8. Bioconversion process for lignocellulosic materials to bio-hydrogen and methane

Based on average composition of lignocellulose, 35–50% cellulose, 20–35% hemicellulose, and 10–25% lignin [220], bioconversion processes for cellulose into hydrogen and methane through dark fermentation, photo-fermentation, sequential dark fermentation-photo-fermentation, and AD are presented (Figure 4). Starting with 1000 kg of lignocellulosic biomass containing 35–50% cellulose, 193.4–276.3 m3 of hydrogen is obtained by dark fermentation, 580–828.8 m<sup>3</sup> of hydrogen is obtained by photo-fermentation and a sequential dark fermentationphoto-fermentation, and 145.0–207.2 m<sup>3</sup> of methane is obtained by AD.
