By the way : "pain" in french means "bread" :)
Introduction
Jean Pain was a self taught Frenchman who designed a means of achieving (at least partial) energy autonomy, using inexpensive biomass fuel, with a mere mound.
The principle
Pile a mound of vegetal waste and wait : after a while, an anaerobic fermentation will take place, emiting heat and smell. The smell is methane gas. After a further wait, the mound will turn into a fertilizing compost. Now grind the material in bits 2-3 mm thick. Build the mound ; the aerobic fermentation taking place is odourless and yields more heat. Jean Pain simply placed ground material inside a steel tank fitted with a pipe ; the tank was in turn placed into a ground material mound.
What does he get out of this ?
- Methane. The pipe from the tank drives the methane produced in anaerobic fermentation to truck air chambers to be stocked. Enough gas is produced to cook and power a (small french) car.
- Hot water. An additional copper tube is coiled around the tanks and uses the heat that both aerobic and anaerobic fermentation provides to heat water running thru it. Enough to use for sanitation and house heating.
- Compost that can be used for home farming or sold.