Q:

Can this world invent gas cylinders early?

QUESTION
I'd like a nation in the world I'm working on to be able to transport natural gas and hydrogen, for fuel and possibly ballooning. Natural gas pipelines and cylinders were first invented in ancient China, but while impressive, these were rather leaky. I'd like it if the inhabitants of this world could store gas over time, and transport it over distance, rather than relying just on proximity to a reserve.

Can my world invent reliable gas cylinders early? How large and efficient could they potentially make them?

NOTES
In general, the technology hovers between classical and medieval, but there are some important exceptions. They possess most metals and woods, but there are large regions of the world that do not have iron or nickle, and this culture may eventually be included among them. In terms of relevant unusual materials, assume also they have:

Vulcanized rubber, from sulfur.
Bamboo and silk equivalents. 

They are familiar with creating relatively complex devices from building automated textile mills and similar technologies. There are good conditions for the exchange of ideas and invention in general. Chemistry, in particular is ahead of the game, so other materials may be available if necessary and plausible. Otherwise I prefer to keep things as outlined.

Finally, this question is related, but distinct.

A:

Vessels capable to withstand pressure, that are simultaneously reliable and cheap are pretty hard to manufacture.
But you do not need pressure to use and transport gases. This is how 19th century limelight looked like:

(A) is a sack made out of skin and filled with hydrogen. Weight (B) provides pressure.
Similar technology was used in 20th century as well. This is car that stores gas in a sack on its roof(other examples):

A:

Make your gas on site via hydrocarbon cracking.
https://en.wikipedia.org/wiki/Cracking_(chemistry)
It requires some spiffy tech to compress gas and keep it compressed.  But it takes very little tech to tote an urn of crude oil around.  Long chain hydrocarbons (like crude oil) can be "cracked" into smaller molecular weight fractions.  This is done industrially using heat, pressure and catalysts.  Your primitives have discovered a mineral which serves as a catalyst to enable low temperature cracking of long hydrocarbons.  When they set up their balloon, they can set up the cracking pots underneath and let the warm methane and hydrogen float up into the balloon.  
For a work of fiction, having urns of black goo and weird chemical reactions might be cooler than Flintstonesque bronze CO2 tanks.  

