Tuesday, May 12, 2026

Brewer’s spent grain transformed into biodegradable paper: A circular economy solution developed in Ecuador

Escuela Superior Politecnica del Litoral

From Brewer's Spent Grain to Biodegradable Paper: A Circular Economy Approach — image:
Graphical Abstract – Alkaline Pulping Process and Economic-Environmental Impact
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Credit: Alcivar-Reyna et al. / ESPOL

The growing global demand for paper continues to exert pressure on forest resources, while numerous industries generate large volumes of waste with high potential for valorization. In this context, researchers from Ecuador conducted a study demonstrating the technical and economic feasibility of producing biodegradable paper from brewer's spent grain, an abundant byproduct of both traditional and craft beer industries.

Brewer's spent grain is the solid residue remaining after the mashing process in beer production. Although it is typically used as animal feed or discarded, this material features a composition rich in cellulose, hemicellulose, and lignin—key components for papermaking. Harnessing this waste represents a strategic opportunity to transform an environmental problem into a value-added industrial resource.

From Industrial Waste to Sustainable Raw Material

The study evaluated the feasibility of converting brewer's spent grain into paper through an alkaline pulping process using sodium hydroxide (NaOH). For this purpose, residues were collected from various beer styles brewed in Guayaquil, Ecuador, ensuring the representativeness of the analyzed material.

The experimental process included several stages: drying and milling the spent grain, alkaline digestion in two controlled thermal phases, washing, sheet formation, pressing, drying, and final characterization of the obtained material. Subsequently, the physical, mechanical, and morphological properties of the produced paper were analyzed.

The results confirmed that the obtained fibers have suitable dimensions for forming stable paper structures. Microscopic analysis revealed fiber diameters ranging from 10 to 61 micrometers, values consistent with cellulosic materials used in the conventional paper industry.

A Biodegradable Paper with Properties Comparable to Commercial Grades

One of the most significant findings was that the produced paper achieved mechanical properties close to those of commercial papers. Tests showed a maximum tensile strength of 2.26 MPa and an average tear strength of 2.19 N, key indicators of structural durability.

Furthermore, the material exhibited low porosity and a high basis weight, characteristics that suggest potential applications in sustainable packaging, biodegradable products, and alternative materials to traditional wood-based paper.

These results demonstrate that agro-industrial waste can be transformed into functional materials without compromising the mechanical performance required for real-world applications.

Circular Economy Applied to the Brewing Industry

Beyond material development, the research focused on evaluating its economic viability within a circular economy model. Initially, production costs at the laboratory scale were high; however, prospective analysis showed that recovering over 80% of the sodium hydroxide used could reduce the cost to approximately $3.28 per square meter, bringing it closer to industrial competitive levels.

This approach enables closing material loops, reducing waste, and decreasing reliance on virgin raw materials from forest resources. Valorizing brewer's spent grain not only reduces environmental impacts associated with its disposal but also opens new economic opportunities for local industries.

Sustainable Innovation from Latin America

The study aligns with global trends aimed at replacing linear production models—based on extract, produce, and dispose—with circular systems that prioritize reuse and comprehensive resource utilization.

The food industry, particularly brewing, generates large volumes of byproducts rich in lignocellulosic biomass. Transforming them into bioproducts represents a key strategy to reduce industrial environmental footprints and diversify raw material sources across multiple sectors.

Developing non-wood alternatives for paper production also helps reduce pressure on forest ecosystems, promoting more resilient and sustainable supply chains.

Challenges and Next Steps

Although the results validate the technical feasibility of the process, researchers identified significant challenges for future stages. These include improving material homogeneity, reducing ash content, and optimizing parameters for industrial scale-up.

Future research phases could focus on integrating chemical recovery processes, energy optimization, and environmental life cycle assessment (LCA) to consolidate the sustainability of the process at scale.

Science with Environmental and Social Impact

This work demonstrates that scientific innovation can emerge from everyday, local problems, generating solutions with global impact. Converting brewing waste into biodegradable paper not only proposes a technological alternative but also a conceptual shift in how industrial waste is understood: waste can become strategic resources within a circular economy.

This research opens the door to the development of new sustainable biomaterials in Latin America and highlights the potential of academic collaboration to drive environmental solutions based on applied science.

In a global landscape that demands reduced emissions, minimized waste, and optimized resources, initiatives like this show that the transition toward more sustainable production systems can begin by harnessing what was once considered mere waste.

Journal

Green Technologies and Sustainability

DOI

10.1016/j.grets.2026.100345

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Feasibility of producing biodegradable paper from malt bagasse: Bridging waste valorization, material performance, and circular economics

Malt Bagasse to Biodegradable Paper: A Circular Economy Approach (IMAGE)