Now the comets are much closer to the sun-nearer to Jupiter's orbit-so the volatile gases on the surface have already been "baked off" by the time scientists can see them, Jewitt said. "That's why I think K2 is the most primitive comet we've seen." from article
Finally a good article.
When applying the chemical composition of the tail comet, the ambient temperature should be taken into account. Between Uranus and Saturn is about 60 ° K. At these temperatures there is no CO, CO2, CH4, etc.

Now the comets are much closer to the sun-nearer to Jupiter's orbit-so the volatile gases on the surface have already been "baked off" by the time scientists can see them, Jewitt said. "That's why I think K2 is the most primitive comet we've seen." from article
Finally a good article.
When applying the chemical composition of the tail comet, the ambient temperature should be taken into account. Between Uranus and Saturn is about 60 ° K. At these temperatures there is no CO, CO2, CH4, etc.


A) Kelvin is not reported in degrees
B) You are claiming the temperature of space between Uranus and Saturn is 60K? Where'd you pull that from?