Circular viticulture: transforming grapevine waste into sustainable fibers

Annually, around 31.95 million tonnes of grapevine prunings are produced worldwide as agricultural waste. These prunings are mostly underutilized and are typically either burnt or left to decompose, contributing to greenhouse gas (GHG) emissions, air pollution, and resource inefficiency. Burning grapevine prunings releases particulate matter (PM), carbon monoxide, methane, and volatile organic compounds (VOCs), all of which contribute to air pollution and global warming. Meanwhile, decomposition emits methane (CH₄), carbon dioxide (CO₂), and nitrous oxide (N₂O). Overall, these disposal methods result in greenhouse gas (GHG) emissions ranging from 3.05 to 58.44 million tonnes of CO₂-equivalent CO₂-equivalent (CO₂e) annually. Aimed at tackling environmental challenges through valorization of lignocellulosic pruning biomass, this study introduces an innovative cradle-to-cradle approach- by using vineyard waste as raw material for production of high-performance natural fibers. Fibres were extracted using an optimised sodium sulphide (Na₂S) treatment and further refined through peroxide bleaching and hydro treatments. The fibres obtained were analysed for their morphological and physio-mechanical properties. With a tenacity of 3.50–4.84 g/d, bark fibres exhibited good mechanical properties comparable to those of jute, flax, and banana. Additionally, their moderate fineness suggested suitability in textiles and spinning. In contrast, the coarser and weaker core fibres indicate potential for use in nonwovens, composites, insulation, and packaging applications. Substituting 9.93–22.43 million tonnes of common cultivation based cellulosic fibres with agro waste based grapevines fibers has the potential to save 7.94–40.37 million hectares of land, conserve up to 201.87 billion gallons of water, and avert 2.68–42.62 billion tonnes of extra CO₂-equivalent emissions. Moreover, valorization of waste grapevine prunings offers rural employment opportunities and supports climate as well as economic resilience in grape-growing regions. This study contributes to circular viticulture and aligns with Sustainable Development Goals 8, 9, 12, 13, and 17, along with COP 29’s objective of bridging the finance gap and COP 30’s agenda of sectoral decarbonization.