Optimization of the anaerobic digestion process of mechanically pretreated algae

The anaerobic digestion of algal biomass is restricted by its complex lignocellulosic structure. In order to reduce the feedstock particle size and to increase the biomass’ specific surface area available to the microorganisms, this paper investigates the mechanical pretreatment effect on the anaerobic digestion process of P. canaliculata seaweeds using the response surface methodology (RSM). Results show that a 60 mins of mechanical pre-treatment has resulted in 74% improvement of methane yield compared with the methane yield obtained from untreated algae. A multi-objective optimization study was carried out with the aim of maximizing the methane yield while minimizing the pretreatment cost. The optimal solution was achieved at 50 min of pretreatment where the net energy at this point was found 2.49 Wh/gVS, a value 28% higher than for untreated algae.