Small Engines (Lawn Mowers, etc.): fuel system, methane gas, college buddies

Question
What is an alcohol additive that is distilled from methane gas and used for gasoline?

Answer
I'm not sure...I'm a math major with lots of EE credits by formal education.  I have had minimal education in chemistry or chemical engineering.  

Have you tried the motorcycle web groups?  I know there are a few chemical engineers on those groups.
If you have trouble finding info I can email some college buddies who test fuels...they will know but it may take a couple of weeks to get it touch with them.
Let me know next week if you can find the answer to you question.  I will send out some emails this week and see what I get.
Eric