An April 2006 Directive in Europe sets new rules for management for farming residues in compliance with the European Nitrates Directive. The new regulation limits the quantity of manure that can be spread on land in relation to the concentration of nitrogen in farms. In order to comply, the implementation of various technologies that will replace the application of manure is needed now more than ever, such as fertilizers. One technology is thermo-chemical management for poultry litter which produce energy and anaerobic digestion, but have a different effect in terms of N-removal in that the former leads to N2 emissions, leaving only a relatively small amount of ash to be managed, while the latter produces a digested liquid effluent with unaltered N concentration. Improvements in thermo-chemical conversion including gasification and pyrolysis will be however be available. On the other hand, anaerobic digestion has many advantages, including lower odor impact, lower phytotoxicity, less pathogens and good fertilizing properties than raw manure and production of energy results in income generation.
