Evaluation of selected Miscanthus genotypes for biogas production as a possible solution of regional bioenergy

Abstract

Plantations of fast-growing crops represent local agroecosystems providing provisioning services in the form of phytomass that can be utilized for energy and/or non-energy purposes. Permanent grasses such as Miscanthus are identified as potentially suitable sources of raw materials for the output of second-generation biofuels. The experiments focused on the production ability of the perennial energy grass Miscanthus were performed in the region of SW Slovakia. It was confirmed that the studied genotypes (Miscanthus sinensis Tatai and Miscanthus × giganteus) exceeded the cost-efficient level of biomass production. The above-ground biomass of the studied genotypes was ensiled and afterwards fed to the experimental fermenters to evaluate the biogas production. The experiments with individual silage mixtures lasted 600 hours. The total amount of biogas produced from M. × giganteus and M. sinensis Tatai silage mixture was 273 dm3 and 328 dm3, respectively. The average share of methane in the biogas of both studied samples of silage mixtures was 51%. On the basis of the 10-year average yields of the studied Miscanthus genotypes achieved in our conditions, it is possible to produce 8 181 m3/ha (M. × giganteus) and 11 248 m3/ha (M. sinensis Tatai) of biogas from the silage mixtures. The achieved production represents sufficient and stable amount of biogas and its use can be economically efficient and sustainable in the long run in SW Slovakia.

Keywords

• anaerobic digestion
• bioenergy
• biogas
• biomass
• miscanthus × giganteus
• miscanthus sinensis tatai