Use of modeling to aid design of a two-phase grass digestion system

► Hydrolysis is proportional to retention time and sprinkling rate. ► The size of a leachate collection tank does not affect the methane yields. ► A methane yield of 370 L CH4/kg VS may be achieved at a sprinkle rate of 800 L/d and a retention time of 30 d. ► Shorter retention times increase daily methane production, but lowers specific methane yield (L CH4/kg VS).