Solid Fuel Production from Semi-Natural Grassland Biomass—Results from a Commercial-Scale IFBB Plant

Abstract

Biomass-based energy accounts for a notable share of renewable heat and electricity generation in Germany. Due to limited alternative uses, biomass obtained from management of semi-natural grasslands is a potential feedstock. Technical and environmental limitations exist in using this biomass for combustion, due to the presence of harmful elements. Converting biomass using integrated generation of solid fuel and biogas from biomass system (IFBB) produces a solid fuel with lower concentrations of harmful elements and a press liquid usable for biogas generation. In this study, solid fuel generation with a commercial scale IFBB unit was investigated. The concentration of harmful elements such as N, S, Cl, and K in the solid fuel was significantly reduced compared to the original biomass silage. Emissions during combustion of the solid fuel briquettes were below German legal thresholds. Elemental concentration of solid fuel obtained from commercial scale process had a significant improvement in removal rate of harmful elements than the prototype. Hence, the limitations of using semi-natural grassland biomass as an energy source were overcome. The commercial scale IFBB plant could be used in practice to handle large volumes of green residual biomass by converting it into a solid fuel with favorable fuel properties.