International Hydrogen Technologies Congress, Edirne, Türkiye, 20 - 23 Haziran 2019, no.315, ss.109
Lignocellulosic biomass consists mainly agricultural and forestry residues which are considered to be the most abundant, economical and substantial feedstock for renewable energy production. Therefore, it has low cost and does not compete with food chain and animal feed. Lignocellulosic biomass includes high amounts of carbohydrates, cellulose and hemicelluloses, which can be converted into various forms of energy such as bioethanol, biobutanol, biohydrogen and biogas. The amount of the cellulose and hemicellulose varies according to the type of material used. Sunflower straw has approximately 30% cellulose, 15% hemicellulose and 30% lignin content, making it a very suitable resource for energy production. Before hydrogen and alcohol production, pre-treatment methods which relatively increase the cost of manufacture processes should be applied to disrupt the complex structure of lignocellulose and convert the carbohydrate polymers into fermentable sugars. Although the pretreatment stages may seem to cause extra costs, agricultural wastes are the most feasible feedstock because of being a very cheap source, having a high energy potential, and the greenhouse gas emissions that are emitted to the environment are much lower than the fossil sources. This study evaluates that it is more feasible to produce hydrogen or to produce alcohol from lignocellulosic wastes in terms of environmental impact, energy efficiency and economics.
Keywords: Lignocellulose, biohydrogen, bioethanol, biobutanol, theoretical energy potential