Vine prunings agro – energetic chain: Experimental and economical assessment of vine pellets use in gasification power plants

Vine prunings are a very abundant by product of the wine industry and their production can be estimated to be between 1 to 5 ton/year for every hectare. In the view of a decarbonisation and the development of the circular economy this biomass should become an opportunity even if in most of the cases it ends up being a problem. This is due to their common burning in situ that has a huge environmental impact, and to their shredding when left on the field that can be an infection source in presence of grape diseases. This work follows the one presented the 26th EUBCE “Gasification and wine industry: Report on the use vine pruning as fuel in small – scale gasifiers” where it was evaluated the possibility of producing electrical energy using this biomass as fuel in APL PP20 gasifier – engine system. The results of the previous work showed quite promising results about the gasification efficiency and the quality of the gas produced using this biomass, however the difficulties encountered during the reactor feeding and the bridging problems have made this process quite challenging. In order to overcome these issues, it was considered the possibility of pelletizing this biomass. More than 2.5 ton of pelletizing vine prunings were successfully gasified with a quite high efficiency, 1.1 kg consumed for every electric kWh produced. The 150 kg of biochar produced through the process were tested on a vineyard as soil improver. The entire supply chain, from the harvesting of the vine prunings on the field, to the pelletization and gasification, was economically evaluated considering different possible scenarios and some of them were quite profitable and therefore practically feasible.