Biomass Generation

I am doing a research project on the possibility of Biomass generators and anaerobic digestors scaled to small and medium sized businesses. I have found lots of information about large scale biomass power generation plants, but the fuel for these is often grown specifically for that purpose. I would like to research a more efficient way to transform organic waste directly into energy with minimal environmental impact.
Does anyone have any information that might be useful to my search? I would appreciate any help I can get.