Methane production by anaerobic digestion of algae 1.

It has been shown previously that marine algae Tetraselmis can be transformed into methane by a one step completely-mixed biomethanation process, in a reliable way and with good yields and good methane production rates. This process can be adapted to work equally well in sea water. Based on previous laboratory results, a pilot-scale 1 m**3 digester has been installed by the authors at Lamezia-Terme (Calabria, Italy). A biogas production rate of 1. 33 m**3 gas per m**3 digester and per day (66% methane) has been obtained with a volumetric loading rate of 4 kg volatile solids per m**3 digester and per day and a mean retention time of 14 days. A yield of 0. 25 m//3 methane per kg volatile solids added, has been obtained at a salt concentration of more than 10g sodium per liter with a volumetric loading rate of 3 kg volatile solids per m**3 digester and per day and 14 days of mean retention time.