Small Cng Storage Cylinders

Have you looked here: Search GlobalSpec?

A gallon's not much.

You will find a few Small Cng storage cylinders manufacturers in this link.

For others GGE = Gasoline Gallon Equivalent. And in this case that would be a US gallon (1 UK gallon = ~1.2 US gallons)

FROM http://www.consumerenergyreport.com/2009/06/19/how-much-natural-gas-to-replace-gasoline/

_______________________________________________________________________

"A gallon of gasoline contains about 115,000 BTUs. (Source: EPA). The energy
content of this much gasoline is equivalent to 45 trillion BTUs per day. The energy
content of natural gas is about 1,000 BTUs per standard cubic foot (scf)."

_______________________________________________________________________

So at just over 100 atmospheres you will require about a cubic foot of cylinder storage to be equivalent to one US gallon of gasoline.

See the links from other posts above for cylinders.

You may want to look at "lecture cylinders" and "pony bottles". Both are small, high pressure cylinders. Pony bottles are used by SCUBA divers as a back-up reserve of breathing air. Lecture cylinders are as the name implies.