Is that a "censored" scene from porn?

Except your wrong.

The lungs use passive transport, not active transport. The CO2 is not pumped away like it is in a car engine. It is not pumped at all. It's just left to mix around due to diffusion.

Your body is not spontaneously creating CO2 gas in any meaningful quantity (there's not enough to exhale). If it did, I could tape your mouth/nose shut and your lungs would quickly EXPLODE. Fuckin' metal, but it doesn't work that way.

The amount of CO2 in your blood stream is TINY compared to the amount of air your need to inhale or exhale. You need that much because diffusion is a very, very slow process, so you need to have it happening in shittons of places at the same time to keep up.

Think of purple kool-aid being continuously poured into a running sink. As long as enough water is being poured, the purple drank mix is washed away down the drain. If the water is turned down (or stopped completely), the kool-aid will start to build up. Too much purple drank and you die.

inb4myterriblegrammar

Tecnically (I LOL'd when you used that word, like you had any technical idea about this), this would not happen. The CO2 exchange is only produced by diffusion. That is, by a lower pressure of CO2 in the outside (air) than in the inside (epidermic cells in the lungs). It is NOT an active transport, but passive. As soon as the CO2 rises its concentration to certain point in that bunch of air you're not going to exhale, it will block the CO2 in the cells from coming out passively any more. And the renewal of air that is naturally produced through air current without respiration will not be enough to lower the concentration on the stored air enough to enable the exchange, either.
AH, and if you expect the infinitesimal increase of pressure produced by the initial CO2 passive dump to rise the pressure in the lungs enough to produce air renowal by itself, you clearly don't understand why we exhale.
"Technically". LOL.

found the 12 years old that just read some biology books of his sister

Pretty smart 12 year old then since he's absolutely correct.

We exhale currently because passive CO2 buildup and release is not possible, as we still need to empty the lungs to take in oxygen. The thing we're talking about here is a chemical that oxygenates your blood without the need to inhale more air. Therefore you my sir are an idiot. You also appear to contradict yourself in your own statement.

Actually, anon was correct, though not very good at explaining it.

CO2 is passed from the blood into the air (in the lungs) due to diffusion. The concentration in your blood is higher than that in your lungs. CO2 will (like pretty much everything in nature/physics) follow the concentration gradient and pass out of the blood-stream into the air.

If you don't physically breath, the concentration in your lungs will quickly increase to match that of your body. After this occurs, your body is no longer able to remove the CO2 and it builds up in the blood stream. This build up lowers the pH of the blood (more acidic) and causes Respiratory Acidosis. In short, your blood becomes more acidic than it should be and you die.

If I locked you in an air-tight box, there would still be plenty of oxygen in the box when you die. The rise in CO2 levels would be what killed you.

So next time, before you call someone an idiot, please be sure you're not wrong.

PS: Look up Apollo 13. Yes. The fucking NASA spacecraft. There was an extremely famous problem with the flight.

They had to jury rig a CO2 removal system. Not an oxygen system. A CO2 scrubber. They had plenty of oxygen, but the astronauts almost died because of the CO2.