CO2 vs Nitrogen for chilling vessels

[Mosaic_Co-Labs]

Then why can I visually see a liquid when I pour ln2 from a dewar? And how does it appear to remain a liquid for hours on end after I pour it from a dewar into a vacuum trap?

[SidViscous]

@Tech1145

In other words, you cannot take advantage of the latent heat of vaporization of CO2 at atmospheric pressure, the only thing possible is sublimation (solid to gas). This is why vessels using the evaporation of LCO2 for cooling must maintain the jacket pressure above about 75 PSIA.

Very, very good point! Back pressure regulators are our friends!

[Roguelab]

Because the liquid nitrogen at atmosferische pressure boils at-196 and proceeds like all boiling at atmosferische pressure it will not change temp untill all is evaporated