Simple designs for DIY home biogas generation?
The other task is "to design an efficient and neat anaerobic digester to market to middle class families." I say "DIY" because making these of simple and widely-available materials is clearly preferable to involving lots of expensive parts.
Collectively we seem to have a good deal of expertise on similar subjects- biodiesel, algae growing and so on, so I wondered if anyone knows enough about biogas to be able to comment on whether a simple design (possibly something like the Appleseed biodiesel processor) could be practical. Any lateral thinking on how to overcome the limitations of small batch processing would also be great.