Can a Subsea Lifting Bag With CO2 Rise to the Surface?

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SUMMARY

The discussion centers on the buoyancy of subsea lifting bags filled with CO2 compared to O2. It is established that CO2, with a density of 1.824 Kg/m3, requires 37% more volume than O2, which has a density of 1.331 Kg/m3, to achieve the same lifting capacity. However, the overall lifting force is primarily determined by the water's density, which is approximately 1000 Kg/m3, rendering the type of gas used in the lifting bag relatively insignificant in terms of buoyancy. The conversation highlights the importance of considering the mass of the gas itself when calculating lifting power.

PREREQUISITES
  • Understanding of buoyancy principles
  • Knowledge of gas densities (specifically CO2 and O2)
  • Familiarity with basic physics concepts such as force and mass (F=ma)
  • Awareness of fluid dynamics and drag forces
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  • Research the principles of buoyancy in fluids
  • Study the densities of various gases and their implications for lifting
  • Explore fluid dynamics, focusing on drag forces in underwater environments
  • Investigate the applications of subsea lifting bags in marine engineering
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cps.13
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This may sounds like a stupid question but...

If you were to use a subsea lifting bag filled with O2 it would rise to the surface.

Would the same happen with CO2? I assume the density of CO2 is different so the amount required would be more or less than O2, but it is still less dense than water so should rise?

Thanks

Edit:

After looking on google I can see that CO2 is 1.824 Kg/m3 whereas O2 is 1.331 Kg/m3. So you would therefore need 37% more CO2 to lift the same mass using O2.

Is that correct?

Thanks
 
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cps.13 said:
After looking on google I can see that CO2 is 1.824 Kg/m3 whereas O2 is 1.331 Kg/m3. So you would therefore need 37% more CO2 to lift the same mass using O2.

Is that correct?
No, it is not correct.
What is the density of water and how does that figure in?
 
There is a similar question, comparing Hydrogen and Helium for lifting power of balloons.
Take a look at this link about balloons (and lifting underwater).
 
I think we just have to consider that the O2 has mass. and the CO2 has mass. and we have to add that in. when its in that giant balloon. we can consider it to be its own object with a certian mass and a certian size (and extremely low mass). so let's just use 1m^3 volume.

I think the force from the water is going to be 1000 times greater than the weight of the O2 or CO2.
so the type of gas (while under water) has a really small effect.
 
I didn't account for F=ma or drag forces.
 

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