The collection and densification of grape vine shoots into pellets

Abstract

Biomass is the third largest source of primary energy in the world, after coal and oil. The main sources of biomass are agricultural and forestry residues, energy crops and organic waste. The biomass used for performing the experimental research regarding the production of briquettes from grapevine shoots was collected from eight varieties within the vineyard of the "Ion Ionescu de la Brad" University of Life Sciences in Iași, with a density of 4347 vines/ha. The average quantity of shoots collected per plant was ranged between 0.327 kg/vine for Cabernet sauvignon and 0.433 kg/vine for Muscat Ottonel. The pellet production process involved subjecting the biomass to high pressures and forcing it through the cylindrical holes of a die, thus forming a solid mass. The experiments yielded the following results: the moisture content of the pellets was 11%, the pellet length ranged between 3.15 mm and 40 mm; the diameter was between 6 ± 0.5 mm for the Fetească regală and Busuioacă de Bohotin varieties, and 6 ± 1.0 mm for Sauvignon blanc. The bulk density ranged from 603.65 kg/m3 for Cabernet sauvignon to 681.63 kg/m3 for Fetească neagră. For all varieties studied, the unit density exceeded 1039 kg/m3. The higher calorific value of the pellets ranged from 18581 MJ/kg for Busuioaca de Bohotin to 19117 MJ/kg for Fetească regală.