Methane (biogas) is a byproduct of a number of green alternatives such as a compost heap. This methane can be captured and processed usefully in small volumes. However it must be compressed to some level that will produce a controlled flow, let's say 14-20 pounds per square inch. In fact the methane could be captured and stored in a bicycle inner tube for later processing.
Anybody got any thoughts on how a bicycle or small aquarium pump could be modified to compress small quantities of methane?