the water never seem to freeze when in contact with dry ice?

Yes there is.

I'm not trying to be an donkeyhole (I think that's how they say it in the USA), but if you're really interested in motors and turbines, now is the best time to do a bit of study. It's secondary school physics and (real) understanding what is meant by work, energy, density, gas laws etc will be a great investment. It'll be hard (it is for everyone) but now you've got a reason to learn it.

An american university built a car powered by liquid CO2. it worked by using a heat exchanger to boil and pressurise the gas which drove a steam type rankine cycle engine, though it may have been a stirling/ericson engine i can't remember now but I think I read about it from CR4 years ago! Of course Dry Ice doesn't liquify before turning to gas so the heat exchange phase may be troublesome to design.

When I was a kid, I copied Mr Wizard (Don Herbert) and put dry ice and water in my model steam engine, it ran for a while on that.

Here is someone's video with one of those air hog motors running on dry ice, same principle.

DaS Energy currently uses Co2 gas to power its turbine, but does not use the Co2 to fuel the turbine. This fully recycling turbine follows the pricipals of the steam recycling turbine, ie water into gas, gas into water. DaS Energy liquid Co2 into gas, gas into liquid Co2. Benefits water +550*C gives 175 bar thrust/force. Liquid Co2 +80*C 9,926 bar thrus/force. Power calculous, 175 bar Toshiba water/gas turbine 350 megawatts +550*C water. Co2 9,926 bar +80*C is plus 6.875 times per +550*C. 9,926 bar divided by 175 bar 56.72 times. Multiply 350 megawatts is 19,852 megawatts. Multiply 6.875 is 138,482.5 megawatts per +550*C in place of water/gas 350 megawatts.

pure bunk again.

maybe

but the way to manafacture dry ice out weighs the cost of gas right now.

http://www.dself.dsl.pipex.com/MUSEUM/POWER/carbonic/carbonic.htm

Back when I was a kid there were model airplane engines that used compressed CO2 in small cylinders to power stick build free flight model airplanes. These engines only ran for a very short time to get the plane high enough to glide back down to earth. The link above has text and photos of such engines.

Don't forget you'll need a pressure vessel to store the dry ice/co2 gas until the CO2 turns from a solid to a gas to provide the power. Have fun

Power source yes fuel no. CO2 does not burn. Under very specific circumstances it can be an oxidizer.

The problem with using it to be a power source is the cost of creating Dry Ice verses the output power.

What you would be doing is running a compressor in reverse by turning a solid into a gas by adding heat to do work.

If you could use a portable heat sourse to vaporize the dry ice you may do well on efficiency but figuring out how to cheaply input that many calories would give you other options.

Brad

It's obvious the the energy to compress CO2 to create dry ice would be greater the then the power produced. The question becomes: How is that energy used and how efficiently can it be used? We do this all the time.

Example: I would hope I'm preaching to the choir. The fuel/energy consumed to spin a turbine to make electricity exceeds the output energy. Lets us never for get. Converting energy from one form to another is never for free.

The question becomes one of efficiency. It always cost more energy (input) then you get out (output.) That's what we do!

Lugging around enought dry ice/compressed CO2 to equal a gallon of fossil fuel (gasoline/#2 oil) may not provide the most practical solution. But then again it might be a choice.

As far as I know dry ice is not made by compression directly.

Liquid CO2 is vaporised into a bag or pre chamber and dry ice is formed from the super heat needed for vaporization. Much like ice is formed when a compressor tank is drained for water. So the power to make Dry Ice is much more than just the power needed for pressurizing.

I don't know the % that becomes Dry Ice from the process but multiply the cost of compression by that factor.

I would look it all up but my 12 hr shift starts in less than an hour.

absolutely NO, NO, NO.

Where did you get the energy to make the dry ice?????

read your thermo books again grasshopper.

The question is about whether or not the expansion that occurs when dry ice vaporizes can be used to power a motor, like steam, not whether or not its an "efficient" way to do this.