Perennial Grasses as a Substrate for Bioethanol Production

One of the possible choices as a biomass for lignocellulosic bioethanol production are different perennial grasses. Cultivating this type of biomass has many advantages in terms of natural diversity and landscape protection. In this study, mixture of red clover and timothy grass was used as a feedstock to investigate its potential as a substrate for bioethanol production. Traditional three step bioethanol production process was used in combination with NED pretreatment. The results show at all pretreatment temperatures similar glucose concentrations and hydrolysis efficiencies, which varied from 4.3 to 5.1 g/l and 15.2 % to 17.7 %, respectively. The ethanol yield, on the other hand, decreased as the pretreatment temperature increased. However, the mass balance revealed that when using this kind of feedstock, 3.3-4.0 g ethanol could be produced from 100 g of biomass. The overall efficiency and yield of the process was lower than expected due to pretreatment, which might not have been suitable for soft biomass.