Technology overview of biogas production in anaerobic digestion plants: A European evaluation of research and development

Anaerobic digestion (AD) technology is used commercially around the world, especially in Europe, which has set some challenging targets to diversify its energy mix with more renewable energy. This study intends to demonstrate, through technology prospecting, the relation between academic research (published articles) and technology development (patent applications) evolved from 1990 to 2015. Published articles were classified under the topics and wastes they cover, which include manure, agricultural and food waste, wastewater, sewage sludge and the organic fraction of municipal solid waste, with the last of these often being associated with co-digestion processes. Meanwhile, the patents in the area are mostly for equipment of the AD process and new methods or means of purifying the biogas obtained. It was found that the patents filed in Europe tend to protect their innovations only occasionally in countries outside the EU. Germany is the clear leader in all the areas of research and the commercial applications of the technologies, followed by Italy, Spain and Sweden. This study also demonstrates the immense potential of biogas throughout Europe, not just for energy generation, but also as a fuel and a by-product of the treatment of different kinds of waste.