Is Separating Oxygen from Air Feasible Without Increasing Pollution?

  • Thread starter Thread starter Quadruple Bypass
  • Start date Start date
  • Tags Tags
    Air Oxygen
Click For Summary

Discussion Overview

The discussion centers on the feasibility of separating oxygen from air, exploring methods for obtaining pure or enriched oxygen, and the implications of using high concentrations of oxygen in internal combustion engines (ICE). It includes theoretical, practical, and safety considerations related to these processes.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants propose that oxygen can be separated from air through methods such as liquefaction, fractional distillation, and using zeolite materials in oxygen concentrators.
  • Others argue that while it is technically feasible to obtain enriched oxygen, the purity achieved may not be absolute, and contaminants will always be present.
  • A participant mentions that introducing pure oxygen into an ICE could lead to overheating and increased danger due to combustion characteristics in high oxygen environments.
  • Some participants discuss the potential for increased power output in ICEs with higher oxygen concentrations, while others challenge the idea by stating that the fuel/air mixture is already optimized for efficient combustion.
  • There is a debate regarding the impact of high oxygen concentrations on pollution levels, with some suggesting it could reduce unburned hydrocarbons and NOx emissions, while others question this assumption.
  • Concerns are raised about the practicality and safety of using high concentrations of oxygen in automotive applications.

Areas of Agreement / Disagreement

Participants express a range of views on the methods for separating oxygen and the implications of using it in engines. There is no consensus on whether introducing more oxygen would definitively improve efficiency or reduce pollution, indicating ongoing disagreement and uncertainty.

Contextual Notes

Participants highlight limitations regarding the purity of separated oxygen and the safety risks associated with high oxygen environments. The discussion also reflects varying assumptions about combustion efficiency and pollution outcomes based on different engine types and configurations.

Who May Find This Useful

This discussion may be of interest to those exploring oxygen separation technologies, automotive engineering, combustion efficiency, and environmental impacts of fuel combustion.

Quadruple Bypass
Messages
120
Reaction score
0
is it possible to separate oxygen from air?

in other words, getting pure oxygen from air
 
Last edited:
Chemistry news on Phys.org
damn, that sounds like its going to take a long time. i was seeing if it was possible to get a car to suck in pure oxygen instead of air, but it would have to make a lot of oxygen in a short period of time

thanks
 
Quadruple Bypass said:
damn, that sounds like its going to take a long time. i was seeing if it was possible to get a car to suck in pure oxygen instead of air, but it would have to make a lot of oxygen in a short period of time

thanks
If it were easy, do you think they wouldn't already have thought about it? :smile:
 
fractional distillation or burn hydrogen, collect the water, preform electrolysys and separate the gases, reuse the H2 and use the O2
 
Hi QB,
Quadruple Bypass said:
is it possible to separate oxygen from air?

in other words, getting pure oxygen from air
Just a disclaimer first: saying "pure" is relative. There are always contaminants in your product, regardless of the method used. Even distillation is only going to give 99.99xx percent purity.

There are plenty of other ways of obtaining enriched oxygen. PSA and other methods using membranes or adsorption are common. Here's a decent overview:
http://www.uigi.com/noncryo.html

As for putting oxygen into an engine however, there's no reason to do that. First, an oxygen rich stream in an ICE is going to overheat the engine. Second, it's extremely dangerous - even steel burns readily in a pure oxygen environment at any significant pressure. And third, it don't believe it improve efficiency. I'm not absolutely sure about the efficiency part, but I know there have been discussions in the ME forum about this. Might want to do a search in the engineering forums, there was a discussion not too long ago.
 
It is possible to separate oxygen from air using zeolite materials in machines known as oxygen concentrators. These devices are used by people needing to breathe higher concentrations of oxygen because of various medical conditions. These machines can provide ~5 liters/minute of 95%+ oxygen.
To learn more about this please read about "oxygen concentrators" and "zeolites" on the wikipedia website.
 
Q_Goest said:
And third, it don't believe it [will] improve efficiency. I'm not absolutely sure about the efficiency part, but I know there have been discussions in the ME forum about this. Might want to do a search in the engineering forums, there was a discussion not too long ago.
It won't. The fuel/air mixture is precisely controlled to provide exactly the amount of oxygen necessary for efficient combustion.
 
Quadruple Bypass said:
is it possible to separate oxygen from air?

in other words, getting pure oxygen from air


Yes, try breathing :wink:
 
  • #10
russ_watters said:
It won't. The fuel/air mixture is precisely controlled to provide exactly the amount of oxygen necessary for efficient combustion.
Don't understand what you mean; if you can introduce more oxygen in the combustion chamber, you can also introduce more combustible, so you have more power.
For "spark ignition" engines (example gasoline engines) there would be the problem to control pre-ignition and detonation, but for "compression ignition" engines (example Diesel engines) there wouldn't be such problem and power would increase dramatically, and pollution would decrease dramatically.
 
  • #11
lightarrow said:
Don't understand what you mean; if you can introduce more oxygen in the combustion chamber, you can also introduce more combustible, so you have more power.
If that's the goal, a turbocharger does a great job of doing exactly that.
...and power would increase dramatically...
Yes.
...and pollution would decrease dramatically.
Why? You've changed nothing about the chemistry of the combustion.

Depending on how you think about it, a turbocharger may increase or decrease fuel consumption. A turbocharger does increase the thermodynamic efficiency of an engine, but the net effect of adding a turbocharger to an existing engine is and increase in power and an increase in fuel consumption. But if, for example, you are looking for a car with 250hp and your choices are a 3.6L V6 and a 2.0L turbocharged 4cyl (both generating 250hp), the turbo 4cyl will use less fuel.
 
Last edited:
  • #12
russ_watters said:
Don't understand what you mean; if you can introduce more oxygen in the combustion chamber, you can also introduce more combustible, so you have more power.
If that's the goal, a turbocharger does a great job of doing exactly that.
Have you ever heard of using compressed N2O injected in the combustion chamber to increase power? O2 it's not used just because the bottle/cylinder contains less of it so it finishes soon.
...and pollution would decrease dramatically
Why? You've changed nothing about the chemistry of the combustion.
You don't change the chemistry but you change the physics. You have much less HC with an higher percent of oxygen, because the combustion is more efficient (O2 is less diluted by N2); furthermore, if N2 percent is very low, you would have much less NOx.
 
  • #13
if you get the right mixture of fuel and oxygen the combustion is more efficent like with cutting tourches in short is what he is looking for the fuel to oxygen ratio is the key
 
  • #14
This thread is over a year old.
 
  • #15
wouldn't introducing high oxygen concentration to an ICE increase NOX; therefore increasing pollution? Or having to get a bigger EGR valve
 

Similar threads

  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 17 ·
Replies
17
Views
2K
Replies
4
Views
2K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 25 ·
Replies
25
Views
4K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 4 ·
Replies
4
Views
3K
Replies
3
Views
3K