A recent bibliometric review published in Green Technologies and Sustainability analyzes over 400 studies on spent coffee grounds (SCG) to explore its potential in bioenergy and circular economy applications. Authors Dayana Nascimento Dari, Lidya Fernandes da Silva, and colleagues highlight that SCG, a byproduct of coffee consumption, is generated in large quantities and holds promise for various sustainable applications. The review of 403 articles published over ten years indicates a growing interest in SCG valorization.  

Coffee is one of the world’s most consumed beverages, resulting in substantial amounts of waste in the form of spent coffee grounds. Traditionally, SCG has been underutilized, with limited applications such as composting and fertilizer production. However, increasing environmental awareness and the push for a circular economy have driven research toward finding higher-value applications for this abundant resource.  

The chemical composition of SCG, which includes carbohydrates, lipids, and phenolic compounds, makes it a suitable candidate for conversion into biofuels, bioplastics, and other valuable products. Notably, research has shown potential for SCG to serve as a catalyst and to produce bioenergy, contributing to both waste reduction and the development of cleaner energy sources. The analysis reveals a growth in publications, particularly between 2020 and 2022, which may be attributed to increased coffee consumption and the search for sustainable energy alternatives.  

While the review indicates promising results for SCG valorization, it also points out that most studies are still at the laboratory stage. Scaling up these processes for industrial application remains a key challenge. Further research is needed to optimize SCG biorefineries and explore the production of biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More, biogas, and bioactive compounds. The authors emphasize that continued investigation into SCG can significantly contribute to a more sustainable and economically viable bioeconomy.  

SOURCE: Dari, D. N., da Silva, L. F., Lima Júnior, A. M. B., Freitas, I. S., Aires, F. I. da S., & dos Santos, J. C. S. (2025). Spent coffee grounds: Insights and future prospects for bioenergy and circular economy applications. Green Technologies and Sustainability, Volume, Pages.