Extruded Porous Protein–Lignocellulosic Blends as Fully Bio-Based Alternative to Single-Use Absorbent Plastics

TL;DR

Researchers developed a fully bio-based, porous material from biomass waste that can absorb more saline solution than existing synthetic absorbents, offering a sustainable alternative to single-use plastics.

Contribution

A novel, fully bio-based absorbent material is created using extrusion of proteins and lignocellulosic waste, achieving record absorption performance.

Findings

Extruded materials with oat husk show 1.5 times higher saline absorption than the reference.

Delignified oat husk and wheat bran improve absorption by 2 times.

Adding 20% keratin fibers from food waste achieves 6.5 g/g absorbency, the highest reported for extruded protein-based materials.

Abstract

Sustainable technologies
have enabled the production of degradable
single-use plastics (SUPs) for various applications. However, environmentally
friendly, porous disposable absorbents still lack the competitive
functionality of synthetic options. In this work, we report the continuous
extrusion of fully biopolymer-based porous absorbents derived from
integrated proteins and lignocellulosic residues, all sourced from
biomass waste. The results show that the saline absorption capacity
of the extruded materials increases 1.5 times compared to the reference
solely by including oat husk, a lignocellulosic byproduct from the
food industry. The absorption was further improved 2 times by including
a delignification step on the oat husk and wheat bran, demonstrating
the importance of the biomass’s chemistry in increasing the
material’s absorption. Here, the addition of 20 wt % of Keratin
fibers from food waste increases the material’s absorbency
to 6.5 g/g, with the ability to retain 2 g/g of the saline solution
in its structure, which is also the highest reported value for extruded
protein-based formulations so far. This work advances the development
of porous absorbent materials with competitive performance, utilizing
industrial methods and upcycling undervalued biomass waste into sustainable
consumer products. Introducing porous biopolymer-based materials as
alternatives to synthetic counterparts used in the hygiene and sanitary
industries ensures the return of safe molecules to nature, paving
the way for microplastic-free, single-use, porous absorbents.

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