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Thread: Compression of CO2

  1. #1 Compression of CO2 
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    Hi guys

    This is my first time using the forum so hopefully I am getting this right!

    I am a very non-science minded person looking to do a bit of research into compressed gases.

    Basically I am looking to see how the rules work for compression of CO2.

    If I was looking to compress about 4 litres of CO2 into the smallest space possible, how would I work this out? (Note: by 4 litres I mean the equivalent space 4 litres of water would take up in a plastic bag)

    I would be looking to safely store the compressed CO2 in a capsule of some sort that could be released when needed.

    Any help on this matter would be much appreciated

    Regards

    cc_melb


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  3. #2  
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    Matter has 3 stages as we learned in schools. Solid, liquid & Gas. The difference in simple words is the state of energy within the matter. For eg. Energy removed from water, it become solid. It become gas when energy induced. Application can be done to CO2. We super cool natural gas for transportation and handling purpose!
    Hope this clarify your question.


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    This article lists the properties of carbon dioxide.

    http://en.wikipedia.org/wiki/Carbon_...mic_properties

    Assuming you are going to keep your carbon dioxide at room temperature, scroll down the table to 20.56 degrees C which is about 69 degrees F. Note the following properties from the table:

    density of vapor = .1956 grams per cc.
    density of liquid = .7639 grams per cc.
    vapor pressure = 5776 kPa

    This means your 4 liters of carbon dioxide weighs 4 liters*.1956 gm/cc*1000 cc/liter = 782 grams.

    If you compress it to a liquid at the same temperature it will have a volume of 4*.1956/.7639 = 1.02 liters.
    The pressure required to compress it to this volume is 5776 kPa which is about 830 psi.

    If you just want a handy container of liquid CO2, you could just get a small fire extinguisher.
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  5. #4 Re: Compression of CO2 
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    Quote Originally Posted by cc_melb
    Hi guys

    This is my first time using the forum so hopefully I am getting this right!

    I am a very non-science minded person looking to do a bit of research into compressed gases.

    Basically I am looking to see how the rules work for compression of CO2.

    If I was looking to compress about 4 litres of CO2 into the smallest space possible, how would I work this out? (Note: by 4 litres I mean the equivalent space 4 litres of water would take up in a plastic bag)

    I would be looking to safely store the compressed CO2 in a capsule of some sort that could be released when needed.

    Any help on this matter would be much appreciated

    Regards

    cc_melb
    You can also cool the container that is going to hold the CO2 in a freezer.

    Then use a bottle of liquid CO2 that has a siphon tube and, just transfer the liquid into the cooled tank. It will just fill it up.


    If you are going to compress CO2 gas be careful. Because when you compress it to a liquid. It gives off massive amounts of heat. You could melt metal with it.



    Sincerely,


    William McCormick
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    It just dawned on me that cc_melb probably meant it was 4 liters of gas at atmospheric pressure, not 830 psi. The density of carbon dioxide gas at atmospheric pressure is more like .0019 grams per cc so that would be only be about 1/100 liter (10 cc) of liquid, not 1 liter.
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    Quote Originally Posted by Harold14370
    It just dawned on me that cc_melb probably meant it was 4 liters of gas at atmospheric pressure, not 830 psi. The density of carbon dioxide gas at atmospheric pressure is more like .0019 grams per cc so that would be only be about 1/100 liter (10 cc) of liquid, not 1 liter.
    I believe you are right.

    I just kind of backwards engineered it. And figured in the end he wanted four liters volume out of the tiny capsule.
    And if he was doing this on any scale he would probably want to use liquid carbon dioxide, and a chilled container. But it was an assumption on my part.

    Sincerely,


    William McCormick
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  8. #7 Compression of CO2 - second question 
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    Hi guys

    Thanks to those who responded to my first query. My question related to the ability to compress CO2 (eg 4 litres expanded) into as small a space as possible so I think we got there in the end!

    I understand from doing some research on CO2 cartridges that off the shelf cartridges are compressed to 60bar/900psi (?)

    Does anybody know whether it is possible to compress the CO2 even further so that it can be housed in an even smaller cartridge?

    Where does the ability to further compress the CO2 stop?

    Any advice on this matter is greatly appreciated!!

    Kind regards
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  9. #8 Re: Compression of CO2 - second question 
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    Quote Originally Posted by cc_melb

    Where does the ability to further compress the CO2 stop?
    1. It can stop with the balance between the gas pressure and the ability of your container to resist it.

    2. More realistically, depending upon temperature, it will stop at the pressure at which the gas becomes a liquid. Liquids are, in general, effectively incompressible. I think Harold's notes and link will help you work out where this point lies for a given amount<sup>a</sup> of gas at a given temperature.


    N.B.

    a. I use the word 'amount' instead of volume because most scientists, in situations like this, prefer to use moles rather than litres, to define the amount of substance being worked with.
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  10. #9 Re: Compression of CO2 - second question 
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    Quote Originally Posted by cc_melb
    I understand from doing some research on CO2 cartridges that off the shelf cartridges are compressed to 60bar/900psi (?)

    Does anybody know whether it is possible to compress the CO2 even further so that it can be housed in an even smaller cartridge?

    Where does the ability to further compress the CO2 stop?

    Any advice on this matter is greatly appreciated!!

    Kind regards
    Take a look at the link in my first post above. If you scroll down the page you will see a table called "Carbon dioxide liquid/vapor equilibrium thermodynamic data." The first two columns show the relationship between the pressure and temperature of a mixture of liquid and gaseous CO2. For the cartridges you mentioned at 60 bar (6000 kPa), the cylinder would contain a mixture of gas and liquid at about 22 degrees C, or 71.6 F. If you had a cylinder of CO2 at this temperature and pressure, you would not know if you had all liquid or all gas, or something in between. If you had 10 cc of gaseous CO2 at this temperature and pressure it would weigh about 2.1 grams (see column labeled "density of vapor." As you compressed more CO2 into your cylinder it would eventually become all liquid and would contain 7.4 grams. The liquid will be practically incompressible, and adding any more CO2 will result in a drastic pressure increase.

    If you expanded this 7.4 grams of CO2 to atmospheric pressure, the density would then become .00198 grams per cc and the 7.4 grams would be 7.4/.00198=3737cc or about 3.7 liter.
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    Off topic, but what if you had an impossibly strong canister? Liquids are effectively incompressible but not totally so. What would be the next limit then? (I always enjoyed the video of Jacques Cousteau open a failed test bathysphere [cracked window] after raising it from the depths. It was spewing water at firehose pressure from seemingly nowhere. I am glad it was just a test though.)
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    Quote Originally Posted by MagiMaster
    Off topic, but what if you had an impossibly strong canister? Liquids are effectively incompressible but not totally so. What would be the next limit then? (I always enjoyed the video of Jacques Cousteau open a failed test bathysphere [cracked window] after raising it from the depths. It was spewing water at firehose pressure from seemingly nowhere. I am glad it was just a test though.)

    You really cannot compress a liquid to any useful purpose. It just does not noticeably compress.

    Once a liquid is compressed, under super pressures, it can become dangerous and unstable. Because even if a slight gas bubble is formed with an electrical impulse. Or electrochemical reaction. The instant compression of the bubble can cause an escalating expansion in the liquid. As it gives off massive heat rays. Blowing apart the container it is housed in.




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    William McCormick
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    Quote Originally Posted by MagiMaster
    Off topic, but what if you had an impossibly strong canister? Liquids are effectively incompressible but not totally so. What would be the next limit then?
    I guess the limit would be a black hole.
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    I thought there were several limits before the black hole stage, mostly based off Pauli's Exclusion Principal. Would none of these limits apply in this case?
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    Quote Originally Posted by MagiMaster
    I thought there were several limits before the black hole stage, mostly based off Pauli's Exclusion Principal. Would none of these limits apply in this case?

    There is no black hole stage. There is an explosion.

    If water cannot boil or evaporate, it heats very quickly, extremely fast. As you go to spot heat, super pressurized water with plasma energy, it super heats well beyond its boiling point. So much so that a miniature steam explosion takes place. To disperse the excited bomb like area.

    This in turn super heats water all around it. And detonates the container. This one gets a lot of really good engineers.

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    William McCormick
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    Quote Originally Posted by MagiMaster
    I thought there were several limits before the black hole stage, mostly based off Pauli's Exclusion Principal. Would none of these limits apply in this case?
    Yes, but Harold was just talking about the ultimate limiting factor.

    After all, neutron stars can be considered a 'limit' on the compressibility of matter (liquid included).
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    Quote Originally Posted by sunshinewarrior
    Quote Originally Posted by MagiMaster
    I thought there were several limits before the black hole stage, mostly based off Pauli's Exclusion Principal. Would none of these limits apply in this case?
    Yes, but Harold was just talking about the ultimate limiting factor.

    After all, neutron stars can be considered a 'limit' on the compressibility of matter (liquid included).
    I have never seen any evidence or demonstrations of a neutron stars existence. Never even heard a good case about them.

    I did all of a sudden hear out of the blue sky, "now with the proof of the neutron star" But I never heard the wining case for neutron stars. Or the neutron either.

    I cannot prove there were universal scientists. But they can prove that there is a neutron star?


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    Basically I am looking to see how the rules work for compression of CO2.
    A good place to look is the NIST Thermophysical Properties of Fluids database. You can generate isotherms showing pressure versus density for many fluids including CO2. If you select a temperature of (say) 70F which is below the critical temperature you'l get acurve showing the sudden change from gas to liquid, and the further increase in density (decrease in volume) of the liquid as it is compressed further. Then if you repeat, but increase the temperature to 90F (above the critical temperature) you'll see a more gradual transition to a supercritical fluid that is neither gas not liquid.

    Try (in US customary units if you cn stand it)
    70 deg F
    14.5 psia
    3000 psia
    100 deg F increments

    Theg try again changing to 90 degF

    You'll see that liquid and supercritical fluids are quite compressible. This is an extremely important issue for CO2 sequestration.

    http://webbook.nist.gov/chemistry/fluid/
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    Quote Originally Posted by Bunbury
    Basically I am looking to see how the rules work for compression of CO2.
    A good place to look is the NIST Thermophysical Properties of Fluids database. You can generate isotherms showing pressure versus density for many fluids including CO2. If you select a temperature of (say) 70F which is below the critical temperature you'l get acurve showing the sudden change from gas to liquid, and the further increase in density (decrease in volume) of the liquid as it is compressed further. Then if you repeat, but increase the temperature to 90F (above the critical temperature) you'll see a more gradual transition to a supercritical fluid that is neither gas not liquid.

    Try (in US customary units if you cn stand it)
    70 deg F
    14.5 psia
    3000 psia
    100 deg F increments

    Theg try again changing to 90 degF

    You'll see that liquid and supercritical fluids are quite compressible. This is an extremely important issue for CO2 sequestration.

    http://webbook.nist.gov/chemistry/fluid/
    A liquid is a liquid, it will not compress further. That chart is probably just showing the stages of a boiling liquid or a boiled gas, condensing somewhat. But once liquefied it will be impossible to compress. At least to any usable purpose.

    I work with high pressure liquids. They do not compress. They will expand the containers they are in though. This could be misunderstood by some. Liquids can expand high pressure pipe, cylinders. The liquids can compress "O" rings, Gaskets. Just about anything. But the liquid is pretty much impossible to compress.


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    William McCormick
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    A liquid is a liquid
    Yes, you are right. Congratulations. A horse is also a horse, unless it's a schmorse.

    it will not compress further
    But here you are wrong. Liquids are considered incompressible for practical purposes at low pressures, but at the sort of pressures encountered in pumping CO2 underground for sequestration the density change with pressure is noticeable and has to be considered in the design of pumps. And as I said above, there is a condition called "dense phase" which is neither gas nor liquid and which is even more tricky for pump designers to handle.

    I work with high pressure liquids. They do not compress.
    So do I, and they do.

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    Hi,

    I am new here, and thought a reply to this thread was warranted instead of starting a new one due to their similarities in topic.

    I am just a citizen scientist, exploring sustainability and would like to know the energy required to compress exhaust from a car?
    Since I am not that good with formula, it would be nice to know the smallest type of system possible to do this, and it's weight.

    My goal is to see if it would be feasible to create a system like this and add it to a car knowing we could potentially reuse at least 80% of the exhaust.
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    The car engine works because the combustion gases expand and are exhausted at a lower pressure. The pressure differential across the piston provides the driving force. The lower the exhaust pressure the better the power and efficiency. So I think that to compress the exhaust gas would use a lot of power, maybe even as much as the engine produces depending on how much you want to compress it. How would you propose to use 80% of the exhaust?
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    The idea is to capture the exhaust that goes out of the car...and reuse it later, perhaps to feed algae that could be used to make bio-fuel, since their main sources of energy are the sun, Co2, and nitrogen helps them as well.


    My idea was to use the moving parts inside a car to transfer the car exhaust (that leaves most gas-burning cars) into tanks which would be compressed, without needing much extra energy, but this will be recycled anyways so I thought it could be worth it somehow?

    I read about gas compressors here on wikipedia..though can't post the link here..
    So for example couldn't we attach Axial-flow compressors to the drive train and funnel the exhaust fumes through them to compress it without even needing any extra energy (besides the added weight to the car costing gas, so this is what I want to find out)?
    Though it's written that they are expensive, I'm sure there are other ways a real scientist or engineer knows that could show if this idea has any merit or not financially..

    So some formulas needed would be to analyze the weight of a system and the energy required (preferably the least of both), if it could capture all the exhaust or would it not be quick enough for a cheaper system, etc, and then I will get in touch with an algae company and see at what rate we could sell them a gas combination of CO2 and nitrogen, and together we succeed.

    Thanks again,
    Alan.
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    Quote Originally Posted by greenspan View Post
    The idea is to capture the exhaust that goes out of the car...and reuse it later, perhaps to feed algae that could be used to make bio-fuel, since their main sources of energy are the sun, Co2, and nitrogen helps them as well.


    My idea was to use the moving parts inside a car to transfer the car exhaust (that leaves most gas-burning cars) into tanks which would be compressed, without needing much extra energy, but this will be recycled anyways so I thought it could be worth it somehow?

    I read about gas compressors here on wikipedia..though can't post the link here..
    So for example couldn't we attach Axial-flow compressors to the drive train and funnel the exhaust fumes through them to compress it without even needing any extra energy (besides the added weight to the car costing gas, so this is what I want to find out)?
    No. The energy certainly would not be free. It would take torque from the engine to drive the compressor, and this torque will be in direct opposition to the torque propelling the vehicle. A machine which produces free energy would be a form of perpetual motion machine which violates the laws of thermodynamics.
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    Quote Originally Posted by Harold14370 View Post
    Quote Originally Posted by greenspan View Post
    The idea is to capture the exhaust that goes out of the car...and reuse it later, perhaps to feed algae that could be used to make bio-fuel, since their main sources of energy are the sun, Co2, and nitrogen helps them as well.


    My idea was to use the moving parts inside a car to transfer the car exhaust (that leaves most gas-burning cars) into tanks which would be compressed, without needing much extra energy, but this will be recycled anyways so I thought it could be worth it somehow?

    I read about gas compressors here on wikipedia..though can't post the link here..
    So for example couldn't we attach Axial-flow compressors to the drive train and funnel the exhaust fumes through them to compress it without even needing any extra energy (besides the added weight to the car costing gas, so this is what I want to find out)?
    No. The energy certainly would not be free. It would take torque from the engine to drive the compressor, and this torque will be in direct opposition to the torque propelling the vehicle. A machine which produces free energy would be a form of perpetual motion machine which violates the laws of thermodynamics.
    This is no where even close to a perpetual motion machine...like saying let's just grow the algae in a car, and extract the oil from it, and use that oil to make biofuel to propel the car, all in the same hour....
    ...but that's not even close to what I am talking about...
    gas engines are extremely inefficient at the conversion of energy as far as I know, last I read they produce 27% actual output?

    I was asking how much energy this system would take..
    is it worth trying to capture this exhaust or not..what's the least weight a system like this could be at what price to manufacture it, to figure out how much torque of the car it takes to maintain it and what this ends up costing in MPG..

    My hypothesis is to see if collecting and selling the exhaust fumes to an algae company could be worth it on a massive scale or not at all. If not for a regular car, perhaps for a fleet of trucks, etc...

    Thanks.
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    Here's an extremely simplified explanation of why the system you describe would not work. Someone please kick me if I've said something completely wrong...

    Say for instance that burning 1 unit of fuel gives out 100 units of energy. We'll say our engine is 27% efficient as you state above, so 27 units, out of the 100 total, is usable by the car to do work (things like move, power electrics, that stuff). 3 units of energy goes to waste heating up your engine block. The remaining 70 units exist as heat in the exhaust gas. In order to compress that gas back down into a liquid, or at least into a small volume, you need to take away those 70 units of heat.

    You can either... 1. Dump the exhaust gas into the atmosphere. The exhaust gas will lose those 70 units of heat pretty quick as it expands into the atmosphere, but you haven't captured it.
    Or you can... 2. Actively cool and compress the gas to capture it. To do this, you will need to spend energy. In a 100% efficient process, you need to spend 1 unit of energy in order to extract 1 unit of heat from the gas.

    We'll be generous and say you have a 100% efficient refrigeration unit on board. But where are you going to get the energy to run it? You could take some of the energy you gained from burning the fuel in the first place, but the more you take, the slower the car will go. Even if you spend all 27 units available to the car, you'll still have 43 units of heat in the exhaust gas.

    What about using an independent power supply to run the refrigerator? Great! So, you've burnt 1 unit of fuel, the car has gained 27 units of energy, the gas has gained 70 units of heat, your independent power supply has spent 70 units to cool and compress that gas back down... Gained 27, spent 70, you've just wasted 43 units of energy. Oops... You could have just spent 27 from the independent supply in order to move the car.

    Unfortunately, no such power supply exists, which is why we burn the fuel in the first place...
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    Quote Originally Posted by Karsus View Post
    Here's an extremely simplified explanation of why the system you describe would not work. Someone please kick me if I've said something completely wrong...

    Say for instance that burning 1 unit of fuel gives out 100 units of energy. We'll say our engine is 27% efficient as you state above, so 27 units, out of the 100 total, is usable by the car to do work (things like move, power electrics, that stuff). 3 units of energy goes to waste heating up your engine block. The remaining 70 units exist as heat in the exhaust gas. In order to compress that gas back down into a liquid, or at least into a small volume, you need to take away those 70 units of heat.

    You can either... 1. Dump the exhaust gas into the atmosphere. The exhaust gas will lose those 70 units of heat pretty quick as it expands into the atmosphere, but you haven't captured it.
    Or you can... 2. Actively cool and compress the gas to capture it. To do this, you will need to spend energy. In a 100% efficient process, you need to spend 1 unit of energy in order to extract 1 unit of heat from the gas.

    We'll be generous and say you have a 100% efficient refrigeration unit on board. But where are you going to get the energy to run it? You could take some of the energy you gained from burning the fuel in the first place, but the more you take, the slower the car will go. Even if you spend all 27 units available to the car, you'll still have 43 units of heat in the exhaust gas.

    What about using an independent power supply to run the refrigerator? Great! So, you've burnt 1 unit of fuel, the car has gained 27 units of energy, the gas has gained 70 units of heat, your independent power supply has spent 70 units to cool and compress that gas back down... Gained 27, spent 70, you've just wasted 43 units of energy. Oops... You could have just spent 27 from the independent supply in order to move the car.

    Unfortunately, no such power supply exists, which is why we burn the fuel in the first place...
    Thank you for the response.

    Remember my point is to try to do good for the world, to see if there could be potential for this to research, say 5 - 10 years from now.

    I did take that into consideration, but what I was getting at is if that exhaust could be funneled through an Axial-flow compressors on the axles of the wheels or the drive shaft, etc... it perhaps wouldn't need even half a unit of energy, maybe just a small amount of electricity(which could be powered by piezoelectric ways) and with the added weight(also adding in a container for this liquid) it would cost in more gas usage, so I would be comparing the cost of producing this light weight axial-flow compressor, or any other compressor with the potential gain in selling the gas mixture to an algae company.
    This system sounds a bit expensive so it could be leased out to consumers or something...
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    The point I'm trying to make is that the energy is conserved. I'm not familiar with an axial-flow compressor, but it would still need energy to run it. Do you mean to say, the spinning of the drive shaft or the wheels operates the compressor? The wheels and drive shaft get their energy from the engine, which gets its energy from the burning fuel, which is also giving the heat to the exhaust gas, which you propose to extract in order to compress it using energy from the wheels and drive shaft, which get their energy from the engine, which gets its energy from the burning fuel, which is also giving heat to the exhaust gas, which your propose to extract in order to compress it using energy from the wheels and the drive shaft, which... Etc etc...

    None of this happens in isolation, all the parts are connected. Everything costs energy and that energy has to come from somewhere. Even if you're running it from electricity, running the alternator in the car to charge the battery to power the compressor is still a load on the engine, spending some of its energy. The electricity doesn't magically increase the amount of heat you can extract from the gas either. It's still a 1 unit spent = 1 unit extracted relationship if we pretend it's 100% efficient.
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    It seems like you might be thinking you can capture some of that 73% of wasted energy. It doesn't work that way. The low efficiency is a function of the operating temperature of the engine and the outside temperature. To improve the efficiency you have to raise the operating temperature or lower the exhaust temperature. There's nothing you can do about it. Read about the Carnot cycle here.
    Carnot cycle - Wikipedia, the free encyclopedia
    The wasted energy is in the form of heat, and that's harder to recover anything useful from. What you need to run your compressor is work, which is a higher grade of energy. It's the 20%. You have to do work on the gas to compress it. The work is a product of the change in pressure and the change in volume - it is called "PV work."
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    I think I posted this question in the wrong forum...

    Capturing the lost heat would be nice, but my focus was in capturing the CO2 emissions. Like instead of allowing the CO2, nitrogen, and other toxins to go into the atmosphere...

    That's why I thought the already moving axles of the car can funnel the CO2 and as it funnels into smaller and smaller compartments it could cool down and eventually turn into the liquid and be stored in the car... imagine a gas engine car without any exhaust escaping? Just all the excess heat...and with piezoelectric crystals, this Carbon capture system could be self sufficient?
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    to store liquid C02 at RT requires a pressure in excess of 1800 psi-- lot of work to do that,,, besides that what are you going to do with the nitrogen and CO?
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    Quote Originally Posted by greenspan View Post
    I think I posted this question in the wrong forum...

    Capturing the lost heat would be nice, but my focus was in capturing the CO2 emissions. Like instead of allowing the CO2, nitrogen, and other toxins to go into the atmosphere...

    That's why I thought the already moving axles of the car can funnel the CO2 and as it funnels into smaller and smaller compartments it could cool down and eventually turn into the liquid and be stored in the car... imagine a gas engine car without any exhaust escaping? Just all the excess heat...and with piezoelectric crystals, this Carbon capture system could be self sufficient?
    The thing is that you would need to extract the CO2 from the other gases, mostly nitrogen but a lot of other things besides, that also come out of the engine exhaust. Don't forget: these engines use air as a working fluid, and ~80% of air is inert nitrogen which passes through the engine doing its job as a working fluid and then escapes in the exhaust along with the products of combustion. Separating the CO2 would not be easy. It would require chemical absorption, perhaps like the systems used in submarines for breathing air, but far bigger, due to the amounts of CO2 produced by an engine.
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  33. #32  
    Forum Freshman greenspan's Avatar
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    Quote Originally Posted by exchemist View Post
    Quote Originally Posted by greenspan View Post
    I think I posted this question in the wrong forum...

    Capturing the lost heat would be nice, but my focus was in capturing the CO2 emissions. Like instead of allowing the CO2, nitrogen, and other toxins to go into the atmosphere...

    That's why I thought the already moving axles of the car can funnel the CO2 and as it funnels into smaller and smaller compartments it could cool down and eventually turn into the liquid and be stored in the car... imagine a gas engine car without any exhaust escaping? Just all the excess heat...and with piezoelectric crystals, this Carbon capture system could be self sufficient?
    The thing is that you would need to extract the CO2 from the other gases, mostly nitrogen but a lot of other things besides, that also come out of the engine exhaust. Don't forget: these engines use air as a working fluid, and ~80% of air is inert nitrogen which passes through the engine doing its job as a working fluid and then escapes in the exhaust along with the products of combustion. Separating the CO2 would not be easy. It would require chemical absorption, perhaps like the systems used in submarines for breathing air, but far bigger, due to the amounts of CO2 produced by an engine.
    Nitrogen is great! Algae love nitrogen! I don't exactly know how much though..or how much is too much nitrogen, but for some algae that is like nitros, super fueling them for reproduction.
    I don't need to separate any of the gases, not yet anyways.
    In fact, there are many algae companies in the world attaching smoke stacks from factories to algae farms.. you know algae can even help break down sewage...
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  34. #33  
    exchemist
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    Quote Originally Posted by greenspan View Post
    Quote Originally Posted by exchemist View Post
    Quote Originally Posted by greenspan View Post
    I think I posted this question in the wrong forum...

    Capturing the lost heat would be nice, but my focus was in capturing the CO2 emissions. Like instead of allowing the CO2, nitrogen, and other toxins to go into the atmosphere...

    That's why I thought the already moving axles of the car can funnel the CO2 and as it funnels into smaller and smaller compartments it could cool down and eventually turn into the liquid and be stored in the car... imagine a gas engine car without any exhaust escaping? Just all the excess heat...and with piezoelectric crystals, this Carbon capture system could be self sufficient?
    The thing is that you would need to extract the CO2 from the other gases, mostly nitrogen but a lot of other things besides, that also come out of the engine exhaust. Don't forget: these engines use air as a working fluid, and ~80% of air is inert nitrogen which passes through the engine doing its job as a working fluid and then escapes in the exhaust along with the products of combustion. Separating the CO2 would not be easy. It would require chemical absorption, perhaps like the systems used in submarines for breathing air, but far bigger, due to the amounts of CO2 produced by an engine.
    Nitrogen is great! Algae love nitrogen! I don't exactly know how much though..or how much is too much nitrogen, but for some algae that is like nitros, super fueling them for reproduction.
    I don't need to separate any of the gases, not yet anyways.
    In fact, there are many algae companies in the world attaching smoke stacks from factories to algae farms.. you know algae can even help break down sewage...
    Since nitrogen is about 80% of the atmosphere already, there seems little to be gained by pumping more at them.
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  35. #34  
    Forum Sophomore Karsus's Avatar
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    Quote Originally Posted by greenspan View Post
    Quote Originally Posted by exchemist View Post
    Quote Originally Posted by greenspan View Post
    I think I posted this question in the wrong forum...

    Capturing the lost heat would be nice, but my focus was in capturing the CO2 emissions. Like instead of allowing the CO2, nitrogen, and other toxins to go into the atmosphere...

    That's why I thought the already moving axles of the car can funnel the CO2 and as it funnels into smaller and smaller compartments it could cool down and eventually turn into the liquid and be stored in the car... imagine a gas engine car without any exhaust escaping? Just all the excess heat...and with piezoelectric crystals, this Carbon capture system could be self sufficient?
    The thing is that you would need to extract the CO2 from the other gases, mostly nitrogen but a lot of other things besides, that also come out of the engine exhaust. Don't forget: these engines use air as a working fluid, and ~80% of air is inert nitrogen which passes through the engine doing its job as a working fluid and then escapes in the exhaust along with the products of combustion. Separating the CO2 would not be easy. It would require chemical absorption, perhaps like the systems used in submarines for breathing air, but far bigger, due to the amounts of CO2 produced by an engine.
    Nitrogen is great! Algae love nitrogen! I don't exactly know how much though..or how much is too much nitrogen, but for some algae that is like nitros, super fueling them for reproduction.
    I don't need to separate any of the gases, not yet anyways.
    In fact, there are many algae companies in the world attaching smoke stacks from factories to algae farms.. you know algae can even help break down sewage...
    Sorry to rain on the parade again, but the Nitrogen found in the atmosphere (Nitrogen Gas) is different to the Nitrogen that algae likes (Ammonia or Ammonium Nitrate). I doubt you would find Ammonia in any useful quantities coming out of a factory smokestack, or from a car for that matter.

    Ammonia usually comes from animal waste or decomposing organic material naturally. It can also be manufactured for fertiliser. Places you see lots of algae thriving are usually where agricultural runoff (fertiliser) has gotten into the water, or in fish tanks that haven't been cleaned in a long time (animal waste). Or, as you mention, being used to treat sewage (animal waste again).
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  36. #35  
    exchemist
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    Quote Originally Posted by Karsus View Post
    Quote Originally Posted by greenspan View Post
    Quote Originally Posted by exchemist View Post
    Quote Originally Posted by greenspan View Post
    I think I posted this question in the wrong forum...

    Capturing the lost heat would be nice, but my focus was in capturing the CO2 emissions. Like instead of allowing the CO2, nitrogen, and other toxins to go into the atmosphere...

    That's why I thought the already moving axles of the car can funnel the CO2 and as it funnels into smaller and smaller compartments it could cool down and eventually turn into the liquid and be stored in the car... imagine a gas engine car without any exhaust escaping? Just all the excess heat...and with piezoelectric crystals, this Carbon capture system could be self sufficient?
    The thing is that you would need to extract the CO2 from the other gases, mostly nitrogen but a lot of other things besides, that also come out of the engine exhaust. Don't forget: these engines use air as a working fluid, and ~80% of air is inert nitrogen which passes through the engine doing its job as a working fluid and then escapes in the exhaust along with the products of combustion. Separating the CO2 would not be easy. It would require chemical absorption, perhaps like the systems used in submarines for breathing air, but far bigger, due to the amounts of CO2 produced by an engine.
    Nitrogen is great! Algae love nitrogen! I don't exactly know how much though..or how much is too much nitrogen, but for some algae that is like nitros, super fueling them for reproduction.
    I don't need to separate any of the gases, not yet anyways.
    In fact, there are many algae companies in the world attaching smoke stacks from factories to algae farms.. you know algae can even help break down sewage...
    Sorry to rain on the parade again, but the Nitrogen found in the atmosphere (Nitrogen Gas) is different to the Nitrogen that algae likes (Ammonia or Ammonium Nitrate). I doubt you would find Ammonia in any useful quantities coming out of a factory smokestack, or from a car for that matter.

    Ammonia usually comes from animal waste or decomposing organic material naturally. It can also be manufactured for fertiliser. Places you see lots of algae thriving are usually where agricultural runoff (fertiliser) has gotten into the water, or in fish tanks that haven't been cleaned in a long time (animal waste). Or, as you mention, being used to treat sewage (animal waste again).
    I was going to make this point, but I find some "blue-green algae" (more properly cyanobacteria, I suppose) can fix atmospheric nitrogen. I suppose the NOx in car exhaust could in principle be a route to fixing nitrogen, however.
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  37. #36  
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    BOTTOM LINE-- Your scheme is TOTALLY impractical from numerous chemical and engineering stand points
    Via Con Dios
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