Is it Possible to Separate Oxygen from Air Using Centrifugal Force?

[JonPriluck]

Is it possible to separate out the oxygen from atmospheric air by centrifugal force. I am not asking theoretically but practically. In other words is there any device that will act as a gas centrifuge which can separate air molecules in real time? A continuous process as opposed to a batch method.

 

[cjl]

Nothing that would be practical, no. The required accelerations are simply too high.

 

[JonPriluck]

cji, I tend to agree with you on conventional approaches but I like to think outside the box. For example, what about a nano-vortex? The laws of physics change with scale, what isn't possible in the macro world might be possible in the micro world. Perhaps we could imagine a MEMS (Micro Electric Mechanical Systems) device that would suck in air and form a microscopic tornado, maybe then the molecules would behave differently?

The reason I ask is I have this idea about an air breathing rocket propulsion system. In order for it to work you have to somehow get the oxygen out of the atmosphere without all the nitrogen, water, and CO2. The method of fractionating the air would have to be very efficient to serve this purpose. If anyone is interested in this idea you can look at the attachment.

Remember, it's just a concept. Which isn't even an idea. I suspect the complexity of it is too much toever be reduced to practice. But you can't blame me for thinking about it :^) Physics is fun.

 

[mfb]

The relevant quantity for the separation power is the kinetic energy of the outer molecules (from the rotation), multiplied with the relative mass difference, relative to their thermal energy. To get a noticable separation, this value should be of the order of 1. For air at room temperature, this needs a velocity of >1km/s or >3 times the speed of sound. The size of the system does not matter, but 1km/s in a microscopic device does not look feasible.
Cooling is easier - the different components will condense at different temperatures.

 

[pmacias]

Yes, it is possible to separate out the oxygen from atmospheric air using centrifugal force. This method, known as gravimetric separation, has been used for many years in industrial processes such as oxygen production and gas purification. However, it is important to note that the process is not as simple as just spinning air molecules in a centrifuge and collecting the separated oxygen.

In order to achieve successful separation, a complex system of multiple stages and precise control of temperature, pressure, and flow rates is required. This is because the different components of air (oxygen, nitrogen, and other trace gases) have different densities and boiling points, and therefore separate at different points in the process. In addition, the centrifugal force alone is not sufficient to separate the air molecules, and other techniques such as diffusion and adsorption are also utilized.

There are several companies that have developed commercial devices that use centrifugal force for air separation, such as the VPSA (Vacuum Pressure Swing Adsorption) and VSA (Vacuum Swing Adsorption) systems. These systems are continuous processes, meaning they operate continuously rather than in batches, and can produce high purity oxygen. However, the efficiency and effectiveness of these systems depend on various factors such as the design, operating conditions, and feed gas composition.

In conclusion, while it is possible to separate out oxygen from atmospheric air using centrifugal force, it is a complex process that requires specialized equipment and precise control. Further research and development in this field may lead to more efficient and cost-effective methods of air separation using centrifugal force.