biogas production for energy in germany residues from food industry prof dr bernd stephan university of applied science bremerhaven anaerobic digestion history starting with utilization marsh gas the 19th century tight drums an diameter about 2 to 3 meter were placed upside down into wet lands collection and cooking similar indian gabor plant beginning around 1920 trucks public services operated compressed sewage sludge fifties ot 20th this was given up due low cost mineral oil last some farmers build plants treatment aninmal wastes technology based on different principles price crisis seventies stimulated broad activities research implementation side agricultural resulted optimized design process performance 200 bulit at that time but could not compete market prices or liquid hydrocarbons policy german federal government now subsidies renewables a result big
