Have you got the right question here?
Ethylene glycol is used to remove moisture from Natural gas.
If you actually want to calculate this you should note that it is prepared by the oxidation and subsequent hydrolisis of ethylene
http://www.ucc.ie/academic/chem/dolchem/html/c omp/glycol.html
You therefore need to calculate how much ethylene you need and how much natural gas you need for that amount of ethylene.
This is complicated by the fact that cracking techniques allow larger polymers to be split to more desirable fractions so it rather depends if you're mean how much would it take if you used the natural gas to it's greatest efficiency or whether you just took what you needed from a typical refinery operation