http://uk.ask.com/web?q=flammable+gas+compressors&search=&qsrc=0&o=312&l=dir&siteid=

Biogas itself as dangerous as it's highly flammable. Try compressing a mixture of biogas and air at pressure and see what happens next. On second thought, don't try it. The results would be very messy to say the least.

i've use an automotive type air conditioner compressor to pump biogas into cylinders. Note the cylinders were first purged. I would not recommend introducing biogas into a city gas network. If you are producing biogas you are in control of the gas quality, filtration, and impurities. In other words, consistency of the product. Who knows what you'll get mixing with an unknown? Would it even be legal? In other words, the ownership of the "other" gas network. You would be upsetting the constistency of their product as well as your own. Their product is undoughtably impure. Your product is undoughtably impure. Who knows what you could get by mixing? People think me crazy for working with flamable/compressed gasses. Even i wouldn't mess with it.

Help-help- here comes another first time poster wanting to do God knows what with an explosive device. And he wants our advice. My lawyer says run like hell. Any advice from us, and when the whole thing blows up and kills people, he says "but 'they' told me to do it!" run,run,run.

Walter, read post #1 and don't do anything until you know what you are doing.

Hydrogen sulfide

If you want pressurized biogas you may consider having a floating head roof on your bio gas generator. Simply put an inverted barrel with a weight on it floating in water can be used to collect gas generated.

Mixing up city gas network and yours may give us the unpleasant news. You have good advice here. So please do NOT do it.

Why would you want to back feed the city natural gas supply in the first place?

What would you possibly gain or accomplish with this action?