English summary

The SCARABEO project has innovatively modified the hemp supply chain to increase its sustainability and quality. In particular, the maceration plant has been redesigned to reduce heat loss and the energy expenditure of operations, equipped with sensors for controlling operations, and designed for the reuse of maceration liquids. The maceration itself was carried out in the presence of soldier fly larvae to reduce the mucilage adhering to the fibers, verifying in which conditions these are most effective (10 days of age, 10% by weight, fed for 6 days). The maceration liquid, in view of a possible reuse, was analyzed for phenol and protein content, highlighting a low protein content, which does not make direct protein extraction convenient. The hemp core was carbonized in a pyrogasifier producing an excellent biochar. A small-scale model of a filter with biochar derived from the hemp core was also developed, to be used for gravity filtration of the maceration liquid throughout the process. The particle size of the biochar proves to be a determining factor for the effectiveness of filtration, thus indicating how to operate in the production of biochar from hemp. Biochar has also proved effective as a soil improver for the cultivation of hemp in agronomic tests. The economic sustainability of the entire supply chain, with the production of fiber and the pyrogasification of hemp core, becomes interesting especially if all products are marketed, including energy, biochar and syngas. In particular, the economic benefit due to biochar as a carbon sequester was also taken into account.

Description of project activities:

• Stalks skutching and carbonization of the woody inner core for the production of biochar (mulcher) and syngas (fuel);

• Bast fiber retting, chemical characterization of the retting mixture, and phenolics compound extraction for food and /or pharmaceutical end use. Enriched biochar production by retting waste clarification through biochar filters;

• Retted fibre clean up by BSF larvae controlled digestion and use of the larval biomass for biodiesel and protein panels production, useful for biogas production;

• Agronomic trials for enriched biochar evaluation as mulcher.