Recent research published in the journal Bioengineering has unveiled a promising approach for converting vine shoot biomass into valuable fermentable sugars, which could significantly impact the energy sector and contribute to a more sustainable bioeconomy. Led by Raquel Cañadas from the Advanced Biofuels and Bioproducts Unit at the Research Centre for Energy, Environment and Technology (CIEMAT) in Madrid, Spain, the study explores the use of choline chloride-based deep eutectic solvents (DES) to enhance biomass fractionation and sugar production.
Vine shoots, a byproduct of grape pruning, represent a substantial yet underutilized source of lignocellulosic biomass. With approximately 1.2 tons of vine shoot waste produced per hectare annually, this research highlights the potential for revalorizing this agricultural residue. Cañadas emphasized, “The revalorization of vine shoots as raw material in a biorefinery can contribute to making a sustainable use of an abundant residue that needs adequate disposal.”
The study investigated two specific DES mixtures: choline chloride with lactic acid (ChCl:LA) and choline chloride with ethylene glycol (ChCl:EG). By optimizing various pretreatment conditions, including temperature, solid-to-liquid ratio, and particle size, the researchers achieved impressive carbohydrate conversion rates. Notably, the ChCl:LA mixture yielded conversion rates of up to 75.2% for cellulose and 99.9% for xylan, indicating its effectiveness in breaking down complex biomass structures.
One of the standout aspects of this research is the incorporation of a washing solvent, specifically a 50% acetone/water mixture, which further enhanced delignification, increasing the recovery of lignin—a valuable byproduct in its own right—by up to 31.5%. This dual recovery of sugars and lignin presents significant commercial opportunities, as both components can be utilized in various industries, including biofuels, pharmaceuticals, and materials.
The findings underscore the potential of using green solvents like DESs in biomass pretreatment processes, which are often more environmentally friendly than conventional methods. Cañadas noted, “This study presents an eco-friendly technology for efficient vine shoot biomass fractionation, yielding valuable fermentable sugars and facilitating lignin recovery.”
As the energy sector continues to seek sustainable solutions, this research offers a pathway for utilizing agricultural residues in biorefineries, thereby reducing waste and promoting a circular economy. The use of vine shoots not only addresses waste management issues but also supports the production of renewable energy carriers and bio-based products.
In summary, the work conducted by Cañadas and her team highlights an innovative approach that could reshape how agricultural residues are perceived and utilized, paving the way for a more sustainable and economically viable bioeconomy.
