What's it made of?

[jerjonas]

How much natural gas does it take to make 1 gallon of ethylene glycol?

[Clanad]

Actually, ethylene glycol isn't made directly from natural gas. The compound <i.ethylene (H2C=CH2) is a gas, made from natural gas (as one source), and is building block of ethylene oxide, which is produced by oxidation of ethylene in the presence of molecular oxygen. There are a number of methods of synthesizing ethylene oxide into ethylene glycol... to lengthy to explain here. So, trying to determine your equation isn't possible, in my opinion, beyond a very general and meaningless estimate...