Propane phase change in a container

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Discussion Overview

The discussion revolves around the phase change of propane in a container under varying pressures, specifically examining the behavior of propane when introduced into a nitrogen environment at different pressures. Participants explore concepts related to boiling points, vapor pressures, and the nature of the processes involved (isothermal vs. adiabatic).

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions whether propane would boil when introduced into a nitrogen environment at 10 bara and 5 bara.
  • Another participant seeks clarification on the definitions of "room temperature" and "bara," suggesting a standard room temperature of 25°C and specifying the use of absolute pressure.
  • A participant inquires about the boiling point of propane at 10 bar and its vapor pressure at 25°C.
  • It is noted that the boiling point of propane at 10 bar is approximately 25°C, with a corresponding vapor pressure of 10 bar at that temperature.
  • Questions arise regarding whether the process is isothermal or adiabatic, with a participant asserting it is adiabatic.
  • One participant discusses how the boiling point of propane changes with pressure and states that once the temperature drops below the boiling point, evaporation occurs. They also mention that increasing pressure with nitrogen will not condense the propane unless the temperature is lowered.
  • Another participant confirms the logic presented regarding the phase change and pressure effects.

Areas of Agreement / Disagreement

Participants express some agreement on the behavior of propane under pressure and the nature of the phase change, but there are unresolved questions regarding the specifics of the process and the definitions used.

Contextual Notes

There are limitations in the discussion regarding the assumptions made about the system, the definitions of terms, and the lack of specific data needed to fully resolve the questions posed.

Kirmandarren
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If I had a container containing 10 bara of nitrogen, and pumped in liquid propane at room temperature would the propane boil?
If I carried out the same experiment but this time at 5 bara, what would be the temperature of the material once the propane had completed its phase change i.e would it drop to around 0C and stop boiling, would the liquid then just evaporate into the vapour space?
 
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Room temperature is what? "bara" is what?
 
Bystander said:
Room temperature is what? "bara" is what?
Take room temperature as 25C, I'm using bar absolute pressure rather than gauge
 
What is the boiling point of propane at 10 bar? What is the vapor pressure at 25?
 
The boiling point at 10bar is approximately 25C. The vapour pressure would therefore also be 10 bar at 25C.
 
Is this an isothermal process? Adiabatic?
 
adiabatic process, I'm aware that there isn't enough info to answer the second question. What I was getting at is: the propane liquids boiling point changes due the the pressure above it no matter what it vapour/gas consists of. Once the temperature drops below its boiling point, evaporation takes over. Also if all the propane turns to vapour (not saturated with vapour), by increasing the pressure by addition of more nitrogen (volume remains constant) the propane will not condense, lowering the temperature is the only way to condense the propane. Is the above logic correct?
 
Kirmandarren said:
adiabatic process, I'm aware that there isn't enough info to answer the second question. What I was getting at is: the propane liquids boiling point changes due the the pressure above it no matter what it vapour/gas consists of. Once the temperature drops below its boiling point, evaporation takes over. Also if all the propane turns to vapour (not saturated with vapour), by increasing the pressure by addition of more nitrogen (volume remains constant) the propane will not condense, lowering the temperature is the only way to condense the propane. Is the above logic correct?
Yes
 

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