In the Reed sweetgrass - from a problem on the shores to a resource project, the utilization possibilities of reed sweetgrass (Glyceria maxima) for biofuel production (biogas and bioethanol) and as raw material for biochar were investigated. The laboratory experiments related to the utilization possibilities were carried out in the HAMK Bio research unit in the laboratories of the Hämeenlinna University Center. The biomass of reed sweetgrass was collected for analysis and utilization application testing several times during the project between autumn 2020 and spring 2022. Biomass was preserved either by freezing whole plants or by separating leaf, stem and root mass. For application testing, leaf and stem biomass was used, which corresponds to mowing material. Dry matter and ash concentrations were analyzed from the biomasses collected at different times. In addition, the monitoring of the natural drying of the biomass was carried out, i.e. the reduction of the water content of the biomass stored in outdoor conditions (between 28.8. and 8.11.) was measured. CHNS (carbon-hydrogen-nitrogen-sulfur) concentrations and carbohydrate and lignin concentrations were determined for reed sweetgrass biomass. The biogas production potential of the biomass was determined using the automatic AMPTS (Automatic Methane Potential Test System) equipment, which resulted in the total amount of methane production and the formation as a function of time. Determinations were made separately for leaf, stem and root biomass. Dried reed sweetgrass was pyrolyzed at two different temperatures (520 and 700 C) and the mass and carbon yield of the produced biochar was determined. CHNS analyzes were performed on the feed and biochar products. The bioethanol production potential of reed sweetgrass was investigated by pre-treating the biomass with pressurized hot water extraction and enzymatically hydrolyzing the pre-treated biomass. The amounts of reed sweetgrass biomass were measured in different water bodies and in several different contexts during the project. Based on the measurements, an average estimate of the biomass yield was obtained, on the basis of which a region-specific energy yield analysis (biogas and bioethanol) was carried out. A local operating model was drawn up for small-scale biochar use.

2022