Terpene boiling points

Hello community! So I have been doing research regarding the boiling points of the various terpene isomers but I have been finding conflicting info. My question is identical to the one posted in the link below, but I am curious about terpenes instead of THC.

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Caryophyllene seems to be the lowest. 264 to 266° F at 14 mm Hg. Found in section 4.2

I wonder how much higher it is at atmospheric pressure?

With all the terpene bps being so high, why are significant amounts lost evacuating solvents with much lower bps like ethanol or acetone?


Check this out, I hope it can shed some light.
Smaller structures need less vapor pressure to evaporate, it’s not about the boiling point. It is the entropy of vaporization.


Please allow me to give some unsolicited advice haha not always based on size. Imagine ethanol or water and butane, pentane, or hexane. The latter molecules are all larger than ethanol/water however ethanol has the higher bp. This is due to hydrogen bonding! Which is a cool concept!

Additionally you are pretty on point i think to the whole boiling/vaporizing thing but I will clarify yet again with an statement not asked for… Vaporization occurs when the vapor pressure=atmospheric pressure. This is why pulling vaccum allows for easier vaporization. You are lowing the pressure of the atmosphere!


Because when you evaporate two or more compounds together, they affect the partial pressure, so the “boiling point” (more properly the bubble point) is different from that of either pure component. Look up Raoult’s law. Even when two compounds are immsicible, they form a heteroazeotrope and the ratio of vapor pressure affects the bubble point and vapor composition.


have you seen the studies using co2 to break ethanol-water azeotrope by high pressure distillation? i ask cause the role of vapor pressure and enthalpy of vaporization are key and im trying to wrap my head around it
r Azeotropic Mixture Separation by Phase Behaviorye2013.pdf (2.5 MB)

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What a great response! That makes sense, so the bubble point of the solution is dependent on the ratio or percentage of solutes in the solution. I guess the only way to find a definite answer is to look at each strains terp profile individually, instead of each terpene by itself


That’s right. Note however that the solvent interacts as well, not just the solutes.

Careful also about which temperature you seek knowledge about, the pot liquid temperature or the condensing vapor temperature, they will be different. The mass transfer and heat transfer characteristics of the device will impact all of this, in addition to the vapor liquid equilibria. Many people assume “equilibrium” for distillation, but in most cases it is really “rate based” which is driven by mass transfer phenomena. There is a chance there is pressure drop from the heating flask to the cold trap. Anyone tracking this during their runs? The pressure has an affect on VLE too.

There are well established methods for determining VLE for multicomponent mixtures. Taking a mixture of terpenes and doing those experiments might be helpful, but maybe not. Can share some articles when I did them out. I’ve seen research labs charge up to $100k for a single study.

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topic not found :frowning:

Shoot, it worked a year ago!

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What about pressure swing distilatation to seperate azerotropic mixtures?