Researchers from the University of Alicante (UA), in collaboration with the Polytechnic University of Valencia (UPV) and international partners, have developed a new photocatalytic process that transforms lignin—one of the most abundant components of plant biomass—into valuable biobased chemicals and biodegradable materials. The research, published in Nature Communications, could help unlock new opportunities for circular manufacturing, sustainable materials development and additive manufacturing.

Unlocking the Potential of Plant Waste

Lignin accounts for approximately 30% of plant biomass and is generated in large quantities as a by-product of agriculture, forestry and paper production. Despite its abundance, its complex molecular structure has made it difficult to process efficiently, limiting its use in commercial biorefineries.

The research team addressed this challenge by developing a photocatalyst based on anthraquinone, a low-cost and highly stable material. Activated by ultraviolet light, the catalyst selectively breaks down lignin under ambient conditions. Integrated into a continuous-flow reactor, the process enables scalable and energy-efficient conversion of plant waste into higher-value products.

According to the researchers, the technology uses only light and mild operating conditions to selectively fragment lignin, creating a more sustainable alternative to conventional petrochemical production routes.

From Lignin to Vanillin and Bioplastic Additives

One of the primary outputs of the process is vanillin, the aromatic compound responsible for the characteristic scent and flavour of vanilla. The team reports a record yield of 7.1% by weight, corresponding to the recovery of 94% of the available aromatic monomer units present in the lignin.

Beyond vanillin production, the researchers also found a use for the remaining lignin-derived fractions. Rather than treating these residues as waste, they converted them into biodegradable plasticisers for bioplastics, creating a fully integrated zero-waste process.

Enhanced Performance for PLA and 3D Printing

At UPV, researchers focused on incorporating the lignin-derived additives into polylactic acid (PLA), one of the most widely used biobased polymers in industrial manufacturing and 3D printing.

Laboratory testing showed that the renewable plasticisers improved flexibility, mechanical strength and shape-memory behaviour while maintaining processability. The materials were successfully used in additive manufacturing applications, including the production of a fully functional biodegradable smartphone case.

The development could be particularly relevant for product designers and manufacturers exploring more sustainable alternatives to conventional plastic additives in 3D printed products and components.

Towards Circular Biorefineries

The researchers believe the technology represents an important step towards the comprehensive valorisation of lignin within future biorefineries. By converting agricultural and forestry waste streams into both specialty chemicals and high-performance bioplastic additives, the process supports the principles of circular economy and resource efficiency while reducing reliance on fossil-derived materials.

As demand grows for renewable feedstocks and lower-impact material solutions, innovations that enable the full utilisation of biomass residues may play an increasingly important role in the transition towards more sustainable manufacturing systems.

Source & images: University of Alicante