Biogas Vol 3: A Chinese Biogas Manual

This book contains the ways that the Chinese perfected the process of making methane from organic material. The manual shows you how to dig a hole, make a brick or earth wall and then cover it for continuous production of free methane from the digesting material. This is a very low maintenance system and the Chinese had over 6 million bio digesters of this model working in the late 70’s/early 80’s. This is one beautiful system that you can build in your own backyard.